texts: How do the chevrons on engine nacelles reduce noise?

texts:
The B787 has these chevron-shaped teeth on the exhaust port of its engines to reduce noise.

And according to the answer to this question they will be incorporated into the new B737's

Can anyone explain how these work to reduce noise?


texts: What are the limits of ground effect over water on an airliner plane at cruising speeds?

texts: What height over a fixed plain (such as water) can a plane begin to take advantage of the ground effect or when air is compressed between the wing and ground near cruizing speed? Could an airliner type plane fly above the water for an added lift for range in an emergency where a plane may lack the power to climb?


texts: Can anyone identify this pusher plane from apparently the 1930s?

texts: I have performed two searches - a photo search and also an FAA NC number search and failed at both to identify this pusher airplane.  My family photo says it was taken by my mother at the Chicago airport in September 1937.  The NC number appears to be NC 15574 and I've tried several variations including dropping the "1" and trying "9" for the "4" but could not get an FAA NC match.  Your assistance in identifying this airplane and anything about it is greatly appreciated.


texts: How do pilots adjust trim on the B777, where the control forces are simulated?

texts:
I know that pilots of small airplanes (e.g. Cessna 172) use force to trim, i.e. they hold the required attitude using the yoke, then trim the aircraft until no force is required to hold the yoke in that position. In that way, they trim using 'feel' to gauge how much trim is needed.

Airliners and some other planes use trimmable stabilizers for trimming, thus the yoke always returns to center if the pilot leaves it.

So I was reading the B777 FCOM and it's written in there that since the plane is fly-by-wire, it simulates control column forces to let the pilot know it is out of trim.

My question is how does the pilot know how much trim to use? I know one way would be to let go off the yoke and see if the plane keeps its attitude or not, but is there another way?

(sorry for the long question, I am a newbie here and did my best to ensure you understand my question).


texts: What is the effect of flying height on helicopter fuel consumption?

texts: Does the height at which a helicopter is flying affect its fuel consumption? Which factors are influencing its fuel consumption?


texts: How do changes in certification requirements affect previous type certificates?

texts:
How does the 2016 part 23 airworthiness requirements rewrite affect older type certificates?

If some aspect of an aircraft does not meet the new requirement do all of those aircraft have to be updated accordingly?
If so, what if the aircraft can't be made to meet new requirements, such as climb rate, etc.
If one of the new rules are less restrictive than the old can those aircraft take advantage of that?
Do newly manufactured aircraft of the same type have to get recertified?
If old type certificates are still valid and the FAA wants one of the new rules to be retroactive will they have to issue airworthiness directives for each type that doesn't meet the new standard?


texts: What is the fatigue life of a fuselage based on?

texts: The fatigue life of the fuselage is based on the number of what? Pressurization cycles?


texts: Why is the normal operating airspeed so much lower than the cruise speed in this table?

texts:
I need to work with the following table. I'm interested in vMO which I assume I can simply obtain from converting MMO to vMO through $M = v/ \sqrt{1.4 * 287 * T}$. (Is that correct?)

However, I noticed that the vNO is more than 100 kts less than vcr in this table. From my current understanding, vcr should be given as a TAS, which would mean that the the only way in which vNO could be lower than vcr would be that vNO is given in IAS. However, in that case the difference should be much more than 100 kts, right?


texts: Why does the F16 HUD give you one number for your speed and the analogue gauge another?

texts: Why does the F16 HUD give you one number for your speed and the analogue gauge another different number?


texts: How does the DA 40 NG automatically control the mixture, pitch and power by just providing one throttle?

texts:
I'm a student pilot and here at my school we have the older gen DA40s which have individual lever for mixture, pitch and power.

I was looking at this video of the DA40 NG, and got quite curious as to how everything from prop to mixture is automatically controlled, and on top of that you don't need to do any run up checks!

Tried using google but nothing really came, so I thought this would be the right platform to ask and satisfy my curiosity.


texts: Is a CFII required in order for a flight Instructor to provide training for added class ratings?

texts:
Must a flight instructor have a CFII to provide multi-engine add-on training to a customer meeting the following criteria:

Holds a commercial pilot certificate with a single engine land class rating.
Holds an instrument airplane rating.
Holds a valid medical certificate.

So, put plainly, our hypothetical customer holds a commercial pilot certificate with a single engine land class rating and an instrument rating.  He/she has a "single engine commercial-instrument ticket" to use industry lingo.
Does the customer's MEI have to have a CFII to give the add-on training?


texts: What does the ACARS Weight and Balance Request page look like?

texts:
In the ATSU AOC Preflight menu of an Airbus (maybe Boeing too), there is an option for a weight and balance request. The selection name varies by airline but it may say "W/B Req" "Send LoadSheet" "LoadSheet REQ & Confirm" "Weight Manifest Request" "Loadsheet Request" "Load Data Report" or "W/T Balance".
What does this page look like? What information does the pilot have to enter in this page?


texts: Why can’t the F28 be deiced with one or both engines running?

texts:
Recently, I was contemplating Air Ontario Flight 1363, which, despite heavy, wet snowfall while it was on the ground at CYHD, could not be deiced before takeoff, as it arrived bearing an inoperative APU, necessitating (as CYHD, at the time, had no ground-starting equipment available) that one of its engines be kept running the whole time the aircraft was on the ground, and hot-deicing an F28 (deicing it while one or more engines are running) is forbidden.  The aircraft eventually took off, and, predictably, crashed almost immediately due to snow and ice accumulation on its wings.

Wikipedia claims that the prohibition against hot-deicing an F28 is to prevent vapours from ingested deicing fluid from entering the cabin ventilation system via the engine bleed air used to heat and pressurise the cabin, but the engine bleeds can easily be turned off before deicing the aircraft, and any residual deicing fluid left in the engine after deicing can be dealt with by letting the engine run for a few minutes to flush out its passages before turning the bleeds back on (and, if necessary, one could start the engine on the side not being deiced at the moment, and route bleed air from there into the other engine to blow out any deicing fluid, or vapours therefrom, that did somehow make it into the bleed-air passages).

What gives?


texts: What are the states that the landing gear can be in?

texts:
What are the valid set of enumerated states for landing gear?

My current working set is:

DOWN
DOWN & LOCKED
STOWED
STOWED & LOCKED
INOPERATIVE
CYCLING_UP
CYCLING_DOWN

Also, are there any definitions in which UP is distinct from STOWED?  (I can't find any.)


texts: Are warbirds allowed to use afterburners?

texts: Suppose a civilian buys a military jet, for example an T-38. Would he be allowed to use afterburners?


texts: How to deal with both a speed and an altitude crossing restriction while in VNAV PTH descent (Boeing 737NG)?

texts:
Suppose you are in VNAV PTH descent and are approaching the IAF for your Approach, The IAF has both an altitude crossing restriction and a speed restriction.
Assume that your VNAV PTH descent is at 240 kt at that moment and the speed restriction is 210 kt.

Will VNAV automatically "see" the speed restriction and reduce the descent rate (pitch up) to meet the lower speed? If yes, won't it then miss the altitude crossing restriction, as the planned path is modified?

If the PIC uses SPD INTV to set the limiting speed, won't VNAV switch to VNAV SPD and thus once again automatically pitch up to reduce the speed? Again, this may result in not meeting the altitude restriction, as you will end up higher than your intended path.

So, the question is, what should you do in a situation like this?
My guess is, revert to V/S and MCP SPD, use Speed Brakes and arrange to be over the IAF at the correct speed and altitude, and then re-engage VNAV.


texts: Have we seen the last significant experiments in the configuration of jet airliners?

texts:
By the 1940s, passenger airliners had pretty much settled down on the shape that has dominated the industry since then: a monoplane, with wing-mounted engines, a roughly cylindrical single fuselage and a tailplane.

The 707 set the template for jet airliners: low wings, and pylon-mounted engines.

Source: Wikipedia

Apart from the few, smaller, models that place their engines on the rear of the fuselage, there are almost no models currently in production that adopt a different template (in fact, the only one I am aware of is the Antonov An-148).

There are no more tri-jets. There are no more radical experiments like Concorde on the horizon, never mind in production. There are no serious proposals for significantly different shapes or configurations.

The only significant configuration choice for medium-to-large size airliners seems to be two engines or four.

Since the 707 slung its engines under the wing on pylons in the 1950s, the only significant development that I can think of is the adoption of winglets in the 1980s.

You might consider the 747's hump and the A380's twin decks to be significant variations, but they are still only variations on the theme, not fundamentally different configurations.

Assuming that jet engines remain viable in 40 years' time, will the airliners of 2058 still look fundamentally like 707s?

If you're concerned that question seems too open to mere speculation, let me ask it another way: is there a fundamental design reason why the low-wing/pylon-mounted engine/cylindrical fuselage/tailplane configuration established by the 707 shows no sign of being displaced by alternatives?

Or, why have the enormous advances in (for example) materials and aerodynamics made so little difference to the fundamental shape of airliners?


texts: How can a VTOL aircraft control yaw while hovering?

texts:
I watched this video of a F-35B performing a flight-hover-flight transition and was pretty impressed by the fact that it was able not only to control pitch and roll (which could be, I suppose, performed by differential power from engine and lift fan) but also yaw — while hovering (at 3:15 in the video).

How does it do that? Bleed air ducts from the engines on the sides of the aircraft? (something alike to thrusters used to control attitude of spacecraft I suppose).


texts: What are the dynamic stability properties of an aircraft with wings exactly at the vertical CoG?

texts:
Please ignore for a moment the practical issues with building and operating an aircraft like this.

Suppose a fixed-wing aircraft which, when viewed directly along the roll axis, has the wings centered exactly at the vertical center of gravity. Suppose that this aircraft is in stable, level flight in otherwise still air. (Yes, this is a little like the spherical cow in a vacuum from physics.)

If there is a disturbance, such as a localized updraft or downdraft affecting one of the wings more than the other, then broadly speaking and as I understand it so far (feel free to address this if I've got it completely backwards), after exiting the disturbance and with no further control inputs, a high-winged aircraft will tend to return to neutral roll (dynamically stable) and a low-winged aircraft will tend to increase its roll angle further (dynamically unstable), as a result of the differences in localized airflow above and below the respective wings.

However, what would be the behavior in such a situation of our hypothetical mid-winged aircraft that I described above?

My hypothesis is that the aircraft would maintain its roll or bank angle, which (unless compensated for, say by rudder input) in turn will result in a rotation along the yaw axis and a subsequent turn.

Am I right or wrong? Why?


texts: What is the difference between iSpec2200 and S1000D specifications?

texts: I know the iSpec2200 and S1000D are the specifications which are used in the aircraft maintenance manual, I have to know how they actually work in the aviation domain and what is the difference between them.


texts: How is fuel vapor dealt with at large airports?

texts:
When I fill my tank at a gas station, I can see fuel vapor coming out of the tank.

I imagine the space above the aircraft tank has fuel vapor mixing with air (at lower oxygen than normal thanks to the inerting system). During refueling, the fuel will replace the space used by this fuel-air mixture and force the mixture out of the tank. If unmanaged, this is a big fuel source and fire hazard.

How is this mixture managed in order to minimize risk of fire or explosion?


texts: Can one "create" a private interpilot air-to-air frequency to chat?

texts:
I've been looking for an answer to this for the past couple of hours and can't find anything on the matter. (Yes, I've read this What radio frequencies are used for intercom in formation flying?  , but it didn't answer my question, as I'd like to know about frequencies that are not in use by any authorities or  organisations and are not used for anything official,  such as search and rescue).

A pilot mentioned to me she "created" frequencies to talk in private with her mate (air-to-air interpilot). I found one link that says pilots sometimes use unallocated frequencies to chat , so I assumed she meant that, but I've just read on AOPA that all 760 channels available in the VHF   aviation band are actually allocated (I'm assuming in the USA, as the reference is an FAA circular) even if some are not used at all times.

So, can you "create" a private frequency? If I'm right to assume that that makes no sense, can you join a private frequency (do they exist??) or use an unallocated one to chat privately? In case it's the latter, how does that work if all frequencies are allocated already (or is that just in the USA)?

Thanks a lot for your help


texts: Do additional passengers impact on weight and balance of a domestic airliner?

texts: Recently my kids and I were denied access to our flight because we missed the check in window.  We were informed that new calculations would have had to have been made by the pilot, despite not having had any check in luggage.  When are these calculations made?  Before or after the passengers board?  Apparently, our names did not make the manifest in time, despite nobody having boarded the plane yet.  We were left stranded at the gate.  Can anybody explain the procedures regarding these calculations, because I cannot understand why we were not permitted to fly?


texts: Is it possible to obtain a PPL after having a brain surgery?

texts:
I am a 24 year old who has always aspired to become a pilot. I've decided to eventually get a private pilot's license so I can fly just for fun. However, a few months ago I was diagnosed with brain tumor which I had removed. There were no complications, I have never had any seizures, I'm not epileptic, etc. As far as I am concerned (and my doctors as well), I am now in perfect health.

With this in mind, is it still possible for me to obtain a PPL?


texts: Is it safe to roll an airplane that isn't approved for it?

texts:
I have heard of pilots rolling airplanes that aren't approved for it (Cessna 172, Learjets, etc.), and other than the obvious legal issues, are there any mechanical or safety reasons to avoid it?

DISCLAIMER
I do not advocate doing anything (like this) that is not legal, but am looking more for additional reasons that I can use to dissuade people from doing this when they say that it isn't hurting anyone or something along those lines.


texts: Why are the wingtips of the Fairchild-Republic A-10 bent downward?

texts: Why are the wingtips of the Fairchild-Republic A-10 bent downwards?It is subsonic aircraft .


texts: What does the airport fuel market look like?

texts:
The single biggest cost for many airlines is fuel. Given this, I'm sure they work hard to reduce the cost they pay per gallon of fuel as much as possible.

How does that translate to the way fuel is bought at major airports? I know there's a fuel truck that comes and fills up the planes. Does each airport partner with one company to provide fuel? Are the multiple providers on each airport? Does the airport itself sell fuel? Is fuel lumped into the landing fee?


texts: Why does a turbine helicopter need to spin a tail rotor?

texts: Should not the exhaust of the turbine supply enough byproduct to deflect and maintain yaw with a simple deflector (i.e. rudder/stabs)?


texts: What is the smallest manned aircraft with four engines?

texts:
What is the smallest (by operating empty mass) quad-engine aircraft that satisfies these conditions?

Current or past airplane
aircraft with fixed wings, not a rotorcraft, not a lighter than air, etc
4 engines, pistons or turbines
fuel as a main source for propulsion
actual aircraft, not scaled model
piloted by a pilot or a crew
used for an actual military or scientific goal or business (not for design tests only).

Added to prevent flying suits to be proposed:

Need to takeoff and land under its own power.
Not a worn wing (flying suit), the aircraft must have a flight deck where the pilot can be.

If this one had been piston or turbine, it would be a good candidate:

... but it's an electric-powered aircraft.


texts: Which jet engines have the highest thermal efficiency?

texts:
Some automakers (Mercedes-Benz, Toyota) have recently been making news about the improved thermal efficiency of their engines, stating that they reached the 50% mark. I was wondering if it was the same for airplanes.

I think I'm pretty sure the aviation industry is well beyond the 50% mark due to the high compression ratio, but what is the most efficient jet engine in existence (currently in use or tested prototype) per category (fan, turbojet, bypass, turboprop, ...)?


texts:
In aeroplanes that are equipped for autoland and landing at an airport with a working and adequate instrument landing system for the conditions, why would a pilot choose not to use autoland?

If I had to guess, I'd say it's due to some of the following:

Autoland is stressful and labour-intensive for pilots compared with flying the plane normally down to the ground in VMC.
Autoland produces less comfortable or otherwise "worse" quality landings.
Using autoland is less fun or enjoyable for the pilots.
The use of autoland is restricted by aviation regulations.

But I don't have any sources to back up these claims.


texts: How are performance classes for helicopters/rotorcraft defined?

texts:
In helicopter/rotocraft literature, such as ICAO Annex 14 Volume II (how to design heliports), there's constant references to performance classes. How can I tell what performance class a helicopter is in?

So far the only definition I have found is: in the event of engine failure, Performance Class 1 helicopters should be able to land within the rejected take-off distance available or continue safe flight, while Performance Class 3 will require forced landing. (https://www.casa.gov.au/standard-page/project-os-1124-incorporation-performance-class-concepts-australian-helicopter).

This is hard to apply to helicopters where I only have some basic specifications. Are there any other, easier to use, definitions for performance classes? I'm hoping for something like runway codes for aerodromes, which are derived from landing distances and wing spans of aircraft that use the runway.


texts: What do the various lights in the overhead aisle light cluster of a Bombardier Q400 NextGen represent?

texts:
I took this picture of an overhead aisle light cluster in a Bombardier Q400 NextGen.

Copyright: self

I am inquiring about the role of the bottom row of six rectangular lights. From right to left they are yellow, dark blue, dark red, green, orange, and medium red.

My observation regarding these lights:

The seatbelt light, when lit (and accompanied by a single ping), lights up the green light, for about five seconds.
A double ping, with the second ping at a lower frequency than the first ping, lights up the medium red light, for about five seconds.

I presume that these six lights are intended for communicating with cabin crew. I would like to know the detailed meaning of these lights.


texts: What is the best way to reapply for a denied Class 3 medical certificate?

texts:
To Become a helicopter pilot is a major life goal of mine. My aunt was a naval pilot, when she took me up in a helicopter it was one of the most memorable experiences of my life.

Background: Today I have a job as a software developer at a successful company, I have graduated college in engineering. I work out regularly and eat healthy, I am able to complete 15 reps of pullups. I have excellent vision. My temperament is mild. I am reliable and prompt at work and I treat others as I would like to be treated.

Last year I was denied my class 3 medical license primarily due to being prescribed an antidepressant, which I was prescribed in February of 2015 as an off label treatment for ADD, I never took a single pill as the side effects scared me, also I am not depressed so it was a little off putting. There were complications due to my having received some counseling for alcoholism in college. In reality I made some mistakes in college and did not drink responsibly on a few different occasions, I have never been a regular drinker. It was possibly the new environment and the fact that I had no experience drinking. I have never been arrested, I have no DUIs or any of that nonsense. Receiving this news was very difficult considering the cost, time, effort and the fact that I did not even take any of the medication.

Currently I am not taking any medications or being treated for any issues. Job is going well, I experience a reasonable level of fulfillment and even volunteer on occasion. Getting my pilots license is a major goal of mine. Recently I decided to cut down on drinking, I now almost never drink unless it's with family or old friends. Realistically that ends up being one or two drinks less than once a week, I would not mind completely abstaining.

My primary question is: would it be worth it to again pursue the class 3 medical? Or will I be denied once more at this point? If this is the case, are there additional measures I can take to ensure that I get this license?


texts: Why is induced drag less on a high span wing?

texts:
I have a basic question and sorry if it is a well known fact.

I understand that the induced drag is due to the tip vortices changing the effective angle of attack (downwash).

I searched some website and they mentioned that for high span wings the disturbance caused by tip vortices is less and hence, less induced drag.

Now the confusion arises.

As per the lifting line theory, the tip vortices strength will be as same as the bound vortex.

Does this mean that the induced drag is reduced only for a high span wing when having same bound vortex strength as a low span wing?

[For simplicity we can assume a elliptical lift distribution]


texts: May an airline replace an airliner's engines without the aircraft manufacturer's involvement?

texts:
Around a year ago in our country, there was an advertisement on TV regarding an airliner's program to modernize their airplanes' power plants. This airline has various types of Airbus and Boeing aircraft.

I am not sure whether all the airplanes are using the same power plant brand or not. The advertisement shows that one power plant's manufacturer is GE. So I am not sure what is the meaning of "modernization" in their advertisement regarding the power plant. But instinctively, that should be to replace it with a newer, better version.

So my question is, does the airplane manufacturer allow the airline to replace their own power plants without the airplane manufacturer's involvement?


texts:
"An aircraft is cruising at FL170. The altitude shown with QNH set is 17,500 feet. The OAT is -10 deg C. What is the true altitude?"

The ISA temperature deviation is 9°C.

My calculation is:

17,500'
 + 9 °C x 4' x 17,500/1000
= 18,130'

The answer provided is 18,100'. I don't understand where my mistake is.


texts: Which prop location creates more lift? Leading edge or blown flap?

texts:
Which prop creates more lift? Leading edge or blown flap?

In distributed propulsion there seem to be 3 prop locations: leading edge (NASA X57, blackfly), blown flap (Lillium), and pusher prop (Kittyhawk).

Which would create more lift, leading edge or blown flap?

Leading edge: The entire wing chord sees about 50% of prop exit speed (turbulent though), the prop pushing 50% of the air under the wing (although it would create lift by hitting the flap (assume 45-90 deg flap position)
Blown Flap: wing sees 100% of prop exit speed but only on about 45% of the of the chord ( assuming 50% chord flap), but the first 45% of the wing sees non turbulent air. Blown flap has the advantage of providing vertical thrust.

See pictures below.

Lillium - blown flap ( assume props, not the actual electric turbines it uses)

Kittyhawk - pusher prop

Nasa X57 - leading edge/tractor prop

Below are 3 Cp plots from xflr.

First plot has no flap, but has a roughly 30 deg angle in (-) pressure drop.

Adding a 50% chord flap, increases the suction at 0% chord???

Was surprised to a spike in negative pressure at 0% chord from
a 50% chord, 45 deg flap!!! Would have thought there would be a negative pressure spike at 50-60% chord....

What would the shape of the pressure plot be when distributed propulsion is added to the flap? See plot below.


texts: What causes pressure disturbances ahead of the wing?

texts:
Can someone post a link to a video that shows an example of this either in a wind tunnel or using some other examples?

  When an aircraft is flying below the speed of sound, the pressure disturbances will be moving faster than the airplane (think ripples on a pond again), and those disturbances that travel ahead of the aircraft influence or “warn” the approaching airflow. This “pressure warning” can be observed in a smoke wind tunnel as it causes the upwash well ahead of the wing.

Quoted from Flight Theory and Aerodynamics


texts: How can ADS-B be secure when it is based on self-reporting?

texts:
By all reports, ADS-B is the future of air navigation and ATC. In the simplest definition, ADS-B is aircraft self-reporting GPS position to benefit everyone.

How is this secure? Seems like someone could simply broadcast a false position for any number of nefarious purposes.

Maybe I am missing something obvious, but I have yet to see an explanation of ADS-B from a security perspective.


texts: Where can I find a list of rules of thumb formulas for navigation?

texts:
Is there any list of formulas for quick counting navigational parameters of the flight, if navigational computer is malfunctioned.

For example, I need to recalculate how long can I fly, if the wind is changed.


texts: Does turbulent flow have boundary layer ? Does separated flow have boundary layer?

texts: I have a little confusion between turbulent flow and separated flow. Consider a flow over a typical airfoil: Does turbulent flow region have boundary layer ? Does separated flow region have boundary layer ?


texts: What is the working principle of a Gurney Flap?

texts:
Recently I came across a airfoil improvement called a 'Gurney flap', see image.

I don't really understand the working principle of a Gurney.
Wikipedia states:

  The Gurney flap increases lift by altering the Kutta condition at the trailing edge. The wake behind the flap is a pair of counter-rotating vortices that are alternately shed in a von Kármán vortex street.In addition to these spanwise vortices shed behind the flap, chordwise vortices shed from in front of the flap become important at high angles of attack.

I don't understand how the flap could generate vortices in front of the flap.
Wikipedia states the following effects:

  The Gurney flap increases the maximum lift coefficient ($C_{L_{max}}$), decreases the angle of attack for zero lift ($\alpha_0$), and increases the nosedown pitching moment ($C_M$), which is consistent with an increase in camber of the airfoil. It also typically increases the drag coefficient ($C_d$), especially at low angles of attack, although for thick airfoils, a reduction in drag has been reported.

Is it simply a ridge that stops the flow, and thereby increases the pressure at the top surface?

How come the drag is decreased for thick airfoils if it generates extra vortices?


texts: Why do narrowbodies have longer life than widebodies?

texts:
Is it fair to say that narrowbody aircraft have a longer life than widebody aircraft? This is the conclusion drawn from a report written by Dick Forsburg from Avolon (.pdf), where he says that the average life of a narrowbody is 26.6 years, while the average life of a widebody is 24.6.

Is it generally accepted that narrowbodies have a longer life than widebodies? If so, what are the reasons for narrowbodies having a longer life that widebodies?


texts: How fast can an airliner (like a Boeing 747) taxi backwards?

texts:
Forgive my lack of understanding, I thought I'd just buy a simulator and mess with it.  I really don't know much of anything in terms of MSFS2020 or simming really at all.
I realize that airliners can taxi backwards.  So, I'm wondering.  At its top speed, how fast can a 747 taxi backwards, if it tried to do so?


texts: Which commuter flight was forced to land in a cornfield in '96 or '97?

texts:
Last night a friend's wife was describing her experience as a child being on a flight that encountered a flock of Canadian geese, where at least one engine was lost to a bird strike. I suspect both engines may have been lost, or at least compromised, because she said the plane ultimately landed in a cornfield. She said the oxygen masks deployed, and she used the inflatable slide to deplane.

If her memory is correct the flight departed Indianapolis, IN, bound for Trenton, NJ. Based on her age, we thought the flight was probably in 1996 or 1997. She said it was a "small plane", but it was certainly a commercial flight, and I believe a jet (not a turboprop). She described two seats straddling the aisle.

Her memory of the event emphasized surreal, sensory details, so I suspect some uncertainty among the facts useful for finding this flight.

TL;DR here are the useful details:

Probably 1996 or 1997
Departed Indianapolis, IN
(Update 2.20.2018: She confirms it was Indianapolis International)
Intended arrival in Trenton, NJ
Engine(s) out, presumably due to bird strikes (Canadian geese)
Emergency landing in a field (possibly a cornfield)
(Update 2.20.2018: This was a Pennsylvania cornfield)

To my surprise I've been unable to Google more information, so I'm hoping someone here has a better angle on researching this interesting flight.


texts: What is the ICAO equivalent of a "point out"?

texts:
In FAA air traffic control, when we have an aircraft that is transitioning through someone else's airspace that we want to talk to we do a "point out":

  Point Out. A physical or automated action taken by a controller to transfer the radar identification of an aircraft to another controller if the aircraft will or may enter the airspace or protected airspace of another controller and radio communications will not be transferred. - source

Can anyone please tell me what the equivalent of a point out is in ICAO (with a reference to ICAO Doc 4444 if possible)?


texts: What do pilots do, when there is a long wait before take-off, after gates are closed?

texts:
Pilots are supposed to carry out the mandatory checks before the flight take-off or taxi. But what happens when there is a delay, when the aircraft cannot push back from the gate, due to non-clearance from ATC, or due to heavy traffic etc.

Do the pilots, re-run the checks, or carry out more extensive checks of the aircraft?
Do the pilots just chit-chat, eat, or make phone calls to their family?
Is there any standard procedure to be followed during this wait time?

Edit: As someone tagged this as duplicate, my question no where suggests time spent by pilots during long haul flight, its about what they do when the pushback is delayed. Hope it helps.


texts: Other than the 747, are there any other current, recent or planned airliners with a nose door option?

texts:
Boeing has recently announced that the 747 program is coming to an end. One of the key features of the freight 747s was the nose door, which facilitated faster loading of freight and allowed the loading of freight that could not otherwise be carried.
Other than the 747 are there any current, recent or planned airliners that have the option for a nose door? will this be a facility that the cargo carriers lose as their current 747s gradually reach end of life? (which granted will be decades after production stops)
I am aware of several other planes with nose-doors but they are either old military-derived types (e.g. the AN-124 and AN-225) or are specialist planes designed for carrying awkward cargo (e.g. the Airbus Beluga and Beluga XL).


texts:
In my answer to this question, I describe how calculated takeoff times (CTOT) are used as a tool in European air traffic flow management to prevent overload and maximize capacity. I expect the ATFM system used in the USA to be quite similar, but I'm sure there are technical differences. I am hoping someone can provide a similar answer, detailing ATFM procedures in the USA.

original question:

Air traffic flow management (ATFM) is a service established with the objective of contributing to a safe, orderly and expeditious flow of air traffic by ensuring that ATC capacity is utilized to the maximum extent possible and that the traffic volume is compatible with the capacities declared by the appropriate ATS authority.

In Europe, air traffic flow and capacity management (ATFCM - notice the additional C) is handled by EUROCONTROL.

Each air navigation service provider (ANSP) is responsible for declaring the capacity of their ATC sectors in terms of a maximum number of movements that can be safely handled in given time intervals.

All IFR flightplans in Europe are processed centrally by the Integrated Initial Flight Plan Processing System (IFPS). If, based on the flightplans, it is calculated that capacity within a sector will be exceeded, flights might be rerouted or level capped, or they receive ground delay (a slot time).

This system works very well, and ensures an efficient and safe flow of air traffic within Europe. However, flights originating outside of Europe cannot be processed in the same way. For example, flights departing outside of Europe will not receive any slot times, which makes the system inflexible, since these flights still have to be taken into consideration, but cannot be adjusted the same way other flights can.

This has made me wonder, why is it not possible to simply link the European system with similar systems around the world, to create a global ATFM network? Specifically, I am interested in how ATFM works in the USA. I would like to identify the main differences between the European system and the system in the USA, with the goal of understanding what prevents these systems from working together.


texts: What is the value allowed for runway transverse slope?

texts: What is the range allowed for transverse slope for runways used by commercial aviation?


texts: Is there a good systematic approach to flying an 800 foot pattern?

texts:
I have a systematic approach to flying a 1000 foot pattern:  abeam the threshold, start a 500 fpm descent; turn when 300 feet below pattern altitude; etc.

Does anyone have a systematic approach to flying 800 foot patterns?  I'm looking for something more definite than "start a descent, don't get too low, turn on the 45, etc".


texts: Using aluminium busbar/cables in an aircraft instead of copper

texts: I have just found out Airbus uses aluminium wiring in the A380 to save weight. However, I didn't see anything about whether all the wiring is aluminium, or if copper wiring is also used. What is the logic behind this, and do other aircraft manufacturers do the same? Does Airbus use aluminium wiring in aircraft produced since the A380 was introduced? Are there any risks associated with using aluminium wiring on aircraft?


texts: What is the influence of drag on an airliner's block fuel consumption?

texts:
I am not sure how widely the software is used, but I am using Piano-X to investigate the influence of total aircraft drag on block fuel consumption and noticed something odd. It is my hope that someone familiar with the software can assist me.

If I decrease the total aircraft drag both the block time and fuel consumed increases, which is the opposite of what I would expect. As expected however, the block fuel/min does decrease.

Shown below is the results from the investigation for the drag systematically decreased :

I expect that the block fuel/time would decrease but don't understand how the total time and fuel will increase for decreased drag.

Is there a rational explanation for this?

The software documentation only states the following concerning drag calculation:

"Aerodynamic drag is calculated in detail (as a function of lift coefficient, Mach number, and Reynolds number) and tuned with actual lift/drag data (‘polars’) whenever these are known. You can either factor the drag uniformly using one overall value or you can adjust certain items individually."

My approach was to vary total drag, i.e. induced and parasite drag simultaneously.

I will add that the software calculated total block fuel including estimates for both taxi's and the climb-out etc. Now in taxi drag doesn't have an influence, but I doubt that this will make such a large contribution.


texts: Do fighter jet pilots ever use autopilot?

texts:
I know that military jets have autopilot, but do the pilots actually prefer to use it?

I ask this question because, unlike civilian airplanes, military jets are more likely to come in a situation where the pilot may have to take quick decision and leave the designated path for some mission (e.g. to intercept a civilian jet flying on a wrong path). In such case, the autopilot may become a problem for quick maneuvering.


texts: How frequently are avionics on large commercial aircraft updated? And how are the systems updated?


texts: Is it possible to accurately measure airspeed without pitot tube?

texts:
This is a follow-up to my previous question:

How does this IMU work and how to convert its output into meaningful information?

for which many people asserted that I need a pitot tube and a static port in order to calculate airspeed and pressure altitude respectively, and errors will build up if I just integrate the accelerometer values from the IMU.

I'd like to know whether it is possible to measure airspeed without a pitot tube, accurately? Is there any electronic sensor that can be used for this purpose?

Also are there any airplanes around the world, Airliners, GA, Military, or even Experimental, that operate without any pitot tubes?


texts: What is the relation between trim setting and constant airspeed?

texts:
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?


texts: Why don't airlines load their passengers like freight?

texts:
Apparently, the time for boarding and deboarding an airplane is a large cost factor and something airlines try to minimize but have trouble controlling because the passengers do it themselves.
A solution would be to have passengers board a passenger cabin outside of the airplane and then slide that cabin into the plane via a nose-hatch, much like large volume freight. Has this been considered? If yes, why was it not pursued?


texts: For calculating $V_{stall}$, why should be used $C_{L,max}$ and not $C_{L,min}$ (that would be more prudent)?

texts:
Premise: In level unaccelerated flight we have relation $W=L=\frac{1}{2}\cdot\rho\cdot V_{stall}^2\cdot S\cdot C_{L,max}$ (taken from book Daniel P Raymer "Aircraft Design: A Conceptual Approach" equation (5.5) at page 85).

Question: Why $C_{L,max}$? Why not $C_{L,min}$? In fact in case the $C_L$ in use is not $C_L,max$, and speed is little more than $V_{stall}$ (valued for $C_{L,max}$), it happen that Lift is not enough and anyway stall happens on aircraft. If using $C_{L,min}$ the calculation is more cautious.


texts: Why is a class 2 medical not valid in Canada?

texts:
Upon reviewing the requirements for the Recreational Pilot Permit and Private Pilot License in Canada, I see that only class 1, 3 and 4 medicals are approved.

Are EASA class 2 medicals not valid in Canada at all?


texts: Is Naproxen (medication) approved for flight?

texts:
Is Naproxen an approved FAA medication? I have found 2 separate websites which comment on this type of medication that seem to be somewhat ambiguous, at least to the degree that I'm looking for.

https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/pharm/dni_dnf/
https://www.leftseat.com/medcat1.htm

Is there a singular location to find out if a medication is approved or not approved? Specifically I'm looking for Naproxen.


texts: How do I log simulator time in my logbook as a CFI?

texts:
I'm a CFII at a 141 flight school, and when I give instrument instruction in our AATD flight simulator I'm kind of confused on how to log it. Should I log "As Flight Instructor" time even though it's not a flight? (My logbook has no "Dual Given" column which would make more sense.

Also, am I able to log "Flight Simulator" time? Even though there's only 1 yoke in the simulator, which I am not manipulating.


texts: What is wrong about this interpretation of QFE and QNH?

texts:
I'm a little confused about the QFE and QNH definitions, and its application on aviation. I learnt that:

$QFE$ = pressure measured by an altimeter which is adjusted to ground level (it gives a height of 0 when the airplane is on the ground).

$QNH$ = pressure measured by an altimeter which is adjusted to sea level (it gives the field elevation when the airplane is on the ground).

So, by those definitions we can say that on ground level $QFE=p_0=101325Pa$ and $QNH=p_{ISA}(h_e)$ where $p_0$ is the SSL pressure and $h_e$ is the field elevation. $p_{ISA}$ is the pressure on a standard atmosphere associated to the height $h$. For the troposphere we have:

$$p_{ISA}[Pa]=101325\left(1-\frac{0.0065 h[m]}{288.15}\right)^{5.25588}$$

So, pressure drops with an height increment. For example, if the field elevation is positive (i.e. it's above the sea level) and the airplane is above the field we have to have $QFE>QNH$, because the height measured by $QFE$ configuration is lesser that the height measured by $QNH$ ($h_{QHN}=h_{QFE}+h_e$ and $h_e>0$)configuration, and by the relation between $p$ and $h$ if $h_{QFE}<h_{QNH}$, then $p_{QFE}>p_{QNH}$.

What I have seen in many problems of QFE determination by QNH and vice versa, is that the definitions used for QFE, QNH were exchanged. See for example this question How can I calculate QNH from QFE?.

I've seen this type of resolution done in many exercises, and so I presume that I'm wrong! But I still didn't get it! What am I missing here?

I can even show you a figure that was used on the theoretical slides of my Aircraft Performance course:

As you can see this figure says that $h_{QFE}=h_{QNH}+h_e$ which should instead be $h_{QNH}=h_{QFE}+h_e$ (the opposite) according to the $QFE$ and $QNH$ definitions.


texts: What may be the cause of hot start problems in a Lycoming fuel injected engine?

texts:
Cherokee Six, 32-300 1969. Lycoming engine is fuel injected with 450 SMOH. Cold starts are easy: 1/2" throttle, full rich, fuel pump on and hit starter after fuel flow starts. Runs great once running.
Hot starts are hit or miss. If it sits over an hour it may start but if I miss it it has to sit for at least another hour till I try again or forget it. I've tried 1/2" throttle, full lean with and without fuel pump; full throttle, full lean with and without fuel pump and all combinations I can think of. Most of the time it spins without any cough or catch. Due for 50 hour oil change and will ask that plugs and magnetos are checked. I'm afraid to go anywhere for fear of being stranded for hours.


texts: What is the service cycle or interval of the Landing gear of an A380 and 747-8, i.e how long between service, eg after how many take offs and landings with particular reference to bearing checks and lubrication of the bearings and axles of the wheels


texts: Can I safely plug something that draws 6 amps into the cigar lighter (power port) in my Piper Archer lll?

texts: Can I safely plug something that draws 6 amps into the cigar lighter (power port) in my Piper Archer lll ?


texts: What is the working principle of tip jets?

texts: Tip jet refers to the jet nozzles at the tip of some helicopter rotor blades, to spin the rotor. What is their working principle?


texts: Where to find information about aircraft type knowing the flight number and date?

texts: Having flight date and exact flight number, I would like to know aircraft type (like Boeing 737-400). Is there any service where I can get such information in bulk (for hundreds of flight dates and flight numbers)? I know that flightradar24 provides us with similar data, but it doesn't have any API to get such information for many cases.


texts: How can one enter an airliner without stairs or a jet bridge?

texts:
I see that big planes (B737, A319 etc.) always need a staircase or a boarding tunnel in order for crew or passengers to enter the cabin since the position of the entry door is quite high (meters above the ground). What solutions are there if none of these options are available? (Except, obviously, for aircraft like DC-9's/MD-82 and 727's which had the rear entrance) How could the pilots get in? Is there some sort of manhole under the aircraft that can be opened to get inside with a sliding staircase or similar?

Living in Africa, I have been to a couple of airstrips where these aircraft do land. Obviously all the airports had stairs but since we cope with some strange situations over here, the question came into my mind. What is the alternative should something go wrong and no traditional means be available to get in the plane?


texts: Why don't fighter jets take off vertically?

texts:
I've heard the claim repeated many times that some modern fighter jets have an installed thrust greater than their weight, so theoretically they could accelerate straight up.

I've never actually heard of this being done, however. It sounds useful, though, especially on the deck of an aircraft carrier. Imagine: we could take out the whole catapult system, and replace it with some sort of a system to pick up an aircraft and turn it vertical.

Why is this not done?


texts: What does "reserve take off" mean in engine parameter documentation?

texts: In ATR 72-500 FCOM document I found engine parameters including power settings as "Reserve Take off". What does that mean?


texts: When/where must a flight go missed on the JFK VOR/GPS 13 L/R approach?

texts:
I'm looking at "exciting" approach plates, and I always come back to JFK VOR/GPS 13L/R.

I think I have come to understand most of the elements of this unusual approach, and enjoy seeing flights make that "dramatic" right turn just before landing, but here is what I can't figure out, even after reading over the plate multiple times:

With such a long distance (relatively) from the MAP to the runway, and additional features such as lead-in lights involved, when and where should the pilot consider, or decide, to break off the approach and go missed (climb and head for DPK)?  Upon crossing the MAP, is it sufficient to have the ground and/or first set of lead-in lights in sight?  Should the pilot see more than that, such as the actual runway?  If weather temporarily (about 3 to 5 seconds) blocks off the view of the ground or lead-in lights can he continue?  Basically, what is the minimum criteria for being able to continue the approach, after the MAP?  Must the runway be in sight at all times, or is knowledge of position (based on lead-in lights, etc.) enough?


texts: Would there be a restriction on my Sport Pilot license if I do my checkride in an aircraft without rudder pedals like the Ercoupe?

texts:
I am training in an Ercoupe 415-C (C-85) that has no rudder pedals. I've read various stories about people taking a checkride in such an aircraft having a restriction on the license and having to take another checkride in a different aircraft to have the restriction removed. I've also seen this referenced as a myth that does not happen in real practice.

My questions:

Does this restriction really exist, or is it a myth?
Does it depend on the examiner?
Does it apply to sport pilot (where I would have to have an endorsement for another model anyways), or just private?
Would I have to take another checkride to have it removed, or could
it be removed with a CFI's endorsement?


texts: Today, commercial aircraft cockpit is manned by 2 pilots, previously  it was 3 to 5. Is safety compromised in any way?


texts: What is this high-wing, single-propeller, possibly military plane?

texts:
I recently acquired a black & white photograph of a group of military people posed in front of an airplane.  I am seeking information about the plane, and maybe the people.

The plane is mostly obscured by the people, but it is a high-wing, single propeller plane.  The wingspan looks to be about 30 feet.  The wings are straight, not swept back.

The people are pretty clearly military, but I cannot tell from what country.  Notably(?) , there is a woman among the two dozen men.

UPDATE:

Friends have speculated that the woman is Amelia Earhart.  The Amelia Earhart Museum says no.

Most military folks say that the uniforms are not military.  They speculate that they are a delivery service or maybe an airline.

UDPATE2:

The back of the photograph has a stamped "992" in red.

Also, the photo is in a nice folder with a matte (not shown).  The matte is labelled "Fas Foto".


texts: What is a hypernym for the ascending and descending legs of a flight?

texts:
If an airline flight is everything that happens in between your starting and ending gates. What is the generic term for each time the plane ascends or descends during an air route? In layman terms, what terminology would define the four '_____?' equally as four separate things.

If the image below indicates the proper terminology for a flight. What is the hypernym for phase 3/4 and phase 6/7 of the air route?


texts: How are attitude indicators kept accurate?

texts:
The attitude indicator is very important for any sort of instrument flying, so it must be accurate at all times regardless of the plane's movements.

I presume that the indicator would be connnected to a gyroscope. However, gyroscopes drift, and a drifting attitude indicator would be pretty useless. Of course, you might have a reset button, but safely using it would require a visual reference to a horizon, which obviously you don't have during IFR flight.

Another idea might be to periodically reset the indicator based on gravity --- many model aircraft use this something like this approach to drive an attitude calculation; however, during coordinated turns, the gravity vector is indistinguishable from the vector during level flight. If a plane continually turns in a coordinated way, such an attitude indicator would be confused in exactly the same way that a human would be, resulting in bad things like the autopilot doing a graveyard spiral. A gravity sensor + accelerometer wouldn't be able to detect the difference between a gradual turn into a steeper and steeper coordinated spiral and simply a gradual gyroscope drift while remaining in level flight.

How are attitude indicators kept from drifting?


texts: Is Flight Following in the USA directly equivalent to Basic Service in the UK?

texts:
This is partially a question on terminology, I have flown in the USA and used a service which is commonly referred to as "Flight Following".

I have read this question: Is there a European equivalent of VFR Flight Following?

And I am interested in whether requesting a "Basic Service" which I use in the UK is a direct equivalent? If not, what are the major differences?


texts: Is there a cockpit indication if the B737 flap load relief is not working properly?

texts: On a 737, does the pilot get any cockpit indication that his Flap Load Relief is not working properly? Say for instance due to a Flap Lever Position Switch failure?


texts: How can I create a fly-over waypoint in the G1000?

texts:
How do I make the G1000 fly over a user waypoint rather than fly by it, therefore not sequencing to the next waypoint until the aircraft has overflown the current one?

I’ve tried ATK Offset but with a sharp turn to the next leg (>120 degrees) this still does not work.


texts: How to calculate required thrust for take-off knowing gross weight and L/D?

texts:
I know that many variables play into the required thrust for a take-off and for climb. Most of those specs boil down to a targeted gross weight, wing loading and L/D ratio. Intended flying speed range is also known but probably not even needed for this estimate. Using these specs then I can roughly assume that many specs have been taken into account for a thrust calculations.

For ex. aircraft is gross weight 400 lb with L/D ratio of 10. Assuming a non-accelerating level flight at optimal cruise speed 50 mph in no wind condition it will require at least 400 / 10 = 40 lb of thrust.
Based on above numbers how to make rough estimate of the minimal thrust required for a reasonably short take-off (say within 500 to 1,000ft roll of runway) ?

Note: please keep in mind I am familiar with many other conditions and aircraft specs affecting the required thrust. Yet for 100 years practical aircraft designers used very simple math approach to estimate needed thrust. I personally knew one of old generation designers who did this well in many of his successful designs using simple math dealing with few numbers (he passed away years ago). He only used gross weight, wing loading and targeted L/D ratio chosen from his experience.
Please share if you know the answer.


texts: What technology is being moved forward to keep pilots from crashing planes?

texts:
So it seems that we have three basic issues (and possibly more but not as prevalent):

Pilots can crash planes.  Someone can just be suicidal, be part of an extremist/terrorist group, can have a vendetta against someone or just thinks might as well take more down with me.
Passengers that get into the cockpits.  I know that the cockpits are locked and pilots are armed but on a lot of flights there is opportunity.
Using technology to override aircraft autopilot.

So what is the long-term plan to keep these things from happening from a technology point of view?  Is there anything in the makes that will help solve these issues?  I foresee some sort of technology that requires some sort of dual sequenced unlocking to allow a pilot to make a certain % deviation from flight plan.

Note:  There have been a lot of answers here that basically say "nothing is being done" and offer up reasons why.  To use the recent incident of a pilot dropping a plane into a mountain as an example, my main question surrounding that is, is there a technology that would see that the pilot was well off course?  Is there technology that would see that the plane had a high risk of crashing?  Is there technology that would prewarn flight control (even if it were a few minutes)?  Is there technology that flight control could override plane and right the ship that is going into the mountain?


texts: Will the new airmen certification standards make it more difficult to add ratings?

texts:
As of June 15, 2016, the FAA has changed from PTS/Knowledge tests to the Airmen Certification Standards which is a relatively significant paradigm shift in how airmen are certified.

The underlying reason to move to the ACS was to evolve the outdated PTS (practical test standards) and to align airmen certification towards risk management and the existing national airspace system.

The question I have though is for people who have earned their certificates under the old PTS system and would like to add a rating like an Instrument rating, or another certification like commercial.

Will the new ACS make it more difficult for existing pilots to add ratings? I'd like to know from the standpoint of part 141 and part 91 training centers.

One of the reasons I ask is I went up with my CFI last week and went into some slow flight. I set up to bring the aircraft into the stall buffet and fly it a few knots above stall speed but he said that the new ACS said that the stall horn cannot sound during slow flight, which seems counter intuitive to me. The point of slow flight is to know how to handle the aircraft at or near stall. There is a lot of handling difference between VS0 and VS0+20kts.

So that got me thinking, what would I have to relearn in pursuit of an instrument rating that would make it harder that I probably wouldn't have to under the old PTS?


texts: Is the Soloy Dual Pac recognised as two engines or one engine?

texts:
The Soloy Dual Pac apparently allows two engines to rotate one propeller -- here's a picture of it on an Otter:

Is this recognised as a centreline thrust twin engine aircraft, a "standard" twin engine aircraft or just an aircraft with a single engine for FAA certification? What about for pilot licensing?


texts: What is the temperature at the center of a gas turbine disc?

texts: I realize that it varies with the temperature at the inlet of the turbine, materials, dimensions, etc. But I would be interested in knowing an orientative value. For example, for a turbine which has at the exit of the combustion chamber a temperature of 1300 K. For the first turbine stage, around what temperature will the shaft/ center of the disc be? We have no cooling system.


texts: What prevents the use of an EMAS along the sides of a runway?

texts:
The NTSB report about the crash of American Airlines Flight 1420 discusses whether an EMAS would have mitigated the severity of the accident, but concludes, based on testimony from a representative of an EMAS manufacturer, that

  ...the benefit of an EMAS in this accident would have been limited by the airplane traveling partly outside the runway edges; thus, the airplane would not have been able to use the full length of the EMAS. The report also concluded that an EMAS would have reduced the speed of the airplane by 15 knots but would not have enabled the airplane to stop within runway 4R’s runway safety area.  [report page 64/PDF page 78]

What I’m not seeing is any reason why an EMAS would have to be confined to the extended track of the runway; extending it from the ends up along the sides of the runway would provide additional protection for aircraft sliding off, or partly off, the sides of the runway (such as AA1420):

(Aircraft tracks shown in these images are merely examples of possible runway-excursion trajectories, and are not intended to represent any specific flights in particular.)

Am I missing something here?


texts:
I am researching a flight I took as a child from LAX to Copenhagen in 1960 in a SAS DC-7C. I know the flight number, route, stops, departure time and date and wish to identify specifically which of SAS's -7C's I was on- either by the Danish registration number or the plane's "viking designator"- Frede Viking, Rolf Viking, etc.

I know this is a long shot- but my question is: Do airports archive the registration numbers of arriving and departing flights, and if so, for how long?

By the way I am in touch with both SAS's corporate office and their museum in Oslo, Norway on this matter.


texts: Can the pitch be very different from the angle of attack?

texts: How much the pitch (horizontal orientation) can differ from the angle of attack? I am trying to understand the claim that "angle of attack indicator was unfortunately not available", contributing to problems during Air France Flight 447. Attitude indicator most likely was available?


texts: What makes a weight-controlled microlight tumble, and can it recover?

texts: As shown in this video, what causes a weight-controlled microlight to tumble, and is it possible to stop it from tumbling once it starts?


texts: How can an Airbus Beluga fly only with two engines and use short runways?

texts: She could land and take off fully loaded on 2000 meters of runway at Hawarden Airport as seen here in this video. At my local airport the runway is 2500 meters long and an Airbus A300 is not allowed to land there. Maximum Airbus A321.


texts: How can multiple airplanes prevent simultaneous communication between ATC?

texts: If two planes try to talk at the same time, do you hear nothing or both? Let's say ATC clears someone to land and they read back. I wait 4 seconds and then ask them something, how do I know another aircraft won't ask something at the same time?


texts: Is there a viable alternative to liquid hydrogen as a fuel for scramjets?

texts: Given the difficulty and complexities of storing liquid hydrogen for commercial flight and the high velocity of air passing through  a scramjet, do other types of fuel provide a feasible alternative or solution for scramjets to achieve their maximum theoretical speed of Mach 24? are there any better alternatives?


texts: What if a flight, transporting a recorder from an aviation accident, crashes?

texts:
Are there any correctives or countermeasures against the rare irony, that objects essential to a flight accident (eg recovered flight data recorder and cockpit voice recorders) are damaged or destroyed on a subsequent flight carrying them? The worst case is if this freight flight crashes.

Context: As in many other Air Crash Investigation episodes, Season 14 Episode 4 (available on Youtube) concerns Copa Airlines Flight 201. Due to a lack of facilities in Panama or Colombia, the recovered FDR and CVR and other parts (including the cockpit instruments) had to be transported to the NTSB's labs in Washington, DC, USA. I presume that for want of expediency, they were freighted by air?


texts: Why do my flights always use runway 24L at LAX airport?

texts:
I have taken several flights (in and out) from LAX (Los Angeles International Airport), both domestic and international and have flown in variety of commercial planes (727, 737, 747, 757, 777, 787, A319, A320, A330, A380, turboprops, etc). at various times of day but have always landed/taken off from runway 24L. According to Wikipedia, LAX airport has the following runways.

Runway     Length       Surface
          ft      m
6L/24R  8,926   2,721   Concrete
6R/24L  10,285  3,135   Concrete
7L/25R  12,091  3,685   Concrete
7R/25L  11,095  3,382   Concrete

I'm sure other runways are also used but why does 24L seem most preferred?


texts: What procedures are followed for a planned landing in a field?

texts:
If an aircraft was making a planned landing in a field/sports ground/other large flat area what landing procedures would be followed?

My thoughts are that it would be very similar to a non-towered airport, with self announcing and flying a bit of a pattern to check the landing area is clear.

Obviously this is more likely to apply to helicopter but it could potentially be a plane.


texts:
The Concorde burnt five times more fuel per passenger mile than the 747. A huge contributor must have been the immense empty weight per seat, three times that of the B747.

B747-300
Concorde

Empty Weight
174,000 kg
78,700 kg

Passengers
400–660
92–128

EW/Passenger
263–435 kg
615–855 kg

This weight excess is distributed among the slender fuselage, thin wings, long landing gear, big engines, and (possibly) material constraints.
But how much of the weight increase comes from each of these components, and why? I am looking for a comparison with the weight breakdown of a conventional jetliner


texts: Where can I find the ownership of a specific aircraft registered in the UAE?

texts: Is there a website where I can find the ownership of a specific aircraft - or in my case a specific corporate jet - registered in the UAE? I am conducting some research on corporate jets and need some detailed information about the ownership of a particular aircraft.


texts: What does this indication of '10∼15 degree' that points toward the both edge of runway means?

texts:
While I study FAR AIM, 2-1-1 approach light system, I saw this indication (on the left side) that I couldn't guess what it tried to demonstrate.

It seems like runway end identifier lights, but I can't conclude since there is no explanation about it.

Does someone have a better idea, or is my guess correct?


texts: Are those devices allowed on a flight which create their own WiFi signals?

texts: I am going from Canada to Mexico but I don't want to be dependent on in-flight entertainment. Thus I got seagate wireless plus so I can stream to my iPad. I couldn't find any policies I can use this device during flight or not. At very least I am trying to determine if it is worth asking the flight company?


texts: What is the technical role of a flight attendant?

texts:
Everyone knows flight attendants represent the airline for the passengers, and have a commercial role by distributing meals, selling goods, managing the entertainment system, and receiving complaints.

One of the well known glamour airline-clichés for flight attendants, circa 1960 (source).

Apart from this commercial role, they also provide the regulatory information about safety. But I feel there is more to know related to their technical role.

What are the non commercial missions or responsibilities of a flight attendant, what are they accountable for? did that role change over years? How are they trained? What is their career path?


texts: FAA Aircraft Registration Form AC 8050-3 doesn't exist

texts: I am preparing to certify a self-built aircraft as flightworthy and legal to fly, and was reading the required documents listed on FAA's Amateur-Built Aircraft Airworthiness Certification page when I realized that FAA does not have the required document "AC Form 8050-3" when searching the form on the FAA Forms website. Is this some kind of mistake? Or is the form possibly a form located inside of a larger form, which could explain why it isn't showing up (Because if that were the case, it wouldn't be its own individual file)? If anyone could provide a link to this form, that would be great.


texts:
The Kawasaki T-4 is a jet trainer aircraft. However, it seems to have two hardpoints.

Armament
Two hardpoints for external fuel tanks

Can these be used to carry weapons? E.g., unguided bombs or unguided missiles?
I suppose guided missiles require avionics for a more sophisticated fire-control system, fire-control radar, and similar — which I suppose the T-4 definitely does not have. However, please correct me if I'm wrong.


texts: Are tower simulators used in civil ATC training?

texts:
Pilots use cockpit simulators, what about training  of air traffic controllers working in control towers?

Control tower of Québec / Jean Lesage airport (CYQB). Source.

How do they train? Are there full visual simulators with runways, taxiways, radio traffic, etc?

The question is valid for a country with large aerodromes.


texts: Why can't I ever get my right ear to pop on descent in a plane?

texts:
Whenever I'm flying, there's a period of descent where my right ear just refuses to pop. This has been bothering me for at least ten years.
There seems to be a long stage of descent where my ear is just in agony. I've tried chewing gum, closing my nose and lightly blowing, opening my mouth, everything. However, when descending into landing (I can see cars at this point) it will start to pop.

Otherwise, it'll pop when I swallow at this stage or even while I'm walking around in the airport. The only thing that makes it pop early and at the same time as my left ear would be when I yawn.

When it does pop, it actually hurts sometimes. It has a very distinct pop, too. Instead of a light pop, it sort of stutters a bit, like it pops twice, and it's much louder.

This phenomenon seems to be very unique to when I'm flying on a commercial airline and descending. It has never happened upon ascension, and from the few times I've driven into mountains it hasn't happened, although that hasn't happened enough to be sure.

What about the descent makes this happen? Is there anything I can do to fix this issue?


texts: How do aircraft refueling in-air deal with wake turbulence?

texts:
Many fighter planes have the capability to refuel in air. When a plane moves in air, turbulence is generated at its back. To refuel, the fighter plane must come near to the parent plane (which has fuel in it).

When fighter plane reaches the back of parent plane, it is actually in the turbulent zone of the parent plane. How does fighter plane manage to fly and precisely adjust its position even in the zone of turbulence?


texts: Are there rules regarding the accuracy of a pilot's delay announcement?

texts: Recently in an advertisement, I saw that a pilot gets notified that the plane will be delayed by 30 mins, but he announces that the plane will be delayed by 3 hours. And then he makes another announcement with the update saying that the flight will now be delayed by only 30 mins with the passengers shown cheering. I can understand the human psychology behind it but I think that there must be some rules and regulations about such fake announcements. Can someone tell me about it?


texts: When using ADS-B are squawk codes still necessary or does the unit provide a discrete code (like a tail number or something) that is recognized by ATC?


texts: Why would there be flight restrictions when the barometric pressure exceeds 31 inHg?

texts: FAR 91.144 states that flight restrictions may be issued by notam when barometric pressure exceeds 31" Hg.  Why would such a restriction be necessary?


texts: Why might an instructor in a small aircraft choose to descend with a substantial yaw on a first lesson?

texts:
Many years ago I took an introductory free (+fuel) flying lesson in a dual-control small aircraft (instructor in right seat) at a small city's municipal airport. There was a third passenger in the back. Near the end there was a report of a helicopter near the airport but there was some confusion as to the location.

When the instructor took us back down they did so in an unusual and exciting way, possibly to impress the third passenger, possibly trying to get back to the ground as quickly as possible because of the situation with the helicopter.

We were descending pitched substantially down, looking at the ground in the distance and with a startling amount of yaw with the right wing advanced by (estimate from memory) 20 degrees!

Is there a name for a descent like this? Are there standard reasons for it?


texts: Where does the difference between calculated and actual groundspeed come from?

texts:
I'm a paragliding pilot. At school we learn that the trim speed of a paraglider is about 38km/h airspeed, the accelerated airspeed is about 45km/h and the minimum airspeed is 22km/h - being inside the weight range of the wing.

If I fly with a headwind of 25km/h, my groundspeed should be: 38-25=13km/h.

Well, from my flying experience (1200 flights in total) with that kind of headwind I never went forward +13km/h groundspeed but much less, near the minimum relative speed (22km/h).

Why there's a difference between the calculated groundspeed 13km/h and the actual groundspeed?


texts: Is there any application where the crescent wing would be the best wing planform?

texts:
To my knowledge the only aircraft featuring a crescent wing that was built in numbers was the Handley Page Victor.

It seems that a crescent wing offers the possibility of a high subsonic/transonic aircraft with a thick wing root but not too much drag at the root. It seems that a crescent wing would work well at airliner speeds.

Why there were not more crescent wing aircraft been built?
Why are they not used on airliners?
Is there any application where a crescent wing would be an ideal or even a good solution?


texts: Does the "west evens / east odds" rule apply when flying without a specific destination (sightseeing, etc)?

texts:
I understand about the rule about odd / even (+500ft) separation at altitudes above 3,000ft AGL, but what about when you're flying without a definitive destination such as sightseeing where your track might change often? I realize that the solution isn't to continuously change altitudes, but what is the generally accepted rule here?

UPDATE: To be clear, I'm not suggesting sightseeing above 3,000ft or anything like that, but rather what is the rule (if any) to help with safety in regards to collision avoidance when flying with no definitive track. Is it normal / expected to be able to simply just fly-about at any altitude?


texts: What material is the smoothest for air to travel over the wing?

texts: Wings are pretty smooth these days and air travels over the wing easier, so what is the smoothest material


texts: What criteria are used to classify an airport as a satellite airport?

texts:
The AIM discusses services provided to satelitte airports of class C airspace.

What determines whether an airport is considered a satellite? Distance, private or public classification,  etc?


texts: Why does the J58 engine of the SR-71 have a diffuser after the inlet spike?

texts: I heard that the diffuser allows the compressed air after the inlet spike to "spread out". What does this mean? If this means expansion, wouldn't it be beneficial to have it compressed before entering the compression chamber, so why would it spread out?


texts: How can I determine the quality of training provided by a CFI at a local flying club?

texts:
I'm considering getting a private pilot license, but considering that it is more dangerous than driving a car (with pilot error being a large factor of that), I want to make sure I train with a CFI and aircraft that are safe, and also ensure that I learn the habits necessary to become a safe pilot.

Are there any objective (or fairly reliable subjective) ways to determine the quality of training provided by CFI at a local flying club?


texts: How are landing aircraft handled during an emergency runway closure?

texts:
A Hypothetical scenario

  A landing aircraft at a busy airport such as London Gatwick LGW
  has an issue during landing that requires the immediate closure of the
  runway.

My understanding is that there could be several aircraft lined up on approach to land at busy times and more circling waiting to land.

If such an incident as the one described above were to happen how would ATC handle the other aircraft?

Obviously they will almost certainly need to be diverted, would they contact each aircraft individually to give instructions starting with the closet to landing and work back or is there a quicker way to give mass instructions to divert all aircraft?


texts: For military helicopters, what is the typical fatigue life of the main rotor dynamic components?

texts:
For military helicopters such as the Sikorsky UH-60 Black Hawk:

What is the typical fatigue life of these helicopter main rotor dynamic components in cycles and hours?

a) Main rotor pitch links (aka main rotor push rod)

b) Main rotor pitch change horn

c) Main rotor blades

Helicopter or Rotary Wing Terminology


texts: Who made the first high-wing jet airliner?

texts:
I thought the only high-wing jet airliners were made by the Soviets but the British Aerospace RJ-100 and Dash 6 series twizzled my mind.

So who made the first high-wing jet airliner?


texts: How much of a plane is replaced over the lifetime of an aircraft?

texts:
A photo of an OC-135 with (presumably) P&W TF33-P-5 engines made me wonder how many of the components had been replaced, and what was left of the original airframe, engines, and other parts. There are many aircraft operated today that are at least 50 years old (no real significance to that particular number).

Over the lifetime of say, a C-135/707 airframe without engine upgrades, is any of the original engine left? Are body panels replaced? Landing gear? Control surfaces?


texts: What are these hexagonal things under the Concorde's neck?

texts:
The Concorde had a pair of dark-coloured hexagons under each of its forward boarding doors, as seen in this picture (showing the hexagons on the left side of the Concorde's neck):

British Airways Concorde, Pictured by LondonAirTravel at the BA Engineering Base, London Heathrow (link)

What are they, and what purpose do they serve?  They obviously aren't passenger or crew windows, and they're far too big to be static ports yet far too small to be cargo doors - some sort of maintenance access panel, maybe?


texts: Are passive or active headsets preferable in an open cockpit?

texts:
My first headset used passive noise reduction (i.e. padding) and when I - very quickly - upgraded to an ANR headset, my instructor recommended keeping the passive one "in case you ever fly something with an open cockpit". I can't remember if he gave me an explanation, but he definitely said that passive headsets "worked better" in an open cockpit.

I haven't flown anything open so I've never had the chance to put this to the test, but is it (or was it ever) true?


texts: Has automatic all-seat reclining been tested?

texts:
Seat reclining in modern economy-class seats is a problem when person in front of you reclines, but you are still in vertical position.

Has there been a consideration of simultaneous reclining of all the seats at the same time right after take-off?


texts: Could a shrouded fan blade with long chord length be efficient?

texts:
I am wondering if it would work to have a fan with two or three blades which have short-ish span and very long chord length, like half a rotation for each blade. Would a shroud (that is molded on the tip of the blades) create/solve any problems?
I am also thinking about tandem blades, but that would only work with shorter chord lengths, correct?

The main objective is to keep noise to a minimum.

I have no background in aerodynamics, just been reading up about it for a while. So please try to dumb it down where possible.

Edit: this is what I came up with, taking all the advice I've received so far.
https://www.thingiverse.com/thing:4069048
Any ideas on improvements?


texts: Some fairly busy airports that you would expect to have Class B or C airspace have class D airspace at the airport and normal class E and G airspace around that. In addition, they have an area drawn on the chart with similar dimensions to a class B or class C airspace area but they are labeled as Terminal Radar Service Area (TRSA). What is a Terminal Radar Service Area (TRSA) and what are its operational requirements?


texts: How does the attitude and heading reference (AHRS) work on Boeing 737 aircraft?

texts:
I would like to know how the AHRS work on Boeing 737 aircraft. If this aircraft (like every the other ones I guess) has an Inertial Reference System (IRS), composed of 3 accelerometers and 3 gyroscopes, what elements compose its AHRS?
3 accelerometers and 3 gyroscopes as well?


texts: When an airport has helipads, why would a helicopter take-off or land on a runway?

texts: At an airport with both runway and helipad (KASH) I have seen both being used for helicopter takeoffs and landings. Is there anything that causes the helicopter pilot to choose to use the runway instead of the helipad?


texts: Can free flying twin drag rudders be mounted on a stabilator, aerodynamically speaking?

texts:
Can free flying twin drag rudders be mounted on a stabilator on an ultralight, aerodynamically speaking, or would it be disadvantageous?

I understand free flying rudders need up to 40% less area than a classical vertical tail arrangmenent with a stabilizer and rudder. Source: Zenith, Flying on your own Wings

I also understand that stabilators  need up to 15% less tail volume than a horizontal stabilizer and elevator.
Source: http://www.ae.metu.edu.tr/~ae451/geometry_sizing&configuration.pdf

I also understand an H-tail can be used as end plates to increase the effectiveness of an elevator by changing it's lift distribution, from an elliptical one to a rectangular one, reducing the elevator area required even more.

I also understand that twin drag rudders are more effective than standard
rudders in a twin rudder configuration, reducing the required area even more.

What about combining the two?

Can twin free flying differential drag rudders be mounted on the end of a stabilator?

See pic below.


texts: How does the Angle of attack vary from the root to the tip of a propeller for a fixed pitch prop?

texts:
I came across a video while learning about propellers where it showed the angle of attack increased from the root of the propeller to the tip of propeller whose pitch was fixed.
I somehow cannot get my head around it. Is it because the tip moves faster than the root? If so, can anyone explain why moving faster changes the angle of attack at the tip?

I am pretty new to all this so sorry for the stupid question, & I tried searching on the site but could not find answers to this question explicitly.


texts: Are there any Boeing 747 still flying for commercial use?

texts:
No American airline flies it anymore, but the Jumbo has been mythic for decades:

ANA B747-400. Wikimedia, photo by Kentaro Iemoto

Is it still possible for a passenger to board a Jumbo Jet?
Which airlines are still operating the B747 in 2018?


texts: Engine(?) & Pressurization Problem in ATR-72

texts:
To clarify, I'm an aviation enthusiast, not a pilot. I have a question for ATR pilots (or anyone with knowledge of the ATR systems).

While travelling on an ATR-72, about 15 mins after takeoff (and presumably at cruising altitude) I felt a very rapid deceleration - to the point I felt pressure on the seatbelt. At the same moment, I felt a sudden change in the air pressure. Checking my altimeter-measuring watch, I saw a reading of 760mb - well bellow the normal ~1000. No masks dropped, however. Several people in the cabin became upset and worried. I was sitting on the second row and, although I can't be certain behind the closed door, I'm pretty sure I heard a 'whoop whoop' alert from the cockpit.

The journey continued without diversion or any emergency landing (frustratingly, no crew announcement either). I did notice that the air pressure remained bellow 800mb for the rest of the ~30min flight, beginning to rise only during descent.

I was wondering if anyone has a clue what might have happened. My best guess is some sort of engine trouble leading to bleed air problems, causing the plane to fly at a lower altitude (unpressurized) for the rest of the flight. But then again, is it normal procedure not to divert/return? I should mention that we had departed a large metropolitan airport headed for a regional one, so a return to the largest, better-equipped airport made more sense, I would think.


texts: How does jet engine water injection work?

texts: How did the "wet takeoff" of old days work? Was the water used ordinary distilled water, or did it have additives? Where is it carried in the aircraft?


texts: I was reading a description of the Boeing X-45 that described it as having "lambda wings." What is a lambda wing and why is it called that?


texts: Why are the wings of some planes changing width?

texts:
I was travelling recently in a Boeing 737 and I noticed one thing that I didn't understand. After the takeoff the wing flaps started retracting into/under the wing, making it narrower. The opposite happened before the landing.

You can see what I mean in this video:

The question is:
Why are the flaps hiding into/under the wing?

I understand that the bigger wing area is better during takeoff and landing. But why is the wings' size reduced during the cruise? Shouldn't bigger wings provide better lift during the entire flight?

Some clarification after comments:
I'm asking specifically why are the flaps retracted and not just remain parallel to the wing


texts: Does the avoidance of thrust reverser save fuel?

texts:
On 2017-06-17 I took an AirAsia Airbus A320-200neo from Hong Kong (VHHH) to Kuala Lumpur (WMKK).

The flight crew did not use reverse thrust for slowing down the plane.

Trying to find an explanation to this, I would like to know so much as possible about the use of thrust reversal by commercial flights, including low-cost airlines, which would probably like to use any feasible technique for saving fuel.


texts: How is data exchanged between Eurocontrol and FAA?

texts:
Let's say I want to fly from Europe to USA.

Then (probably):

I'm filling flight plan message(FPS) and it goes to Eurocontrol system.
It is somehow transmitted to FAA. How?


texts: What medical issues or procedures can cause denied medicals?

texts: Are there a lot of things that can cause a denied medical? Can fairly routine procedures be grounds for denial? (Please don't hate me for having 2 questions in one!)


texts: What is this red canister on the tail of the YF-22?

texts:
On the tail section of the YF-22 further back in the image below, there is a red canister. What is that canister for? I suppose it is for some flight testing purposes from what I can see.

I can't pinpoint the image source.


texts: Does the NTSB and other investigative agencies charge airlines for investigations?

texts: Does an airline have to pay the investigation team? For example the NTSB? And if Boeing or Airbus participate in the investigation, do they also charge the airlines?


texts: Does flying an airplane upside down imply negative AoA? Why?

texts:
I saw the statement below in this answer:

  Note that for normal level unaccelerated flight $C_L$ is always > 0. The minimum $C_L$ is a negative value for negative AoA, and would mean that the aeroplane is flying upside down.

This would seem to me to imply that flying an airplane upside down implies a negative angle of attack.

But the typical illustration and explanation of angle of attack is that it is the angle between the airstream and a reference line, the latter of which in airplanes is normally the wing chord.

How can the two be reconciled? Alternatively, what am I missing?


texts: Where is the formal ICAO flight plan text format specified?

texts:
I want to write a parser for ICAO format flight plans, like the one shown below.

(FPL-AEE036-IS
-A320/M-SCDE2GHILORTUWY/S
-LGTS1635
-N0471F310 LEKPO UL617 SKP UB1 ABLON
-LGAV0042 LGSA
-PBN/C1B2S1 DOF/160805 REG/SXDVD)

The thing is that everything I come across is related to flight plan filling and not about this format, what to expect, what not to expect, field meanings, possible values etc.

I am looking for something like that but formal, preferably from some ICAO document


texts: Which books should I study to understand more about Supercritical airfoils?

texts: I want to understand the theory behind supercritical airfoils and all the details about them. It would be nice if I could get a standard supercritical airfoil, its experimental Cl, Cd data in the transonic region and its verification from theory. I haven't been able to find anything concrete on the internet.


texts: Why would an airport be depicted with symbology for runways longer than 8,069 feet even though it is reported on the sectional as 7,200 feet?

texts:
This airport, KMKO, Muskogee-Davis Regional in Oklahoma southeast of Tulsa is depicted on the sectional chart with symbology normally reserved for airport with a hard surfaced runway longer than 8069 feet, but this one is only reported on the sectional as 7200.

Is this a mistake by the FAA or is there some clear explanation about why this is?


texts: Can a F-4 Phantom II pilot control weapons?

texts:
In the F-4 Phantom II, can the pilot in the front seat control the weaponry as well, or do they only fly the aircraft?

And can the weapons officer in the back fly the aircraft in emergencies, e.g. if the pilot is unconscious?


texts: What is the procedure to contact EASA to evaluate the certifiability of a system?

texts:
I work in academia, and often we are "accused" of living in an ivory tower with no connections to the real world.

To reduce the gap between academia and this "real world" I've heard about, I would like to involve EASA in the research project I am currently involved in.

What is the correct procedure to do this?

For clarity:

it would be only about software
it is not something covered by DO-178C/equivalents (I have problems/questions about the high-level requirements, that are an input for the procedures in DO-178)
it is a program running on a machine with a real-time operating system (RTOS) on board the aircraft. Currently we have no plans concerning maintenance cycles, so I would not be able to say if it could go on a easily exchangeable module (but my guess is no).


texts: Why isn't there a "check engine" light in airplanes?

texts:
Why don't small airplanes (like Cessna or Cirrus) have "Check Engine" lights, like cars do?  For the most part, the people flying these airplanes don't know much more about the plane than they do their car.  Wouldn't a "Check Engine" light be useful to many people flying these planes?

Or do the rigorous maintenance schedules required for airplanes invalidate any use that a "Check Engine" light would have?


texts: Effect of touchdown on angle of attack, tailwheel vs tricycle

texts:
I have a theory but I can't find any documented confirmation. Please let me know if my theory seems right:
My theory:
During a regular touchdown, a tricycle gear equipped airplane, since the main wheels are behind the center of gravity, rotates around its transversal axis (nose down), thus reducing the angle of attack. This should reduce the plane tendency to rebound (unless the nosewheel touches the ground).
On a tail-wheel airplane, the effect in reversed, on touchdown the airplane rotates around in transversal axis, thus increasing the angle of attack.
Does that make sense?


texts:
What is the front glass in fighter planes called? I mean the one which had the reticle marked in them not the canopy glass. Cockpit part on google doesn't seem to tell what I want to know.

Are there any other uses of it besides targeting, because I have seen them only in fighter planes/jets?

When were they first employed?


texts: What lights are used on top of a building or structure near an airport?

texts: What type of light (strobe, beacon, color) should be displayed on top of a building or structure near an airport ?


texts: What is APS (Aircraft Prepared for Service) Weight? What does it include?

texts: I am looking for a complete explanation of what APS weight includes and how is it different from Dry Operating Weight and Basic Weight.


texts: What is the standard way for the ATC to ask a pilot to repeat him/herself?

texts: There is a lot of information on how the pilot should ask the ATC to repeat a statement, but is there a standard way for the ATC to ask the pilot to repeat a readback, or any new information that the pilot provides?


texts: In which cases the lift distribution is not elliptical? (i.e. e≠1)

texts:
I understood that Oswald coefficient doesn't modify the induced drag (i.e. =1) if the lift distribution is elliptical.
When is the lift distribution not elliptical? What are the physical or ideal causes?


texts: If I am pushing my aircraft into the hangar with a tow bar, at night, with the engine off, am I required to activate my rotating beacon?

texts:
I know there is a similar question here: When to use Beacon, Anti Collision, Strobe, Logo and Navigation lights?, but it doesn't answer my specific question.

Do I need to have my rotating beacon on at night while I park (push) my airplane after I've turned off the engine?

It sounds like an urban legend, but someone told me they heard of someone facing disciplinary action by the FAA due to moving their airplane at night without the rotating beacon turned on, even though they were just pushing it back into the parking spot with the tow bar.

I know the AIM 4-3-23 says

  Use of Aircraft Lights

  a. Aircraft position lights are required to be lighted on aircraft
  operated on the surface and in flight from sunset to sunrise. In
  addition, aircraft equipped with an anti-collision light system are
  required to operate that light system during all types of operations
  (day and night).

But is pushing an aircraft into parking with the engine stopped (in a non-movement area), considered "all types of operations?"


texts: In G1000, how can I intercept a victor airway with multiple legs?

texts:
Suppose we are in HDG mode.

Trivially, we may visually judge which leg we on the victor airway and activate that leg.

However, in real-world, I found sometimes the fixes are so close and the airplane is relatively far from the airways. It is difficult to tell exactly which leg I am going to intercept, without "ruler" assistance. Meanwhile, ATC may change HDG assignments, and therefore the intercepted leg may change.

Is there a way to "activate the nearest leg and intercept" in G1000? or how would you solve this problem other ways?


texts: What causes aileron and elevator flutter?

texts: This video shows a Hawker jet with the wing fluttering up and down like it's about to break. What can cause flutter like that? Can it actually cause a wing or stabilizer failure? How can flutter be prevented? What should be done if something like this happens?


texts:
In the next picture what are the items circled in red?

Photographed by Adrian Pingstone in August 2002 and released to the public domain.


texts: Does a nuclear weapon (B-61) equipped F-35 have the same nuclear confirmation failsafes as other nuclear device delivery aircraft?

texts: Several sources cite that the F-35 will be able to be modified or simply equipped to carry some variant of the B-61 nuclear bomb. However, I know that most strike aircraft such as the F-15 Strike Eagle seat two crew as so for nuclear weapons there must be confirmation of arming the weapon by both crew members. No variant of the F-35 seats two, so I assume that there must be some way of having two-factor authorization of this protocol anyways. Is there a publicly known practice of arming nuclear devices on the F-35 or any other single seat aircraft or were the sources stating it could deliver the B-61 incorrect?


texts: What is the blue range indicating on this manifold pressure gauge?

texts:
This is baffling me. Does anybody with experience with this type of indicator have any idea what the blue range of this gauge means?

It's mounted in a mock-up panel. I know nothing about where it originally came from, though it seems pretty clear that it's from a turbocharged piston twin.


texts: What is the purpose of the cabin temperature probe run from the gate?

texts:
I'm on a JetBlue flight and noticed a cable running from the gate / gangway into the plane, which appeared to be labeled "Cabin Temperature Probe" or something to that effect.  The cable is draped over the divider in front of the first row of seats. Further, the console outside the plane appeared to have only a single yellow light (which was off), no display or additional controls.

What is this for? It seems like a sensor actually installed in the plane would be more accurate (it would work even when the door is closed). As is, I imagine the probe is picking up much more ambient air than cabin air.


texts:
There are two "excrescences" Near the end of diffuser of some combustion chambers. e.g. CFM56 and F101
What's the name of this part of combustion chamber and what is it for?


texts: What is this weapon spotted at an airshow in South Africa?

texts:
I was at an airshow in South Africa, and they had this trailer sitting about.  No one knew what it is.

Those little red plates all say "warning, high voltage".  Those buckets are open at the bottom, and made of aluminium.

These finned pointy things are hollow, not sure what they are made of.  Were not solid plastic, but didn't look like fiberglass either.

A couple of specific questions:

What is it?
If the hollow things are covers, why are they so oddly shaped?  And if they are covers, why do they share features with liquid tanks?
Why are there half a dozen "High voltage" stickers attached?
What are those bins and chains?


texts: Qualification Requirement of Aircraft taxi and landing lights?

texts:
Can anyone provide any standard through which taxi and landing lights are certified for use on aircraft?

And which certification is required for military aircraft lighting systems?


texts: Where can I find information about post-WW2 airports in Saudi Arabia?

texts:
Where can I find historical information about airports in Saudi Arabia since 1945?

I am in the middle of a research project about airports in KSA (Kingdom of Saudi Arabia) since 1945, especially the period from 1945 to 2008. Any information, books, documents or images will be helpful.