Who is responsible for airspace separation when an IFR flight is cleared for a visual approach? In areas tightly packed with airports (FXE, PHF, and countless others) it is possible to enter the airspace other than that of your destination airport. Some are less than 5 miles apart.

In particular,  say you are on an IFR flight plan and cleared for a "visual approach" to your destination.  While proceeding with the visual approach and descending, you could enter the class D airspace of a nearby airport.

You are in communication with the destination tower but not the tower of the other airspace you have just entered.

Is it the pilots responsibility to avoid the surrounding airspace or the tower controllers responsibility to coordinate with the other towner when IFR and conducting a Visual approach as referenced in AIM 5-4-23.

Visual approach responsibilities
§5-5-11
Pilot's end:

(3). The pilot must, at all times, have either the airport or the preceding aircraft in sight.

Controller's end:

(3). Provide separation except when visual separation is being applied by the pilot.
(7). Continue flight following and traffic information until the aircraft has landed or has been instructed to change to advisory frequency.

—AIM

For coordination with/between nonapproach control towers
§2-1-14 Coordinate Use of Airspace

(a). Ensure that the necessary coordination has been accomplished before you allow an aircraft under your control to enter another controller’s area of jurisdiction.
(b). Before you issue a control instruction directly to a pilot that will change the aircraft’s heading, route, speed, or altitude, you must ensure that coordination has been completed with all controllers whose area of jurisdiction is affected by those instructions unless otherwise specified by a letter of agreement or facility directive. If your control instruction will be relayed to the pilot through a source other than another radar controller (FSS, ARINC, another pilot, etc.), you are still responsible to ensure that all required coordination is completed.

§2-1-16 Surface Areas

(a). Coordinate with the appropriate nonapproach control tower on an individual aircraft basis before issuing a clearance which would require flight within a surface area for which the tower has responsibility unless otherwise specified in a letter of agreement.
(b). Coordinate with the appropriate control tower for transit authorization when you are providing radar traffic advisory service to an aircraft that will enter another facility’s airspace.
(c). Transfer communications to the appropriate facility, if required, prior to operation within a surface area for which the tower has responsibility.

§2-1-17 Radio Communications

(a). Transfer radio communications before an aircraft enters the receiving controller’s area of jurisdiction unless otherwise coordinated or specified by a letter of agreement or a facility directive.

—ATC (JO 7110.65W)

Short version of the above
ATC (terminal or tower) will need to instruct an altitude and/or heading so you don't deviate and surprise/buzz a Class D you're not going to. Otherwise they'll need to transfer the comms, which I'm sure they don't want to. Unless there's a prior agreement between the different facilities.
Pilot needs to have preceding traffic or field in sight.
Terminal ATC needs to keep an eye on all traffic and provide traffic information, until they handoff the pilot to tower or CTAF.


Why is there a disparity in the conversion from runway visual range (RVR) to statute miles? TBL 5-4-1 in the Aeronautical Information Manual (AIM) provides conversion from RVR to visibility in statute miles. I've reversed the first two columns from the AIM table to allow for comparison of the listed RVR to the actual distance in resulting from multiplying 5,280 by these fractions.

Why would there would be a difference of more than 100 feet? I understand that the RVR equipment may not be accurate enough to measure a value like 1,320, but why use 1,600 rather than 1,300 or 1,400?

Furthermore, the lack of RVR actually allows flight in lower true RVR for the 1600/quarter mile level. Let's say that the RVR was 1500 on an approach with mins of 1600. If suddenly the RVR equipment failed and a report 1/4 statute miles was substituted the approach would again be available. Usually the failure of a more precise piece of equipment substituted for a less precise calls for added margin of safety. Why the opposite approach here?

SM          RVR          ACTUAL
-           -            -
1/4         1600         1320
1/2         2400         2640
5/8         3200         3300
3/4         4000         3960
7/8         4500         4620
1           5000         5280
1 1/4       6000         6600

Some light on the mysteries of conversion...
Types of devices used for RVR measurement
A RVR device is composed of a light source and a light sensor. The light source is an incandescent lamp in a transmissometer, the oldest device, while in the more modern scatter-effect device it is an infrared LED. The sensor can determine RVR in a certain range, with the accuracy varying in the range:

Incandescence: Down to 600 ft by 200 ft increments within 600-3,000 ft, 500 ft above 3,000 ft.

Infrared: Down to 0 ft by 100 ft increments below 800 ft, 200 ft within 800-3,000 ft, and 500 ft above 3,000 ft.

RVR unit conversion
To make RVR ft-m conversion easy, rough equivalences are established:

100 ft = 25 m
200 ft = 50 m
500 ft = 150 m

Visibility unit conversion
Countries can also report visibility, which is different from RVR, in statute miles or nautical miles. Again rough equivalences are in place:

1/4 SM = 400 m
1 SM = 1,600 m.
1 NM = 11/4 SM.
1 NM = 2,000 m.

Substituting visibility to RVR
With all these approximate conversion factors defined, we can build a table for visibility by increments of 1/4 SM or 400 m (on the right hand of the table below), and use meter values, the common unit, to establish approximated RVR-visibility pairs.

(Source: Jeppesen)
Visibility, contrary to RVR, is not an exact measure. It's based on eye performance and available distinctive features of the surrounding environment. Moreover, visibility isn't generally evaluated for the same volume of atmosphere than RVR.
Sources:

FAA Order 6560.10C, Runway Visual Range.

Jeppesen Explanation of Common Airport Operating Minimum Specifications


Statute miles to runway visual range Is there a formula to converting statute miles to runway visual range? If so, what would it be? I'm seeing how 1 mile is equal to 5000 feet, but I am so confused because 1/2 of a mile is equal to 2,400 feet. I would think 1/2 would be 2500 feet. If it was half of a mile, you would take 5000 and divide that by .5 or 1/2 to get 2500. (I'm not a pilot yet)

Memorization.  This is the FAA definition:

Vis / RVR
1 SM / 5000
3/4 SM / 4000
1/2 SM / 2400
1/4 SM / 1600

This and a few more are spelled out in the Airman's Information Manual, TBL 5−4−1, RVR Value Conversions


Why so much throttle work on navy fighter during final approach? • Look at his left hand: why so much throttle work while flying? What is he doing?
• Is the throttle response very slow?
It seems to me that the fighter don't accelerate so much when he gives full throttle.
• I read that landing on carrier is extremely difficult, does that mean that navy fighter pilots are even more skilled than acrobatic pilots (Red Bull Air Race)? Or is this a subjective topic?

The rapid motions you see are normal, are not excessive in magnitude, and the duration is relatively brief.  The constant corrections are a direct result of the precision required to maintain glideslope, coupled with the sensitivity of the carrier’s Fresnel lens Optical Landing System.  (OLS, the orange “meatball” centered between two rows of green datum lights)

Navy pilots are taught to control the angle of attack with pitch, and glideslope with power.  (he is not trying to accelerate when he adds power, he is slowing his rate of descent)
Deviations from glideslope should be fixed immediately with a three part power correction:

If you are low, add power to drive the ball up until it is just starting to crest high above the datums, then reduce the power sharply to stop further upward travel, then reset power to a new position that should be correct…
If you are high, reduce power to lower the ball until it is centered between the datums, (never allow it to go low!) add a good handful of power to catch it in the middle, then reset power to a new position that should be correct…

The issue that you can never truly find that sweet spot where you can just leave the power set and ride it out.  There are just too many variables, and the ball is very sensitive.  So, one three part power correction leads to another three part power correction, and so on and so forth.  The reality then is what you see; almost constant throttle jockeying in order to control the ball as best you can.
Fine control requires much more rapid corrections.  Think of it this way, if I asked you to ride a bicycle along a painted white stripe 24” wide you could probably do so quite smoothly.  However, if I asked you to strictly follow a line merely the width of the 4" painted stripe along the side of the road, your handlebar movements would be much more rapid as you made corrections to attempt to avoid straying from this thinner line.  Your bike might follow a more precise path, but you would be a bit more jerky in keeping it there.
For comparison, probably one of the more precise optical glideslopes available to civilian pilots is the 4 light PAPI.  (“P” for precision…)  This pales, however, compared to the sensitivity and precision of the Navy’s OLS.
With PAPI the white light fades slowly into red, and even when the colors are distinct the incentive for immediate correction is not as urgent.  If you have three red lights and one white, so what?  You are a little bit low…  Check your VSI, maybe squeak a little more power on, but if you are assured of making the runway your focus is probably on being smooth.  Nobody is watching, nobody really cares that you are a little bit low, and you have more time to correct it.
It is different on a Navy carrier.  You have 15 to 18 seconds from the time you roll wings level until you touch down.  If you are high or low at the start you need to fix it.  You need to fix it NOW.  If you carry that trend for more than a couple seconds people will start talking to you on the radio offering not so friendly “suggestions”.  There is a team of a half dozen Landing Signal Officers (LSOs) standing at the back of the ship watching and recording your every move.  Their first job is to keep you from hitting the ramp, their second job is to get you aboard on the first pass, their third job is to document every deviation (in short hand) for pilot trend analysis and determination of a landing grade that will rank you against your peers.
Video of every approach is broadcast live on closed circuit television all around the ship.  Your squadron commander, your peers, the airboss, captain of the ship, and a host of other random personnel on the ship are all watching you in real time. The LSOs will send you around with a “wave off” if they don’t like how you are responding to deviations, and your landing grades and reputation will suffer.
There is pressure, therefore the incentive to make immediate corrections is strong.  The ball moves noticeably to indicate the slightest deviation from glideslope, so the pilot is going to move the throttle just as rapidly as needed to keep that ball smack dab in the middle where it belongs, and avoid a wave-off or bolter to get aboard the first time.
Worth noting, but this pilot went to full power well before crossing the ramp, so he must have gotten pretty low in close!
Engine spool-up time is not nearly the issue it was in the early days of jet carrier aviation in the 50s and early 60s.  The Navy learned the hard way back then and these days most jets are optimized for acceptable throttle response at approach speeds.
Regarding your final question, the answer is yes.  Navy pilots are even more skilled than Red Bull air race pilots.


What is currently the longest commercial flight in terms of distance? Flightradar24 has announced few hours ago, that Qantas QF7 is taking off for its 13,804 km long flight and named it the longest commercial flight (by distance).

Is that correct? I was more than sure, that I heard few years ago, that current record belongs to Singapore Airlines, that has at least one commercial route of a little bit more than 14k kilometers.

According to Wikipedia, the flight you are referring to, SQ21, got discontinued in November 2013. The runner up, still from Singapore Airlines, SQ37, got discontinued one month earlier.

The same page reports that QF8 is the current holder of the title of "longest non-stop flight" and has the same destinations as today's QF7 as of February 2017 Qatar Airways flights 920/921, covering 14,534 km (7,848nm / 9,031mi) from Doha, Qatar (DOH/OTBD) to Auckland, New Zealand (AKL/NZAA), beats QF8 by about 395 NM.

If we instead include 1-time-only flight by a commercial airliner, the longest one has been flown in November 2005 between Hong Kong and London, as a demo by Boeing.

The title of absolute longest flight without refueling is instead held by a non-commercial flight done in an aircraft specifically built for the purpose.


Do I need a checkride for an initial SIC A320 type rating? I have an FAA A320 initial pilot-in-command (PIC) type rating but haven't flown the actual aircraft.

Currently I am undergoing the second-in-command (SIC) type rating. I have completed the ground school program, Fixed Base Simulator and the Full Flight Simulator exactly like the Practical Test Standards for PIC.

Do I now according to FAA need to do a check ride? Or should I be issued the SIC privileges?

A PIC type supercedes and SIC type.  An SIC type is really just a formalism of 121 initial first officer training to satisfy specific ICAO requirements.  A typical route to an SIC type is airline ground school, FFS and then company checkride (no APD, no DE, just a check airman) and the issuance of the SIC type.  If you already had a PIC type you'd go through the same training and company check (required by company approved training), but you wouldn't get an SIC type as you already have a PIC type.

The FAA shouldn't require anything out of you if you are PIC typed already.  The company may require you to do the full FO training and the FO company checkride as part of its own FAA approved requirements.  If you want a more specific answer, you could provide more details about how your training is being conducted or you could ask your facilities training department or director of training.


Does the commercial helicopter training in 61.129(c)(3)(i) require a CFII? For the commercial ticket in a helicopter you need 5 hours of hood time. Can any CFI provide this training or does it require a CFII?

14 CFR 61.129(c)(3)(i):

  Five hours on the control and maneuvering of a helicopter solely by
  reference to instruments using a view-limiting device including
  attitude instrument flying, partial panel skills, recovery from
  unusual flight attitudes, and intercepting and tracking navigational
  systems. This aeronautical experience may be performed in an aircraft,
  full flight simulator, flight training device, or an aviation training
  device;

A CFI can give the training because it's training "solely by reference to instruments". If it were "instrument training", you would need a CFII.

See the Jablecki (2016) interpretation, which addresses your specific question:

  In order to provide instrument training for a commercial pilot
  certificate or ATP certificate, a flight instructor must have an
  instrument rating on his or her flight instructor certificate.
  However, §61.129(c)(3)(i), unlike its counterparts in §61.129,
  does not have a requirement for "instrument training" as defined in 14
  CFR §61.1. Instead, §61.129(c)(3)(i) requires training on the
  "control and maneuvering of a helicopter solely by reference to
  instruments." Therefore, the training in §61.129(c)(3)(i) is not
  considered "instrument training" that requires a certified flight
  instructor to have an instrument rating on his or her flight
  instructor certificate.


What makes it safe for the DC-8 to use reverse thrust in flight? For most jets, the use of reverse thrust to slow down in flight, where even possible, is extremely dangerous, and strictly prohibited.

Not so on the DC-8, which is certified for the safe in-flight use of reverse thrust on the two inboard engines throughout its entire flight envelope, and which, in fact, uses in-flight reversing as a standard part of a normal descent - this despite the severe disruption in-flight reversing causes to the airflow over the wing.

What is it about the DC-8 that makes it capable of safely using reverse thrust in flight, unlike other jets?

Juan is correct, inflight reversing was a bit noisy; however, it was a MEL requirement to have the inboard reversers operational to operate above FL350. The procedure was as follows: For a steep or emergency decent all throttles are retarded to idle and the inboard thrust brake levers are put into "Reverse Detent Thrust" and when the "Eng Thrust Brake" indicating lights come on the throttles are moved to the reverse power stop. The outboard engines will be at flight idle as reverse in engines 1 & 4 is not possible until the landing gear is extended. Additionally, the use of reverse thrust was to be discontinued below 190K. Sorry Juan, no speed brakes on the DC-8, but yes on the DC-9. The spoilers on the DC-8 were used to augment flight control (three outboard on each side) but only when the gear was down. This made handling the aircraft in gusty weather much easier giving a quick roll response. On landing the spoilers(two inboard each side and three outboard) would deploy when armed by a signal from rear wheel spin-up or, as a back-up, by nose gear compression. The crew could also deploy the spoilers manually by pulling the spoiler lever back and up.


When to log time as PIC, Dual or Co-Pilot? I'm currently finishing up my Canadian PPL. I have questions around logging my time appropriately.
Most of it is pretty straight forward. Looking at 401.08 the only thing I'm unsure about is how to log (c) the flight crew position in which the holder acted;

I have a "Pilot Logbook" from VIP Pilot Centre. I'm not using it as I'm maintaining my log online but I use it as a template. It distinguishes between the following three roles: Dual, PIC and Co-Pilot.

Here's how I interpret them:

Dual: during instruction, when CFI is PIC
PIC: student solo flight / solo flight once I hold my PPL

What about Co-Pilot. Is that only relevant when acting as co pilot in an airplane that requires two pilots? What about if, once I have my PPL, I fly around in a C172 with a friend as the PIC, can I log that as Co-Pilot time?

Canadian law is as follows:

At no time can anyone in a private C172 log SIC or co-pilot time, because the 172 is certified only for single pilot operations and the aircraft is not flown under the provisions of an Operating Certificate that mandates two pilot operation.

You can log dual (instruction) time when you are receiving instruction from a Flight Instructor certified to do so. (In Canada CFI refers exclusively to the Chief Flight Instructor of a Flight Training Unit.)

Otherwise, you can log PIC time, when you are PIC, otherwise you cannot log time at all.

If you are in simulated IMC, either you or your friend can log time, assuming you are both qualified to be PIC, and depending on who you agree between you is Pilot In Command, but never both of you, unless he is a qualified flight instructor. Even then, only one person can log PIC time, in Canada.

Note that in Canada it is not required for the "lookout" or "safety person" to be a qualified pilot of any kind, if the PIC wants to fly under the hood. It remains the PIC's responsibility to fly safely and look out for traffic, and he or she can discharge that responsibility by asking any responsible person to help them.

These rules are rather different from the ones that prevail in the US.

Hope that helps!


Why are swept wings better for breaking the sound barrier? I'm told that swept wings perform better when an aircraft is trying to break the sound barrier.  I was wondering why that would be?

It's all about the 'effective' Mach number that the wing sees.  In essence, for a swept wing, the Mach number that the wing 'sees' as far as compressibility effects are concerned is the Mach number of the component of the freestream normal to the wing chord:

(Source: stanford.edu via archive.org)

By sweeping the wing back, you can get closer to the speed of sound without getting supersonic flow over the wing (remember, a wing generates lift by accelerating the air flowing over it, thereby decreasing the pressure - so you'll get supersonic flow over the wing before the freestream is supersonic).  Of course, once you fly supersonic, there's really no getting around having shock waves over the wing - however, you can reduce their strength with wing sweep.


Are there more accidents in winter months, and if so, why? I was watching The Flight Channel videos and have noticed that the accidents seem to happen more often in winter months (for the Northern Hemisphere). Are there some statistics to back this claim?

It seems logical: Winter months means icing on wings, slippery runways, etc. Are there any not so obvious reasons for the increased accident rate during winter?

I'd argue fall and spring bring more unpredictable weather, and slippery runways are year-round in the tropics.

That being said, for all jet (commercial) accidents, the weather-related contributing threats are:

Meteorology (e.g., failure to identify threats before a flight) 30%

Windy conditions 16%
Poor visibility 10%
Thunderstorms 9%
Icing 1%

Poor braking action (e.g., slippery runways) 10% (falls under airport facilities, not meteorology)

All figures are from PDF page 172 of the IATA 2017 Safety Report.

Given the opening statement, [near ground] icing is more attributable to cold winters than the rest. The rest are not limited to Dec–Mar in the Northern Hemisphere. The report does not attribute the seasons to the accidents.


How can take-off slots suddenly become available even when airspace is congested? Here is something that happened to me: my flight was 3 hours late because the plane arrived late. We were told that a further 3-hour delay was expected because our flight had lost the slots it had in the air traffic system, and we couldn't immediately get new slots due to very high congestion in the skies.

Nevertheless, all the passengers were immediately boarded, all the flight procedures were initiated (safety film etc.), the plane taxied towards the runway and immediately departed.

After landing I asked the pilot how the 3 extra hours we had to wait due to congestion suddenly "disappeared". He told me that congestion is fluid and sometimes things change.

How can things change so much so quickly? Is the pilot's explanation plausible or is there another story behind what we were told by the airline?

It's a very credible explanation.

Slots to allocate scarce ATC and airport resources are created based on a known rate at which the airport/airspace can handle traffic, and they are apportioned out based on things like when the flightplans are filed, allowing for time enroute and expected arrival times.  (This is a little general -- trying to give a big picture without getting mired in too many specifics of EDCT's, Ground Delay Programs, and so forth -- some of those details can be found in answers to this question.)  When total demand is below capacity, it's common to be told to "contact Clearance Delivery 5 minutes prior to Push for your wheels up time to XYZ," and then on calling Clearance, you're either given a wheels-up time in about 15-20 minutes (i.e. push on time, taxi out, and take off with no delays) or even "released with no restrictions."

However, when demand is greater than capacity (most common when a bottle-neck is caused by something like bad weather at the destination reducing the allowable arrival rate, although also caused when a runway or an approach is unusable for some length of time), then things start to slow down, and you may be given a wheels up time farther off in the future.

Better to sit at the gate not burning gas than burning gas at idle out on a taxiway, or burning a LOT of gas holding in the air, but not most flyers' idea of a good time.

When things are HIGHLY saturated, as it sounds like the OP's scenario, you can't get your slot time issued until you are actually ready to go, but you (or your dispatcher) may have a sense for what sort of delay is likely.  In these cases, you often can see where some aircraft have been given a significant delay, and anticipate something similar -- but you don't actually know what you'll get until you call.

Sounds like the crew for the OP's flight anticipated that they MIGHT be pretty far back in line, and explained things accordingly, but when they actually called then either conditions had improved, OR a particular slot was available (perhaps another flight had cancelled or been delayed) and they got it.  That's not all that uncommon -- you call for your time, hoping for the best & prepared for the worst, and sometimes you get the "wheels-up" time 90 minutes out, and sometimes you get "can you be wheels up in 12 minutes?" and if the answer's "yes" then there's a quick high-five in the cockpit and "tell 'em to shut the door, we're going!"

Due to the lead times involved, when a slot opens up like this, ATC typically does NOT call every flight "in the queue" to shift everybody forward by 5 minutes; that slot either gets used by somebody, or it's just unfilled.  But when we've told our passengers "you can get off the airplane, be back by X so we can leave," making adjustments to that X time isn't practical, so for us that time is pretty well set.  Somebody else who IS boarded up & ready may get that fallout slot ahead of us, and when he does, good for him.


Why are some item numbers missing in ICAO flight plans? I was looking at an ICAO flight plan and observed that there are only specific ITEMS mentioned in it (see example below)? What is the reason behind excluding the item numbers 1, 2, 3, 4, 5, 6, 11, 12, 14 and 17?

(source: FAA)

To complement @ocirocir 's answer and link, the messages used by air traffic services are not limited to flight plans.
Below from ICAO Doc 4444 are all the fields and the intended use. As you see, the FPL is just one row, and other "missing" fields appear in other messages, while others are just currently not used:


Could turbine or compressor stages of a jet engine be switched off to improve fuel efficiency? Active fuel management is a technology developed by General Motors, which is used to improve engine efficiency in the times when the engine is operating under loads which are considerably less than the rated load, as shown in this link. This technology exploits the property of piston engines where some of the cylinders are turned OFF while only few of them work, and hence improving the overall efficiency of the engine. Can a similar technique be employed on an aircraft's engines, where some of the turbine stages (Compressor or Turbine) are switched off in order to improve the performance efficiency of the engine?

You cannot "switch off" a stage of a turbine engine.

As seen elsewhere jet engines are a single block mechanically locked together: all the stages (compressor AND turbine) connected to the same shaft. If the shaft turns, all connected stages turn with it.

You can have designs with multiple shafts, but this increases the complexity (design and maintenance) heavily.

Even if we assume for a moment that you could have 1 shaft per stage, stopping one of these would be generally a bad idea.
For acoustic reasons the number of blades on the stationary part of the stage and those on the rotary part must be prime to each other (example: 37 blades on the stationary side and 39 on the rotary one); this means that when the rotary part stops you cannot align all the blades with the stationary ones, creating drag and losses within the engine, thus reducing the efficiency.

  How would efficiency of a Jet Engine change, if we assume for a second that its a possibility, to stop a few stages(turn them into free instead of locked)?

You would still decrease the efficiency: compressor stages are the ones actually pulling the aircraft forward (you would then produce less thrust*) and the turbine stages are the ones extracting energy from the exahust.

*: you could even risk having the flame going upstream if you stop too many compressor stages and not having enough pressure at the combustion chamber inlet.


Do some radial engine planes have a two-speed starter motor? (YouTube)

Watching the Connie fire up her engines I wondered, do some radial engine planes have a two-speed starter motor to replace the ground crew "pulling the props through"?

In other words, low-speed–mags-off to test for a potential hydraulic lock.

I do realize the props could have been pulled through off-camera before being towed out for the show.

There seems to be only one starter speed:

  Proper sequence for starting radial engines...DC-6B style, with P&W
  R-2800's.

  Engage start and start safety switches.
  Rotate thru 9 blades.
  While continuing to rotate the engine with the starter, engage primer and
  ignition boost switches, and at the same time, select magnetos to
  'both'.
  When engine fires, continue starting with the fuel primer
  engaged, releasing the start and start safety switches.
  Slowly move
  mixture control to the autolean position, then release fuel prime
  switch.
  Engine continues to run (hopefully).
  Taxi in autolean, until
  engine run-up desired.
  Complete run-up and propellor checks in
  autorich.
  Return mixture to autolean.
  Prior to takeoff, ensure engine
  mixture controls are in autorich (very important).

  Have a pleasant day, thereafter (hopefully). ;-)

  DC-3 about the same, except...

  use autorich for all ground ops.
  Engine
  type, P&W R-1830-92.
  Curtis Wright engines...can't remember.

  Stratocruiser, same as the DC-6B. DC-7 and Lockheed 1649, same also,
  as the DC-6B.

  NB. Operating in autolean helps to prevent plug fouling while on the
  ground.

[Posted by 411A on May 18th, 2008 at pprune.org]


How are missiles attached/detached from a combat jet aircraft? What is the mechanism holding a missile onto the hard-point of a wing, and how does it smoothly release the missile when it's ready to fire? What about the electric cables that also need to detach without getting caught?
I just want to get an idea of how simple or complex it is. I hope it's not some hydraulic "nightmare" device.

AIM-9 Sidewinder and AIM-120 Scorpion are mounted on LAU-7 or LAU-127/8 launchers, known as "rails".
Upon signal from the pilot, the motor fires. The missile goes forward.
The umbilical cable connecting the missile to the launcher breaks away as the missile moves forward.
As far as how they're held on, there is a spring loaded lock mechanism, that is overcome by the missile motor.
pg 3-22 here:
https://www.globalsecurity.org/military/library/policy/navy/nrtc/14313_ch3.pdf

DETENT,  DETENT  LOCK,  DETENT-LOCKSOLENOID, AND SNUBBERS.—The detent, detentlock, detent-lock solenoid, and forward snubbers (fig.3-18) make up an  electromechanical system that restricts longitudinal and lateral motion of the mounted missile. This system prevents accidental launch or release during catapult takeoff or arrested landings. A slotted detent wrench/safety pin is installed through the mechanism assembly to prevent movement of the aft detent and to safe the launcher firing circuits. It is also used to raise the aft detent lug sufficiently to clear the missile  hanger  during  loading. The  slotted  detent wrench/safety pin is removed before flight. When the detent is down (normal), the striker points make contact with the buttons (contacts) on the forward hanger of the missile. The forward striker point does not have a function for the missile; the aft striker point makes contact between the missile and the firing safety switch

Body mounted missiles such as an AIM 7 or AIM -120 on a F-15 are kicked out away from the fuselage a couple of feet before the missile motor activates. There is a long cable that breaks away once the missile starts to leave.
The ejector foot is actuated by a small explosive charge.


Is the TIS-B traffic filter on board or on the ground? This question is asked in the context of small certified GA aircraft in the US.

The TIS-B traffic that is displayed on board is a subset of all the TIS-B traffic in the area. It's often described as a hockey puck surrounding your aircraft where other traffic that is outside the puck is not displayed.

My question is whether the algorithm that filters what does or doesn't get displayed resides on the onboard box or the ground station.

Does the ground station (which knows your position because of your ADS-B out) send a custom set of traffic suited for your hockey puck? OR...
Does the ground station send out all traffic it is aware of and your on-board box filter only the ones in your hockey puck and send them onto your display? OR...
Something else?

TIS-B is part of the ADS-B system that will be required in class B and C airspace come 2020. The processing of traffic relevant to your aircraft is done on the ground to keep the airwaves "clean" as it would require transmission of much more data to show all aircraft and then have your local device filter it. In order for you to take advantage of your own "hockey puck", you first need to have installed in your aircraft the appropriate avionics, namely a GPS with WAAS and an ADS-B out or Mode S transponder. Your transponder will broadcast your location and altitude, then the ground station will process which traffic is relevant to you without the 3D boundaries of the "hockey puck" surrounding your aircraft, then it will broadcast that response out to the air. The key is that not only your aircraft can pick up the response - any aircraft with an operable ADS-B In system can read it and thus display traffic/give traffic alerts even if you don't have an ADS-B out. The key though is that without an ADS-B out the traffic information is not customized for you so critical information/traffic may be missing (what is transmitted is might not be in YOUR hockey puck).

Note: It is also possible for you to pick up signals directly from other ADS-B out equipped aircraft in your proximity without an ADS-B ground station to relay that information and they will display directly on your ADS-B in equipped system.


How to deal with turbulence while flying glider? (Cautions in applying rudder) I just watched video explaining how the American Airline Flight 587 crashed

It led me to think about glider flying. The cause of that crash was that the first officer aggressively and unnecessarily applied full rudder left and right in turbulence, the air force against the moving rudder stressed the vertical stabilizer and caused it to snap.

Is such risk realistic in glider flying? If one encounters air turbulence in while flying glider, how to deal with it, and what to avoid?

Everyone chooses what to worry about. I would not choose to worry about this.

Is such risk realistic in glider flying?

What does "realistic" mean to you?  If it means "could it happen" then sure, it could.  Plenty of things could happen.  If a possibility greater than zero is all it takes for you to worry then by all means, stop reading.  Don't forget your shark armor and anti-meteor hard hat when you go out next.
However, most people consider "realistic" to include likelihood. Is it likely? Well, I searched through the last 8 years(1) of the NTSB accident database for glider accidents involving the term "breakup". Of the three relevant results, two involved aerobatics.  How many glider flights have there been in the last 8 years? Probably plenty of them.  Do you plan to do aerobatics?  If not, then your accident statistics are one in plenty.  Only you can decide if that's too scary for you.
It is not on the NTSB 10 most wanted list.  I have not read about it in FAA Safety Briefings.
In my experience, new students don't know what is important, so as a proxy, they worry about things that are vivid.  In-flight structural failures that have videos made about them are highly vivid.  That's why my original answer started out by saying "this is not a valuable use of your attention".  If I were your instructor, I would advise you to focus your concerns on flying proficiently and learning good decision making.  If you do that, the concerns here will take care of themselves.

If one encounters air turbulence in while flying glider, how to deal with it, and what to avoid?

There is no "if" here.  You are definitely going to encounter air turbulence. That's how you know you're doing it right.
How to deal with it? Pay attention to your instructor, monitor your attitude, remain calm, and fly the aircraft.

(1) - Why 8 years?  Because I got bored.


How does CDI work when flying to VOR without DME? Let's show what I mean on an example.

Flying towards a VOR (not knowing the distance), HSI course pointer pointing
   towards the VOR. Let's say the plane is really far from the VOR and we turn
   the course pointer 5 degrees (no matter what way) CDI will move to one side
   (far because of the distance). If the plane was close to the VOR and we turned
   the course pointer 5 degrees CDI would not move as much (or should not because the
   deviation is really small).

based on this example CDI needs to know distance from VOR to work properly, yet it works without knowing the distance. How?

(If I'm wrong about something, quickly correct me)

The VOR and ILS CDI indicates difference, in degrees, between the radial selected and the radial sensed.

If the plane was far from the VOR and we turn the course pointer 5 degrees, the CDI will move to one side. If the plane was close to the VOR and we turned the course pointer 5 degrees, the CDI would move exactly as much, because it indicates the angular difference in degrees.

This is in contrast to a CDI slaved to GPS, which indeed indicates lateral distance from the selected track in miles (en-route; GPS approach has to simulate ILS).

VOR does nothing with DME. DME is completely independent piece of equipment that was introduced later than VOR. The only relation is that there is a standard correspondence between VOR and DME channels and the DME receiver automatically tunes to the DME frequency corresponding to the VOR or ILS frequency tuned on your VOR/ILS receiver.


What is the relation between trim setting and constant airspeed? I'm having an argument regarding elevator trim. According to a book my friend showed me, trim is for constant airspeed. So, let's say we are flying level at 100 kts with 2300 RPM and it's trimmed. My buddy claims that if we reduce power (1800 rpm for example), and do not touch elevator trim and yoke, pitch will be set for 100 kts by airplane itself and we can descend at 100 kts with 1800 rpm.

However, what I think is to maintain 100 kts with reduced power, the nose of airplane should be lowered and forward trim should be readjusted by a pilot.

Can somebody give me an answer to end this argument?

Your friend is right.  Elevator trim isn't setting a pitch, it is compensating for control forces on the elevator, which vary with speed.  If you are trimmed for level flight at 100 kias and reduce power the plane will initially slow.  As it slows the trim will cause a nose-down moment causing the plane to pitch down.  Given no input, the plane will equilibrate at whatever nose-down pitch is needed to regain the forces it was trimmed for, which means speeding back up to 100 kias.

You are correct that to maintain 100 kias with reduced power the nose should be lowered, but the trim will take care of that for you.

You might have a misconception about how trim works, based on your argument.  A typical trim setup in light airplanes is essentially another control surface on the elevator:

The elevator is the large control surface and that smaller control surface is the elevator trim.  When you adjust the pitch trim you are adjusting this trim tab which provides a force on the elevator that counters aerodynamic forces.  This is why the airplane responds in pitch to maintain constant aerodynamic forces (e.g. constant indicated airspeed) for a given trim setting.

You can test this in the airplane easily.  Take your plane up to the altitude you practice maneuvers at, set 75% power (or some other number) and trim for straight and level.  Add power and watch the plane climb, decrease power and watch it descent, both without touching the trim.  Go back to straight and level and trimmed and accelerate without climbing -- note you are having to retrim as your speed increases.  Decelerate without descending  -- note you are retrimming as your speed decreases.


Might a large commercial jet dump fuel if an engine were on fire? In my mind this seems like a bad idea for a lot of reasons, like the dumped fuel lighting on fire itself, or perhaps leaving fuel vapor in the wing tanks (which may be even worse than regular liquid fuel) or even just because if you do put the fire out you would now have a new emergency.

But, I've been wrong before.  Perhaps it would actually help put out the fire and being forced to glide would be an improvement over an engine fire, right?

So I thought I'd simply ask the experts.  Might a large commercial jet (like a B747, A380, etc) dump it's fuel if an engine caught on fire in order to starve the fire of fuel?

PS- For the sake of this thought experiment, pretend the fire had robbed the engine of the ability to cease fuel flow to it...  Unless that really makes no sense, in which case please feel free to call me on it and that can be the answer.

An airliner experiencing an engine fire might dump fuel, but not to starve the engine. That is much more easily accomplished by simply shutting down the fuel pumps to that engine, which would be a first-line firefighting technique as it's the most economical and the most likely to allow for a restart (less maintenance is required on an engine that's simply shut down versus one that's been doused with chemical suppressors, and those same chemical suppressors might extinguish the fire but would also inhibit relighting it).

There are several redundant fuel shutoff systems in most airliners, from the fuel pumps themselves to actual shutoff valves in the fuel lines in case the pumps themselves are the failure point. Any failure that would completely prevent the crew shutting off the fuel supply to a damaged engine would likely create much more immediate problems, like severe structural damage to the wing or fuselage of the aircraft. All of these shutoffs in addition to active fire suppression systems such as chemical extinguishers are under the flight crew's manual control; an engine on fire is usually still producing at least some thrust, which may be more important than extinguishing the fire in certain critical phases of flight.

The plane is more likely to dump fuel if it's close to its departure airport when the emergency occurs. In such a scenario, the aircraft is likely above its maximum landing weight (which is less than the max takeoff weight as the forces on the landing gear and the runway are less on takeoff than for landing and the plane is expected to burn most of its fuel weight by the time it gets where it's going), and therefore the fuel dump is simply to reduce the aircraft's weight for an emergency landing, so the landing gear doesn't collapse on touchdown. Additionally, if anything else goes wrong during the landing, dumping fuel would leave the plane with as little fuel as possible to minimize the spread or intensity of a fire on the ground, which can impede or prevent escape from the plane. However, fuel dumps from commercial aircraft are rare, used in situations where the necessity of dumping fuel to land safely and spare the passengers outweighs the financial costs of losing the fuel and the environmental costs of cleaning up the spill.


Why does the A380 not have front windows on the top floor? The title says it all.

On the 747, the cockpit is in the upper level and in the lower there's equipment (radar, avionics, etc.)

But on the A380, the cockpit is in the lower floor and there's no equipment in the upper floor. So I think it could be technically possible to place some front windows in order to get a pilot-like view.

I guess that would reduce the aerodynamic efficience of the aircraft, but maybe it could be compensated by higher prices on those exclusive view seats?

Has any aircraft like that ever existed or designed?

(flightglobal.com)

You'll need to zoom above 100% to read the legend, but up there it's not empty. There's the crew rest area (5), where the pilots rest for example, and it is easily accessible from the cockpit (see below for how it interacts with the upper deck).

There is also an electronics bay (29), and toilets (12).

Note that the cockpit is not on the main deck, it's between the main and upper decks, the mezzanine if you will.

Design-wise, the forehead is very sloped for aerodynamics, so to offer a forward-facing window view (if the area was empty), there will be an enormous unused legroom (for head clearance). The view also wouldn't allow seeing a big distance ahead and below, so it will be more like a skylight window, especially that airliners typically cruise with the nose pointing above the horizon. And with the area clear of walls and supporting structures, the plane will gain weight to strengthen the shell in that area.

For the secondary question see, 'Has any passenger airliner ever offered forward-facing windows?'

(source)


What is meant by a fused radar track? Can anyone explain what a fused track is from the perspective of radar?

A fused radar track is a track (series of radar detections belonging to the same aircraft) that contains information from detections by multiple radars.

Creating a fused track seems a simple thing to accomplish, however it is not as easy as it may seem.

First of all, lets look at a mono-sensor track. That is a series of detections by a single sensor belonging to the same aircraft. The tracking system has to determine for each detection to which track it belongs to associate the flight data (e.g track label) for that track to the plot (display of the detection on the screen). For primary radar systems (and to lesser extent Mode A/C radar) this can already be difficult when tracks are crossing each other at shallow angles. Especially when you know that the measurements are a bit noisy; an aircraft flying a straight line does typically create a somewhat randomly jagged line.

Now suppose we want to add a second radar to the mix, because the coverage area of a single radar is not big enough. Now we have a situation where there is a common coverage area where the two radars provide overlapping coverage.

In an ideal world, this would show the detections exactly in line with each other. However, each radar has their biases are other measurements error (with various sources, partly external to the radar system). So instead of one track for one aircraft, we end up having two tracks for one aircraft, sometimes a mile apart. This is of course not ideal and can even lead to safety risks.

A simple solution is to have a mosaic system; in such a system there is for each geographical area exactly one radar appointed to provide the surveillance data to the air traffic control's display. The down side of such a solution is that at the edge of the mosaic tiles, when the aircraft moves from one radar area into another, the track may jump because of the differences in measurement errors in both radars. Again not an ideal situation.

That is where radar fusion comes in. In a multi radar tracker, data from multiple radar is combined into a single track. In the process, biases and other measurements errors are greatly reduced, resulting in a track that generally much smoother than a single sensor track. Because of the identification of radar biases, there is no discontinuity (jump) when track move out of coverage of one radar. And due to the higher rate of updates from multiple radars, the update on the radar screen can often be increased as well.

The fused radar track is no longer a depiction of detected positions, but calculated estimate of where the aircraft is based on data from all radar (or other sensors) used in the fusion process. The mathematical process behind the fusion often uses on a form of Kalman Filtering, highly adapted for this task. Outliers are discarded to improve the smoothness of the track.

Trackers like ARTAS or Phoenix do not only fuse radar data into the track, but also include data from ADS-B and Wide-Area Multilateration (WAM). We then speak about a (fused) multi-sensor track instead.


What techniques, tools, or instruments are used while performing zero-g parabolic dives? There are companies that sell "zero g" rides, where the aircraft is configured specifically to take people and possibly experiments through a parabolic dive to experience a short period of micro-gravity (possibly not the proper term).

This question asks about possible risks associated with the maneuver.

I'm interested in what specific techniques, tools, or instruments are in the cockpit that allow the pilots to properly follow the proper trajectory, while not pounding the occupants against the walls of the aircraft?

A G meter seems pretty obvious, but are there other less common things used? Are there special techniques for managing energy buildup, or for reminding the pilot when to pull out of the dive so as not to over-stress the air-frame?

Any other interesting information that I may not be thinking of in a similar vein is also welcome.

I'm an aerobatic pilot, with exactly 0 hours of turbine time, so this is a guess:

Climb to altitude and establish a predetermined airspeed.
Gently push to an 'A' degree nose down attitude, and maintain throttles at 'B'(accelerate to the highest airspeed permitted)
When airspeed indicator shows 'C', gently pull up to a nose-up attitude of 'D' (use the G meter to ensure you do not exceed 'E' Gs)
When airspeed indicator indicates 'F', reference the G meter and slowly push over to 0 Gs.
Monitor the changing pitch attitude and airspeed.  Warn the passengers when certain limits are passed.  (i.e., 10 seconds to recovery)
When nose-down pitch of 'G' is achieved, stop pushing and begin pulling back to level flight, taking extreme care not to exceed Vne (or other appropriate limit) and the G limit of the airplane.

Instruments required: Altimeter, Airspeed Indicator, G-meter, Attitude Indicator


How can an aircraft hover almost vertically? (Source: https://fat.gfycat.com/)
The aircraft in this GIF (although being an RC plane) seems to be flying vertically, just meters above the ground. How is this possible? How is it possible to control it in this scenario? Would this be possible with a real aircraft?

The aircraft in the video is a remote-controlled (rc) airplane. Why it can "hover" is simply:
The thrust generated by a big fan / rc-jet-engine is much higher than the weight of the plane.
If the force generated by the turbine is the same as the downward-force of weight of the airplane, it hovers.
By very carefully adjusting the thrust and placing the aircraft in this "nose-up" position, a skilled rc-pilot can hover the plane until the battery runs out or fuel gets low.

As example:
An aircraft that weights 10,000 kg's produces a downforce:
$$F=m\cdot g=10,000 \cdot  9.81  = 98,100N $$
To make this aircraft hover, you have to create a upward force of at least $98,100 N$. If you manage to do that and you can align the generated thrust / downforce perfectly on the Y-Axis, the aircraft will hover:
$F_{down} - F_{up} = 0N$, the two forces will cancel each other out and you don't have any movement in the Y-Axis.
However, if you have engines that create more thrust than the downforce, the following will happen:
$F_{down} - F_{up} \geq 0N$, that means the aircraft will climb vertically (On the Y-Axis).
The same principle applies to other "real" aircraft, like the Sea-Harrier:

It uses the engine to create a force facing upwards. Because the force is greater than the downward-force created by the aircrafts weight, the Harrier can land / takeoff vertically.
The hovering airctaft is controlled by a trust-vectoring fan / turbine. Controlling the plane with the "normal" surfaces is not possible, because the airflow over the controll-surfaces on the wing is to slow. Therefore, only planes with trust-vectoring capabilities COULD hover like the rc-plane in your question.


What's the minimum allowed flying height of a light aircraft over a town? I mean a Light aircraft, in Germany and a town like Heidelberg. And I mean not landing, of course, but overflying.

In Europe this is regulated by SERA.5005 Visual flight rules (source, emphasis mine):

(f) Except when necessary for take-off or landing, or except by permission from the competent authority, a VFR flight shall not be flown:
(1) over the congested areas of cities, towns or settlements or over an open-air assembly of persons at a height less than 300 m (1 000 ft) above the highest obstacle within a radius of 600 m from the aircraft;
(2) elsewhere than as specified in (1), at a height less than 150 m (500 ft) above the ground or water, or 150 m (500 ft) above the highest obstacle within a radius of 150 m (500 ft) from the aircraft.


Center of Gravity and Center of Lift stability I have recently been reading about the center of gravity and center of lift. On the German Wikipedia there are many different graphics about the relation between the center of gravity and the center of lift. The one that struck me the most is the one where the description is the one where the center of gravity is the same as the center of lift:

Image according to: https://en.wikipedia.org/wiki/Wikipedia:Image_use_policy
The article in Wikipedia mentions that having a center of gravity (theoretically) coincide with the center of lift constitutes for a very unstable aircraft. It says that even the slightest turbulence will cause very bad nose attitude changes as the airplane becomes very unstable along the lateral axis.
I am having a really hard time understanding how this is any different from any other CG/CL configuration. Why is the airplane more laterally stable if the center of gravity is in front of the center of lift and the elevator is compensating the ensuing torque around the center between center of lift and gravity?

If you ever read something along the line that "even the slightest" cause will result in "very bad changes" when before all was stable, you know that the writer was out of their depth. But you have come to the right place.
The way you formulate the question it concerns lateral stability. The combined center of all side forces (= lateral lift) should be behind the combined center of gravity of all components of the airplane to give it weathervane stability. Since the law of conservation of momentum applies also to a flying airplane, all movements should happen around its center of gravity, so all moments should be summed up there to see what effect they will have. In order to see their effect on stability, it is even better to focus on the force changes effected by a change in sideslip. If they produce a moment which will rotate the airplane away from that sideslip, the airplane is laterally stable.
Why only the changes in sideforce with sideslip? This will become more clear when we look at longitudinal stability, which is implied by the graphic in your question. Here the same principles apply, only that a constant downward acceleration is added, namely gravity. To compensate its weight, the airplane needs to produce an opposite force, namely lift. This lift has to act at the same longitudinal and lateral position of the center of gravity. Any deviation would produce a moment around that center of gravity which would start a rotation. In order to shift the center of lift to the desired location, the pilot will deflect control surfaces to modulate the lift force at the extreme ends of the airplane (tail rsp. canard and wingtips) so that any moment around the center of gravity disappears. This is one meaning of "trimming" the airplane (the other one means to remove all stick forces in order to stay at this state).
Theoretically, the pilot could balance the airplane in the desired state using the control surfaces like you can balance a broom on your fingertip. But that becomes tiring quickly. So it is preferable that the airplane itself will produce moments when the trimmed position is left, without any additional control deflections. This is achieved by having the changes in lift force act at a location behind the center of gravity.
The point where all lift forces can be summed up is the center of pressure, (Auftriebsmittelpunkt) whereas the point where all changes can be summed up is the neutral point (Neutralpunkt). Now you know what the author of the Wikipedia article wanted to say but failed to do so. He is by far not the only person to confuse those two points.
In fact, only when the center of lift coincides with the center of gravity will flight be straight and steady. All other positions will cause the airplane to rotate away from its current attitude. In order to return to its old state, only the neutral point needs to behind the center of gravity.


Airport Security Pre-1970-s? I just accidentally discovered a few pictures on the web, that seem to imply, that there were some sort of airport security checks on passengers all the way back in the 1960-s. It was always my general understanding that airport security screening was not a thing before the Hague and Montreal conventions in the early seventies and the various national regulations that followed, so I was really quite surprised about the photos, but I have a suspicion that they could be dated incorrectly or the descriptions might be wrong.

For example, here is a press article photo, of what apparently is an early metal detector.

The description on the back of it clearly says that this device is to replace searching of passengers at the airport. Does that mean that all the passengers boarding aircraft were searched in some other way before that?

Here is another picture that left me puzzled.

It seems to be taken at Zurich Kloten airport, with passengers queueing for some booths, where, they will be "inquired on weapons". What does that mean, what is happening inside those things? Was there some kind of security procedure, exclusive to Swissair flights, or to the Swiss airports? If such a thing existed, when did they drop that, in favor of the normal screening? Those "ladies" and "gentlemen" signs look really weird...

And one more picture.

The uploader claims they found it on the Atlanta airport website, which then claimed this was a test of some airport security machine as early as the year 1960! I mean that was before the first hijacking of a commercial flight in the US, if I am not mistaken!
I think this one could probably be fake or a joke, or just something irrelevant to airport security. I do not think I see any electronic equipment here except for the data logger in the front, yet judging by the way the people are dressed this seems to be taken in the sixties, even though I am no fashion expert. The picture circulates in the web with this description, but I could not find any more information on it. And that just makes me even more interested to know what is actually happening there.

If anyone knows what these things are all about, and how it used to work back then, I would absolutely love to hear that. So any explanations strongly appreciated!
Thank You!

Other airport questions have been answered here and the FAA seems to have been involved in early regulations so Id say this is in scope here.

Airport security is a bit older than the 70's. The first serious criminal  aviation incident occurred in 1955 but hijacking has occurred since the dawn of aviation with cases being recorded as far back as 1930. The first serious increase in security appears to have come in 1961 (bolding my emphasis)

  Antulio Ramirez Ortiz hijacks a National Airlines flight to Cuba after
  it takes off in Florida. It is the first aerial hijacking of a U.S.
  passenger plane.

  The U.S. government begins placing armed guards on commercial planes
  when requested by airlines or the FBI.

If you follow the citation in the metal detector wiki it sounds like the FAA started to make mandates in the early 70's following the DB copper incident but it clear things were happening before then.

  But sky marshals couldn't ride on every flight, and the hijackings
  didn't end. So in December 1972, the FAA gave the airlines one month
  to begin searching all passengers and their bags. Dennis O'Madigan,
  then Director of Security for Piedmont Airlines, says metal detectors
  known as magnetometers were rigged up from a device originally used by
  loggers.

You should also keep in mind that in the earlier days of aviation ticket prices were extremely high and traveling via air was not as accessible as it is today thus some level of security was closer to what we see on private jets today. As ticket prices came down and the popularity grew greatly security became more of a concern.

On a similar note airport security has varied over time around the world. El Al the flagship carrier for Israle has generally implements security well above what most others are doing.

As for your pictures, the first one is dated 1970 which is in line with the timeline following the slew of incidents in the late 60's and the FAA's mandate of metal detectors in 72. The second picture is a bit of a mystery, it could be mis-labeled or they could simply be asking about weapons leaving the country as Switzerland historically has fairly liberal firearm laws and many other countries do not. The third photo looks staged or like a special situation, you can even see another photographer in the background. The Woman may in some way be famous (I cant identify her) and appears to be posing. That also looks like an EKG or polygraph machine...


Can an airline lay off its flight attendants and use pilots to fill the role? IcelandAir recently announced that it will be laying off its entire flight attendant staff, and plans to have pilots fill the role in the meantime.
Can an airline lay off its flight attendants and replace with pilots without requiring further training or certification? Generally, pilots are trained to fly the airplane and oversee the safety of the flight - but are they qualified to act as flight attendants? Is there any area a flight attendant maybe more qualified than a pilot, excluding passenger service and a smile on the face?

When I was flight crew on CRJs for a private operator we got abbreviated FA training for pilots, which was mostly a kind of crowd control course, taught by a contract FA. Their training is about managing a chaotic cabin full or panicking passengers. FA's are more or less under-cover riot control cops who spend their careers working as servers/attendants and are very unlikely to use their actual training.
So theoretically, airlines could offer flight crews FA postions, if they were willing to take the pay cut and were willing to be reminded every day where they are not, performing that undercover waiter/waitress function.  Yes, additional training would be required because airline flight crews don't get significant FA (crowd control) training and a pilot would have to take the FA course.
This is an opinion, but I would say not a difficult call; you would NOT get any takers. Every pilot will take the furlough and go look for another flying job, or change careers.  There is just no way that someone who loves flying enough to jump through all the hoops to get into a flight deck would take that kind of "demotion" (maybe... maybe... one person here or there would agree to it out of sheer desperation, but not enough to be significant).


What is the difference between an Instrument and Equipment? In an aircraft, what things is an instrument and what things is an equipment? For example the ILS, is the Antennas located in the runway considered to be an instrument or an equipment? Or is there another example to differentiate both?

In the aircraft an instrument is related to equipment providing displayed data.


How do aircraft land on snow? It is very common today for planes to land on snow (for example, in Antarctica). How are planes kept in control with so little friction against the ground? What is the procedure to perform this kind of landing? How much extra distance, on average, does an aircraft cover by landing on snow, compared to landing on dry pavement? (Video)

4 US Air Force Hercules aircraft at Willies field, Antarctica Source

It is very common for planes to land on snow (i.e. packed snow) or even ice runways.

  How are planes kept in control with so less friction on ground?

Snow/ice friction is a function of the outside air temperature, so it depends. Another factor is whether the runway was packed, fresh snow - and the temperature the previous day. The colder it is, the more friction the snow will have (i.e. adequate braking). In warmer temperatures the snow will be slick (scarily slick at times - as in nil braking).

While flying a multi-engine airplane, one can use differential power. If you're flying a single-engine airplane - one is better off with small taps on the brake during slick conditions. If the OAT is relatively cold (well below freezing), braking can be pretty good.

  What is the procedure to perform such kind of landing?

The procedure is the same as a standard landing. However, it is awfully nice to have good contrast on the snow to see the runway. Often runways that are pure snow/ice will be more visible than the surrounding terrain. At the very least - the runway will be outlined with some sort of runway markers.

  And, on an average how much extra distance does an aircraft
  covers by landing on snow, as compared to landing on ground?

As I said before, it is really dependent upon the outside air temperature and the condition of the runway (i.e. packed snow or fresh snow).

For example, suppose there were fresh snow on a relatively warm day (30 degrees farenheight) and the snow is compacted (i.e. by humans) that day. Say, night-time temperatues drop to 0F, and the next day you land with an OAT of 30 to 35+F... that runway is going to be SLICK. However, if the temperatures were to stay at 0F - you would actually have decent braking. Even further, if the OAT dropped to -40 below...you will have excellent braking.

TLDR:

Snow conditions are always changing and braking/control of the airplane are dependent on those conditions. Snow-conditions are highly dependent on the outside air temperature and to some degree human-maintenance (for better or worse).

*source: Personal experience from flying in the Arctic.


How to say the name of this approach clearance: COPTER RNAV (GPS) 027° JFK has this approach: https://aeronav.faa.gov/d-tpp/2006/00610COPTERR027.PDF

How is this approach said on frequency? Is it the "copter RNAV zero two seven approach" or the "copter RNAV zero two seven degree approach" or the "copter RNAV heading zero two seven approach" or something else?

Based on the 7110.65 2–1–17h, "degrees" is never used. Based on Note 9 under 4–8–1a, the text in paranthesis is omitted. So, ATC would say:

Cleared Copter RNAV zero two seven Approach

or

Cleared Copter RNAV heading zero two seven Approach

If you were requesting it, you'd say "Requesting Copter RNAV zero two seven approach."
However, since it is the only Copter approach at JFK, you could probably just request "the copter approach" and they'd know exactly what you're talking about. But ATC is required to use the phraseology as indicated in the Order linked above.


How are credit cards processed during flight? If telephones/smartphones/tablets are not allowed on planes, how comes when you buy duty free items from the cabin crew and pay by cc they will use the card reader?

I suppose that in order to remove credit there must be some sort of connection to the various credit cards circuits in real time in order to achieve this?

Presumably, they use an off-line transaction. The reason your credit card has raised numbers is that, in the old days, before ubiquitous data connections, a card transactions used a machine like this

to transfer an imprint of your card details onto a form, using carbon paper. You would then sign the form and the merchant would send it off to the bank to get paid. It wasn't possible to verify in advance that you had enough money in your account but the deal was that the bank would honour the transaction and then come after you with a big stick.  The point of my mentioning this is that, although we're now very used to the idea that the merchant talks to your bank while you make a card transaction, this wasn't the case even 20 years ago.

Today, it's still possible to make a card transaction without verifying in advance that the card has sufficient funds, so that you can still buy stuff on your card even if the merchant's phone line or internet is broken. In fact, the last-case fall-back is to go back to the swipe machines and carbon paper.


Which FARs does the Boeing 737 MAX conform to with respect to turbulence? Based on this question/answer it seems that the FARs in relation to turbulence handling have been updated several times over the years. Does the Boeing 737 MAX conform to the latest FARs or to the FARs in place when the Boeing 737 was first certified?

Testing standards for things like turbulence and fatigue are not related to any specific aircraft type certificate. Yes, the MAX shares the same type certificate as the first 737-100, but the TC only makes reference to the certification standards to which the design complies. If you look at the TC you will see that it references the advisory circular for fatigue and damage tolerance testing (AC 25.171-1x), but as new models are introduced the TC makes reference to the latest version of the AC at the time the modified TC is issued to include the new model. The latest version of the AC is -1D.


What license will one need to fly the Aeromobil flying car in 2022? Aeromobil are launching their "flying car" in 2022, after successful test flights.
What kind of license / certification will be required to own / fly one of these? Presumably something less than a PPL, otherwise the barrier to entry will be too high.

Short answer: You will almost certainly need a PPL at least.
On the subject of licensing for flying cars, nobody really knows, because no company has even come close to bringing one to market - and the term "bringing to market" for a flying car involves all the legalities of certification and licensing.

The U.S. based Chinese-owned firm Terrafugia and AeroMobil are also attempting to develop a two-seat flying car called the Transition, however, safety and development of the law for flying cars are just two of the challenges that must be met before they become a reality and not just a novelty. The Transition is designed to operate both on land and in the skies.

source: Aviation Law: An Analysis of the Development of Flying Cars for the 2020s Decade
In terms of aviation certification the Aeromobil specifications state

Aerospace: CS 23 Rev 5/ELA 1 (EU) & 14 CFR 23 Rev 5 (US)

That means for the US it is certified under Part 23 which will almost certainly need a minimum of a private pilots license. In the EU it is pretty much the same deal as many of the aviation standards/certifications around the world are based on ICAO norms.

Not that you asked for it, but in my opinion the only likely route to market for personal flying vehicles is ones where you're not doing the flying. One day I'm sure we'll have something like an automated Uber which ferries you A to B short distances. But something where you drive and fly is hugely unlikely.


Why do some airports have class E airspace to the surface only at certain times? Below is the depiction of the Truth or Consequences airport on the VFR sectional.  Notice that it states that Class E to the surface is only effective for certain hours.

The Chart Supplement lists the effective hours as 9:00 - 17:00 local (converted from Zulu).  My question is why are the Class E surface hours limited to 9:00 to 17:00 local and not effective for 24 hours each day?  I understand that airspace reverts to less restrictive airspace when a control tower closes but there is no airport tower at this airport or a towered airport anywhere near this airport.

The class E airspace protects IFR traffic departing and approaching the airport from incursions by VFR aircraft.

visibility and cloud clearance requirements for Class E are more strict compared to Class G (which is what the airspace reverts to after-hours).

3 statue mile visibility, 500 below, 1000 above, and 2000' horizontal from clouds for Class E

Compare that to 1 sm / clear of clouds for Class G

You could see that someone pushing the limits of VFR, scud-running to/from the airport might pose a danger to an IFR aircraft on approach to the airport and might pop out of the clouds and get a surprise.

As to the choice of hours, that's likely an FAA decision based on traffic volumes.

Normally you see this at airports that serve rural locations with scheduled passenger service throughout the day (and possibly later at night as well).  Pellston, MI is another airport that comes to mind with a Class E surface area, but it is 24 hours a day.  I think Delta serves Pellston with 1 or 2 flights a day from Detroit.


Are there certification requirements for an emergency descent? In case of emergency, an aircraft may have to descend very quickly. Is there some performance (L/D ratio with full spoilers, descent rate, ...) to be proven in the certification process for such descent?

There is a descent requirement, but it's perhaps not in the way you imagine as it has to do with oxygen supply. FAR 122.333 subpart K states:

  (b) Crewmembers. When operating at flight altitudes above 10,000 feet,
  the certificate holder shall supply enough oxygen to comply with
  §121.329, but not less than a two-hour supply for each flight
  crewmember on flight deck duty. The required two hours supply is that
  quantity of oxygen necessary for a constant rate of descent from the
  airplane's maximum certificated operating altitude to 10,000 feet in
  ten minutes and followed by 110 minutes at 10,000 feet. The oxygen
  required in the event of cabin pressurization failure by §121.337 may
  be included in determining the supply required for flight crewmembers
  on flight deck duty.

This specifies that a turbine aircraft must be able to descend from it's maximum certificated altitude to 10,000ft in 10 minutes or less. This means the maximum descent speed is variable to maximum certificated altitude, so if an aircraft's ceiling is 42000ft it must be able to descend at least 3200fpm, it it's 25000ft then 1500fpm.

As for how that's done I don't think the regulations say, it's up to the manufacturers to develop aircraft that can meet the requirement.


Is 1N2 (Spadaro) in class G or D airspace? I am confused about the situation where an airport is located in class G airspace and at the same time located in class D airspace. As we can see the picture below Spadaro (1N2) is located inside the Francis S Gabreski (KFOK), am I right? If so, do I need to call tower before entering class D?

Strictly speaking class D airspace generally has a radius of 4 NM. If you take a look at the TAC chart or hop on your favorite flight app you will see the field actually sits just outside the airspace.

The sectional is likely drawn this way to allow for 49N and 1N2 to both be properly depicted.

Officially the airport is closed according to the current AF/D it appears to have been shut down in 2016, so it may be listed there simply for visual reference as the physical runway seems to still exist but traffic overlap is no longer an issue.


can the wreckages of a hot air balloon and a hang glider be salvaged for a working hang glider? I'm currently working through my collection of Spike and Suzy albums, and in the album I'm currently reading, one of the main characters crashes with a hot air balloon near the wreckage of a hang glider without sail cloth. The main character, who is usually characterized as a somewhat smart man with skill in engineering, tore a large section from the balloon cloth, tied it to the hang glider wreckage and managed to make a functional hang glider that could even make a reasonable ascent in the Alps, near the Mont Blanc and catch up with his friends who were in other hot air balloons.

The hang glider looked like this (I couldn't find a bigger image, sorry):

How would this type of makeshift hang glider work IRL? even though hang gliders and hot air balloons are made from the same kind of fabric (ripstop nylon), wouldn't the holes between the frame and the cloth totally ruin the thing?

To expand a bit on what @ratchetfreak said in a comment...

The leading edge on that glider is not secured properly.  It would need to go around the bar all the way along the leading edge of the wing, otherwise the holes would make it so the airfoil doesn't function.

As it is right now, the air would hit those gaps and make the cloth flutter, which would break up the airflow over the glider itself.  Thus you'd just have turbulence over the wing, which would make the wing stall.

So, yeah, in a nutshell, that wouldn't work as a glider as pictured above.

But, if he had found some string or wire from the wrecked balloon and properly secured some of the Hot Air Balloon cloth to the frame...  There's no reason it shouldn't work.  Hot Air Balloons are made out of fabric that is very very similar to what hang gliders are made from.


Is there a database of European surveillance radar installations? Does anybody know a link to a database or appropriate webpage where I can find the locations of surveillance radar installations in Europe?

Meanwhile i found an answer to my question. Location data of radar stations is for most countries provided in the AIP ENR chapter 1.6 "ATS Surveillance Services and Procedures". Some countries do not provide the coordinates of radar location, but only a coverage map. European AIP may be accessed through Eurocontrols EAD service.


Why do aircraft use 400 Hz AC instead of the 50 or 60 Hz of wall outlets? Large aircraft electrical systems usually use 400 Hz alternating current (AC), while common household electrical outlets deliver AC at 50 or 60 Hz.  Why the difference?

Induction motors turn at a speed proportional to frequency, so a high frequency power supply allows more power to be obtained for the same motor volume and mass. Transformers and motors for 400 Hz are much smaller and lighter than at 50 or 60 Hz, which is an advantage in aircraft (and ships). Transformers can be made smaller because the magnetic core can be much smaller for the same power level.  Thus, a United States military standard MIL-STD-704 exists for aircraft use of 400 Hz power.

So why not use 400 Hz everywhere? Such high frequencies cannot be economically transmitted long distances, since the increased frequency greatly increases series impedance due to the inductance of transmission lines, making power transmission difficult. Consequently, 400 Hz power systems are usually confined to a building or vehicle.

Source

Further discussion of aircraft electrical systems

Further, further discussion of aircraft electrical systems

Added: cool discussion of the use of 400hz with Cray supercomputers on another S.E. forum


Why do almost all overwing exit slides open over the trailing edge of the wings, and almost none over the leading edge? Almost all narrowbody jetliners, and many widebodies as well, use overwing exits to augment their evacuation capabilities; to escape the aircraft, a passenger or crewmember in the exit row pops the hatch next to their seat, and then everyone else1 chases them out onto the wing.
At this point, depending on the aircraft, they may simply slide down the flaps to safety, or a slide might inflate if the wings are too high above the ground.  Either way, though, they’ll be going over the trailing edge of the wings if it’s a land evacuation;2 even if the aircraft has multiple overwing exits per side (common among the larger jetliners), or if there’s a tail-mounted engine waiting to gobble up trailing-edge evacuees (like with the Fokker 70), everyone going out on the wings still evacuates off the trailing edge.
I know of only a few airliners with overwing exits that specifically direct evacuees over the leading edge of the wings, and two of these are very special cases:

The Concorde’s wings extend for most of the length of its fuselage, so it would be essentially impossible to fit enough exits in without having some going over the leading edge.
The Il-62 has a set of engines so close behind the wings that even the emergency-exit designers realised it would be a bad idea to send evacuees over the trailing edge (also, its overwing exits don’t have slides - instead, you have to slide down a rope over the leading edge of the wing).
The DC-10/MD-11 family has overwing evacuation slides that go over the leading edge of the wing, as do some A310s, making these, so far as I am aware, the only subsonic airliners without engines right behind the wings to use leading-edge overwing exits.

For low-slung narrowbodies, where you slide down the flaps to get to the ground, the predominance of trailing-edge overwing exits is excusable, as the flaps are on the trailing edge of the wing; however, even for large narrowbodies and widebodies with inflatable overwing evacuation slides, the slides still overwhelmingly open rearwards, over the trailing edge.
Why are overwing exit slides leading off the trailing edge of the wings so much more common than ones that go out over the leading edge?

1: I exaggerate slightly; some of the passengers will likely lock themselves in the lavatories or run up and down the aisle(s) screaming like chickens with their heads cut off, and one or two might even use the exit doors at the front and/or rear of the plane.
2: Ditchings work somewhat differently, and some aircraft do call for occupants to fall off the leading, rather than trailing, edge in this case.

The special cases you listed (minus the very special case Concorde) hold the clue.
The Il-62, DC-10, and MD-11 are all tail-heavy due to the tail-mounted engine(s).
The emergency exits are designed inside-out, not outside-in, meaning, the locations are not only dictated by each exit's size, but by the cabin's seating arrangement first.

(e) Uniformity. Exits must be distributed as uniformly as practical, taking into account passenger seat distribution.
(...)
(4) For an airplane that is required to have more than one passenger emergency exit for each side of the fuselage, no passenger emergency exit shall be more than 60 feet from any adjacent passenger emergency exit on the same side of the same deck of the fuselage, as measured parallel to the airplane's longitudinal axis between the nearest exit edges. (14 CFR § 25.807)

The tail-heavy examples by design have the main wing more aft, leading to that scenario. The rest, the opposite.
The DC-9 extended family[a] is more special, as there's an exit in the tail (also usable for entry):

Source: aircollection.org

And with the floor-level exits right ahead of the engines being not full-size (compared to the forward doors), it's been balanced that way. Otherwise it would have used an exit arrangement similar to the Il-62's, or the Vickers VC10 with a large exit forward of the wing in some configs, and/or over-the-leading-edge overwing exits in others:

Different VC10 configs; sources: wikimedia.org and wikimedia.org

The A310's reason is the original A300 fuselage that was shortened. If there are other configs, it would be related to passenger capacity.

a: optional on DC-9, standard on MD-80/90, removed from B717[1]
1: Becher, Thomas. Douglas Twinjets: DC-9, MD-80, MD-90 and Boeing 717. Crowood, 2002.


Why are special aircraft used for the carriers in the United States Navy? Why are aircraft such as the legacy F-14 and now the F/A-18 used by the US Navy carriers?

It seems to me that developing a new aircraft from the ground up is very expensive. Is it not possible to have converted F-16 or F-15's for carrier operations? Obvious modifications such as folding wings, stronger undercarriage, hook, etc. I'm sure there are many more I'm not aware of.

Is the reason that these aircraft (F-16, F-15) are not suitable for carrier operations, even with modifications?

Isn't this what the Russian Navy did with their fighters? The carrier versions of the MiG-29 and Su-27?

What are the reasons the US employs unique carrier aircraft? Is the reason political? Technical?

It's technical, not political

The F-35 was an attempt to do exactly what you propose, lowering costs by planned sharing of 80% of parts across variants, but it turns out that the USN's F-35C costs over twice as much as the USAF's F-35A, and only shares 20-25% of it's parts. The project has been a disaster practically since day one, and the services are already working on separate replacements tailored from the start for their very different missions.

Per Wikipedia, the USN decided a carrier variant of the F-15 would be too expensive and the YF-16 was inherently not suitable for carriers, so they modified the YF-17 into the F/A-18 by making the changes you propose. The USAF didn't need those changes, so they stuck with the faster and cheaper YF-16, which became the F-16.

Keep in mind that all US aircraft carriers combined hold the fourth largest air force in the world. That sort of volume means the USN can afford to customize planes for their exact needs, whereas other countries with far smaller carrier fleets may be forced to make do with planes that the USN considers "unsuitable" or "too expensive", especially if they aren't US allies.


How does landing gear affect thrust on a light twin-engine airplane? I'm working on my commercial multiengine rating.  And I got this question from my examiner, and I answered: landing gear produces penalty drag, so it decreases thrust.
 But the examiner says this isn't correct... ?

Thrust is not decreased.  The drag penalty means that more thrust is required to achieve a performance condition than without the drag penalty.  In level flight, more thrust is required to go the same speed.  When climbing, more thrust is required to achieve the same climb rate.  Your maximum thrust available is what the engine can produce, so the extra drag subtracts from whatever surplus thrust is available.

In a light twin the key thing is the surplus thrust margin available for climb at the most efficient speed for climbing while single engine (blue line speed).  To fly in level flight single engine at blue line speed, we'll say you need 500 lbs of thrust from the good engine.  To climb at that speed requires more than 500lbs, and to get a decent rate of climb, say 400 fpm, you might need 800 lbs (about what you'll get with a Lyc O-360 running flat out), which we'll say is what the engine makes at full power at sea level (a piston twin that can climb better than 300 fpm single engine at gross is a pretty good performer).

Add more drag by leaving the gear down, and the thrust required just for level flight goes up from 500 lbs to, say, 700 lbs because of the 200 lbs of drag of the gear sticking out.  Instead of 300 lbs of surplus thrust margin available for climb, you only have 100 lbs and it's a struggle to get any climb at all or to avoid descending, and only if you use perfect technique (on-speed, 5 degrees bank into the live engine).

So the proper answer for leaving the gear down is, surplus thrust available for climb is decreased and therefore climb performance at maximum thrust is decreased.  Which in a light twin at gross on a hot day means, as the old saying goes, "the remaining engine takes you directly to the scene of the crash".


How to land a sports plane with tailwind? Let's say we have a Cessna 150 or some other lightweight two seater and no chance to land with head wind for whatever reason.
We're trying to land with a constant tailwind of 7 knots.
I would try to land as close to stall speed as possible to compensate the tailwind. So much for the theory. In reality, the wind is not constant. If I'm close to stall, dying wind will give me trouble. What's a general good approach for such situations? What configuration would you choose?
If the runway is very long, one can just go faster. But often, runways are rather short.

Land normally.  Check your POH (Pilot Operating Handbook) first to ensure you have enough runway including the extra needed for a tailwind.  The only thing to watch out for is that winds tend to moderate as you get closer to the ground.  In a headwind landing, the relative wind will decrease, In a tailwind landing the relative wind will increase, so there will be an increased tendency to float way down the runway.  Be on speed for a short field landing technique.


What are the evenly-spaced "bumps" on Bell X-1 tailplane? The tailplane of the Bell X-1 had four evenly-spaced "bumps" on each side--what was their purpose?  (Screen shot from The Right Stuff.)

Another image

If they're hinges for the elevators, then how come the rudder and ailerons have flush hinges?

This documentary is about the X-1 breaking the sound barrier. It shows that the bumps are indeed hinges, and that the horizontal tail was indeed originally designed as a trimmable stab and elevator. At 25:40 the control surfaces can be seen moving.

At 35:00 Chuck Yeager talks about losing control at M.94 with this configuration, and then having the tail config reworked into an all flying tail, directly connecting the stabiliser to the stick.

Update Aug 2019

The original clip has been removed, this is the new link. Starts at the movement of the all flying tail.


Did Concorde really fly above 55k feet as mentioned in this report? Here is a report of the last journey of Concorde from JFK-LHR, which mentions "The highest altitude we reached was 58000 feet." Is this height aerodynamically feasible to reach?

Yes. The extra height was necessary in order to reach lower pressure air, and thereby reduce drag, and heating of the airframe from supersonic compression of the air.

Concorde's windows were extra small, so that if a window did blow out, the air compression system could actively compensate by pumping air in faster than it could escape, until the pilot completed his emergency descent.

More details can be heard on this podcast.


Which fixed-wing aircraft has the highest number of required flight crew members? Most modern airliners require two pilots to operate. Older airliners require a flight crew of three: two pilots plus one flight engineer.

Has there ever been an aircraft where the number of required flight crew members is extraordinarily high, for example five or six?

To clarify the question:

"required flight crew member" is the number required by relevant regulations, not the number needed to physically operate the plane. If that number is not met, the plane could not legally have taken off
gunners / weapon operators of military aircraft who are not necessary for a safe flight are not included
flight attendants are not included

The Antonov An-225 Mriya requires a crew of six- you have the pilot, copilot, 2 flight engineers, navigator and a communications specialist/radio operator.

An-225 cockpit; image from sas1946.com


Why UA954 was diverted to Houston IAH on 25th Feb? Fligth UA954 on 25th February was diverted to IAH when in flight from SFO to TLV.

Passengers were updated and told that the plane had a technical issue that was preventing it from crossing the ocean.

According to flightaware the plane was close to the border between Wyoming and Montana. It continued flying and landed in IAH.

What was the reason for the flight not being able to continue flight over the ocean, but still allowing it to continue flying safely for around 4 hours?

They told ATC they had an unknown odor in the cockpit. When ATC asked for more detail they said they had narrowed it down to the cockpit heating element. They specifically said they were not declaring an emergency.
It just happened to have occurred while they were within range of the LiveATC receiver so the transaction is on the recording (normally you can only hear ATC on the en route feeds). The recording is here. After ATC tries to raise them several times they check in at about 17:22 on the recording and tell ATC about the odor and need to divert. About 5 min later, I presume after conferring with the company, they tell ATC they are not declaring emergency but they're diverting to IAH. When asked for further details the say it's the cockpit heating element. After a few more exchanges with ATC they fly out of range of the LiveATC receiver.
Here's my transcript.

Times are per the recording (MM:SS). The recording starts at 0630Z so add that to the times listed for UTC
16:15 [ATC] United 954 change to my frequency if you're not there, 127.75
16:28 [ATC] United 954 Salt Lake
16:38 [ATC] United 954 Salt Lake Center
17:10 [ATC] United 954 Salt Lake Center
17:23 [UA954] Salt Lake united 954 checking in 350
17:27 [ATC] United 954 Salt Lake Center, roger. Welcome
17:30 [UA954] Yeah, it looks like we've got some unknown odor in the airplane. Were gonna - were either gonna go to Houston or San Fran. I'll get right back with you.
17:40 [ATC] United 954 thank you
21:54 [UA954] Salt Lake 954
22:13 [UA954] Salt Lake 954
22:16 [ATC] 954 go ahead
22:20 [UA954] Yeah, we are not, I repeat, not declaring emergency. We just need to turn to Houston for an unknown odor in the cockpit.
22:27 [ATC] United 954 roger, clear to Houston airport via direct. Maintain FL350
22:36 [UA954] Ok, 350 direct to houston, thank you. United 954
22:52 [ATC] United 954 I just want to confirm that's India Alfa Hotel. Is that what you're showing?
22:57 [UA954] India Alfa Hotel, affirmative
23:00 [ATC] 954 roger, thanks
23:07 [ATC] United 954 they're gonna want to know maybe a little bit more details. Is there something else maybe you can tell me about the odor so I can pass that along?
23:17 [UA954] Stand by
23:23 [UA954] Yeah, we've narrowed it down to the cockpit heating element is, we believe, the source of the smell. But that's the best we can deduce at this point.
23:34 [ATC] United 954 roger, thank you.
There are a few further routing exchanges before 954 flies out of range.


Is there any plan to create GPS approaches to water areas for seaplanes? Is anyone working on differential GPS approaches for seaplanes? They are a largely ignored resource with great capabilities for certain remote places

Yes, such plans exist. The Aarhus Harbour Seaport (ICAO code: EKAC) is planning to implement an RNAV approach to allow seaplanes to land in conditions below normal VMC, however, the authorities have yet to approve it.


Do FAA endorsements have to use the current language word-for-word? When pilots are going through the instruction process they receive many endorsements from flight instructors. It's common for a pilot to possess a logbook that has a prefilled endorsement in the back. It's also common for the logbook to use language that was current at the time it was produced, but for that language to have been superseded.

The FAA publishes and updates AC 61-65. At the current time, we're up to AC 61-65G.

My question is this. Are endorsements valid if they don't use the current language found in AC 61-65?

Here is verbiage from the FAA's AC 61-65G, appendix A, regarding endorsements.

Also, in my view as long as the instructor's endorsement verbiage covers the essential elements in the regulation underlying the actual rquirement(s) that must be met, there are no mandatory words that must be used.  However, should a question arise regarding the action, level of proficiency, or other requirements specified by the regulation the instructor is attesting to, using the recommended language shown in AC 61-61G, appendix A, should eliminate any potential ambiguity.

(emphasis is mine)

  The following examples are recommended sample endorsements for use by authorized
  instructors when endorsing logbooks, or other means found acceptable to the Administrator for
  airmen applying for a knowledge or practical test, or when certifying accomplishm
  ent of
  requirements for pilot operating privileges. Each endorsement must be legible and include the
  instructor’s signature, date of signature, certificated flight instructor (CFI) or certificated ground
  instructor certificate number, and certificate expir
  ation date, if applicable. The purpose of
   this
  advisory circular (AC) is to provide guidance and to encourage standardization among
  instructors.


Can I get a sport pilot license while taking Mirapex? May I get a sport pilot license while taking the medication Mirapex for Restless Leg Syndrome?

Assuming you have never applied for a medical certificate:

You need to ask your doctor. Sport pilots don't need to have a medical certificate, but they do need to be capable of operating an airplane safely. Mirapex is on the do not issue, do not fly list, so the presumption is that you cannot fly while taking it. In order to legally fly solo or with passengers while taking Mirapex, your doctor must tell you that it's safe to do so.

Your doctor may tell you that it's not safe to fly while taking Mirapex. In that case, you only have two options: stop taking the medication (with the approval and supervision of your doctor), or don't fly (except as a student receiving instruction).

If you have applied for a medical certificate ever in your life: You need to get a medical certificate in order to fly solo or with passengers. In this case, you need to talk to an aviation medical examiner for advice; there's no way around this.