texts: What is common number of flight hours a year for an airline pilot?

texts:
Reading various reports including number of flight hours of the pilots I always wonder how it relates to years of service. In most professions, people work 40 hours a week, which gives around 1900 hours a year (assuming 4-5 weeks vacation as is usual in Europe). But pilots seem to have much fewer flight hours. I even read that in certain military operation the norm was 750 hours in a year. But that was difficult military operation and I haven't seen any number for common airline operations.

So how many flight hours is usual for full-time airline pilot to log in a year? And what does he do in the rest of his duty time? Or does he have less duty time than the usual 40 hours a week?


texts: Did any WWII aircraft only use a turbocharger but not a supercharger?

texts:
In doing some basic research, I have concluded that all WW II aircraft equipped with turbochargers also used mechanical driven centrifugal superchargers.

These include the P-38, P-47, B-17, B-24, B-29, etc.

Is this correct, and are there any exceptions where the engine lacked a mechanical supercharger and only used the turbocharger for boost?


texts: What is the meaning of the triangular markings in the A320 cabin?

texts: Travelling in a chartered A320 from Titan Airways. Does anyone know what these triangular markings mean? They can be seen on both sides of the cabin, a few rows before and after the emergency exits.


texts: Has a commercial passenger airliner ever had its cockpit fully upgraded?

texts:
In an earlier question What are the barriers to feasibility of stratospheric cruising for commercial air travel? (i.e. Concorde?) it was suggested that Concorde was not properly maintained as its analogue flight deck had never been upgraded.

Concorde production ceased in 1979. Fourteen Concordes saw commercial service. By end of operation in 2003 there were nine Concordes in use.

Excluding the military, has any airline or manufacturer ever retrofitted a new design of flight deck to an existing fleet of old commercial airliners?


texts: Do I have to do all exercises during a checkride, even if I did them in a previous one?

texts:
I am currently a private pilot with an instrument rating and multi-engine rating.  I own and regularly fly my own twin engine airplane and have been thinking about getting my commercial rating.  Part of the PTS requirements for the commercial multi-engine include the emergency procedures for engine out/emergency descents, etc.

Since I have already had a check ride (multi-engine rating) that included ALL of these maneuvers, do I still have to perform these on a commercial multi-engine check ride?


texts: What aircraft is in The Do’s music video?

texts:
There is a band call The Do, in one of their videos there is a plane with a strange configuration of turbines, it looks like a version of a 747.

You can find the video on Youtube "The Dø - Despair, Hangover & Ecstasy"

Does anyone know what plane it is?


texts: Has this type of "gyrocompass" ever been used in an aircraft?

texts:
One type of instrument commonly referred to as a "gyrocompass" is commonly used in ships.  It detects true north based on gyroscopic precession, and is not slaved to any magnetic compass or any magnetic sensor of any kind, nor is it necessary that the instrument be frequently manually corrected by reference to a magnetic compass.  Has this instrument ever been used in aircraft, and if so, what are some examples?

The intent of the question is to ask about specifically about instruments that benefit from an intrinsic north-finding property related to the earth's rotation, including cases where this property is used to correct for various errors that would otherwise eventually cause the system to drift out of its initial orientation.


texts: What are typical control surface deflection "rate" limits for transport airplanes?

texts:
I was wondering if anyone knows what are some typical control surface/actuator deflection "rate" limits for transport airplanes (i.e. aileron/elevator/rudder deflection rates)? I haven't found any useful information about the deflection rates yet.
Also, are there any ATR-42 500 manuals/references that give control surface deflection limits?
Thanks.


texts:
Does airflow at upper surface allways goes outward at sweept wings(which is opposite from flat wings)?
Airflow on lower surface also goes outward even more than on upper surface?
At 18° AoA airflow goes parallel to the wing!


texts: Is the longitudinal stability achieved the same for all aircrafts or does it differ?

texts: If there is a difference in longitudinal stability how are they achieved?


texts: Where can I find Take off and Landing Zones for GIS Integration?

texts:
I am a GIS specialist and looking to plot the take off and landing zones into major and minor airports across the UK. This is dominantly to see land affected by noise pollution from air traffic. If data exists for private airfields as well that will be a bonus.

High altitude flight paths data such as this website is not necessary as I simply require the bearing of take off and landing zones into airports to an altitude of ~3280 ft. The referenced website download file formats are not exactly GIS friendly and the option to batch download multiple files does not exist.

File formats I'm looking for are either shapefile, gpkg, kml (google earth) or GeoJSON and a batch download for all landing and take off zones will be desirable.


texts: Is the shear centre of a wing the same as its aerodynamic centre?

texts:
How can the shear centre of a wing be located and is it the same as the aerodynamic centre of a wing?

Lastly, I know how the centre of pressure interacts with the aerodynamic centre but not the wing's shear centre, so how does the centre of pressure relate to the shear centre of a wing during flight?


texts: Is there a common maintenance issue requiring filling a hole in the tail on the A321?

texts:
I was on a flight recently (AA 705) and a maintenance worker used a forklift to go on top of the plane shortly before the captain announced that we were going to have to wait at the gate for an extra 25 minutes while they filled a hole with putty near the tail of the plane. The aircraft was an A321.

Can anyone tell me what was wrong with the plane? The pilot said it was a common problem and part of routine maintenance. I am wondering if this is a maintenance issue that an A321 expert would immediately recognize as part of routine maintenance or a problem common to these aircraft.


texts: Why was the "Dispatch Reliability" of the A320 "low" during its first years?

texts:
I found the following Statement on the German Wikipedia page about the A320 family of aircrafts.

  Nach erheblichen Schwierigkeiten in den Anfangsjahren erreicht die A320-Familie mittlerweile eine Abflugzuverlässigkeit von 99,7 Prozent.
  (https://de.wikipedia.org/wiki/Airbus-A320-Familie#Wirtschaftliche_Aspekte)

This roughly translates to:

  After significant difficulties in its early years, the A320-family reaches a Dispatch Reliability of 99.7% nowadays.

I could not find more information about this statement, so my question would be why the Dispatch Reliability of said aircraft family was supposedly significantly lower in its early years? Is it normal for completely new types of aircraft to have such a low DR that it's worth mentioning?


texts: What is the difference between GVI and DVI?

texts:
In any maintenance program I found some terms like General Visual Inspection (GVI) or Detail Visual Inspection (DVI) or Detailed Inspection (DTI). I want to know the difference between these types of inspection.

And which type of inspection is required in which cases.


texts: With today's technology, why can't we find crashed planes

texts: How can a plane just go missing? It's mad surely with the technology these days they could at least pin point the location of a plane. We have the technology to transmit pictures of Pluto back to Earth million miles but a plane goes missing and can't be found?! Even if my iPhone got lost, I'll be able to have an app locate it for me.


texts: What is the meaning of a flashing white signalling light in Aldis Lamp?

texts:
In my source, I couldn't understand the flashing white description.

I translate for you; in the last row: 'çakarlı beyaz: flashing white' says that: Leave the manoeuvering area in accordance with local instructions.

My question is: What is the meaning of local 'in accordance with local instructions' Is it meant that there were some instructions before electric power was gone and the previous instructions must be followed before leaving the manoeuvering area and returning to the apron?


texts: How many turbine powered aircraft are in the air at any given time?

texts: I know there are a lot of statistics about how many planes are in the air on average, but not all aircraft flying are turbine-driven. How may turbojet, turbofan, and turboprop aircraft, on average, are in the air at any given moment?


texts: Could an airliner be as efficient lower and slower?

texts: Could an airliner ever be as efficient at 15 or so meters using ground effect as it is at 50,000 km even if it has to go slower and be shaped differently?


texts: What is meant by a "pressure system" in FAR 91.205?

texts:
FAR 91.205 states:

  § 91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.

  (a) General. Except as provided in paragraphs (c)(3) and (e) of this section, no person may operate a powered civil aircraft with a standard category U.S. airworthiness certificate in any operation described in paragraphs (b) through (f) of this section unless that aircraft contains the instruments and equipment specified in those paragraphs (or FAA-approved equivalents) for that type of operation, and those instruments and items of equipment are in operable condition.

  (b) Visual-flight rules (day). For VFR flight during the day, the following instruments and equipment are required:
  ...

  (5) Oil pressure gauge for each engine using pressure system.

What is a "pressure system" in this regard?

Background: Our aircraft has an oil pressure gauge that erroneously reads high pressure. The A&P checks this every year and notes that the oil pressure is within the normal range.

EDIT: "I guess I should be clear about what "erroneously high" means, the gauge pegs the needle so it isn't just a little high". – Ron Beyer

The sender has been replaced and the only thing left is the gauge. We've been flying like this for years. Recently one of our CFI's has determined that we are in violation of 91.205 and has told us to ground the aircraft until it can be repaired.

Have we been flying against FAR's? Is a "pressure system" meant to mean a pressurized oil system, or does it mean an aircraft with an altitude engine? Like I said, our A&P (two different ones in fact) have signed off on this since the engine was replaced 10-ish years ago.


texts: Are NACA airfoils used in modern aircraft design?

texts:
I know that NACA is famous for its ducts:

Gratuitous Ferrari F-40 from Wikipedia. Mmmm... pretty...

It is also well known for its airfoils, and many planes in the early years of aviation used NACA designed airfoils for their wings (for example the Piper Cherokee referenced here).

Piper PA-28 also courtesy of Wikipedia

Do current aircraft manufacturers still use stock NACA airfoil designs, start with a NACA standard design then modify it to meet needs, or are the airfoils completely bespoke?

I'm asking about the major airliner manufacturers like Boeing & Airbus, regional jet builders like Embraer, as well as private/GA companies like Cessna, Gulfstream, and, of course Piper. Information on the (few, dozens, hundreds?) of other aircraft manufacturers (and kit designers) that don't pop to the top of my head is also welcome and appreciated.

Thinking about this further, I realize it could quickly devolve into a very broad this aircraft uses a NACA standard wing, that one doesn't list. That's not really my intent. A simple yes, this aircraft/wing from 5-10 years ago uses a NACA standard would answer the question completely, as would a the last one I'm aware of is from 35+ years ago.

Also, the use of "modern" is rather vague as the Boeing 757 certainly feels "modern" (having been launched in 1982) but has been out of production since 2004, while the 747 started production in 1969 and is still being built. If someone wants to jump in to help define "modern", I'd take no offense.


texts: Why was the Electra uniquely vulnerable to whirl-mode flutter?

texts:
The Lockheed L-188 Electra, notoriously, suffered from early problems with whirl-mode flutter, which caused two Electras to break apart in flight in 1959 and 1960, forcing an expensive redesign of the Electra's engine mounts and killing off Electra sales.

In contrast, the other similar quadturbopropliners of the era (Viscount, Britannia, Il-18, An-10, CL-44, Vanguard) - even those which entered service before the Electra ever flew - had no such problems.

Why?


texts:
Are tyres custom designed for each new aircraft model or is there a lot of standardization & cross use across models? When a designer starts on a new model is there a list of standard tire sizes to choose from?

Is the situation similar for general aviation / military aircraft?


texts: Why does an aircraft use less fuel while landing as opposed to takeoff and climb?

texts: I read that the weight ratio of an aircraft after and before landing, was larger than the ratio after and before takeoff. The weight is lost only due to fuel burn, so why does an aircraft appear to consume more fuel during takeoff than during landing? How does the 'ground effect' play a role here?


texts: How does airfoil affect the coefficient of lift vs. AOA slope?

texts:
I'm trying to understand whether the airfoil shape can affect the slope of Cl vs. AOA (coefficient of lift vs. angle of attack) in the "linear" portion, e.g., from a few degrees negative to about 10 degrees. As an example, I picked 9 different airfoils from the NACA 4 and 6 series on airfoiltool.com and they all have pretty much the same slope in their linear regions (Rn 1'000'000):

The question I have is, if I would like a steeper slope (more effect on lift with less change in AOA) are there specific airfoils I should look at? Or any specific airfoil characteristics? Or is this slope basically given by physics for "reasonable overall well-performing" airfoils?


texts: Why are the engines on the MAX and neo prone to bowing?

texts:
The engines of the 737 MAX$^1$ and Airbus A320neo family$^2$ are [more] prone to bowing (shafts deforming if no debow is applied during start – as I understand it, this happens in a turnaround while the core is still hot).

The debow solution is cold motoring to harmonize the temperatures of the various engine parts. This in turn leads to much longer start durations (was upwards of 7 minutes on the A320neo until a dual-cooling button (shown below) was added to allow the motoring of one while the other was being started, which brought the delay down, but still takes longer than the ceo).

(YouTube)

Operational impact aside, why are those engines prone to bowing? The only other jet-liner I'm aware of that needed a debow procedure was Concorde.

My first thought was the higher overall pressure ratios (OPR) of the new engines, while plausible, Concorde's OPR on ground was nowhere near the levels of the new engines (15.5 vs. 40).

What design element/changes made those engines require the noticeable debowing procedure?

$^1$ http://www.b737.org.uk/737maxdiffs.htm
$^2$ http://aviationweek.com/commercial-aviation/new-pw-president-has-nothing-hide-gtf-starting-issue


texts: Fuel price actually used in the industry

texts:
I know it's a bit off-topic but I guess some of the terminology used in the aircraft community is the same as in marine transportation.

I know that both aircraft and marine vessels use fuel. But if I'm looking at the fuel prices on a commodities exchange, I guess the price is a bit different from the actual prices someone must pay for fuel used in the industry.

Do you have a name/term for fuel prices used in the industry, like fuel industrial price or something like that?


texts: Is the visual artifact seen over the wing from different air densities, a reflection or something else?

texts:
I have noticed a strange visual artifact over the wing of a Boeing yesterday. You can see two manifestations of the artifact in the pictures below.

The first shows it at the front edge of the wing. There were actually many of those, but I only managed to capture one. It looks very similar to a scratch in the window, but moving my head in front of the window didn't move the artifact. So it must have been in a distance somewhere above the wing.
The second pictures shows something similar which looked a bit like there was some kind of reflection on the wing, but the sun was on the other side of the plane, so I wasn't sure what caused it. An odd thing was that the stripe moved kind of in sync with the turbulences

Both of those things moved during the flight and were not always on the same position on the wing. Is it possible that those were caused by pressure/density differences of the air or is it just some reflection (or even something totally different)?


texts: Why don't nonrigid airships have multiple gas cells?

texts:
Nonrigid airships (blimps) differ from rigids and most semirigids in having the entire envelope form a single large gas chamber, rather than dividing the lifting gas among several redundant gas cells.  Having only one compartment for the entirety of the airship's lifting gas raises the specter of an envelope rupture causing the loss of the airship's entire gas load,1 resulting in ungood things happening to the airship and its occupants.

In contrast, having multiple discrete gas cells (either by using a number of separate internal gasbags contained within the outer envelope, or else by dividing the envelope itself into compartments using gastight septae), in the fashion of all rigids and almost all semirigids, would allow the airship to remain airborne even if one or two2 of the gas cells were ruptured and completely deflated,3 and would allow gas cells of uncertain structural integrity to be filled only partially (to reduce the stress on the cell walls, and, thus, the likelihood of a complete rupture) while still maintaining full inflation on the known-good cells.  In addition to the obvious safety benefits, the use of multiple gas cells would also allow better control of the envelope's shape (by allowing different gas cells to be inflated to different pressures to - for instance - stiffen the parts of the envelope experiencing the greatest loads), and would allow minor to moderate maintenance and repair work to be done on the envelope and/or individual gas cells without having to deflate the entire airship.

So why don't nonrigids have multiple discrete gas cells, rather than a single, undivided envelope?

1: This would be exacerbated by a nonrigid airship's need to maintain a considerable positive internal gauge pressure in order to prevent the aerodynamic forces on the airship from distorting its envelope; this positive internal pressure would greatly accelerate the escape of gas from the envelope, and the tension forces on the envelope resulting from said positive internal pressure would tend to produce severe tearing emanating from the site of any rupture (think of what happens when you pop a party balloon).

2: Or, potentially, more, depending on the size of the airship and the number of gas cells contained therein.

3: Note that this does not necessarily mean that the airship will remain capable of forward flight (although, depending on the circumstances [primarily which gas cell(s) lose pressure, and where within the envelope they happen to be located], it very well may), only that it won't be in danger of plummeting to the ground in the event of a rupture.  If a gas cell near the middle of the airship were to lose pressure, this would likely cause the envelope to distort to such a degree as to render controlled forward flight impossible, as @A.I.Breveleri correctly points out - but the key is that the airship would still have one or more intact gas cells providing a considerable amount of residual lift, allowing a controlled forced landing.4

4: This would be an especially great advantage in the case of a major rupture occurring at altitude (where the undivided envelope of a typical nonrigid could easily lose its entire gas load during the time needed to descend to ground level), and even more so if the temperature gradient of the ambient air is greater-than-adiabatic (in which case you lose lift as you descend even if you aren't progressively losing gas).


texts: Why does overspeed cause structural damage or failure when limit load factors are not exceeded?

texts:
The positive and negative limit load factors in this diagram are around 4.5 and -1.8, which means the aircraft experiences structural damage when the aircraft is flown beyond these limit load factors, and beyond the positive and negative ultimate load factors, which are around 6.6 and -2.8 respectively, the aircraft would experience structural failure. These excessive loads typically occur when the aircraft is maneuvered abruptly as in steep dives and steep turns or when the aircraft is flown in turbulent air.

I understand it's excessive loads that cause structural damage or failure when an aircraft is flown beyond the positive or negative limit load factors. But what induces structural damage or failure when the same aircraft is flown within the limit load factors?

My best guess is the parasite drag, but the fact that the normal operating range (green) within the limit load factors jumps to structural failure (red) without going through structural damage (orange) leaves me at a loss, because if the cause is the parasite drag, I don't see the reason structural failure should occur without the structural damage being first experienced.

Edited in response to Simon and kevin's advice


texts: At what altitude might a pilot be able to see at least the brightest stars during the day?

texts:
In this comment I pondered if I should ask:

  "Did Test pilot and astronaut Joseph A. Walker see stars during the day when flying the X-15 above the Karman line?

But instead, I'll just ask at what altitude might a pilot be able to see at least the brightest stars during the day?

Assume cockpit lights and panel illumination are dim-able and a high tech high altitude aircraft (e.g. the X-15 or something modern or near-future) is used.

I don't think it's easy to see bright stars during the day at cruise altitude by eye without some help, but at some altitude it should be.

Is there any information on what altitude this might be?


texts: Why do propeller blades not have winglets?

texts:
On the first look this question might sound ridiculous and maybe it is.
But as propeller blades act by the same physical laws as wings, and winglets reduce the induced drag by quite a bit, then why are they not put on propeller blades?

I could imagine that it might be a material problem. But are there any more reasons? And why exactly might it be a material problem?


texts: How do pilots make rudder inputs during negative G flight?

texts:
During negative 'G' flight, the forces on the pilot (or pilots) will tend to push their legs up and away from the rudder pedals on your airplane.  Needless to say, this is not conducive to making rudder pedal inputs!

Given that, if you are in negative 'G' flight in a suitable aircraft, and wish/need to make a rudder input during that negative 'G' maneuver, how do you do it?  Do military and acro aircraft use any sort of special mechanism (such as foot pedal straps) to help the pilots keep their feet on the pedals during negative-'G' regimes?


texts: Will I be denied or fail a first class medical if I have a recent history of depression?

texts:
I plan on going to get a medical exam for a first class medical certificate to attend flight school. Now, a couple months ago I met with a primary physician to get my blood and urine checked as a pretest, and everything checked out okay.

However when the physician asked me about my mentality, I mentioned I feel depressed from time to time (due to my current job which was at a call center) and he put this on my medical history "Depression, major, single episode, mild"... I currently am not and won't consider antidepressants because the depression is not bad at all, it more or less was just the job I was in.

Will having that on my medical history without being prescribed any medication cause me to be denied the certificate?


texts: What is the structure of the crew documentation used in flight for a commercial aircraft?

texts:
Common documentation easily found online (using A320 family as an example):

Flight crew operating manual (FCOM, multiple volumes)
Flight crew training manual (FCTM)
Standard operating procedures (SOP)
Quick reference handbook (QRH)

(Source)

What are they used for? What are the other major documents necessary to fly? Do they differ with manufacturers or airlines? Are they available on paper or display?


texts: How do I enter the traffic pattern if I am coming from a nonstandard direction?

texts:
I have some questions on entering the pattern, VFR at an uncontrolled airport:

Scenario: let's say I am going to land on a one-runway airport (36-18). Also,
let's say I will be landing on 36 (left pattern) and I would like to enter left downwind.

I would like to know the proper pattern entry for left downwind for 36 for these different routes:

What is the proper entry if I am coming from 090°?
What is the proper entry if I am coming from 020°?
What is the proper entry if I am coming from 180°?
What is the proper entry if I am coming from 200°?


texts: How to correct these garbled tail numbers?

texts:
I have a collection of tail numbers of US aircraft which flew a bunch of domestic flights in the 2000's, but some of them seem to end with @ or @@, or @@@, which are obviously not a valid tail number characters. My question is - are these prefixes of tail numbers with the last character/digit removed? Or are these valid tail numbers if we just drop the @'s?
Examples:
N71@@@
N9346@
N93@@@
N795@@
N796@@
N797@@
N400@@
N401@@
N402@@
N403@@
N3744@
N405@@
N406@@
N404@@
N407@@
N3753@
N3752@
N3756@
N408@@
N409@@
N411@@
N3759@
N3765@
N3766@
N3767@
N3768@
N410@@
N412@@
N413@@
N414@@
Now, I could go look up these numbers in the registry. But - that would look up current data, while I need data from 2001 and 2002. Today, some of these numbers (when dropping the @'s) are registered to private individuals, some to non-airline companies, and some aren't registered at all.
Note: The carriers owning these specific numbers in the list above were Southwest Airlines and Delta Airlines.


texts: How/Where can I get additional weather information for flight planning?

texts:
METARs, TAFs, the area forecast (FA), and flight service briefings are great tools, but if I'm planning a flight with an overnight stay (or a flight that itself might take me a couple of days of travel time) I often feel that the weather picture I'm getting is a little too short-term for my liking.

Aside from watching The Weather Channel are there any supplementary weather sources I can look at which are useful for aviation/flight-planning purposes?

I'm interested mainly in resources for the USA but answers for other countries would be interesting too.


texts: Why did flight NH175 divert back to Los Angeles?

texts:
In the news recently is All Nippon Airways flight NH175, which returned to LAX after four hours towards NRT when it was discovered that a passenger aboard did not have the correct ticket, although his ticket was nevertheless to Tokyo. Two points immediately come to mind:

If a security issue was suspected, why did they not immediately begin diverting to the closest available airport that could accommodate a 777?
If there was no security issue, why did they not simply continue to Tokyo?

Perhaps another way to state the overall question is to ask why ANA protocol necessitates a return to the originating airport in this case.


texts: How and where is the ILS Glide Slope DDM to dots conversion defined?

texts:
The Instrument Landing System (ILS) gives output in terms of Difference in Depth of Modulation (DDM) to the avionics. But all display uses dots, also TAWS system definitions also uses dots as reference.

There is a generic convention that 0.175 DDM is 2 dots. This is why one dot is 0.0875 DDM and this value is the range for boundary used in ILS. Is there any formal reference for this conversion? I am looking at ICAO Annex 10, but could not find any relations yet.


texts: What are the "Static Ports" in a Boeing 767?

texts: Recently while I was on a flight, I've noticed this area near the front door on a Boeing 767 aircraft. I'm a total aviation noob, I just wonder what are these and what they are used for.


texts: What is this device protruding from the rear of this 787?

texts:
While looking at the photos from this question
I noticed a small protrusion from the side of the plane. You can see it in the photo:

and in the diagram from l@aeroalias answer:

In the diagram it appears to have something to do with the apu or is fire protection system. There's a shaded line running to it.

What is this object?

Edit: It does look like an antenna. I found a diagram of 777 antenna placement here, but it doesn't show anything in that area.


texts: What exactly does "clipped wing" mean? Been having a rather heated debate. My understanding is that clipped means the tips were removed after manufacture. The other party claims that if it was designed squared off and built that way, it is called clipped.


texts: Can we borrow Formula One's ground effect for airplanes?

texts:
(Source)

Inspired by the now banned late 70's F1 ground effect, I wondered if it can be adopted by airplanes. So, I came up with this:

(Own work)

The system

A belly door that opens at slow speeds and leads to a narrowing cavity—inverted diffuser.

In essence, the same as the F1 image above, but enclosed since there's no ground. And inverted since we need lift, not downforce. An F1 car's ground effect is the opposite of a plane's ground effect. The door is to stop its operation at high speed.

Theory of operation

The narrowing cavity will speed up the air, the air in the cavity thus will lose pressure (potential energy tuned into kinetic), the air outside the plane and underneath the cavity will be higher pressure, forcing the plane up.

There's no mission, just an experimental racing Howard Hughes kind of thing.

The engineering why is higher top speed, and low angle of attack slow flight.

The way I see it at slow speed the center of lift will shift aft, thus lowering the required angle of attack, I'm not sure about the longitudinal control authority and stability though.
Also, there'll be no need for high-lift devices and their associated systems, and possibly shorter wings, thus shedding weight and increasing top speed.

Can it fly? Are the assumptions above correct?

Engine location, nose gear location, etc., are not part of the question, just a pure aerodynamics question if we can make a cavity produce lift.


texts: Is it possible to suffer barotrauma during decompression?

texts:
Barotrauma is damage of lungs by air overpressure and may occur at overpressure as low as 30 kPa (4 psi). Overpressure in most aircraft is about double that value. So is it possible to suffer barotrauma when rapid1 decompression occurs? In an airliner or only in small airplane? And did it happen?

1If the decompression is explosive and the aircraft falls apart almost certainly, but it does not matter as all occupants will be dead either way. Only consider the case when the aircraft remains controllable.


texts:
What is the highest age at which you can decide to become a pilot for a major airline, a pilot for a cargo airline, or a private pilot?

I'd like to know for Canada or France mainly. But I wonder whether these countries will have rules that are too different from the US and EU.


texts:
Where can I find polars for multi element foils?

Unless I missed them, couldn't find any on airfoiltools.com

Is there a family of multi-element foils like Naca,or Selig, etc.?


texts: Does momentum theory include deflected slipstream thrust lift at high alpha?

texts:
Does momentum theory include deflected slipstream thrust lift of a wing at high alpha?
I understand that momentum theory calculates lift due to the angle at which the air is "turned" over chord the wing.
What about wing at 30 deg alpha?  The lift should also include the downwards x component of thrust, or is this already "included" in the calculation?


texts: Why have cargo hybrid airships not succeeded in the market?

texts:
Using a Lighter Than Air (LTA) Hybrid Airship to efficiently transport cargo to remote areas seems like an idea that should flourish.  It allows access to remote places in the world that have no airports, harbors, or roads leading to them by providing a point-to-point delivery system with vertical take-off and landing, all while providing a greener solution.  I see at least three players all trying to enter this market which seems perpetually stuck as coming about in the next 4-5 years and all seem to have benefited from the U.S. Army's Long Endurance Multi-intelligence Vehicle (LEMV) project that was canceled in January 2013.

Hybrid Air Vehicles in the U.K. has partnered with Northrop Grumman owns a prototype that came out of the LEMV project and plans to build a 50-ton capacity airship in about five years.
Aeroscraft in the U.S. has a prototype and plans to build an airship that carries a 66-ton load as shown on the History channel.
Lockheed Martin has a P-791 / SkyTug prototype derived from the LEMV program and hopes to build a SkyFreighter to lift a 70-ton cargo.

It appears none of these companies has any current orders and are all looking for funding to build their proposed cargo airships.  Apparently an investment of on the order of 50 to 250 million USD would allow one of these to be built for commercial use.  While this is a lot of money, it is small compared to other aviation investments. For example, the Boeing 787 Dreamliner required 32 billion USD as of 2011.

Today, all such airships use noble gas helium instead of the very flammable hydrogen used in the Hindenburg accident, so the historical fear of using such ships should not apply to the new technologies.  These proposed ships are planned to travel at between 70 and 115 MPH, so while not as fast as airplanes, they do compete with trucking and shipping speeds.

So the question is, given the relatively small cost to develop one of these cargo lift systems, why hasn't a company like Boeing with deep pockets wanted to invest in such systems and these companies continue to search for funding?  Is there some kind of flaw in the proposal that such a new cargo shipping approach would save money?  Is it that the market is too small to interest big companies? The hangar space required to store and maintain these ships is huge and little such infrastructure currently exists, perhaps that is their downfall?  Alternatively, maybe their maintenance requirements are their Achilles heel?


texts: What is the difference between a spin and an uncontrolled roll in an high speed dive?

texts:
A comment I had on another (now deleted) question states that Air china 006 didn't spin. For me it was a spin (unwanted roll due to asymmetrical stall). The comment states it was "it was a slow roll during a very-high-speed dive".
How can I make the difference between both? What makes this occurrence of uncontrolled roll not a spin?


texts: How do I determine odd or even when working with altitudes?

texts: I am always confused about how to calculate safety altitude, especially when it comes to even heights and odd heights, e.g. is 7500ft even or odd?


texts: Could someone use an axe to break through a locked cockpit door?

texts:
Could someone accomplish entry with an axe, considering how tough cockpit doors are?

Do planes carry axes?


texts: Why has the folding wing option of the Boeing 777 never been ordered?

texts:
The Boeing 777 has an optional folding wing mechanism to fit into tighter spaces, but it has never been ordered by airlines, according to Wikipedia. Why is this option so unpopular?

Now with the Boeing 777X, Boeing is again offering a smaller, less complex wing folding option. Has this been ordered, and are other airliner models planned to incorporate folding wingtips?


texts: What are the triggers of the MD-80's takeoff configuration warnings?

texts:
I'm helping develop sounds for a MD80 simulation and I've noticed the MD has up to 5 alarms that fire when you advance the throttle and the aircraft is not properly prepared for takeoff:

"Beep beep flaps": I assume when flaps < 11 degrees.
"Beep beep slats": (???) Don't slats move along with flaps? Isn't it redundant?
"Beep beep brakes": I assume you have parking brakes set.
"Beep beep spoilers": I assume you have spoilers in other than stowed condition.
"Beep beep stabilizer": (???) Stabilizer trim is off for takeoff? What is the correct setting?


texts: In modern commercial aircraft, is it possible for pilot inputs to exceed the tolerable structural loads?

texts:
It seems that modern fly by wire systems should / could limit pilot inputs to prevent structural damage.

For example, American Airlines 587:

  From the NTSB report of the accident:

  The National Transportation Safety Board determines that the probable
  cause of this accident was the in-flight separation of the vertical
  stabilizer as a result of the loads beyond ultimate design that were
  created by the first officer’s unnecessary and excessive rudder pedal
  inputs. Contributing to these rudder pedal inputs were characteristics
  of the Airbus A300-600 rudder system design and elements of the
  American Airlines Advanced Aircraft Maneuvering Program.


texts: Another airplane almost hit me, but an ACAS Resolution Advisory told me to climb first. Now what?

texts:
So when a pilot is flying along and suddenly hears a "Climb...  Climb..." Resolution Advisory (RA) from ACAS/TCAS, we are trained to immediately climb to avoid a collision with another aircraft.

There is a reporting requirement in NTSB 830 which states (bold added by me):

  49 CFR 830.5 -  Immediate notification

  The operator of any civil aircraft, or any public aircraft not
  operated by the Armed Forces or an intelligence agency of the United
  States, or any foreign aircraft shall immediately, and by the most
  expeditious means available, notify the nearest National
  Transportation Safety Board (NTSB) office when:

  ...

  (10) Airborne Collision and Avoidance System (ACAS) resolution
  advisories issued either:

  (i) When an aircraft is being operated on an instrument flight rules
  flight plan and compliance with the advisory is necessary to avert a
  substantial risk of collision between two or more aircraft; or

  (ii) To an aircraft operating in class A airspace.

  ...

So my questions are:

Is the phrase "compliance with the advisory is necessary to avert a substantial risk of collision between two or more aircraft" defined somewhere or is there any guidance to say when the report is required?  I.e. is it anytime that we get an RA (even if we visually have the aircraft in sight), only if we actually respond to an RA, or is it if the two airplanes get within a certain distance from each other?
When a report is required, how do we report it and what information is required?  Is there a form that needs to be filled out?


texts: How is the A320neo engine different from the A320ceo engine?

texts:
I've looked up at internet about the differences. And the only difference they mention is that the new engine has a higher bypass ratio (making it more fuel efficient), quieter and has an improved range. Are there any other differences other than these?

Are the engines lighter than its predecessor (are they made of lighter alloys?)

Do the new engines have the reduction gearbox which lacks in the ceo engines?

And what is TAPS II combustor technology?


texts: What is the difference between an Non-Directional Beacon and a Compass Locator Beacon?

texts: What is the difference between a Non-Directional Beacon and a Compass Locator Beacon?


texts: For a rotor in vertical autorotation, what is the relation between pitch, vertical speed and rpms?

texts: In other words, what happens to vertical speed and rpms in vertical autorotation if I change the pitch of the blades of the gyro I use to fly...?


texts: Is there a regulation against having uncaged dogs or other animals as passengers on private aircraft?

texts: There is flight club at our field and this discussion came up.  A regulation cited would settle the matter.


texts: Could the captain of Ryanair 4978 have ignored the Belarus request to land?

texts:
It's all over the news, Belarus Forced Down a Plane to Seize Dissident.
The situation with Ryanair 4978 created a "diplomatic incident" between Belarus and the West.
Since the aircraft was near the Lithuanian border, could the captain have ignored the request to land (from a rather "hostile" country), and expect the Belarusian MiG-29 fighter jet to give up after the plane entered the more friendly airspace (probably after a couple minutes)?
Related: does the fighter jet have a "deterrent" effect only, or is it capable to physically force the plane down? (without using its weaponry)


texts: What happens when a person dies during the flight? What kind of procedures exist regarding deceased passenger on board?

texts: I was just reading about a young woman who died on the long haul flight from LA to Melbourne. Heartbreaking. Young life cut short. RIP. But this horrible situation made me wonder about a presence of a deceased passenger on board. the article says that she died mid-flight. So there could be another remaining 8 hours of flying. I wonder if there are any regulations on how to proceed with a deceased person on board. where would they put her body? I am sure they probably covered her but still, where would she remain for the rest of the flight? I dont think they would put her back on her seat, and not sure if it is ok just to put her on the floor by the kitchen/bathroom areas. I am sorry i know it is weird but seriously does anyone know if there are any provisions regarding logistics of that kind of unfortunate situation?


texts: How much fuel does an airliner consume during passenger boarding?

texts:
As I understand, sometimes APU is running during the passenger boarding. How much fuel do the APU consume during this process?
Of course, it must depend on the total boarding time, so I think it should be estimated in amount of fuel consumed per minute.

Is there an approximation for different aircraft sizes? How does it change if the aircraft is connected to GPU or PCA?


texts:
Does an airplane require a key to unlock the doors and start the aircraft engines?

Is it somewhat like how a car does?


texts: Can a pilot with an ICAO Multi-Crew Pilot License fly an airliner into the U.S.?

texts:
In the question How do non-US pilots get the hours necessary for an ATP?, the question was raised of whether we have 250 or 500 hour foreign pilots flying airliners into major U.S. airports. DeltaLima's answer mentioned the ICAO Multi-Crew Pilot License (MPL), which

  allows a pilot to exercise the privileges of a co-pilot in a commercial air transportation on multi-crew aeroplanes.

Of particular interest is the large gap in the minimum experience requirement between this license and an ATP license that would normally be required to fly an airliner in the U.S. While the FAA normally requires airline pilots to have at least 1,000 flight hours (or 1,500 if they don't have a degree in aviation,) the requirement for the ICAO MPL standard is much less. According to ICAO:

  The ICAO Standard for the MPL specifies 240 hours as the minimum number of actual and simulated flight hours performing the functions of the pilot flying and the pilot non-flying.

While the U.S. has no such pilot certificate, what I'm wondering is:

Is a pilot who receives an MPL from another country allowed by the FAA to fly an airliner on normal scheduled passenger service routes into major U.S. airports?
If so, are there any further restrictions on doing so? For instance:

Can they fly a route subject to ETOPS regulations into the U.S.?
Can they fly a 777 into the U.S. or are they limited to smaller aircraft (e.g. turboprops and the like?)

What is required for a pilot to fly in another country? and I have a European EASA license - what do I need to do to be allowed to fly in the US? cover some general points about the certification requirements to fly an aircraft in a country other than the one where the pilot obtained their license, but they don't address issues specific to flying airline routes.

Interestingly, ICAO seems to suggest that pilots with an MPL would indeed be able to fly in the right seat of an airliner into any ICAO country:

  International recognition of flight crew licenses

  The Convention on International Civil Aviation, often called the Chicago Convention, provides for worldwide recognition of flight crew licences issued by any member State of the International Civil Aviation Organization (ICAO) provided that:

    1.the licence meets or exceeds the ICAO licensing Standards of Annex 1 – Personnel Licensing to the Convention on International Civil Aviation; and

    2.the licence is used on an aircraft which is registered in the State which has issued or validated the licence.

  If the licence is to be used on an aircraft which is not registered in the issuing State, the licence holder must obtain a validation of the licence from the State of Registry or alternatively obtain a new licence issued by the State of Registry.

Can someone provide a reference to the FARs (or something of similar authority) or cite personal experience to confirm whether this is indeed allowed and, if so, what restrictions are placed on such operations?


texts: Is there research suggesting that VFR cruise altitude rules improve safety?

texts:
In the United States, 14 CFR 91.159 prescribes cruising altitudes for level flight under VFR:

  (a) When operating below 18,000 feet MSL and

  (1) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude + 500 feet (such as 3,500, 5,500, or 7,500); or
  (2) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude + 500 feet (such as 4,500, 6,500, or 8,500).

In other words, planes going generally east use one set of altitudes, and planes going generally west use another set of altitudes.

Now, it's not obvious that these rules are the best possible rules for VFR cruising altitudes. Some alternatives would be:

No cruising altitude rules at all. All VFR flights select a cruising altitude arbitrarily.
VFR cruising altitudes are given as blocks instead of single altitudes. For example, planes going generally east cruise at 3,200 through 3,800, or 5,200 through 5,800, and so on.
Cruising altitudes are prescribed in such a way that aircraft with different courses are always given different cruise altitudes. For example, require aircraft to cruise at an altitude such that the 100-foot needle on the altimeter points in the same direction as the "N" on the heading indicator.

The Wikipedia article "Navigation paradox" mentions a couple of papers which state that random cruising altitudes would result in fewer mid-air collisions than the VFR cruising altitudes prescribed by regulations.

Is there any research suggesting that the current VFR cruise altitude rules do, in fact, improve safety? In other words, are there any studies which compare the current rules to at least one alternative, and show that the current rules are better?

(The specific rules I mentioned are the US FAA regulations, but I'm also interested in research about other countries' VFR cruise altitude rules.)


texts: What does it mean when an aircraft is statically stable but dynamically unstable?

texts:
I am reading this book: "Flight Stability and Automatic Control", second edition, Dr. Robert C. Nelson. In the chapter 2, page 42, the author wrote:

Note that the vehicle can be statically stable but dynamically unstable. Static stability, therefore, does not guarantee dynamic stability. However, for the vehicle to dynamically stable it must be statically stable.

I understand static stability, but I am not sure I understand dynamic stability. Can someone help me understand the above texts and give me an example of this case?


texts: Between land and sea, which route is preferred?

texts:
Suppose that you have to connect two destinations like Phoenix and Anchorage, which are 5850km apart. Now, you have two choices: to either fly over the land, or completely fly over Bering Sea (Arctic Ocean). So, what would be the better route to choose? Currently, the route is partially over the sea and partially over the land.

Also, this is just a case, in general out of land and sea, which route is preferred? One common argument is that you are safer by flying over land in case of an emergency, but are there any aerodynamic concerns also involved?


texts: How do turbofans and piston-engines compare in terms of maintenance costs?

texts:
I want to compare piston engines and turbofans on a maintenance basis. Let's say both engines are capable of 100 kN of thrust. Let's say both engines fly for 10,000 hours.

Over that time, what kind of maintenance can we expect from those engines. In particular:

How many times will the engine need major servicing?
How many man-hours does that servicing require?
About how much does it cost to do that servicing?

Major servicing for a piston engine would be something more than an oil change. For a turbofan it would be an overhaul.

Come to think of it, I don't know exactly what kind of servicing goes on for a piston engine other than an oil change. Is it like an overhaul where you dissasemble it and make sure everything fits together properly?

In case you're wondering, I'm envisioning these engines in a commercial cargo role. So no excessive dirtiness or hard throttling.


texts:
To be clear I am referring to a given aircraft at a given weight, speed, attitude, etc everything else the same except one is at say 0.5g and the other at 2.5g will there be a difference in roll rate if both have the same aileron deflection etc.

From my reading I think the answer is no but I am looking for something definitive. The question arises because the typical nose low UA recovery is UNLOAD then roll and recover to the horizon. For what reason is the UNLOAD? Some have suggested that it is because you will get a better roll rate to get the wings level. This I am not sure about.

I believe the main reasons for unloading are that (1) you want to avoid asymmetrical 'g' loads and (2) when holding a large amount of elevator force the pilots ability to input up to maximum aileron deflection is limited.

So I would appreciate someone confirming or denying if there is an aerodynamic reason that roll rate is affected by load factor?


texts: What are the methods of reducing vortex?

texts: I have tried reading the notes on the wing tip, but didn't understand well. How will the vortex be reduced on the wing tip.


texts: What is the most overlooked item during preflight inspection?

texts:
Have there been any studies that gathered statistics on overlooked items on preflight inspections, or even statistics on how many pilots actually perform a good preflight (following a checklist, etc.)?

If such a study exists, did it uncover anything that proved to be something that was often overlooked?

Is there an industry "best practices" document for preflight inspections (beyond just following the manufacturer's checklist found in the POH)?


texts:
Is the content of spoken communications used by air traffic control and pilots defined as part of a rigorous language definition? Such as a morphological or lexical foundational system, or is phraseology the extent of formalization?

And with the advent of text/computer based communications and automation on the horizon so to speak, what is the state of formalizing a language of communication? (If not already answered in the first part of my question.)

References to white papers and other research is fine if the answer requires you to almost write one.


texts: FAA: May I log as cross-country a flight with two or more short legs?

texts:
Consider a hypothetical flight plan from Redstone to Cullman to Gadsden and back to Redstone. This flight would have legs in order of 26, 42, and 52 nautical miles.

14 CFR 61.1 provides

Cross-country time means—
…
(ii) For the purpose of meeting the aeronautical experience requirements (except for a rotorcraft category rating), for a private pilot certificate (except for a powered parachute category rating), a commercial pilot certificate, or an instrument rating, or for the purpose of exercising recreational pilot privileges (except in a rotorcraft) under §61.101(c), time acquired during a flight—
    (A) Conducted in an appropriate aircraft;
    (B) That includes a point of landing that was at least a straight-line distance of more than 50 nautical miles from the original point of departure; and
    (C) That involves the use of dead reckoning, pilotage, electronic navigation aids, radio aids, or other navigation systems to navigate to the landing point.

The original point of departure is Redstone Army Airfield, and Northeast Alabama Regional is farther than 50 nautical miles away. Would the entire flight count toward the cross-country experience requirements for a private pilot certificate, commercial pilot certificate, or instrument rating? Must the pilot fly the 50+ nm leg first?


texts: How do I execute this instrument approach at Larnaca (LCLK)?

texts:
I am on course 200 degrees and got a clearance for the VOR-ILS X RWY 22 approach at Larnaca International Airport (LCLK):

Where is the/an IAF in this case? Do I have to join a holding pattern over the LCA VOR for a course reversal to course 041 inbound to the VOR, and then another base turn for a course reversal to the final approach course?


texts: Is it economically viable for Emirates to use a 777 for some of these routes?

texts:
This question may sound rhetorical or not well posed, but I wonder what the economic viability or sustainability of certain Emirates routes is.

Among its 164 destinations, Emirates is currently serving a whole host of non-major airports (airports which, according to this list, are not among the 30 busiest in the World). Among them are:

Newcastle upon Tyne (NCL)
Prague (PRG)
Bologna (BLQ)
Harare (HRE)

and so forth.

My question: on the majority of these routes, a Boeing 777 is deployed. But how economically viable could it be to fly such a high-capacity plane to destinations where the target market is not so wealthy or not big enough? In some of these instances, Emirates is the sole airline operating the Boeing 777. Also, I speculate that other airlines would probably use another, smaller aircraft to some of these destinations. I am sure Emirates does its market researches with adequate meticulousness before opening any new route, but I am still doubtful - couldn't the people living around Bologna take a train to Milan to get to Dubai, for instance, given their close proximity?


texts: Is there currently any heat shielding and paint for speeds of up to Mach 6?

texts:
The Blackbird SR71 could travel faster than Mach 3 but its speed was limited to prevent its skin from melting. Its newer variant is said to be named the SR72 and it and other, civilian hypersonic aircraft in development are expected to travel at speeds of up Mach 6.

Is there currently any heat shielding and paint for repeated use at speeds of up to Mach 6, and travelling at the cruising altitude of the Concorde?


texts: Is the FAA the only authority with specific medical requirements for transgender pilots?

texts:
The FAA/CAMI imposes certain testing requirements on transgender pilots, listed in the Guide for Aviation Medical Examiners under Item 41 (G-U System), subheading "Gender Identity Disorder".

Is the FAA the only authority that has these requirements, or do other countries have similar policies?

EDIT:
the link above is broken but I think there might be value leaving the old URL in case people want to try to get there on archive.  The updated reg is at https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/aam/ame/guide/app_process/exam_tech/item48/amd/gd/


texts: Why are videos call and voice calls prohibited on airplanes?

texts: I'm taking a flight to Japan this summer and noticed that on United, they may have wifi but it says everywhere that no voice calls or video calls are permitted and strictly prohibited during flight. They don't say why, but out of curiosity why is that such a big deal?


texts: Is roll control achieved exclusively with spoilers on an A320 on final approach?

texts:
As a private pilot I have zero knowledge about how big jets are being flown so I was a little surprised to see that smaller Airbuses (A32x) only use spoilers for roll control on final approach.

During the initial phase of the approach ailerons are being used but at a certain point they stay in the neutral position and roll is controlled by the spoilers.

When I mentioned this to the pilot when exiting the aircraft he was a little annoyed by the question and he said I must have seen it wrong. I've seen this numerous times since then so I'm pretty sure I wasn't mistaken.

Is this actually how the spoilers are used on approach, and if so, why?


texts: Are there any known cases of swing-nose or swing-tail cargo aircraft coming undone in flight?

texts:
Large dedicated cargo aircraft frequently (though not always) have swing-nose (Super Guppy) or swing-tail (Dreamlifter, CL-44) designs, in order to allow cargo to be shoved straight in rather than having to pass through a conventional cargo door.

One can imagine the issues that might happen if the nose or tail on one of these aircraft happened to swing open in flight.

Has this ever actually happened?


texts: Can a turbo aircraft be converted to non-turbo?

texts:
I'm specifically thinking about the Arrow III. There are hundreds or possibly thousands of turbo Arrow III's, but almost no non-turbos.

Could I buy an Arrow III Turbo (PA-28R-201T) that is at TBO and just put in a non turbo engine? Would it then become a PA-28-201? Can you do that to any aircraft that has a non turbo version as well? For instance, could you convert an Cirrus SR22T to an SR22?


texts: How do linear actuators for flight controls work in fighter jets?

texts:
I've built some rc planes and know that in order to control an aileron in a rc plane, that you need a servo, a control horn(sticking out of the aileron), and a pushrod. However, I was wondering how fighter jets control their ailerons. I was researching and I found that it control is via linear actuators. I was wondering how exactly it worked and tried to look for a video or an animation. However, I couldn't find anything that explains exactly how a linear actuator moves an aileron. Can you please help me understand this with a video or something like this. Thanks so much.
This is a picture of an f22 raptor someone sent me when I asked this question on Flite Test...they didnt respond after this this. You can see orange actuators in the picture but it doesn't really help me besides that.                     https://conceptbunny.com/lockheed-martin-f-22-raptor/


texts: For airliners, what prevents wing strikes on landing in bad weather?

texts:
For any low-wing aircraft, particularly the MD-80 or some of the private jets, CRJ's, the wings appear about 5ft or less above the ground. It seems that just few degrees of roll before touchdown would cause a wing strike on the runway and a disaster.

How do pilots and aircraft manufacturers avoid this ? It seems like with the thousands of daily flights - in all sorts of inclement weather conditions - this (fortunately) isn't a problem. (I'm not saying it's never happened, just that it seems exceptionally rare.)

So my question is, why isn't this a serious problem? I would expect turburlence and wind gusts to do all sorts of unpleasant things to aircraft, one of which might be disrupting the roll a couple degrees and planting the wingtip into the runway. What steps do pilots and aircraft designers take to mitigate this?


texts: What are the vertical pieces of metal on the Slingsby Swallow wing for?

texts:
I was watching James May's Toy Stories, particularly the one where they try to fly a glider across the English Channel.  In the middle of the episode they mention a glider that was used for training in the RAF during the 1950s.  It was called the Slingsby Swallow, and it looks like this:

When I saw those pieces of metal coming out of the wings I was...surprised.  At first I thought they were split flaps but then I found another picture and became even more confused:

The devices are clearly coming out of the top and bottom of the wing, not the trailing edge.

Does anyone know what these are and what they are used for on the Slingsby Swallow (or any other aircraft the employs a similar device)?  My only guess is that they are some sort of spoiler that may reduce lift to help get the glider on the ground...but I'm uncertain.


texts: Where can I find the standards for airborne systems software design? Is there a central repository for this information?

texts:
In reading about software and equipment design for aircraft I'm finding a lot of references to various standards like "DO-178B, Software Considerations in Airborne Systems and Equipment Certification", but I'm having a hard time finding copies of these.

Is there a central repository or location where I can review or purchase these standards?


texts: What's the refueling process like for a light aircraft?

texts:
This is for a writing project. I've only been able to find descriptions of refueling large jet aircraft. The plane, a de Hallivand DHC-6 Twin Otter, carries 4 passengers, all minors. None have any significant medical issues. I have no knowledge of flight procedure in any form. How would the timeline look for the whole refueling process? How long would it take? Would the passengers have to leave the plane? If so, where would they be required to go?

Thank you very much, anyone who answers; this stuff is gold to an aerial neophyte like me :)


texts: What is Tropopause height, and how is it determined?

texts: I have seen the term "Tropopause height" used in a flight navigation plan. What is it and how is it determined?


texts:
I've been wondering for awhile to myself, how long can one stay supersonic?
How long before one ran out of fuel?
What would the issues of staying supersonic be (aside from control)?


texts: Does anyone know where I can find old TFRs?

texts: Looking at the FAA TFR site (http://tfr.faa.gov/tfr2/list.html) I can only view current or future flight restrictions. Does anyone know of a resource where I can find past flight restrictions?


texts: Is it possible to be a pilot for both the RAF and a Commercial company?

texts:
I have always wanted to be a pilot for both the RAF and Commercial airlines.
Would it be possible for me to serve, for say 6 months in the RAF, and then when not deployed work as a commercial pilot. Just asking this as I saw a video a few months ago of a US Air Force member who works for United when he is not working for the USAF.
Thanks - Jay.


texts: Why don't jetliners maneuver to avoid a bird strike if spotted in time?

texts:
With 75%* of the bird strikes hitting the wings and engines, why isn't there any training to avoid such strikes by banking if a flock was spotted with enough time to react?
It seems what Boeing recommends* is to ride it out then assess the damage.

Avoid or minimize maneuvering at low altitude to avoid birds.
(...)
Fly the airplane and maintain flight path control.

In the Flying Wild Alaska TV show one time the pilot of a light plane supposedly (exact clearance not shown) banked to avoid the birds. (YouTube)
Is there a correct banking maneuver? Suppose the flock is heading for the right wing, here's what I think of the two alternatives:

Dip the right wing to move the upwash away from the flock's path, or
Raise the right wing because birds are better divers than climbers.

In US Airways 1549 both engines suffered, and I don't know if dipping one wing or the other could have saved one engine. According to the CVR transcript, from announcing "birds" to the strike there was a full second. With a typical human reaction time of 0.3 seconds to announce birds, there would have still been a complete second to roll the plane one way or the other. Enough to roll 15° in an Airbus (max normal law FBW roll rate is 15°/s).
Why is riding it out better than a bank? (Worst outcome is the same for doing nothing and doing something.)
I'm neither claiming a solution, nor discussing flight 1549 in particular, rather inquiring about the flaws in my understanding of bird strikes and the related avoidance maneuvers.

* https://www.boeing.com/commercial/aeromagazine/articles/2011_q3/4/


texts: What does it cost to get a hot air balloon to 30,000ft?

texts:
I'm interested to know what it would take to get a hot air balloon, with a 600lb load, to 30,000 feet. Is this cheaper than flying a plane with a similar load to the same altitude?

If a special balloon is needed, what is the cost of that balloon compared to the typical recreational hot air balloon? What is the quantity and cost of fuel necessary to make it to that altitude, and hover for a few minutes prior to descending?


texts: Do presidential aircraft use additional call signs?

texts:
From the answer to another question I learned that the call sign Air Force One (or Marine One, Navy One or Executive One) is transferred immediately to the aircraft currently carrying the president of the USA.

When president Obama visited the Netherlands (and probably on other occasions as well), I remember him arriving in one of two identical helicopters, to not give away his aircraft to would-be attackers. Using the call sign Marine One for either would defeat that purpose.

So are additional call signs used in such a situation?


texts: How are conflicts between pilot flying and pilot not-flying over aircraft control resolved?

texts:
A question about the "my aircraft" protocol led to several answers that explain how the pilot flying (PF) can delegate control to the pilot not flying (PNF).

It also seems that a pilot (e.g. returning from a break) can assert "I have control" without the other pilot first offering control.

From what I've read, unlike with ATC communications, the exact phrases used vary from airline to airline and are not the subject of rules or guidance by authorities such as the FAA. It also seems that in some airlines, some pilots are more casual about the use of standard phrases.

The only fixed idea seems to be that as long as both pilots have uttered some complementary phrase, both should now be aware that a transfer of control has occurred, and to whom.

This led me to wonder: under what circumstances can the PF refuse the PNF's request, how would they phrase this and does the other pilot or pilots always defer to the senior pilot?


texts: What is the upper deck on converted freighter long-hump 747s used for?

texts:
All 747s1 have an upper deck directly behind the elevated cockpit, a legacy of the 747’s genesis as a design for a strategic-airlifter competition (the upper deck and elevated cockpit were partly to allow the use of a swing-up nose for easier cargo loading without having to disconnect and reconnect all the wiring and control cables and whatnot every time the nose was opened, and partly to keep the main-deck cargo from crushing the flightcrew in the event of an accident);2 this gives the 747 its distinctive hump and unmistakeable silhouette.  There are two 747-upper-deck major versions:

The original-length, short upper deck, used on almost all first- and second-generation 747s (the 747-100, -200, and -SP) and on all 747s built as freighters, has one emergency exit per side, and the hump begins to taper down almost immediately; as a result, the rear end of the hump ends forward of the wings (except on the -SP, whose shorter fuselage brings the hump’s rump rearward over the wing roots, even with the original short hump).  On passenger aircraft, the upper deck was originally used for a first-class lounge, but was later replaced with a few extra rows of passenger seating; on freighters, it contains a few rows of seats for crew rest and carriage of supplementary/supernumerary crew, cargo-handling personnel, and nonrevenue passengers.
The later, stretched upper deck, available as an option on the very last passenger -100s and late-model passenger -200s, and used on all -300s3 and passenger -400s and -8s,4 has two exits per side, and produces a hump that extends well back over the wing roots; it provides a considerable increase in passenger capacity for the 747s so equipped.

As even relatively-new 747s become increasingly uneconomical to operate as passenger aircraft in a world of rising fuel prices and big, efficient, ETOPS-300+-certified twinjets, many long-hump 747s are being converted for freighter service; the conversion process for these aircraft (known as Boeing Converted Freighter, or BCF, 747s) involves stripping out the main-deck seating (and ancillaries like lavatories, galleys, overhead bins, etc.) for cargo rails and tiedowns and cutting main-deck cargo doors into the fuselage.  It does not, however, involve cutting the upper fuselage down to a short-hump configuration (which would be a far more involved piece of surgery than the other BCF modifications), and, as such, leaves the BCF aircraft with an upper deck that is all wrong for its new role; it can’t be used for large, containerised cargo á la the main-deck and lower-lobe5 compartments (the upper-deck fuselage profile doesn’t leave enough space, and there’s no upper-deck cargo door), and, yet, it’s far too large for carrying any reasonable amount of supernumeraries, cargo-handlers, or would-be jumpseaters.

What do operators of long-hump 747-BCFs do with the upper deck?  Do they leave the seats in, on the off chance that they have to transport something that requires a LOT of handlers/escorts/whatnot?  Use it for small bulk cargo (mail, parcels, checked baggage that didn’t make its owners’ flights, etc.)?  Tear out everything but the front few seats and just haul it around empty?

1: ...well, except for these ones, but those are a very special case.

2: The proto-747 lost out to the Lockheed C-5, which has a full-length upper deck used for personnel transportation.

3: The -300 had no dedicated freighter version, although many passenger -300s were eventually converted to carry freight.

4: The -8’s upper deck is slightly longer than that used on earlier long-hump 747s, due to the 747-8’s stretched fuselage.

5: The space (divided by the wing centre box into separate forward and aft compartments) below the main-deck floor, which, in the aircraft’s previous passenger-carrying life, was known simply as the “cargo hold”.


texts: Can someone provide details about airlines dividing crew into personality groups?

texts:
In this answer about crew bidding/scheduling, it's mentioned that crews may be divided into groups based on personality.

What personality traits may be considered? How are people matched? Is this common around the industry?


texts: What is the minimum separation for aircraft operating on or intersecting the same runway?

texts:
How capturing of this photo was ever possible:

(photo courtesy of jetphotos.com)

Shouldn't there be a bigger time / distance separation of three aircrafts using, operating or intersecting the same runway?

Shouldn't pictured situation be considered as a bit dangerous in terms of ground operations?


texts: How much could human power add to the endurance of an electric gyrocopter?

texts: If we take a single seater electric gyrocopter like this one, could a human-powered propeller like this add to the endurance of the aircraft? The gyrocopter only needs a 32km/h forward speed to stay airborne.


texts: Is it a literal hood that's used to simulate IMC?

texts:
I know this is a basic question, but a lot of Q&As on here talk about being "under the hood" to simulate IMC.

My question is, is this a literal hood? Can someone please explain what this actually means to a non-pilot?


texts: What performance issues/symptoms can a pilot expect while taking off above MTOW?

texts:
Lately I've been flying a Cessna 162 Skycatcher, primary as a cheap way to build time towards the Instrument Cross Country requirement and my glider club's hours requirement to tow gliders.

One issue with the 162 is it's relatively low Useful Load.  Here are some figures relevant to my question:

Maximum Takeoff Weight: 1324
Equipped Empty Weight: 857
Useful Load: 467
Weight of full fuel: 24*6 = 144
Weight of 3/4 fuel: 18*6 = 108
My Weight: 215
Max Weight of passenger full fuel: 108.24
Max Weight of passenger 3/4 fuel: 144.24

Note: All Weights above are in pounds(lbs).

Because weight is an issue with this plane and almost any passenger I would consider bringing along, there is a diagram in the FBO's flight book that can be shown to the person fueling that depicts points inside the tanks that denote full, 3/4, 1/2, etc:

Last week, I did a flight with a 130 pound passenger.  On the first refueling I was sure to show this diagram to the person filling to ensure he only filled to 3/4.  I generally make it a habit to inspect the tanks after fueling to ensure they have not gone over the asked for amount.  Takeoff was normal with no noticeable degradation in performance.  Note: the fuel gauges in the 162 tend to show the same value whether the tanks are full or 3/4 full, with no noticeable decrease until until values go below 3/4.

We then proceeded to fly roughly 1.5 hours to another airport.  At that airport, I went through the same routine but (in a hurry of course, isn't that how most mistakes are made!) I did not follow up to ensure he had not "overfilled" the tanks.  On takeoff, I noted a notable (though by no means catastrophic) degradation in performance:

I needed more runway to rotate.
I could not climb above 55kts (Vx/Vy in the 162 are 57/62).

As I was able to climb at a safe enough airspeed, things seemed to stabilize and I had no other issues, I chose to proceed with the return flight.  Performance for the rest of the flight was fine with no extra RPM needed to cruise or do later climbs.

It wasn't until I was thinking about it later that it occurred to me that the refueler might have filled my tanks to full.

So my question is, do these symptoms sound indicative of being overweight?  Or, more generally,
What performance issues can a pilot expect while taking off above MTOW?

Note: I have reviewed several questions related to this, including:

Can a commercial airliner be too heavy to take off?
Does weight and balance of an airplane matter more on takeoff?
Questions tagged with weight-and-balance

However, I didn't find a question dealing specifically with the performance degradation felt by a pilot taking off above MTOW.

Update

After thinking on this a bit more, reading some of the answers and talking it over with my daughter (the passenger mentioned and a pilot in her own right), I'm leaning towards a different conclusion.  Since I was first checked out in the 162 last winter, this was the first time I'd had a passenger.  My first takeoff was from KJYO (5500 feet runway length / 390 ft elevation), whereas my second was from Eagles Nest (W13) (2004 ft runway length / 1436 ft elevation).  My new theory is that what I felt on the second takeoff was the added weight I wasn't used to since I've flown the previous 20+ flights alone.  I believe I didn't notice this as much on my first takeoff because I had much more runway to work with.

Nonetheless, I think the question and answers are still relevant/useful.


texts: Does the USA government operate any business-jets with mid-air refueling capability?

texts: Today I saw a business jet, 10 or 12 passenger or so fly over, evidently on approach to Whitehouse Naval Outlying Field (NOLF) (KNEN), said jet had some sort of probe on the nose and was painted white.  I was not able to discern any markings.  Does the USA government operate any business jets with mid-air refueling capability?  Another obvious question is: why would a passenger jet fly into NOLF?


texts: Do landing planes brake with wheel-brakes or air-brakes or both?

texts: I suppose they do both, but what percentage of the kinetic energy is absorbed by the wheel brakes and what percentage by air-friction (in typical cases)?


texts: What are service letters and service bulletins?

texts: How do a service letter and service bulletin differ.


texts: Can the mass flow rate for different power settings be determined?

texts:
Is it possible to determine the mass flow rate for different power settings? Unfortunately I was unsuccessful in finding the engine specification for the PW2037 so I used the data from this source, which states that the mass flow rate at take-off for the PW2037 engine is 1210 lb/s. Given this flow rate, would it be possible to calculate the mass flow rate at idle setting? And therefore also the mass flow rate for 50% engine setting (or 25%, 75%, etc.)?

An answer in this question suggests using thermodynamic equations to approach this. However, I am not too sure on how to use these equations.


texts: Do autopilots in non-glass cockpits feed off of the gyro instruments?

texts: Do autopilots in non-glass cockpits feed off of the gyro instruments to determine aircraft attitude, heading and rate of turn? Or do they have their own internal gyros? Since I can set the heading using the heading bug, I suppose it needs to be able to read the heading-bug offset at the very least, so there's some connection.


texts: Can I use radar service instead of DME or GPS for this ILS approach?

texts:
At the top of this approach chart for KDNN in the briefing section, it is stated that "Simultaneous operation of I-DNN and GQO DME required."

If my aircraft is not RNAV/GPS or DME equipped can I fly the full ILS approach and rely on "Radar" to identify ROLTE INT (IF)?


texts: What's the minimum roll rate a commercial airliner would have with maximum aileron deflection?

texts:
If the maximum aileron deflection possible was commanded on a commercial airliner, how fast would the aircraft roll?

I don't think there's many reasons to bank a large aircraft quickly, but what I want to know is whether it's even possible to roll it at rates such as 10-15 degrees per second or more.


texts: What is the heaviest aircraft fitted with a central control stick?

texts:
Primary control surfaces for roll and pitch are controlled either by a wheel (C-172, Concorde, ...) or by a center-stick (mirage 2000, most gliders, ...). Wheel tend to be used for bigger aircraft. E.g. I don't know any airliner fitted with a center stick.

What is the biggest aircraft (highest MTOW) fitted with a center-stick? (Airbus style side-stick are excluded.)


texts: How is rotor airfoil analysis different than fixed wing airfoil analysis?

texts:
What the is difference between rotor airfoil analysis and fixed-wing airfoil analysis?

Intuitively, it seems that the airspeed at the tip of a rotor blade would be more than that at its root. Wouldn't this result in irregular torsion along the blade? Subsequently, wouldn't this affect the airfoil analysis as compared to a fixed wing?

If this is the case, then what software (hopefully free) can carry out this analysis?


texts: Did the Mig 21 have differential stabilators to help the ailerons?

texts: The MiG 21 had all-moving tailplanes or stabilators. When rolling, did one stabilator pitch up and the other down to act as secondary ailerons and help the main ones on the wing?


texts: What did they do before on-board toilets?

texts:
I was researching Jimmy Doolittle this morning, and I found this on History.com:

  To aid his record-breaking 1922 coast-to-coast flight, U.S. military
  strategist Jimmy Doolittle invented a funnel-and-tube-based "pilot
  dehydrator"—possibly the earliest airplane toilet.

That led me to the question: What did they do before 1922 when they felt like they had to go?


texts: Is it legal to fly without a transponder?

texts:
Everything is legal / airworthy.
Except:
Transponder is installed.  It does work.  It has NOT been inspected in any time frame that would show it is properly maintained.
Flight is
Golf, Echo, Delta < 2500 AGL
Can I shut off the transponder and fly legally?


texts:
Requesting for some clarification.
Part 91 operator. 0-0 visibility and ceiling minimums
Departing Rwy 15 at ADS
Can I depart with a standard 200 ft/nm cross DER 35 ft. since I don't need to comply with the 400-2 1/2 wx? (0-0 ...right?)
or
Do I fall under the std.(which from what I understand, is ...0-0?) w/ min. climb of 325' per NM to 1100?


texts: GPS Magnetic Declination and current database

texts: Can I fly with an expired GPS database if I verify the waypoints locations? or is the magnetic declination part of the database?


texts: What is pressurization influence (if any) on maximum G load an airliner can withstand?

texts:
Reading here about skin thickness of airliners I was wondering if, considering  some pressurized airliner at cruise altitude, there are differences in maximum operational acceleration loading the fuselage can withstand.

For instance, could an "inflated" cylinder better withstand compression stress during a 2.5g turn, compared to a similar unpressurized airframe?

Are there different limitations related to pressurization level?


texts: What standard of English are Air Traffic Controllers held to?

texts: While I'm sure it varies by territory, and that airports around more cosmopolitan areas have controllers better versed in English, I was wondering how well controllers have to know English. I imagine that there are places where all of the English they know is aviation-related. I can imagine that there are situations in which lack of knowledge of the language outside of memorized aviation vocabulary could be harmful, and situations in which a translator might be needed. How well versed in English are ATCs?


texts: What does the practical CPL skill test contain?

texts:
In EASA Part-FCL, FCL.310 containts on several hundred pages all the required knowledge for the theoretical skill test for a CPL. However, different from other licenses described in Part-FCL (PPL, Aerobatic, VFR Night, Mountain, ...), there is no list of what's in the practical skill test.

What's included in the CPL practical skill test? What are the tolerances for maneuvers etc?


texts: What would be logged as the destination for an emergency landing in a field?

texts: When logging flights you have a departure point and an arrival point, how would you log the arrival point if you were to have to perform an emergency off field landing in a field or on an interstate?


texts: Is there any regulation that authorizes autopilot use when cleared for a visual approach?

texts: Is there any FAA reference that recommends or specifically allows for the use of a coupled approach (such as autoland) when the pilot is specifically cleared for a visual approach?


texts:
What is the Keel Effect and how does it happen? Is it the same as Pendulum Effect or it doesn't exist?

The Pilot's Handbook of Aeronautical Knowledege by the FAA has an explanation that says:

  An aircraft always has the tendency to turn the longitudonal axis of the aircraft into the relative wind. This "weather vane" tendency is similar to the keel of the ship and exerts a steadying influence on the aircraft laterally about the longitudonal axis. When an aircraft is disturbed and one wing dips, the fuselage weight acts as a pendulum returning the plane to its original attitude

I know I'm like answering my own question, but is this explanation quite right? Because in this question it is said that perhaps it doesn't exists or it means something different.


texts: How does a Boeing 737 look like at night from 2000 meters away?

texts:
I am asking about the current crash of a Boeing 737-800. Due to the unfortunate crash of Ukrainian 752, I am trying to figure out what can be seen from the launch pad when they decided to shoot the plane. I determined the plane was at 4620 ft AGL and climbing. According to my calculations, the line of sight distance from the operator to the plane was 2058 meters = 6729 ft away.

So I want to know how a 737-800 looks like from the ground 6729 ft away at night.

I would like to know if it is possible to mistake a 737-800 for anything else from that distance at the night time with full visibility. Can anyone provide a picture of that?


texts: How do modern commercial aircraft handle dust storms?

texts:
I live in West Texas where dust storms are an occasional fact of life. I am interested in how modern jet aircraft handle dust storms such as the one seen in the photo. From a pilot POV I can see that sand is no different than fog with high winds. However, from a mechanical standpoint, this is a high velocity abrasive being shot at the vehicle and through the engines.

How do modern airliners and their crews deal with a large sandstorm?

Would a standard weather briefing warn a pilot of the possibility of a sandstorm?

What would the appropriate action be for a pilot who suddenly finds themselves above a sandstorm in a piston or turbine aircraft?

How would a pilot judge when a dust storm is too dense to enter safely?


texts: How should you coordinate with traffic at non-towered airports?

texts:
I am a fairly new pilot. I recently flew to a non-towered airport in Quebec, Canada (Lachute, CSE4). There is a significant displaced threshold on each end of the runway. The airport has one taxiway which goes up to about half the length of the runway. Because the taxiway doesn't extend all the way, back taxi is required on one of the runways.

When I attempted to depart I noticed that all CTAF announcements were being made in French. Before I got to my holding point I had to cross the runway and I spoke in English before I did so. I do not speak or understand French. Once I got to the holding point I noticed two aircrafts which were performing touch and goes. There was really no time for an aircraft to takeoff before one of them would be on the base leg or the final. I waited for several minutes. I noticed another plane also waiting at another holding point. A third aircraft was taxiing and about to queue up behind me.

My question is:

What is the correct procedure in this situation? Do we continue to
wait until the other aircraft finish their touch and goes?
If there is no procedure defined (I'm not aware of any), what is
the correct etiquette in this situation?

After waiting for a while I waited for one of the aircrafts to take off. Then I immediately stated my intentions to back taxi on the active runway and started the back taxi. I saw the second aircraft turning from base to final and I accelerated towards the end of the runway and positioned myself towards the beginning of the runway/displacement threshold. There was no way I could have attempted a takeoff.

However, what I did made a number of people very unhappy and they berated me and told me that I should brush up my procedures (in English this time). I haven't come across this situation in my training. Can someone please help clarify the correct/accepted process?


texts: What licenses/endorsements or type ratings do you need to fly a fighter jet?

texts:
As the title says, what endorsements and licenses do I need to obtain before I can legally fly a decommissioned single seater fighter jet or trainer jet (like a L-39 Albatros or even a F22 when the time comes)

Simply assume I could afford everything the jet needs and the jet itself, I am aware that a lot of jets (mostly newer) will never see civilian pilots.

I am mostly asking for the Netherlands / EU, but I am interested in American laws as well, if there are big differences.


texts:
How do you build a sail for a blimp/hybrid airship and what would it look like? Similar to a sail boat how could a blimp maneuver without propellers? Can a blimp sail against the wind? Wind can travel in opposite directions over the same location depending on altitude.

Jet stream patterns.

https://earth.nullschool.net/#current/wind/isobaric/500hPa/orthographic=-41.18,34.22,610/loc=-58.714,40.895

On worldbuilding.SE: Could a city be built out of Balloons?


texts: What are the advantages of a variable-incidence wing as used in the F-8?

texts:
What are the advantages of a variable-incidence wing as used in F-8?

Do weight and other issues outweigh the advantages and that's why it's not found in many (any?) other aircraft?


texts:
If I departed a heliport in Class B airspace, on my way out can I tell approach that I want to cancel my VFR flight plan to pick up an IFR flight plan?

I figured I could because Approach will be controlling me while I'm in the Class B airspace but I want to make sure before I request it.


texts: In a constant speed propeller, why does the RPM drop with a prop pitch increase?

texts:
When a constant speed propeller changes its pitch from low to high, RPM would decrease.

Why is that the case?

Wouldn't the RPM increase when we increase the blade angle since there's less drag and the blades are more aligned to the relative wind, compared to when it's in a low pitch angle? Also, does higher blade pitch allow us to fly any faster?


texts: In Ethiopia, what are the minimum hours to be a pilot in a passenger jet?

texts:
With regards to the flight crew on board the Ethiopian flight, I have read many times that the young F/O with only 200 hrs wouldn't have been allowed to transport passengers if he were a pilot in the USA. Like in this article:

  In the Ethiopian Airlines crash this week, one of the pilots had just 200 hours of flight time, less than a seventh of the time the F.A.A. generally requires to fly a passenger plane.

I don't know about FAA regulations, but cadets that come out of MPL or Integrated ATPL route have around 250 hrs and hold an ATPL frozen that allows them to be a co-pilot of a jet with hundreds of pax. Even stranger for pilots with an MPL who are not allowed to fly in single pilot planes until 1500 hrs.

Are Ethiopian requirements really so different compared to western countries (North America, Europe, Australia, NZ)?

  On Mar 18th 2019 the airline clarified, the first officer had accumulated a total of 350 flight hours

from AVHerald


texts: How are flight schedules displayed without ambiguity on DST change days?

texts:
Flight schedules are based on the local time of the station of departure or arrival. Twice a year though, this is either ambiguous or impossible. What happens on these boundaries?

Say, for instance, a flight is scheduled for departure daily at 1:30 A.M. This year, DST ends at November 2nd, 2 A.M., meaning the local clock will go from 2 A.M. back to 1 A.M. Will this flight depart on the first 1:30 A.M. or the second?

And the other way round, say next year a flight is scheduled for departure daily at 2:30 A.M. When DST starts, the clock will go directly from 2:00 A.M. to 3:00 A.M. and 2:30 doesn't exist. What happens for this flight?


texts: If a tail dragger is converted to a tricycle gear airplane, what will be the effect on weight distribution?

texts: If a tail dragger airplane is converted to one with conventional tricycle landing gears, how will this affect the balance of the airplane? It is possible to offset the effect by shifting weights around the airframe?


texts: What should I do to become a commercial pilot?

texts: I am 25 years old, I have completed my bachelor  degree  from electrical  engineering. So what should I do to become a pilot?


texts: Why aren't any wingsuits able to sustain flight?

texts:
I'm aware that under zero power it is a glider, but there are gliders that sustain flight and have enough lift to climb etc (Edit: this is not always true. See below answers for why). So, would it not be an interesting idea to make a wingsuit that you can use to climb and not just fall?

With longer wings could it be done? Or maybe a longer airfoil?


texts: Are there a toilet and (small) kitchen in the Su-34?

texts:
It seems that there are a toilet and small kitchen in the Su-34. The Su-34 is a medium range fighter-bomber with a range of action of 4000km able to transport 8 tons of bombs and missile.

I know that the pilots enter from the bottom and they sit side by side (so there is some space). Some people say that there is a toilet, some other comforts (microwave,bed) and others say that there is just this:

Is that a toilet? Can you confirm if the Su-34 really has those features?


texts: On the F15-E, can the WSO take over if the pilot is incapacitated?

texts:
The F15-E Strike Eagle features a two-man cockpit. The pilot in the front seat and the WSO (Weapons System Officer) in the back seat.

If the jet is cruising straight and level is mechanically sound but the pilot becomes completely incapacitated (from a heart attack for example) can the WSO take over and land the aircraft? I could imagine that the correct procedure may be to just eject both the pilot and themselves. Do WSO's learn to fly the F15?

The following image is the backseat cockpit area of a F-15 E where the WSO sits. Note the control stick and the throttle control I've highlighted with red arrows. Surely this means the WSO has the ability to take over control?

source(http://i61.tinypic.com/dbqp2q.jpg)


texts:
An old flight book that I am reading discusses the aerodynamic moment about a wing and talks about an upper and lower lifts. I can see how the pressure distribution on the top surface produces an upper lift force while the the pressure distribution on the bottom surface produces also a lower lift force. The upper lift force points upward while the lower lift surface points downward. Both lift forces point away from the respective surfaces.

Wouldn't local forces (whose vector sum produces the upper lift force) due to upper pressure distribution point towards the surface, not away, in the normal direction?

As the angle of attack is increased, the upper surface lift increases while the lower surface lift decreases?

It is said that no change in moment takes place about the point where
the lift change occurs. I am not sure how to interpret that either...


texts:
It is normal to see older planes (20+ years) quite frequently. In fact, a few months ago I saw a plane over 50 years old (not in a museum but on a runway, about to take off).

Comparing to cars, there are not many cars on the road which are older than 10-15 years.

What are the reasons for this besides the following?

Airplanes are very expensive. A new 172 would be over USD 300,000, and a thirty year old can be around \$50k or less.
Airplanes follow a very strict maintenance schedule and are inspected thoroughly (ideally speaking). Hence their life is increased.
Pilots are very well trained compared to car drivers, so they know a lot more of what they are doing. Hence they are more aware of the condition of the plane.
Cars crash a lot more often than airplanes.

It appears that this holds true for both general and commercial aviation.


texts: How useful are simulators in pilot training?

texts:
For commercial pilots' training, airlines rely heavily on the training at computer simulators (fixed base simulators), where one can learn the cockpit controls and how to use the cockpit displays to control the airplane. But this does not give them the physical feel of controlling the airplane (which can be felt while using a real physical simulator (Hydraulic Simulators), as used by NASA in training their astronauts). Do airlines use such physical simulators to train pilots or are computer simulators the only ones used? Moreover, what is the usefulness of simple computer simulators as such then?

As a follow-up, do military pilots undergo training in physical real life simulators or they too are trained first in the computer simulators and then directly in the training planes?


texts: Will the Honda CG 125 engine be able to lift a 200kg weight at 2100 RPM?

texts: I found a Rotex company engine with a maximum RPM of 5800. However, company allows 70%  mean 4000 RPM, so I'm sure that 2100 RPM will be enough for lifting or take off and be able to climb. I have seen a lot of video clips on YouTube of bike-engined aircraft flying, but in all videos nobody shown bike engine, so I'm also doubtful that some of the videos real. Will the Honda CG 125 engine be able to climb with 200 kg weight or not?


texts: What are these engineers doing sitting on a large format drawing of B-47s aircraft?

texts:
This answer about solid-jet-assisted takeoff links to the page B-47 Jet-Assisted Take Off (JATO). An image there took me to a collection of historical aviation images, apparently from a LIFE Magazine archive.

Browsing there led me to the image below, of what looks like several aviation engineers sitting on a very large format drawing of a B-47 aircraft and its major components.

A reverse image search leads mostly to sites written in Russian, which I can't read.

Does anyone recognize what's actually happening here? It's not scene one would normally see these days.

source: http://images.google.com/hosted/life/2ce91e390933d837.html

  B-47 Stratojet Bomber, Date taken: September 9, 1950 Photographer: Howard Sochurek


texts: How is a stolen aircraft returned to its owner?

texts: Once the authorities figure out where a stolen GA aircraft is, do they get the owner to come take it back? do they fly it back to its home airport? How exactly does the owner get his hands back on it?


texts: Can repeated call-signs be present in one day?

texts:
I am working with a big ADS-B traffic sample of one day Europe, and identified repeated call signs. Examples include:

Flight that ends in an airport and repeated call sign starts from there.
Two flights with the same call sign, ADEP and ADES.
Four Different ADEP and ADES.

I thought in one day it was not possible to have repeated call signs.
Is this possible? Is my data wrong?