texts: Do commercial airlines have procedures for evacuating pets from the cabin in an emergency?

texts:
I recently got into an offsite discussion about flying with pets in the cabin and what would happen in an emergency on board. I brought up the fact that United Airlines' pet policy states, "In the event of an emergency, oxygen service will not be available for pets." Southwest has a similar phrase in their pet policy, though I couldn't find anything similar in American Airlines' or Delta's pet policies.

Beyond oxygen service, I was arguing that if an evacuation took place, I wasn't aware of any procedures for getting a carryon pet evacuated safely. I said that the human lives of the other passengers on board would take precedence over a pet. To my knowledge, pets in carriers are essentially treated as a carryon bags in the cabin. I also hypothesized that letting a pet out during an emergency could be extremely dangerous and would likely invoke the ire of the crew, if not get you into legal trouble.

TL/DR: The discussion left me wondering are there actually any procedures for getting carryon pets out of the cabin in an emergency? This is mostly directed at pets that would be in a small kennel and stowed for the duration of the flight under the seat in front of you as a personal item. Are they considered carryon luggage, which should then remain stowed (as awful as that sounds), or treated like infants? Have there been instances of serious accidents where carryon pets were also evacuated in the past?


texts: Difference between multi slats and three slats on B737 ? (leading edge devices)

texts: What is the difference between multi slats and three slats on a B737 ?


texts: Is it okay to ask the Call Sign of the plane to Pilots / Flight crew during boarding?

texts:
I sometimes open "Live ATC" app on my iPhone and listen to the "status" of my airplane when I'm taking off until my plane reaches the runway (I know the phone have to be turned off but its exciting to listen to ATC communicating with your pilot). In order to know the status, I have to know the call sign of the plane. If I'm taking off from a small airport, I kinda guess the call sign based on the conversation between the ATC and the pilots and the position of my plane (for example if the ATC says United 220 hold short of Juliet and if my plane is on Juliet, I know my plane is United 220). There have been times when the pilot announces the call sign of the plane before pushback.
My question is, Is it okay or weird for me to ask the call sign of the plane to the pilots / flight crew during boarding.


texts: Are electromechanical actuators used in aircraft other than the Boeing 787?

texts: Are there any large (non-experimental) civil or military aircraft that use electromechanical actuators (EMA), other than the Boeing 787?


texts: Can having too small of a roll or yaw stiffness destabilize the dutch roll mode?

texts:
For a dutch roll mode, can having too small of a roll or yaw stiffness destabilize it?

I would think not because you want a lower value to maintain it?


texts: Do Cargo flights carry anyone other than the crew?

texts:
This question talks a bit about the crews that are involved in a commercial cargo flight, but I'm wondering if Cargo flights every carry other sorts of people on their flights?  Say, a photographer to take pictures of operations for advertising or something.  Or maybe one of the crews kids who want's to see what Mom does or something like that.  Or, perhaps there's even another person who's normally there?

If they do, here's a couple bonus questions:

Do they have jump seats?  And are they in the cockpit, or in the cargo hold?  (Just in general, I assume different planes have different setups).
Are there any regulations regarding this?


texts: Why are European low-cost carriers not running long haul flights to destinations like the USA, Asia, or the Middle East?

texts: Does this benefit them somehow, by only travelling within Europe?


texts: Why was the engine of the Ju-87 Stuka not replaced with a more powerful one?

texts:
Related to this question
Why did the Ju-87 Stuka have a siren?

I would like to know the reasons why they have not changed the engine of the Stuka when they realised it was easy prey for Hurricanes and Spitfires in 1942/43.

Couldn't they have replaced the engine with a bigger one?

It is a heavy aircraft, but certainly could have gone through some improvements in order to increase its speed and manoeuvrability.

Ok it is a bomber, not a fighter, but still...


texts: What button do I push on the instrument panel to activate DME in VOR navigation?

texts: For some strange reason I cannot seem to find any information about what button to push on the instrument panel to active the DME.  There is plenty of information about how DME works with interrogation and slant distance, but I cannot seem to locate any information about what button to actually push to activate DME when I am sitting in the cockpit (in a Cessna 172, for example) or where to look on the instrument panel to read the measured distance the DME is telling me.  So if the DME is measuring 8 nautical miles, where on the instrument panel will that "8" be displayed?


texts: Why is the angle of the horizontal stabilizer marked on the fuselage?

texts:
Why are the angles displayed on the fuselage?

I understand having markings with depth on the hull of boats, but I don't understand the use case on a plane.

Photo of the root of the trimmable horizontal stabilizer on an Embraer ERJ-170 (wikimedia.org).


texts: How to find runway direction classification, code number and code letter?

texts:
I am creating a solution that generated the limitation surfaces for runways according to ICAO Annex 14. One of the parameters that I need is the runway directions classification, code number and code letter. But so far I only found one country that has this information in their AIPs.

Are there anyone who know this stuff enough, that would be able to provide some guidelines to how I could guess these information based on thresholds and declared distances etc?


texts: Did the Swiss Air Force assist Austria in self-defence during the Yugoslav War?

texts:
I was told a story a story by a friend that went along the lines of:

On multiple occasions, eastern european military aircraft strayed into Austrian airspace during one of the Yugoslav wars.
Neutral Austria did not have air-to-air combat capability in their J35Ö Draken, so the Swiss Air Force F-5s helped them out instead.
On one occasion, the Swiss air force came in and swiftly destroyed the aircraft in question before returning to base.

Note that I'm not completely sure of the exact sequence of events. I cannot find any reference for this story. Other aircraft downing during the war, especially NATO ones, are well covered.

Did this actually happen?

Updates with a few notes:

This must have occurred before 1995 when the Austrian Air Force outfitted their aircraft with Sidewinders AAM.
There is one case of a MIG-21 Pilot deflecting to Austria. Even this event is very vaguely documented.
Several sources suggest neutral Austria was very shaken up and upset by the foreign fighter jets overflying their country.
Information seems to be generally patchy, as this was before the days of the internet and there appears to have been much confusion and disorder.
As much as Switzerland is perceived as neutral, Austria was also very much so since it was a small country sandwiched between the east and west during the cold war.
Perhaps there is an international law that the Swiss were obligated to help, but kept it quiet out of concern of negative media publicity?


texts: Can the commercial night cross country be done under IFR?

texts:
The below doesn't mention anything about needing to be night IFR, so if you were to shoot an approach on this flight, would it be legal?  Also, if the instructor isn't a CFII, but PIC does have an instrument rating?

https://www.law.cornell.edu/cfr/text/14/61.129

  (iv) One 2-hour cross country flight in a single engine airplane in
  nighttime conditions that consists of a total straight-line distance
  of more than 100 nautical miles from the original point of departure;
  and


texts: Does any one know if the PFD or ND or any other screen on an commercial aircraft work like a computer or something else? Like does the screen work like a computer and read 0s and 1s like maybe for sensors for smoke it sends a particular amount of 0s and 1s to show on the screen there is a fire and have hard drives and graphic cards and all that stuff or do they work completely different?


texts: What aircraft model is on this old photograph?

texts: I would be grateful if anyone could identify this - Copyright Real Photographs Co. No. 750


texts: How do you spot the difference between an A320 and a B737?

texts: I'm constantly having problems with identifying aircraft, and was wondering whether there are any tricks with easily identifying whether an aircraft was a Boeing 737 or Airbus A320?


texts: Why aren't runway numbers painted in a higher aspect ratio?

texts:
I'm watching a lot of aviation youtube channels and it seems to me that when attempting a landing on a "normal" glide path, it must be quite hard to read the runway numbers until you're on short final, which might affect the number of "wrong runway landings", especially on uncontrolled airfields.

Are they actually easier to read in reality than in the videos I'm watching?
If not, why aren't they painted with a higher aspect ratio (e.g. the numbers being twice as high, thus making them appear "less vertically compressed" when approaching on a "normal" glide path)?


texts: Is a fly-by tower legal for civilians not during a show?

texts:
Suppose a civilian wants to fly-by tower in a small plane, like a Cessna 172, would it be legal for him to do it?

I assume here that if it is legal he still would need to ask permission from the ATC.

The region in place would be USA and the European Union.


texts: What are these unsymmetrical parts at the tail of the Tupolev TU-144?

texts:
On a recent trip to the Technikmuseum Sinsheim, I noticed that the back of the Tupolev TU-144 is not symmetric.
Please take a look at the picture I took to understand what I mean:

(Please don't mind the crane, the Tupolev was getting cleaned that day)

Those parts most likely serve some aerodynamic/stabilizing purpose, but what exactly do they do? Why aren't they the same on both sides?


texts: Is airflow deflected inwards or outwards by wing sweep?

texts:
We are often told that wing sweep causes the airflow to be deflected outwards. I can understand this for the underside, but for the upper surface it seems inconsistent with other effects.

For example on a sharply-swept delta, sideways flow out from below, up around the leading edge and back in again over the upper surface becomes dominant. It feeds the vortices employed by Concorde to enhance lift at low speeds. The sharper the sweep, the more the air over the upper wing flows inwards. The same effect is seen in miniature with tip vortices on a straight wing. This makes sense to me because the pressure above the wing is low, so that would naturally attract air in towards that zone.

So, does sweeping a straight wing really reverse such effects, or do say wing fences on the upper surface actually stop the air flowing inwards?


texts: How can one calculate the maximum instantaneous bank angle a plane can do in a certain time?

texts:
I know that there is a limitation to do an instantaneous banking angle a plane can do. These limitations are due to the airplane (infrastructure - aerodynamics) and limitation on the pilot (due to his ability to withstand a certain maneuvering calculated in g), so how can one calculate an accurate or approximate value for the maximum instantaneous bank angle taking into account the (military and civilian) planes infrastructure and also taking into account the pilot (with or without) a g-suit.

Also i want to know how long can a pilot withstand that instantaneous bank angle?

Thanks in advance.


texts: What is the Saint-Venant formula for calculating equivalent air speed (EAS)?

texts:
I'm studying some ground exams (for a lapsed IR). In the course notes it says that EAS (Equivalent Airspeed, i.e. a compressibility-corrected airspeed) is calculated (e.g. by an aicraft's Air Data Computer) using the "Saint-Venant formula". The course notes don't actually give said formula.

I assume they are talking about this guy who derived a forerunner of the Navier-Stokes equations. However, most of his work seems to be to do with waves in shallow water and not aerodynamics. I think I know how EAS is calculated, and it doesn't seem to involve anything as hairy as Navier-Stokes (although it does require isentropic flow relations.) But I can't figure out how Saint Venant has anything to do with it. From another forum: "In the EASA learning objectives I can find no reference to 'Saint-Venant' so it is probably just something somebody thought up to confuse you." Can anyone shed any light on this?


texts: Taxi to spot?? Hot spot? What is meant by this?

texts:
I heard ground controller at KPHL say taxi to spot so and so?
What do they mean by this during taxi procedures.


texts: What is supposed to prevent a commercial crew from flying to the wrong airport?

texts:
Context

Obviously:

Crews are skilled and well trained.
In a crew of two, one can fix others confusion.
There is a flight plan, ATC can inform of a deviation.
GNSS / ILS / VOR / DME frequencies and distances increase situational awareness.

But still:

February 2014: "Planes landed at wrong airports 150 times over 2 decades".
March 2014: Security Alert, NTSB reminded pilots to take care of not landing at the wrong airport.

After having posted this question, I did an additional research, to find NTSB came back to this problem recently, in May 2015:

NTSB releases two recommendations to FAA. One for ATC clearing to land, the other for software detection of wrong location.
Related article: "After 5 planes land at wrong airports, the NTSB has a few words of advice for the FAA".

Relatively few errors, but consequence could be tragic

150 approaches or so wrong are a very small fraction of the many millions of flawless flights, however the NTSB emphasizes the consequences could have been tragic, e.g. if the erroneous airport didn't provide the expected runway length.

Questions

Did the analysis of these incidents show distinct patterns in their occurrence that could be prevented by different procedures or different navigation instruments?
Did the involved pilots, or other professionals think specific improvements had or still have to be made to avoid recurrence?


texts:
There are several questions about livery changes and livery in general on this website. Yet, I fail to find information about paint removal.

As a routine maintenance for an airframe that can live for up to 30 years, livery is redone several time as explained here. When changing painting, it should be preferable to remove the old one (I'm mostly thinking about weight as a big airliners has a lot a surface to paint). Moreover, I imagine that for military aircraft changing their operation theater, paint must be redone to adapt camouflage, and thus accumulating many layers of paint may have consequences.

Given material and other aviation-specific constraints, I also imagine there are special techniques to handle any intervention on the airframe.

Is this paint removal done and if so, how?


texts: Why would a foreign military aircraft be parked at a US Air Force base?

texts:
The aircraft in the attached Google Earth screenshot appears to be a Eurofighter Typhoon, parked all alone on the tarmac at Eglin AFB, Florida.  Why would one single foreign fighter like this be found on a US military base?  Granted, the Typhoon is mostly operated by US allies, but it still seems strange.

Also, can anyone identify the livery/operator of the aircraft in question?


texts: In a pusher configuration with turboprop(s), how is the superhot exhaust avoided?

texts:
I actually looked around for turboprops in a pusher configuration, and so far I only found one: P180 Avanti. You can see the propellers are behind the turbine, and in fact it looks like two exhaust ports lead right into the propellers.

How is this possible? Turbine exhaust is very, very hot. "Superheated steam" is actually a technically accurate term. Won't this disturb the propellers and cause them to fail or else need huge maintenance? Is there some elegant way to avoid this geometry in a pusher configuration?


texts: What are the differences between Bearing vs Course vs Direction vs Heading vs Track?

texts:
This answer from English.SE does not focus on aviation, and does not explain 'Track'.

In basic, simple English, would you please compare and contrast all 5 terms in my question's title? The differences between 'course' vs 'heading' was generously explained in this answer.


texts: Can jet engines be used for VTOL civilian aircraft?

texts: Why do almost all civilian VTOL aircraft existing today use propellers (or rotors) for take off and landing and not jet engines (as the Harrier does)? Is there a technical reason for this?


texts:
In a recent post it could be read that by definition, turbofans do not produce power in the static case (at velocity zero). The statement could be a bit confusing since turbofans and propeller engines are at their highest power setting just before the take-off roll commences.

What is the referenced definition that results in zero power for turbofans at zero speed, regardless of the throttle setting?


texts: Why is the position of the pilots' head (eyes) so important?

texts:
From this question:
What are these Lights on Center Holm between Windows on the A320?
I learn that the pilots' eye position is important. Enough to justify an extra piece of equipment.
But why? Can't a pilot tell if they see enough, above/below/on each side, by just looking?


texts: Helicopter tail horizontal stabilizer angle

texts:
In helicopters what factors decide the horizontal tail stabilizer angle?
By angle I mean that in some helicopter they are -6 deg relative to tail boom while in some -3 deg.
These angle were remain fixed although provision is there to change the angle.


texts: What is the absolute velocity change through compressor+burner?

texts:
I thought that the velocity going through a turbojet increased as it went through the compressor and the burner. Intuitively, if the pressure/enthalpy increases, so would the velocity, right? I came across with this image, though:

As you can see, this image says that overall velocity actually decreases at the exit of both compressor and burner.

What is the logical explanation behind this? Shouldn't the compressing/burning effect actually accelerate the flow?


texts: How Earth's rotation affect flight times?

texts: How much does Earth's rotation affect flight times in going East or West, and how could you calculate if zero winds?


texts: Can instrument training be done in IMC with an instrument-rated safety pilot?

texts: I'd like to fly some hours towards an instrument rating by flying with a safety pilot.  I have a safety pilot who is instrument-rated and current (he's working on building time towards a commercial rating).  Since he's instrument-rated, can we fly in IMC on an instrument flight plan?  If we do, can I be the manipulator of the controls, and can I log PIC time for the time that I'm the sole manipulator of the controls in IMC?  And if we're in IMC on a instrument flight plan, do I need to be under the hood by using a view-limiting device, or is just being in IMC good enough to count as instrument time?


texts: What happens to the ejection seat after a pilot ejects?

texts: When a pilot ejects, what happens to the ejection seat? Does the pilot stay in the seat until he lands, or does it get disconnected from the pilot somehow?


texts:
I recently came across a part of the electrical system of aircraft named SHED BUS. I am specifically asking for the Embraer Phenom 100.

Source (Page 122), Added red square

What is the SHED BUS for and what is it doing?


texts: Why haven't airlines added safety pads to their carts?

texts:
I chanced upon this question at 5:11 of this YouTube video. Their answer is "no idea".
A cynic would answer profit motive, for it costs money to add safety pads to all these carts and airlines aren't profiting especially in this COVID19 pandemic.


texts: Where can I find the active time of a MOA on the VFR chart?

texts: I am trying to find out the time when the HILLTOP MOA is active and its elevation. Where is this information located in a VFR chart?


texts: How do anhedral and dihedral affect the efficiency of a wing?

texts:
Higher pressure air on the underside of a wing generally rolls outboard around the wingtip and over the top of the wing reducing lift and therefore increasing induced drag.
My intuition would tell me a wing with a dihedral would increase this effect as the higher pressure airflow on the bottom of the wing would flow outboard easier than anhedral. Is the opposite true with anhedral? Would the airflow flow inboard?
Are there any other factors that could contribute to efficiency?


texts: What was the airline attendants looking at in LED display before light off in A320

texts:
I was journeying on Indigo Pune-COK back and forth. At both the times, I noticed airline attedants looking at some LED display which seemed to be some sort of balance scale. At first, I thought they might be looking to check at some sort of weight distribution sensor to check whether things are distributed evenly all across the aircraft or something else. I am not sure now but would be glad if somebody could chime in. The plane is and was single class 180 Airbus A320. https://seatguru.com/airlines/IndiGo/IndiGo_Airbus_A320.php

Edit : Update - . Both times, it was before the takeoff procedure. The LED/LCD display was located above the flight attendants chair on the left . The chair on which they sit in the front during take off. The one which is located to left of the refreshments and just before the pilot cabin/cockpit.  The LED/LCD display was above the flight attendant's chair at eye-level.

While I'm sure it had to do with probably some sort of avionics controls they were looking at, I am not sure what.


texts: How far can the sound of a sonic boom travel?

texts: Are there conditions or distances from the plane to cloud to the observer in which a sonic boom from a plane is muted?


texts: Why wasn't MH-17 flying at 33,000ft before it entered Ukrainian airspace?

texts:
I was looking at the path of the MH-17 flight that crashed in the Ukraine on FlightRadar24 and noticed it was flying at FL310 (31,000ft), then because of the Ukrainian NOTAM which went up to FL320 (32,000ft) and below, it then ascended to FL330.

Why wouldn't it be flying at FL330 already from the start? Doesn't a higher altitude mean less air resistance (because the air is thinner) and therefore better fuel efficiency?


texts: Which was the first pressurized aircraft?

texts:
Which aircraft was the first one to fly pressurized?

High altitude breathing apparatus, 1918 (source)

I mean an aircraft which didn't require to don an oxygen mask above a certain altitude, excluding very high altitude where a mask is still required due to quick loss of consciousness after a depressurization event.


texts: How can I find a final approach fix (FAF)?

texts:
I have a problem understanding FAF - how can I find FAf on a precision approach without the lightning bolt/zigzag symbol. I know the Maltese cross means FAF for a non-precision approach.

According to the Jeppesen airway manual,

  by the glide slope/path intercept point on precision approaches

Which means that wherever I intercept the GS, I can say that point is FAF?

I added a chart. (In case you cannot see the picture I will explain the chart) FAF (Maltese cross) is positioned at DME 5.1 and 1700ft on a 3 degree glide path.

At the moment I pass the Maltese cross at 1700 ft, the GS indicator will be below because from 5.1DME on a 3 degree glide path, altitude will be about 1620ft so I need to descend at a steeper rate to intercept the GS. Then I will intercept the GS after FAF of a non-precision approach. In this case the FAF for the precision approach is positioned after the Maltese cross?

Is the FAF of aprecision approach not fixed at a specific position?

Until now, I have regarded the Maltese cross as the FAF for precision approach because there was no lightning bolt symbol.

Please correct my misunderstanding...


texts: Question about federal airways in Class E airspace going from 5500 MSL(USA)

texts: Class E with a floor of 1,200 feet AGL is shown with the "fuzzy" side of the blue. And sometimes Class E has a floor higher than 1,200 feet. They will print the floor of the Class E altitude in the "fuzzy" side of the blue. I know the Class E with a floor of 1,200 feet AGL is usually the floor of an airway. It goes from 1,200 AGL to 18,000 MSL. But if there is a designated specific altitude higher than 1,200 AGL for Class E airspace floor covering a federal airway, at what altitude does the Federal Airway start?


texts: How do flight crews handle a death aboard a commercial aircraft?

texts: Kinda a morbid subject I know, but whether a prince or a street sweeper, we all dance with the Grim Reaper - sooner or later.  And there’s no reason he cannot visit you at 30,000 feet, if it’s your time.  Therefore if a person, or a member of the flight crew succumbs and dies, how is this handled in a professional manner?


texts: Why don't airliners have a navigation GPS as back up in case of a pitot tube malfunction?

texts:
Why don't airliners have a navigation GPS as "back up" in case of a pitot tube malfunction? Aeropero 603 and Air France 447 plus many other im sure, could have been saved if these aircrafts would have had a simple Navigation GPS as a plan B. The GPS could have given the pilot the basic information needed to keep flying instead of leaving them confused about what the instruments were showing due to the blocked pitot tubes. having reliable information of ground speed, heading and altitude would have helped the pilots recognize the situation they were in, which was caused by Pitot tubes blockage. Most private pilots now use GPS why not the big airliners?
There is many blogs about why airliners do not have GPS tracking so the planes could be found after a crash, but none talking about why GPS is not use to help prevent some of those crashes.


texts: What are the safety events definitons for Flight Operations Quality Assurance (FOQA)?

texts:
I am searching the definition and parameters of safety events which are used in Flight Operations Quality Assurance (FOQA).
I tried searching by myself but I can't find anything valuable. Are this definitions events different for airlines/ FOQA provider/ airplane producer or is there one set of events with event number? E.g.: I found in Data Report for Evidence-Based Training August 2014 (FOQA doc) a few definitions like in the screenshot below, but there isn't every events which I need to check.
I have also severity level in data: which factors influence on Low, Medium, High severity?


texts: What are the main differences between scimitar and regular propellers?

texts: I am looking to know the main differences between scimitar and regular propellers. Can somebody help me on this?


texts: The relation between Euler-angle rate and body-axis rates?

texts:
A
paper  about quadcopter dynamics and control
shows the relation between Euler-angle rate and body-axis rates as:

Q1: why are there $R_{v2}^{b}(\dot{\phi})$, $R_{v1}^{v2}(\dot{\theta})$, and $R_{v}^{v1}(\dot{\psi})$?
I understand these are rotational matrices, but how could we use the $\dot{\phi}$, $\dot{\theta}$ and $\dot{\psi}$ to replace $\phi$, $\theta$ and $\psi$?
Q2: is the eqn(7) the approximate representation of the relation between Euler-angle rate and body-axis rates?  if YES, what are accurate representation?


texts: Which is the smallest available widebody on the market?

texts: I'm interested to find out which is the smallest (capacity wise) modern widebody aircraft in production/ operation.


texts: What is the main materials of the windshield? And how do they function in bird strike?

texts:
I would like to know what the latest materials used for civil and military aircraft windshields are.
And I wonder if the materials are advantageous in the event of a birdstrike.


texts: When does the FAA require OEM involvement for the approval of an STC?

texts:
There appear to be many instances when companies modify aircraft (or introduce after-market systems) without the involvement of the original equipment manufacturer (OEM), up to conversions of passenger aircraft to freighter aircraft.

Is there guidance from the FAA on when an aircraft modification requires the involvement of the OEM?


texts: Why do eastbound transpacific flights fly at lower latitudes than their westbound counterparts?

texts: I’ve seen some routes for flights from Asia (mainly Hong Kong and Shanghai) to the west coast of North America, which fly at lower latitudes than flights in the other direction (which they fly closer to the North Pole). From what I know, the jet streams go eastward, and are stronger near the poles. So why don't flights from Asia to western North America fly closer to the pole to take advantage of stronger tailwinds? Or did I get it wrong?


texts: Does a skinless fuselage add to the likeliness of an unrecoverable spin?

texts:
While at Air Venture this week, I happened to hear a pilot of a small experimental airplane say that he liked the skinless (Naked) look his airframe had at one point during the build, but that he believed flying it that way made it more susceptible to an unrecoverable (I assume flat) spin.

Thinking about it later, I realized that I wasn't sure I understood how this could be.  My understanding of airplane behaviour is that a flat spin is mostly a result of CG being to far aft.  Anyway, I was wondering if anyone knew this?


texts:
I know that the F-16 VISTA tech demonstrator incorporated 2D thrust vectoring and could perform this maneuver. I also know that military variants of the F-16 are prevented from intentionally entering such extreme angles of attack via their flight limiters.

However, I also know one more thing; there is a switch just in front of the throttle that allows "manual pitch override". This disables the pitch-plane limiter of the FLCC to allow the pilot to recover from certain types of deep stalls when normally the flight limiters would freeze the control surfaces due to the detected extreme AOA.

The question is, can U.S. military-variant F-16s, with MPO enabled, perform a "Cobra" maneuver like Pugachev's Cobra?


texts:
Why is the FOV of the Synthetic Vision of the Prodigy Flight Deck asymmetric?

I am just reading through the manual of the Prodigy® Flight Deck 100 and came to the chapter about the synthetic vision. The document states:

  [...] The field of view is 30 degrees to the left and 35 degrees to the right. [...]

Source (Page 510)

What is the reason and what are the advantages of having such a FOV with 30° to the left and 35° to the right?


texts: What are the restrictions preventing more intelligent autopilot systems?

texts:
Current autopilot system is integrated with Flight Management System (FMS) for navigation such as LNAV and VNAV; both of them are based on preset parameters given by the pilot prior to departure (IRS alignment, total fuel/pax, waypoints/airways, flight level, etc) or in short, expert system

What are the restrictions for intelligent system autopilot in which the autopilot shall assist the pilot for making decision (or the autopilot decides per se)? For example, during flight under certain condition where some sensors are failed and flight control system reverts back to direct law (in case of FBW) and the intelligent system autopilot recognizes this case so it helps pilot to decide what to do or controls the aircraft thoroughly


texts: How much mathematics and what level should commercial pilots have?

texts: Continuing off the title, do different types of pilots require different mathematics level? Since as a pilot you have to calculate such as how much fuel will be used and needed, the weight of the cargo, etc. Since all of this will affect your flying since as how very heavy cargo will require more airspeed before taking off.


texts: Why is the most common hydraulic fluid so poisonous?

texts:
The usual hydraulic fluid, Skydrol, is poisonous. If it makes it to the air conditioning system, it causes fume events that may have adverse health effects up to and including at least one fatality. And it is not easy to completely prevent the possibility of it creeping into the air ducts as bleed air is also used for pressurizing the hydraulic reservoirs (at least on some aircraft).

So why was this organophosphate-based fluid selected over anything safer? Are there no safer alternatives?

Update: I should have linked the Qantas A332 at Sydney on Dec 15th 2019, hydraulic leak prompts evacuation accident, which actually inspired the question. That one is clearly hydraulic-related (while in most other fume events we never know for sure), and there is a comment down the page:

  By geezer on Monday, Dec 16th 2019 14:48Z:

  Nothing to do with the apu other than the duct by the packs. Hydraulic reservoirs are (gas) pressurised by either an engine bleed or from the pneumatic duct in the pack bay. Hence a tee piece. If one system loses pressurisation, say overnight, then with a couple of leaky check valves one reservoir can slowly fill another back through the hydraulic service manifold, as all three systems are serviced from one inlet using a three-way valve. Eventually one tank is overfull to the point where the fluid now travels back down the air pressurisation pipe (a small bore pipe). Another check valve stops it flowing back to the engine so it ends up dribbling into the pneumatic duct in the pack bay. We know this because we have found skydrol in these small bore pressurisation lines. I hope you get all that. I think I need a little lie down now.

It should be noted that this is not verified and may not be the cause, but A330 has APU intake on the bottom, so the APU could have also ingested the hydraulic fluid dripping from the bottom of the fuselage into the inlet.


texts: Is the 250kt limit below 10,000 feet MSL varied according to airfield height?

texts:
FAR part 91 Sec 91.117 for example states that "unless otherwise authorized by the Administrator, no person may operate an aircraft below 10,000 feet MSL at an indicated airspeed of more than 250 knots".  All of the major jurisdictions I can find reference to have the same rule.

I've highlighted MSL (mean sea level).  Why is MSL used?  What's the point of such a regulation when aircraft would be able to manoeuvre at high speed close to the surface of high elevation fields?

How, if at all, is this varied when operating to or from an airfield with a high elevation, for example Quito, Ecuador (SEQM) at 7,910 feet?


texts: Can a commercial airliner be used for military purposes?

texts:
Is it possible that in case of some very serious emergency, a commercial airliner such as the B777F could be used for dropping bombs or to serve some other fighting purpose?
 I am simply asking about this from a technical standpoint.


texts: What is the difference between static and dynamic seals?

texts: What is the difference between static and dynamic seals and  How much leakage is allowed past each seal?


texts: Is a hold short expected when given taxi directions to a runway?

texts: When a ground controller gives taxi instructions to a runway, are pilots expected to hold short by default if an explicit instruction to hold short isn't given?


texts: Are parked airliners always connected to a ground power unit?

texts: I'm wondering if commercial passenger planes, like the A320, are always connected to the ground power unit (GPU) when they are at the gate? Even if for a quick turnaround.


texts: How to communicate a circling approach over CTAF?

texts:
The FAA ATC job order says:

  Circling approach instructions may only be
  given for aircraft landing at airports with operational
  control towers.

But I could not find a phraseology example that can describe the circling approach below (which I drew based on this image).

So for non-towered airports, is there a standardized phraseology used to describe the non-standard circling loops to other pilots in the area? Be it good weather or not.

According to this site, there are hundreds of ways to fly a circling approach. Any jurisdiction is fine by me, it's just a curious question.


texts: What does the crosshatching mean on this VOR-DME?

texts:
I noticed that the frequency of this VOR-DME is covered by crosshatching.

The FAA chart guide says this "indicates shutdown status."

What does this mean? Is this navaid being decommissioned?


texts:
Imagine I am in a straight down dive, at terrific speed, and if I wanted upward sharp turn and got the stick back far enough, would I stall (or spin)?
Does normal laws apply when the aircraft nose is vertically down?


texts: How are airliners AoA-Sensors calibrated?

texts:
Airflow around the fuselage is not free, even near the aircraft nose. I assume some correction is applied to the measured angle to get the corresponding freeflow angle.

How is the reponse curve for this correction obtained (for narrow/wide-body airliners)? There must be some other sensor to compare with. This cannot be GPS, since that would give pitch, not AoA.


texts: What causes Mach No. to increase with altitude at a constant cost index?

texts: If a jet aircraft flies at a constant cost index but changes flight level the Mach no required by the FMC will increase with increasing altitude and decrease with decreasing altitude. Why is this? (Disregard aircraft weight changes due to fuel burn etc)


texts: Why mount multiple autocannons on a fighter or CAS aircraft as opposed to a revolving barrel auto-cannon with a higher rate of fire?

texts: Why would one design an aircraft with multiple chain guns instead of a single large rotary cannon, like the GAU-8 Avenger, and similar weapons?


texts: What do these symbols indicate on the ATC display?

texts: I just got found ATC controller display on the internet and could you tell me what are these symbols indicating? For example the ones I highlighted in red?


texts: How else can snowy/icy conditions disrupt airport operations?

texts:
In casey's fabulous answer here, he identifies several ways snow/ice can disrupt airport operations:

  Continuous heavy snowfall can eventually close an airport if it
  becomes impossible to keep the runways clean, taxi routes become
  unusable due to drifting snow or snow transitions into sustained
  freezing rain (or runs out of de-ice fluid, yes IAH I'm looking at
  you). This is a transient problem and the closure would end as soon as
  conditions ease and the facilities can keep up with it.

Are there other ways that heavy snow (or ice) can disrupt airport operations?  Could it perhaps interfere with lighting or navaids?  Are there other airport functions that stop or slow in snow and ice?


texts: Why use jet engines instead of propellers when designing new airplanes?

texts: I'm looking at the 100 people project and I am looking at clean airplanes. Why did we stop using a clean source of lift, the propeller?


texts: How often is the name painted on fighters?

texts:
This question is restricted to US Air Force fighters, as I don't know if other air forces paint the pilot's name on the fighter.
This question pops into my mind because of 2 reasons:

this comment reminds me a fact I saw on a comic strip long time ago: the name of the pilot is written on the fighter cockpit, at least in the US Air Force and perhaps in the US navy.
in this video (smarter everyday, episode235) there is one scheduled flight with the videographer. For this single flight they took the time to write the videographer's name on the fighter (see at 6min17s).

How often is this name (re)painted?

is it updated for every scheduled flight if needed?
is it updated for a single flight flown by another pilot of the same squadron?
is it updated when the fighter is operating on an external theater?
if no update is needed, is it repainted more often than the rest of the airframe?
does this answer varies from squadrons to squadrons?

Bonus question: is it actually painted (I may have made a false assumption, in which case I should substitute "painted" by another more suited word in the whole question)?


texts: How long does it take for pilots to become unconscious after an uncontrolled depressurization at FL 340?

texts: I've just read a news article on the depressurization incident that happened today in Australia. How much time did the pilots have before they lose consciousness if they hadn't used their oxygen masks? This incident is said to have happened at FL 340.


texts: How can I find my grandmother's OLD instrument rating documentation?

texts:
This is my grandmother, Nathalie Myrtle Brown:

The big-eared kid she's posing with is my dad.

She has a claim to fame in that she was the first female instrument-rated pilot in the state of Iowa, a fact that figures prominently in her obituary

  In the 1960s [...] Nathalie and Walt took flying lessons and became licensed pilots. Natalie, the first woman pilot in the state of Iowa to hold an instrument rating, enjoyed flying their planes back and forth between Iowa and Colorado.

I distinctly remember, though, my mother telling me that Nana was the first female instrument-rated pilot west of the Mississippi River.

That memory is the only basis I have for thinking the achievement might have been more than 'first in Iowa'. Unfortunately, Mom died a few years ago and no one else in the family remembers anything bigger than the state of Iowa for the claim.

So, I'm curious. How can I read her pilot certifications from the 60s, possibly earlier?

The sub-question here has been answered to my satisfaction. The "west of the Mississippi" memory is nothing.

next day: I found a newspaper clipping from The Carroll Daily Times Herald, 19 June 1965, showing that she landed in Carroll, Iowa that week. Apparently all landings at the Carroll airfield made the paper. Amusing.

Here's an undated photo from the website of my cousin, Maribeth:

Perhaps there's a clue in the picture to date the plane? I have no idea which came first, the Piper Cherokee or the Cessna. @reirab points out in comments that people without an aviation background often call small planes Cessnas and the fact that Cessna is misspelled on the picture certainly supports the idea that it was done by someone without said aviation background. This could be the Piper Cherokee?


texts: Why do cockpits with ACARS have printers?

texts:
Most cockpits with ACARS have a thermal printer that is used for printing out information received.  Why is this information printed out rather than displayed on a scrolling computer screen?  Maybe I'm not used to ACARS or too used to 21st century technology where all messages and documents are on a screen, but it seems like the flight plan, maintenance, and weather information transmitted over ACARS could be saved and read off a screen as easily as a piece of paper.
What are the advantages of having a printer in the cockpit for ACARS and other systems, and is this technology being replaced at all in modern glass cockpits?

Edit:  As originally written this question didn't address other information that could be printed by advanced printers like charts and weather maps, but if you feel this is a relevant detail, you can include other systems other than ACARS in your answer.


texts: How do I pick the right ATC channel to listen to my flight?

texts: I'm trying to listen to my flight's ATC communications (flying United out of SFO). What is the difference between ramp, ground, and departure channels? Ground and departure have multiple frequencies, so I'm wondering which ones I should listen to for my flight?


texts: What is the correct holding altitude for the missed approach at Unalaska (PADU)?

texts:
On this approach plate, the holding pattern shown is depicted for a missed approach:

However, in the notes, it says to

  Descend to 6000 in holding pattern.

even though you should only climb to 4700 feet, according to the missed approach procedure:

  Climb to 3000 via 166° bearing then climbing left turn to 4700 direct DUT NDB/DME and hold.

What does the note actually mean (especially since it seems to be implying you would be higher than 6000 on the missed approach procedure)?


texts: How does one train for making landings and takeoffs in bad weather?

texts:
I thought of this while coming in on a bumpy flight into Memphis, TN. The pilot of the airliner brought in the aircraft nicely, despite having to fight it quite a bit during the slowest portion of the approach. Now, Memphis is fairly flat, and the airport isn't near any large buildings so this isn't too much of a problem, but how do pilots practice bad weather approaches and takeoffs? It's kind of dicey to drop a newbie pilot into swirling bad weather, and I know as the aircraft gets smaller handling rough weather becomes harder. Is it done purely through simulators or do they use training flights where they intentionally fly during really rough weather? How does this training differ between general aviation and airline pilots?

I'd imagine flight simulators are good up to a point, but may not simulate all of the bad emergencies that could happen in bad weather (choppy crosswinds, hail, rain, lightning, etc.) so to train properly one would have to go up on training flights. However, I know that is very dangerous, and probably expensive, so it wouldn't be preferable. What platforms do current pilots use to get proficient at bad weather flying?


texts: Off-center fan in geared turbofan - does this exist?

texts: Has anyone ever heard of a geared turbofan in which the axis of rotation of the fan is offset from (i.e. not the same as) the axis of rotation of the turbine? In all the current geared turbofans I've encountered, the input shaft from the turbine to the gearbox is co-axial with the output shaft to the fan.


texts:
I am looking to create one of these graphs for a simple model I tested in a wind tunnel.

I have managed to define the lift coefficient and thus I've been able to create the parasitic drag line. The problem is that I am having issues with finding the correct formula to use for the induced drag. I have been looking a while now and the only formula's I have found had the induced drag increase with a higher velocity.

the problem i'm running into is that the formula i see around is

$D_i = \frac{L^2}{\frac{1}{2}\rho V^2   \pi b^2 \epsilon}$

this formula has Lift squared above the divider and lift itself is dependant on velocity so whenever I use that formula the graph I get is of one that increases with speed instead of decreases.

What I'm asking for is the correct formula to use here


texts: Dropping an object from really high, landing at 0 velocity due to 'free' reverse thrust

texts:
So a friend had an 'idea' where you could make an object land with 0 velocity.

Basically the idea is that you drop an object (like a rocket shape) from some altitude. To the object you attach fins (fixed propeller blades so to speak.) as it falls it starts rotating, due to the attached fins.

Now at some altitude above the ground you either:

1) You rotate the fins to get reverse 'thrust' (you don't really have thrust, but you would slow down rotation.)
2) Retract the fins and expand new ones that face the opposite way (so they counter spin)
3) something along those lines (like extending flaps)

Now one of the arguments he had as to why this works is because you could expand larger fins for the counter rotation, therefore getting more drag and generating more 'lift'.

It feels like you cannot do this, but I cannot give a (good enough) reasonable explanation as to why it would or would not work (I'm a noob in this area.) So let's ask the people in the know... that's you.

I would love to see some 'proof' more so than speculation.

Thank you in advance.


texts: How far away from the airport is the descent for approach and landing initiated?

texts: I am wondering if there is a rule-of-thumb formula for the speed, altitude and the distance from the airport that the descent for approach to land is initiated? I see airlines do it about 25 to 30 minutes before landing. When, say a King Air, TBM, etc.,...doing 275 Kts at 28,000 feet will start the decent for landing at a sea-level airport, barring unusual weather or traffic conditions?


texts: What are the role and responsibilities of "fleet captains"?

texts:
I understand that fleet captains are usually experienced airline captains that take over this management position and deal with training, staffing and administration of a particular aircraft type (or family). Can someone elaborate on the actual duties of fleet captains?

Besides the respective responsibilities, do they to a certain extent have directive authority over all pilots flying the respective aircraft types (like being their direct boss)?


texts: What is the difference between Flight Test and Test Flight?

texts:
What is the difference between Test Flight and Flight Test?
Are they the same thing or synonymous?


texts: When is a transponder required below class B airspace?

texts:
I just wanted to clear up questions I have about flying within the 30 mile veil of Class B. My understanding is that the Class B is the inverted wedding cake, having tiers as the airspace moves towards the center. If I remain outside of the published altitudes, yet within the 30 mile veil, am I required to have a Mode C transponder?

What are the requirements if I have no electrical system on my plane?


texts: What is the difference between SUA (Special Use Airspace) and FUA (Flexible Use Airspace)?

texts:
The EUROCONTROL Concept of the Flexible Use of Airspace (FUA) is that:

  an ASM concept currently applied in the ECAC area and based on the fundamental principle that airspace should no longer be designated as
  either pure civil or military airspace, but rather be considered as
  one continuum in which all airspace user requirements have to be
  accommodated
  an airspace management concept applied in the European Civil Aviation Conference area on the basis of the “Airspace management
  handbook for the application of the concept of the flexible use of
  airspace” issued by Eurocontrol

EUROCONTROL also defines Special Use Airspace (SUA) as:

  Airspace of defined dimensions identified by an area on the surface of
  the earth wherein activities must be confined because of their nature
  and/or wherein limitations may be imposed upon aircraft operations
  that are not a part of those activities.

Question: what is the relationship exists between SUA and FUA? Can they be considered as the same thing? Is SUA a special type of FUA or vice-versa?
What is the difference essentially?


texts: May an A330 depart with with empty outer fuel tanks?

texts:
Airbus does not recommend flying with empty outer tanks, to reduce stress on the wings. Also, when the outer tank transfer valve is inoperative, the MEL says to fill the outer tanks with fuel and it will all be unusable during flight.

Otherwise, I couldn't find a specific restriction anywhere about departing with empty outer tanks. Is it acceptable or not?


texts: Has anyone built a paragliding simulator?

texts:
I am searching for a manual on how to build a paragliding simulator, where you can practice controlling the paraglider. My idea of the project is that you sit in a paraglider seat and you can experience the behaviour of the seat in a flight.

If you have any references to already built projects, it would be awesome.


texts:
I wonder what is exactly different between HIR and DIR?
What is different between HIR (Hold Items Record) and DIR (Deferred Items Record)?


texts: Would a laser dazzler be militarily useful?

texts:
I saw Why don't combat aircraft have rear-facing *laser* weapons? pop up in the Hot Questions list and that motivated me to join here and ask this question.

Weapons that blind are banned. But what if they merely dazzle?

I'm imagining a little box with a laser pen in it - like those that so trouble landing pilots when wielded by foolish people on the ground. The box can point the laser around the sky and switch it on or off. It's a relatively cheap unit. It's probably controlled from an air defence computer that is looking at radar, IFF etc, that tells it where to point. If a hostile aircraft arrives, dazzle it.

Of course, the first thing the hostile aircraft will do is shoot up the box. (So you wouldn't want to be a human defender pointing a laser pen.) But if the boxes are cheap enough, you could scatter a hundred or so around any base you were trying to defend, and target an attacker with just one box at a time. When it gets blown up, use another box.

Without fancy radar, IFF etc (you may have no aircraft so you want to dazzle all of them) you could put a camera and image recogniser in each box.

If it all goes wrong and points at a friendly aircraft or even a human on the ground, probably no harm will come. But it seems it would make it much harder for an aircraft flown by a human to attack a target. It could work against drones, too, even relatively high-flying ones.

Would it work?

Would such a system be legal? Practical? Has anyone deployed one? Is anyone working on one?


texts: What are the meanings of various reference lines and sections in a take-off distance graph?

texts:
I am trying to solve a numerical problem related to determining take-off roll using a take-off distance graph. The parameters are Temp: 90F, Press. alt: 2000ft, wt: 2500lbs, headwind: 20 Knots. I got the following graph (solid red lines):

My questions/clarifications are as follows:

It looks like the first reference line is the "density altitude", correct?
Looks like the second section of the graph is a relationship between aircraft weight and take-off roll (where take-off roll distances are represented vertically on the second reference) at various density altitudes. This seems to make sense because for a certain weight, if I go up, meaning I intercept higher density altitudes, the take-off roll increases.
It is not very clear to me the plotting of the diagonal lines. The way I understood it is that they go from the point of interception of the reference line to a point on the vertical weight line which is midway between the inclined curves intercepting that vertical weight line.


texts: What role does this ground crew member fulfill?

texts:
At the Miramar airshow a couple of weeks ago I noticed that in addition to the crew chief of each Blue Angel there was one additional individual standing behind the crew chiefs between aircraft #3 and #4:

What role does that individual fulfill?


texts: Did Concorde's sonic booms affect other air traffic?

texts:
Given that Concorde's sonic boom reached the ground, it also must have reached other nearby air traffic.

How was this dealt with? I imagine passengers would not welcome hearing a loud boom during their flight.


texts: In aircraft construction, what is the difference between a firewall and a bulkhead?

texts: I'd like to know the difference between a firewall and a bulkhead.  They both separate segments of an aircraft, so how are they different as it pertains to their design and purpose in aircraft construction?


texts: Can I save money on becoming a helicopter pilot in the US if I do flight hours in Mexico?

texts:
Flight hours costs approximately $285 per hour. Below is a screenshot from a local (Newport Beach, CA) school regarding what it takes to become a private pilot.

So I was hoping that maybe there might be a school in a local country like Mexico where I could do that for less money. If so, are there any things that I need to take into consideration. Or how do I make sure that those hours will be applicable to my license to be able to fly in the US?


texts: What are the recent developments in the satellite-based tracking of aircraft?

texts:
I find it pretty unsettling that in 2016 it is still not possible to track transoceanic flights using flightradar24 or flightaware, because of lack of coverage.

When the unfortunate MH370 accident occurred, I stumbled upon news of the British company Inmarsat launching, or discussing the launch of, a series of satellites to help track transoceanic flights anywhere in the World, that could also be useful to determine vertical separation.

Quite a few months have passed and I seem to have lost track of this. So I am here to ask those who know more about it:

what are the recent developments in the satellite-based tracking of aircraft?


texts: When you throw a paper airplane, it flies for a couple of seconds before losing speed and stalling. With a glider, it has a very long wingspan, but you take off with another plane or winch tow pulling it and then it is released on its own. Shouldn't the glider lose all speed and stall?


texts: What is the purpose of these labels on an aircraft's wings?

texts:
During a flight on an Airbus neo I was looking at the wing on my left, and noticed a set of labels on it. A few can be seen in the below image:

(The third one on the right is not readable, I was focusing on capturing something else.)

After a bit of working on it I think I found part of the pattern, with letters starting from A in the front of the engine and going B, C, D, etc. while moving farther from the front, and R, L and T standing for Right, Left and Top.

Now, while building a Lego plane set it could absolutely make sense, or maybe if you buy a plane from IKEA... But why on a real life aircraft? Just for something like visual inspection after build?


texts: How to interpret the N and R sections in SNOWTAM

texts:
I am trying to decode this snowtam for 2 days now and I followed this Snowtam Guideline.

So N is taxiway state and multiple taxiway states can be combined. R is apron state and multiple apron states can be combined. But in the example below, I cannot see how it makes sense. For example in R, are 1,2,3,4,6,7,East,North all apron names?

SWES0698 ESSB 12261815 COR
(SNOWTAM 0698
A) ESSB
B) 12261815 C) 12 F) 1/1/1 G) XX/XX/XX H) 5/5/5
N) G1 R S T Y Y1 Y2 Y3 Y4 Y5 YU YW/1/GOOD.
R) 1 2 3 4 6 7 EAST NORTH/1/GOOD
T) RWY 12 BA 67/72/67. RWY 12 COVER 100 PERCENT. APRON SANDED.)
CREATED: 26 DEC 2019 18:32:00
SOURCE: EUECYIYN


texts:
There is a question related to this one right here but I'm more interested in the danger of those vortices. Are they very dangerous to cause a wake turbulence for the aircraft that  comes behind this? Can it cause an accident or so?

Source


texts: What is the regulatory landing distance for turboprops under FAR 121-135?

texts: Flying a FAR part 25, N registered turboprop, within couterminous FAA airspace, under FAR parts 121 & 135 operating rules and performance wise, what are the requirements regarding computation of a suitable runway length as a function of airplane weight and runway surface conditions?


texts: Can ATC terminate flight following AND approve (arbitrary) frequency change while still inside Class C airspace?

texts:
Unusual (for me) event inside Class C. Can ATC terminate flight following inside Class C and approve frequency change.

Background: Requested and received VFR FF at 6500 msl prior to approaching ONT Class C (top is at 5000). Intent was to over-fly ONT and not enter Class C, however after reaching north of the field, ATC said “free to descend altitude at your descretion ” (Point A). My response, “6500 ft decending to 4500”. At about point B, I dropped into Class C and continued to 4500. After leveling off, still in Class C, ATC said “Squawk VFR, frequency change approved.” I responded “Squawking VFR, and immediately departing Class C to the North”. (Point C) His response, “You don’t have to do that as the tower still has you on radar.” I said “departing Class C to the north”

Here is my confusion: First squawking VFR is not an issue, I’ll squawk whatever is requested and maintain my own flight separation but when he said “frequency change approved” I would no longer  be in radio contact in Class C if I actually did as approved. This would mean, to me, I am illegally in their airspace.  What am I missing???


texts: Could this helicopter's body be a flying wing?

texts:
This question: Could a helicopter fly like a plane this way? asks if a helicopter can turn sideways using additional wings to tip forward to allow the rotor blades to act as a propeller. The tail-setter and other types of planes came up as answers. Similar to the tile Setter their first function of this aircraft would it be to hover then to fly as a plane.

Would this model helicopter with a body shaped of a flying wing be able to fly at a 90 degree angle and at a 90 degree twist transferring lift from the rotor blades to the body?

I have sketched out a picture below on how on might and apologize for imperfections. The body could be longer to create more wing span.

The pilot would need a special seat or controls to adjust for tilt but they would enter it like a normal helicopter. Could this model fly, keep maneuverability and feel of a helicopter foremost?

The pilot would only need to dive Rotor head first to allow the body to serve as a wing.


texts: Details about video equipment used to help assemble X-59?

texts:
On 2020 Dec 14 NASA reported
on Lockheed Martin's construction of the X-59.
The report's photos include an unexplained apparatus, comprising what looks like
two Panasonic video projectors and two video cameras mounted on a stand.

Green markings
on a wing being assembled, and on one of the worker's arms, may be coming from these projectors.
The stand might be mobile, because it's missing in this overview.
Any authoritative details are welcome, such as:
Does this apparatus have a name?
If it guides workers, how do they use it?
What are its capabilities and limitations?
What are the cameras for?
Why does it need more than one projector and camera?


texts: How does the in flight entertainment system works?

texts:
I board an aircraft, wait for it to takeoff, then find the headphones somewhere near my seat plug them into the two-pin point, and it works! But, how does it works for hundreds of other passengers simultaneously? Where is all the content stored, how are the screens connected to it, and how powerful is the computer controlling so many screens? Also, why is IFE required to be connected to aircraft's main computing system, which may eventually lead to the hacking of an aircraft?

Side Question : On an average, what is the size of content stored in a typical In-flight entertainment system?


texts: What would be the expected approximate ROD when descending at 250 kt IAS using LVL CHG at 10,000 ft, assuming a GW of 60t?

texts: The question refers to a B737NG but I suppose most similarly sized airliners would show a similar ROD under the circumstances.


texts: Is it bad for the engine to perform a touch & go?

texts:
I just watched a video about the traffic pattern. In the comment section below, the uploader spoke about touch & go's:

I don't like to do touch and go's, as a student pilot I used to do them cause you saved money, but its not worth it. Always better to get off the runway, let the engine stabilize**, and then set up properly for the next flight/takeoff.
** by stabilize I mean let the engine warm up under its own power on the ground, because the engine was just at idle or low power for a while during a landing, with the air flow turning the prop and cooling it, and abrupt power-up for a takeoff can "shock" it, that is when usually engines fail.
Dont get me wrong, I'll do a go-around in a second and engines are tough and this does not happen often, but the bigger the engine, the less you want to do that. Some flight schools even forbid touch & go's now.

By GVad The Pilot. Video Link.

Is it really bad to make touch & go's for the engine?
Do some flight schools really forbid touch & go's?
Are his concerns reasonable?


texts: so I finished my ATPL exams in July 2019 and started in April 2018 . I just want to know in EASA when do my atpls expire ?


texts: How can I deal with insurance requirements for flight hours and training in order to carry passengers?

texts:
I just completed a helicopter rating and was excited to take friends for a ride in the R22 and R44. Then I learned that my flight school's insurance requires a total of 100 hours in helicopters and attendance of a 4-day course at Robinson in California to allow for taking guests. Are there alternative ways to make it legal to take friends for a flight without having to meet these requirements? E.g. can I buy insurance elsewhere?
Thanks!


texts: Is it true that the red lights on building antennas help the aircraft "detect/visualize" ground objects?

texts:
I was thinking that red lights on the antennas on buildings help aircraft to see if there are tall objects in the ground. Is this right?

Source


texts: Why is the relation of height and temperature different when calculating altitude?

texts:
I'm trying to grasp the essence of altitude calculations. One thing I can't figure out in my head is this:

In the International Standard Atmosphere (ISA) the temperature of the air decreases with the altitude, which is called the lapse rate. This is an approximate of 1.98 C (degrees Celsius) or an even more approximate 2 C per 1000 feet. This is usually described through dry adiabatic lapse which means simply that when you go up the pressure rises and the air expands thus through the ideal gas equation it makes sense for the temperature to drop as well.

However when calculating the density altitude we need to "correct" the pressure altitude with this formula:

DA = PA + (118.8 ft/C) x (OAT - ISA temperature)

(from https://en.wikipedia.org/wiki/Density_altitude#Calculation)
Here the height change per degree Celsius is only 118.8 feet (approx 120 ft).

My question is this: Why is the relation of (change rate) height and temperature different? With just "going up" it changes 2 C / 1000 feet (ie 500 ft/C) but when adjusting for temperature it changes 120 ft/C).

These both are simple linear equations but have different coefficients.


texts: Can a lightning strike lead to structural damages of the fuselage and eventually cause decompression?

texts: I know that modern aircraft are designed to withstand lightning strikes. Still is there a possibility for aircraft to sustain significant damages of the fuselage due to lightning strikes and subsequently face decompression?


texts: Do employers prefer to hire younger pilots?

texts: Do companies, regardless of country, tend to shy away from hiring older low-hour pilots? "Older" meaning mid-30s to early 40s.


texts: Why do Dassault Falcons only have one thrust reverser?

texts: Using all 3 engines would slow it down much faster. No?


texts: Why are Inline Engines more commonly used than Radial Engines?

texts:
Back in the early days of aviation radial engines were very popular, it seemed like all of the big planes of the 20s, 30s and early 40s used them.  But some time during WWII (or so it seems to me) aircraft manufacturers switched from radial engines over to inline engines.

Why was there a switch?  Why do modern manufacturers rarely, if ever, use radial engines?

Example of a Radial Engine for those who are unfamiliar:


texts: Heaviest Boeing vs Airbus aircraft: Why large (150 ton) difference in Weights?

texts:
An aircraft tug manufacturer's website had this interesting table:

Just curious, why the heaviest Airbus is a good 150 tons heavier than the heaviest Boeing? Otherwise, these two rivals have close competing aircraft for most specs.

I mean, how do the rivals end up with such different operating points. Obviously, I don't mean its an apples to apples comparison (different payloads) but what I mean is whatever market segment it was that Airbus was trying to serve with an A380, did Boeing not find that an interesting segment? Is this a strategic difference in a large plane / smaller plane sense?


texts: Is it possible to start another engine of Mil Mi 8 with one engine started and APU off?

texts:
In the 737NG, it is possible to start the other engine without APU if one engine is already started, by routing air from the started engine to the other one.

Is this possible in the Mil Mi 8 helicopter?


texts:
Why is the sideslip angle, $\beta$, defined as

$$\beta=sin^{-1}\left(\frac{v}{|{\bf v}|} \right)$$

and not the same as freestream azimuth angle $\psi$

$$\psi=tan^{-1}\left(\frac{v}{u} \right)$$

where ${\bf v}=u \hat {\bf b}_x+v \hat {\bf b}_y+w \hat {\bf b}_z$ is the airspeed of the aircraft in body coordinates, $\hat {\bf b}$, and $|\cdot|$ is euclidean norm of $\bf v$. $\psi$ can be interpreted as the angle between $\hat {\bf b}_x$ and the projection of $\bf v$ onto the bodies $x$-$y$ plane. What is the physical interpretation of $\beta$?

Thanks in advance!


texts: After the most recent US instructions, are there any prohibitions against transporting spare lithium ion/metal batteries in the cabin?

texts:
Per the recent directive from Transportation Security Administration (TSA), except for medical devices, electronic devices which are larger than a cell phone/smart phone cannot be carried in the cabin of the aircraft from some countries into the United States. Many airlines are implementing this instruction and are requesting that all passengers traveling to the United States pack all electronic devices larger than a smart phone in their checked-in baggage.

The ICAO, IATA & FAA have already prohibited carrying spare lithium ion and/or lithium metal batteries in the aircraft hold area.

Is the transportation of spare lithium ion and/or lithium metal batteries in the passenger cabin of the aircraft now prohibited? Is it considered a rule violation to carry spare batteries this way?

Where can the spare lithium ion and/or lithium metal batteries be stowed during the prohibition period and how can they be transported?


texts: Can a company without an AOC hire out pilots to another company that does have one?

texts:
Is it legal for a company that does not hold an Air Operator Certificate (AOC) (company A) to hire out a pilot a second company that does have an AOC (company B)? Company B would be the one actually carrying out the aerial operations.
Would this be considered a franchise arrangement?
Edit: Company B knows about a pilot who is a sole director/owner of company A (no other employees). Company B came to company A to have the pilot fly the plane for company B's operations/contract with a third party (their pilot was unavailable).


texts: Is interfering with the "go/no-go" decisionmaking of a flight crew a violation of 14 CFR 91.11?

texts:
ASRS Callback #216 tells the sordid tale of a pilot who was inappropriately intimidated by an armed guard at a public-use airport into performing an unsafe and illegal flight after landing there for an unplanned overnight stay and fuel stop:

I estimated that we had just under one hour of fuel remaining, and as it was getting dark and I was completely unfamiliar with the mountainous terrain, I decided not to fly on. I landed at ABC, a public-use airport. The only telephone available connected us to the lodge, which also operated the FBO. We told the desk clerk that we could simply camp overnight and buy fuel in the morning. The desk clerk said OK. We parked on a corner of the ramp, pitched a tent under the wing, and went to sleep.
Around midnight, we were awakened by an armed man in a "Special Police" uniform, who declared, "Leave immediately or I will arrest you for trespassing and you will spend the night in jail." We told him everything noted above, but he was adamant: leave or spend the night in jail.
I estimated that I had enough fuel to make it, although certainly not enough for legal night VFR flight. Faced with the alternative of going to jail, I decided to depart. It was a pitch black, moonless night. Although clear and with about 10 miles visibility, there were no lights visible and there was no discernible horizon. I climbed above the MOCA, flew on instruments for about 20 miles to the nearest airport, and landed. The FBO there pumped 21.6 gallons of fuel into my tanks, which have 22.5 gallons usable.
My mistake was in allowing myself to be forced, even by an armed guard, into making a flight which was against my better judgement, probably beyond my capabilities, unsafe, and illegal. It was only luck that it turned out all right.
I was able to reach the manager of the FBO later. He said that the "special police" had no authority to order a pilot to take off from the airport and that he would make certain the police knew this in the future so they would never do this to another pilot.

While this behavior from any sort of airport security personnel is beyond the pale and the FBO manager's response to hearing about it is absolutely correct -- the incident raises a burning question in light of 14 CFR 91.11:

No person may assault, threaten, intimidate, or interfere with a crewmember in the performance of the crewmember's duties aboard an aircraft being operated.

Is intimidating or threatening a pilot into taking off (vs staying put) considered a 91.11 violation by the thug, considering that the "go/no-go" decision is one of the most safety-critical decisions a pilot makes when preparing for a flight?


texts: Can an instructor sign off for my check ride if I didn't fly with him since a year?

texts:
I am at the end of my training as a student pilot with an overkill amount of flying hours, but I had a couple of complications in the way.

I flew with my old instructor (instructor A) for about 3 years, and he signed me off for everything but the check ride.
When it was time for me to go to college, I had to find a new instructor (instructor B) and we trained for about a year until he decided it was about time I go for the check ride. Sadly our plane had engine issues and I had to cancel my check ride.
So I had to go back home to my old instructor (instructor A) who I haven't flown with for about a year. The last time we flew, he also said I was ready for the check ride, but that was about one year ago.

My question is this: Can my hometown instructor (instructor A) sign my off for my check ride even though I haven't flown with him in a year?

I stayed current with my flying and I even flew the same type of plane (One was a Cessna 172n and the other was a Cessna 172m).


texts: At what Mach Number do variable cycle engines (VCEs) start showing benefits over turbofans?

texts:
Currently, most supersonic engines engines are low bypass turbofans. However turbofans start becoming infeasible as the mach number increases. Variable Cycle Engines, still have noise and weight issues but are purported to give significant improvements in spillage, airflow matching and mixed mission cycle efficiency.

I wanted to know what is the lowest mach number (roughly) at which the benefits of the VCE's attributes are purported to give it an advantage over turbofans.

I'm mostly interested in benefits in specific fuel consumption thrust, spillage and matching losses etc. and am not that worried about the noise, weight and complexity problems (though useful information regarding this is appreciated).

most literature regarding this that I found were from the 1960's to the 80's so links to newer resources, literature, etc. are appreciated


texts: Is it permitted to land amphibian plane in the ocean on Californian coast?

texts:
Given the length of the Californian coast, I was surprised to find so few seaplane services.  I would expect air taxis between Long Beach and the coast, for example.

Is it permitted to land seaplanes along the coast at, say, Zuma Beach geo://34.016286,-118.820402 and do whatever local boats do for mooring?

  In California, for example, you will not need to obtain certification of either a landing area or mooring area. Seaplane Pilots Association

There appear to be very few seaplane bases in California. Seaplanebase only lists five.


texts: How do you calculate indicated airspeed on a flight plan?

texts:
I'm planning my cross country journey for my flight test and it seems I forgot how to calculate my indicated airspeed.

The indicated airspeed must be from the POH, right?
The the true airspeed is from the IAS and TAS correction table in the POH?
Then the ground speed is based on TAS, with the wind factored in?

I'm flying a mid-late 70s Cessna 172 skyhawk.


texts: What is the method to calculate a finite wing's lift from its sectional airfoil shape?

texts:
I am struggling to get my head around a concept that I believe should be fairly simple to understand.

Lift versus drag and AoA data of many airfoils are freely available, for instance the NACA 4-digit airfoils.

The data is that of sectional, or 2D, lift and drag, or $C_l$ and $C_d$.

Now, if I were to build a 3D finite wing using a certain airfoil, how would I go about calculating the 3D coefficient of lift $C_L$?

I know that the aspect ratio $AR$ and Oswald efficiency factor $e$ come into play and that $C_D<C_d$ because of 3D effects such as tip leakage.

As an example, let's look at the NACA2412 airfoil: At $\alpha=8$ and at $Re=5.7e6$, it experiences $C_l=1$.

If I now manufacture a wing of $AR=7$ which has a planform giving an efficiency $e=0.8$, how would I go about calculating $C_L$?

Are there any exact methods to calculate this or perhaps approximations?


texts: Is there a global map of aviation waypoints?

texts: Is there such a map or database available to the public?


texts: Is it possible to drive into Gibraltar Airport's runway?

texts:
The runway of Gibraltar Airport crosses an active 4 lane highway

Example Video.
My question is are there any security measures which prevent normal traffic from entering the airport through the runway when the runway is not in use?
How much security risk does such a runway intersecting with a civilian road entail?
Edit: To make the situation more realistic, assume that some very hostile elements are heading towards the airport, and maybe they need only 5 minutes to throw a grenade at an aircraft, or open fire or cause some other similar destruction.
I am specifically looking at how fast would the response of airport security at Gibraltar Airport would be in such a situation, especially given that it's a small airport with only around 15 departures a day. And simply if there are any measures to prevent normal traffic from entering the airport boundary in the first place?


texts:
Does Rolls Royce produce any engine that matches the capabilities of the GE9x?

If not, does Rolls Royce have any public plans for such an engine in the future?


texts: Is there any FAA Regulation who may wash a private aircraft such as Cessna Skyhawk or Citation?

texts: Should it be mandatory to hire a mechanic? or someone else with any kind of FAA license? or could anyone wash one?


texts: Is it legal and safe to take off or land in zero visibility?

texts: Is it legal for planes to takeoff and land in zero visibility? Is it safe?


texts: Does FAR 91.155c apply to class E surface extensions?

texts:
Federal Aviation Regulation (FAR) 91.155 says under (c):

  Except as provided in §91.157, no person may operate an aircraft
  beneath the ceiling under Visual Flight Rules (VFR) within the lateral
  boundaries of controlled airspace designated to the surface for an
  airport when the ceiling is less than 1,000 feet.

Does this regulation apply to class E surface extensions to class D airspace?

For example the class E extensions at KSTS. Specifically, suppose the ceiling is 900ft (agl) in this class E extension and vis is 10 nm. As a VFR helicopter, can I fly through this airspace at 400ft (agl) (3 -  5/1/2 being met)


texts: Is there a GPWS volume control in the audio control panel for the B737?

texts: So, I was sitting in the front rows of an A320 and could obviously hear the AP disconnect. But I could not hear the GPWS altitude and RETARD callouts. I assume this is because the pilots set the GPWS to their headsets instead of speakers in the ACP. Is there a system on the 737NG?


texts: How many emergency/abnormal checklists are there for a typical airliner?

texts:
(Related to, but hopefully not a dupe of, this question)

The latest NASA ASRS newsletter includes the case of an A320 crew that forgot to retract the gear and started detailed troubleshooting without noticing that the gear was still down. The captain said in his report that:

  I instructed the First Officer to coordinate landing at the divert
  airport while I briefed the Lead Flight Attendant and then performed
  the Airframe Vibration Checklist

The mention of an airframe vibration checklist caught my attention because it's such a specific scenario. So, excluding normal operations, how many checklists does a typical airliner (like the A320) have for unusual/abnormal/emergency scenarios?


texts: What is the difference between SUA and SAA?

texts:
I would like to understand the difference between Special Use Airspace (SUA) and Special Activity Airspace (SAA). I found the following definitions.

Eurocontrol Lexicon for SUA (from FAA):

  Airspace of defined dimensions identified by an area on the surface of
  the earth wherein activities must be confined because of their nature
  and/or wherein limitations may be imposed upon aircraft operations
  that are not a part of those activities.

Eurocontrol Lexicon for SAA (from FAA):

  [U.S.] Any airspace with defined dimensions within the National
  Airspace System wherein limitations may be imposed upon aircraft
  operations. This airspace may be restricted areas, prohibited areas,
  military operations areas, air ATC assigned airspace, and any other
  designated airspace areas.

Can you please help me to understand what the difference is?


texts: What is the purpose of having contra-rotating props on an aircraft?

texts:
Why do planes, like the famous XF-11 and the Tu-95, have contra-rotating props? What is their purpose?

Image credit: Mike Freer / Touchdown-Aviation / Wikimedia


texts:
Related to the answer of the following question:

How are evolution and variants of aircraft considered by certification authorities?

Are the terms "Aircraft Version" and "Aircraft Variant" synonyms? The answer uses the term "Aircraft Variant" but I have also come across "Aircraft Version" elsewhere.


texts: Why hasn’t the Wankel rotary engine seen more use in aircraft?

texts: The Wankel rotary engine seems to have several advantages over traditional reciprocating cylinder-and-piston designs. In general, they have a much higher power-to-weight ratio, less vibration, and drastically reduced rate of catastrophic failure, among many other benefits. I can only find disadvantages related to emissions and fuel efficiency. So my question is, why hasn’t it seen more use in aviation even though it seems very well suited to this application?


texts: Why are thermal switches connected in parallel to each others?

texts: Why are thermal switches fire detection system connected in parallel to each others?


texts: What is "scintillation" and are "qualified pilots" aware of it?

texts:
This answer to Has great eyesight been necessary for astronomers? mentions Astronomer Jocelyn Bell Burnell's recounting of a likely first visual observation of a pulsar. This can be found for example in Nature's Air force had early warning of pulsars

Wikipedia's Crab Pulsar includes this passage:

  Jocelyn Bell Burnell, who co-discovered the first pulsar PSR B1919+21 in 1967, relates that in the late 1950s a woman viewed the Crab Nebula source at the University of Chicago's telescope, then open to the public, and noted that it appeared to be flashing. The astronomer she spoke to, Elliot Moore, disregarded the effect as scintillation, despite the woman's protestation that as a qualified pilot she understood scintillation and this was something else. Bell Burnell notes that the 30 Hz frequency of the Crab Nebula optical pulsar is difficult for many people to see.

Question: What might "scintillation" be in this context, and are "qualified pilots" generally aware of it?


texts: Is this frost or frozen bacteria in clouds?

texts:
I was recently flying back from Palma de Mallorca Airport (PMI) to Birmingham Airport (BHX/EGBB) and I had the luxury of sitting at a window seat behind the wing. I think the plane was a Boeing 737-800 via Jet2.

Halfway though the flight I was looking out the window and noticed little specks on the outer window and was trying to work out if it was frozen water or frozen bacteria from the clouds?

Does anyone know what this is or how it forms? Does this happen to the pilot windows also?


texts: Why is the alternator connected only to one electrical bus in the C152?

texts: I am a noob in electrics so pardon my ignorance. What I see from an electrical system of C152 (pasted below): there are two busses, connected to each other, but alternator is fed only to the first bus. Does it mean that each component connected to the second bus takes energy from the battery and due to that battery is constatly discharging and alternator must additionally load the battery? If that is true (correct me if I'm wrong please) why don't connect alternator to both busses?


texts: What Oil thickness is used for the geared turbofan jet engine gearbox

texts: In light of the huge operating speed of the geared tubofan gearbox gearing down the fan speed, what Oil thickness is used for the geared turbofan jet engine gearbox and does it use use regular gearbox oil used in cars and trucks, also in light of the huge difference in operating speeds of these gearboxes?


texts: What type of airspace is an Atlantic Low Control Area?

texts:
Could someone explain what the blue zipper line 'Atlantic Low Control Area' is in the images below?

What type of airspace is this? How far off the coast does it start? Would it still be G to 1200 and E to 18000 in this area? Is this related to a Warning area which begins 12 NM off the coast? Why are there two parallel lines? I'm not really sure what questions to ask about it but I want to understand it well enough to be able to explain it in a check ride.


texts: Could a Dyson fan displace more air without increasing the fan size?

texts: So the Dyson Fan is cool. But it has a thrust to weight ration of 0.6. Not very efficient for flight. Its great at sucking large amounts of air but not at a very high velocity. Thrust is small amounts of air at high speed correct me if I'm wrong. Is there any way to get the Dyson Fan to blow air at a faster speed without increasing the size of the fan.


texts: Why do newer 737s use two different styles of split winglets?

texts:
All new 737s use split-tip winglets, which are more efficient than the simpler blended winglets previously used.

However, for no clear reason, they use two different types of split-tip winglet:

New 737 Next Generations (the 737-700/-800/-900)1 use split-scimitar winglets, which have a main body shaped like a blended winglet, but with its upper tip hooked backwards, and also have an additional scimitar-shaped fin projecting outwards and backwards from the upbend in the winglet.

(Image by Mnts at Wikimedia Commons.)

The 737 MAX series uses the eponymous MAX winglets, which have a simpler shape than the split-scimitar winglet, looking essentially like if someone decided to put a winglet on the bottom of the wingtip in addition to the one at the top.

(Image by Aka The Beav at Flickr, via Helmy oved at Wikimedia Commons, modified by Altair78 at Wikimedia Commons.)

I don’t get it - why go to the trouble of producing two slightly different styles of winglet alongside each other for two mostly-similar families of the same aircraft?  Why not just go with the more efficient style of the two (be it the split-scimitar winglet or the MAX winglet), and use that on both the Next Generation and the MAX?

1: The 737-600 also belongs to the Next Generation family, but it left production long before the Next Generations switched from the blended to the split-scimitar winglet.


texts: Do Airbus aircraft have an "off" position for their landing gear?

texts: I know some Boeing aircraft feature an up, down, and "off" position for their landing gear lever. I know that some Boeing wide-body jets do not have a 3rd lever position, but still have an "automatic" "off" setting that takes effect after a time-delay (which begins when the gear comes up). Do airbus, bombardier, embraer, etc. have a 3rd gear lever position in any of their aircraft? If not, do they have an "automatic" off setting?


texts: Is there any evidence that the downwash vortices impact the performance of a wing?

texts: Or is it merely flow separation on the upper surface towards the end of the wing? The assumption seems to be that the air "leaks" from under the wing to low pressure above with sufficient rapidity to overcome or offset the forward flight speed.


texts: Is it true that high-bypass engines are inherently inefficient at higher speeds?

texts:
Power consumption=Kinetic energy=$1/2mv^2$.
Thrust=momentum change=$mv$.

I keep being told that aircraft engines are most efficient when their exhaust velocity closely matches the freestream.

The second graph shows the propulsive efficiency vs exhaust/freestream velocity ratio

I can understand that higher bypass engines have greater intake losses than narrower ones. But the ratio of airspeed to exhaust speed being the defining factor, as opposed to the absolute difference?? I have only one way to justify this - as speed increases, mass flow rate through an engine of given cross sectional area also increases.

Research on propfans, and on supersonic through-flow turbofans calls into question the idea that lower bypass ALWAYS = higher high-speed efficiency. And the above equations don't help either.

What mistake am I making?


texts: Is a certificated pilot considered to be a student pilot when training in a new category or class?

texts:
Inspired by this question, is a pilot certificated in one category or class considered to be a student pilot when training in a new category or class?

To take a specific example, if a pilot holds a Private Pilot - Glider certificate and then decides to add ASEL, is he considered a Student Pilot while he's training for his ASEL? By "considered" I mean, do regulations that refer to "student pilot" apply to the pilot?

Or, to put it as simply as possible: what is the FAA's regulatory definition of "student pilot"?


texts: How do investigators always know the logged flight time of the pilots?

texts:
Almost all incident investigation reports include the flight experience of the both pilots with hour accuracy. For instance, for MH370 just a few small fragments of the plane have ever been found, yet the investigators know the captain had 18,365 hours of flying experience. How do they know?

From that I have seen on a web, a pilot logbook looks like an unprotected paper document, often unlikely to survive. Do pilots actually keep the book at home or in the office, or maybe someone else apart the pilots logs the flight hours?


texts: Why are F-15s usually taking off with afterburners?

texts:
If there's no emergency, is it a big waste of money for military aircraft to take-off with afterburners? Why are they doing it, what are the advantages?
Like here:


texts: What aerodynamic data (drag/lift curves) exists for the A-10?

texts:
This is one of 3 question in "series" - one question split up in 3 to better reward those responding about each aircraft. Other questions: Yak-131, L-159

A-10 is one 3 planes that are used in the ArmA 3 combat simulator, but its aerodynamics modelling currently lacks significantly. I'm planning on writing a short "essay" to developers regarding what and how can be specifically fixed in the flight model, but I'd like to back my research with some hard data. Specifically, I'm interested in any of the following:

L/AoA
D/AoA
Side lift/SA (Slide angle)
Max G/velocity
Flight envelopes (like one below for F-15):

Torques can well be left out - it's not a full fledged simulator, but the above data can give quite a good estimation of high level characteristics already.

Are there any good sources on any of the above data? I've found some (see below), but the quality leaves a lot to desire. Low-mach data is good enough for me.

I understand this is a tall order, but, well, SE is for expert answers - maybe a wonder happens and someone here has it? :)

What I've found so far:

Some superficial modelling of A-10
A-10 airfoil: NACA 6716 root, NACA 6713 tip
Set of A-10 documentation


texts: Can I log time in a Cri-Cri twin-engine aircraft?

texts:
I was looking at potential experimental projects when I read this fascinating website about a tiny aerobatic-capable twin-engine airplane. It's light enough to be an ultralight, but much too fast:

Aside from the obvious fun of flying this little plane, I wondered whether:

I'd be able to log time in the Cri-Cri as multi-time? My guess is yes.
Assuming I'm MEL-IFR, could I log multi-IFR with a two-way radio, altimeter, Dynon-type AI, HI and at least one cert. VOR & glide slope? An approach cert. GPS setup would be too heavy I assume. My guess is this is wishful thinking...


texts: Accelerated Stall, what is it, how do you prevent it?

texts:
I've read a lot of NTSB crash reports regarding small, GA aircraft (just trying to figure out what went wrong and what to avoid.)  There seem to be a lot of reports that talk about "low altitude high speed stalls" (accelerated stall) happening on approach.

What is an accelerated stall, and how is it created?  What is the best way to avoid one?  As they seem to cause a lot of GA accidents...


texts: Are there any ducted propeller or fans without a shaft in the centre?

texts: Are there any propeller or fan designs that hold the propeller or fan in the duct and do not have a boss or propeller shaft? This could reduce the drag of the  centre. Are there any other advantages?


texts: How do the air conditioning packs work for the CRJ 700/900?

texts: Please provide details on how the packs on the CRJ 700/900 work. How does the system use air from the packs to make cold air for the aircraft?


texts: Is a magnetic assisted takeoff feasible?

texts:
I have seen that there are many companies working toward hybrid electric aircraft. It is very exciting some of the ideas.
The primary reason seems to be for limiting CO2 emissions acceleration, especially during take off. In theme parks acceleration is often performed by powerful magnetic forces.
I was wondering if in the long run a powerful electro-magnetic system could pull planes, fitted into a track on runways for take off?


texts: Why is the quality of radio communication bad?

texts:
Why don't modern planes and ATC centers have good-quality audio for communication? For example in this video:

Or basically any other example of pilot communication(some are worse, some are better).

This is not terribly bad of course, but this is comparable to a cheap $4 headset, the sound is so distorted. This can cause trouble when a pilot does not understand some words and asks to repeat the sentence. And even more problems if the pilot or flight dispatcher are not native English speakers.

Is there some technical reason behind this, like antenna/signal limitations within the plane? The quality is the same when the pilot is just taxiing on the ground, so I suppose this has nothing to do with speed or altitude.

P.S. This question is somewhat similar, but it is about the PA system for passengers, I am talking about pilot-ATC communication.

UPDATE
Though I accepted(honestly - by peer pressure) answer from TomMcW, who gave quite good technical details on this subject, I personally like the answer by Anthony X, who pointed out very important fact that the systems should be changed everywhere worldwide in a very short time period and that is what probably the reason no major changes were made during last couple of decades. So I suggest to read his answer too, not only top-voted one.


texts: Do plug nozzles improve efficiency on lower throttle settings?

texts: Plug nozzles are used to adjust for the overexpansion/underexpansion of the exhaust with altitude. Do they also adjust for overexpansion/underexpansion of the exhaust caused by lowered mass flow experienced at lower throttle settings? Or does throttling not have an effect on the exhaust shape?


texts: Or is it just commercial aircraft? I was watching an episode of Scorpion where an "F-120 Firehawk" crashed and they looked at its black box. So, do normal, non-imaginary fighters have them?


texts:
I was reading about plane de-icing the other day, and someone posted a comment saying that was their job, and when no planes needed de-icing they just slept/waited in the de-icing truck.

I was looking just now at de-icing jobs, and found one at heathrow that said it was a permanent 40-hour/week job.

So what do they actually do during summer? Do they do a different job or do they just wait in case a random (unlikely) snow storm passes by?


texts: Why does this holding pattern have both minimum and maximum altitudes published?

texts:
Reference the VOR-A Approach to Stellar Airpark (P19), in Chandler, Arizona (shown below):
When JAROD INT is used for missed approach holding the published procedure calls for the aircraft to climb to 3900 feet.  The terminal transition from STANFIELD [TFD]  to JAROD is a NoPT route at 3900 feet (no holding/course reversal [unless approved by ATC]), and the terminal transition from PHOENIX [PXR] to JAROD is 4700 feet.
Why then is it necessary to publish a hold altitude of (Maximum) 6000 feet and (Minimum) 3900 feet at JAROD when anything other than 3900 feet (missed approach altitude) or 4700 feet ( would seemingly have to be assigned by ATC?
For perspective, I have annotated the position of JAROD and Stellar Airpark (P19) on the Phoenix Terminal Area Chart (IWA R-220, PXR R-150, TFD R-355) shown on the second image below.


texts: Is it possible for an airliner to safely fly with doors open?

texts:
From another question asks about the possibility of dropping bombs from converted airliners. My question: is it possible to safely fly aircraft with a door open for the whole flight envelope? Would the aerodynamics be affected if we did not close the door?

I am not asking about the need of oxygen for the crew, just about the aerodynamics involved. I know the plane would not be pressurized.