texts: What was the first aircraft designed with a plug-system fuselage, and why?

texts:
Nearly all modern transport aircraft are designed with a plug-system fuselage, allowing longer and shorter variants to be built by adding or removing plugs.

In addition, the plug system simplifies construction, as large sections of the aircraft can be assembled from modular parts.

What was the first aircraft to employ this system?

And what was the reason for adopting it in the first place:

to make possible the construction of variants
to enjoy efficiencies and economies of design and manufacture
both of the above?


texts: Why should autofeather only be used for take off on the Dash-8 Q400?

texts:
The Bombardier Dash-8 Q400 FCOM says (emphasis mine):

  The autofeather system provides automatically initiated propeller feathering following an engine failure during take-off, and power uptrim of the operating engine (Figure 12.22-5). Autofeather is selected on for take off only, using the AUTOFEATHER switchlight on the engine instrument panel.

(source: smartcockpit.com)

It only says autofeather should be used for take off only, but fails to explain why. I would assume autofeather would also be useful when landing. The uptrim (automatic power increase for remaining engine) might not, but it is independent anyway:

  Uptrim is triggered (regardless of autofeather selection) [...]

Why should autofeather not be selected during landing?


texts: How good is the ground visibility by a moonless night In the Grand Canyon?

texts:
My night flying experience is limited to light-polluted coastal southern California.

When flying over low-population countryside on a clear, moonless night, do the stars provide enough light to identify the contour of the ground or is it completely dark?

If anyone has specific knowledge of flying over the Grand Canyon at lowish altitude under those conditions, I would appreciate your impressions.

Background - I'm writing a fiction novel where characters make that flight and want to accurately describe what they can see if anything.


texts: Is it possible to hear a sonic boom when the aircraft is exactly at Mach one?

texts:
Will an observer on the ground hear a sonic boom if a plane passes overhead at exactly the speed of sound? That is, the plane does not cross the sound barrier. The plane just hits Mach one - and continues to travel at that exact speed.

This is a bit of a problem because the speed of sound changes with altitude, so we assume it remains at the exact same altitude. I imagine there are other caveats also!

I would guess that there is a sonic boom, but I'm not sure.


texts: What is the purpose of a Traffic Pattern?

texts:
I always see images with a runway and a rectangular flight path over it and ask myself why do the pilots take off, fly around the runway and get back and land, what is the purpose of doing that: take off, fly parallel to the runway and land? Am I missing something?

Source


texts: Why do some aircraft carriers have an upward starting runway?

texts: I noticed that some aircraft carriers have an upward starting runway while others don't. What's the reason for this? What are the advantages of both designs and how come not one of them has prevailed over time?


texts: Why does the A350-900 call out to retard at 20 feet above the runway?

texts:
I watched this video of a delivery of an A350.

at 14:50 there is the sequence I'm interested in: the ground radar normally counts down the distance to the ground, but shortly after the 20 feet mark, it calls the typical "retard" to pull the levers back.

Why is it like this and not like normally at 0 feet?


texts: Explaining development of sideslip due to bank

texts:
In lateral static stability:
"Once an airplane banked due to a disturbance, the airplane develops a sideslip in the direction of the bank because of a spanwise component of the weight w*sin($\phi$)"
I need to understand that in terms of forces and moments acted on the airplane.
Let me say:
the resultan of thrust force and the component of the lift.sin($\phi$) force, which developed when banking, makes the airplane moves in a sideslip angle.
Is it correct?
Can someone explain in it with images?


texts: Is aerodynamic braking really effective?

texts:
(YouTube)

In the frame above the pilot is pulling back, as evident by the stabilator's position, and this technique is usually cited as a means of slowing down.

But wouldn't the brakes have better effect if the struts are fully compressed as with jet-liners? What makes aerodynamic braking effective for jet-fighters then?

Clarification:

Presumably that fighter pilot is applying some brakes at least (otherwise they wouldn't have added a drogue chute).

My thinking is, if the nose gear was planted, the same braking force will have a better effect (reduced lift), even without spoilers present since the jet engines won't be contributing to the struts decompression. Also the nose tire will add to the rolling friction.


texts: Calculating the horizontal drift for parachute, is it okay to assume the "starting speed" to be terminal velocity?

texts:
Plus in the worst case of the maximum range, can we assume we are already at the terminal velocity when we're deployed at 600m?
If we assume that we are deployed at 600m, we "freefall" for a few seconds while the parachute completely opens, catches air and reaches terminal velocity.
So then its just a case of balancing the total drag (from both components - falling and sidewind) with the estimated mass of the payload?


texts: Departure and arrival fix loading via FAA website

texts: About 8 years ago I was involved in a project that would hit an FAA website for fix loading. It was departure and arrival fixes and their associated data. The URL included a command line where you could request an airport, date, time, and increment. Does anyone know what happned to that site or if there is a replacement? The data looked something like this:


texts: How do coefficient of lift/drag variation with speed differs between swept and unswept wings?

texts:
Trying to understand the coefficient of lift/drag of swept and unswept wings as speed increases.  Some example questions and statements-
A swept wing will have a lower max Cl at subsonic and supersonic speeds.  I understand the lower max cl at subsonic, but the lower max cl at supersonic has confused me?
When the speed increases for a swept wing from subsonic to supersonic Mach numbers, the max CL is more or less?
CL is more at supersonic and less for subsonic.
Comparing swept and unswept wings as angle of attack is increased the swept wing will produce less lift(this i understand) and more drag.  Why more drag?  Is it due to the span wise flow being greater?


texts:
Is the distance to PNR (point of no return) affected by wind?

I did research it and found some links, but none discussed about the wind.


texts: Why do planes sometimes make a touch-and-go?

texts:
I have seen airplanes on YouTube and even in my country doing a touch-and-go.

I don't know why planes come down from thousands of feet just to touch the runway and then fly away:

Is it for show?
Is it to check the landing gear?
Is it because of a malfunction?
Does it increase the use of fuel?

Why do planes make a touch-and-go?


texts: Is the location of an aircraft spoiler really that vital?

texts: I was wondering that spoilers in most of the aircraft are always placed aft (towards the tail) the CG location. Why aren't they placed ahead of the wings or near the nose of the aircraft? The same is the case with parachutes. For small UAVs, the parachutes are either at the CG location or placed behind it. Is there a really strong design point to this method? Any suggestions/information would be appreciated?


texts: Why does the Pilatus PC-12 go faster than the King Air C90?

texts:
Pilatus PC-12 (source: www.what2fly.com)

King Air C90 (source: www.ok-aircraft.cz)

I am wondering this because of the blades on the propellers on both of the planes. The Pilatus PC-12 can travel up to 360mph with its 4 blades on the propeller. The King Air C90 has 2 engines with 4 blades each, is around the same size and can travel at a slower speed of just 300mph. Why is this when the King Air has 2 engines instead of 1 with 4 blades and travels slower, and the Pilatus only needs one engine with 4 blades to go 360mph?


texts: What is the propeller efficiency, $μ_p$, of modern propellers for light sport aircraft?

texts:
Roskam's book on preliminary design gives a value of 0.7 for "homebuilt" aircraft and 0.8 for general aviation. What explains this difference in propeller efficiency? The content of Roskam's book is fantastic but some of the constants that he gives may be a bit dated as was the case for specific fuel consumption which was given as 0.7 for homebuilt aircraft when a modern engine like the Rotax 912UL has a sfc of 0.47.

On a search of Wikipedia, it is written that modern propellers can have an efficiency of 0.9.


texts: Why is this plane flying in such a tight circle?

texts:
I was in a car in NYC on 2/18 going from Queens to Manhattan. While going over a bridge I noticed some (what looked to me like) very tight circular contrails in the sky.

The plane was still there but very high up and/or far away and I couldn't make it out.

The photos here are from my phone, through the window of a moving car on a bridge, so not the best, but it's all I could get.

I never noticed anything like this before and I was curious what this might be.


texts: Are test pilots who work for the FAA paid on the GSE pay tables?

texts: Many employees of the US federal government are paid according to the GSE salary tables. Are the FAA test pilots paid on the same table? For example someone could be in the grade 14 step 6 rate. Or, are they paid according to some other pay table?


texts: What disadvantages does flying a drone close under a ceiling have?

texts:
If I want a drone (quadcopter) to be flying always under a surface and close to this surface (i.e: under a table 5cm away from the surface), which are the disadvantages this would have in the lift generation of the drone?

How much would be the lift lost due to this flying conditions (in percentage or with calculations if possible)?


texts: Why do jet nozzles close at different rates?

texts:
After recently seeing the trailer for Top Gun 2, I was reminded of something that I always wondered about: why do the nozzles of some jet aircraft seem to close at different rates?

Sure, it's likely that both engines of the aircraft won't spool up at the same rates, but what about the nozzles? Are the nozzles dependent on the engine power output (which would then answer this question), or are they independently controlled? If so, what causes them to close/open at different rates?

Here's an example from the Top Gun 2 trailer:


texts: Why do most single propellers have a clockwise rotation?

texts:
Why do most single propellers have a clockwise rotation (seen from the pilot's point of view)?

There are though multi-engine planes that have each propeller rotating different directions, but in the case of single propellers, it seems that clockwise rotation is dominant, or even the only option. Is there any single propeller plane with counterclockwise rotation?


texts: Why are the Boeing 747-8 engines on the wings spread apart?

texts:
I ask this because the Boeing 747-236 had the engines close together while the 747's have them spread apart. Does it have anything to do with the amount of thrust of the aircraft?

Look at how spread apart the engines are:

Now look at how close together those engines are on the Boeing 747-236:


texts: Do unused parachutes need to be repacked? If so how often and why?

texts: I was reading some military fiction and saw a comment that army airborne operations were required to repack all parachutes every ninety days, allowing parachutes that were due to be repacked soon to be cheaply used for training. This got me thinking: do parachutes need to be repacked on a schedule? Is this uniform across all types of parachutes and use cases? (are there differences between military and civilian requirements?) How long is the repack cycle? Why is scheduled repacking needed?


texts: For a coaxial rotorcraft, Do horizontal and vertical stabilizers in the tail really make much of a difference?

texts: Can we design a coaxial rotorcraft without tail and tail boom completely? What might be the consequences?


texts: Artificial horizon - "horizon bar" or "symbolic airplane adjust"

texts:
(Student pilot, ~ 22hrs training)
On a box-standard AI in a C172 there is a knob that allows you to move the symbolic airplane up and down. I've never managed to ask what it is for, but have now been intrigued enough to google it. An RC Allen instrument manual points out that it "adjusts the Symbolic Airplane to compensate for viewing parallax. Adjust Symbolic Airplane so that it is visually aligned with the horizon from pilot’s normal sitting position."

Two questions:

My best guess is that I could/should adjust it during the run-up along with the "instruments check" item on the checklist. However, is the Cessna always sitting correctly for that to be exact (or exact enough)? If there is a slightly different pressure in the nose wheel oleo the nose wouldn't necessarily point to the horizon, or when there is a slight slope of the taxiway/run-up area. Would it be better to (re-)adjust it in level flight?

Why do more modern AIs no longer appear to need that? The viewing parallax is still there, why isn't the button?


texts: Why is a reciprocating engine air intake a reverse bell shape?

texts:
Why would this inlet for the induction system get wider as the air approaches the filter?
What net effect does this have on intake pressure, and how would an inlet that starts wide and then narrows down perform differently?


texts: Why aren't aircraft cabins pressurized to sea level pressure?

texts:
From an article on WHO's website:

  Although aircraft cabins are pressurized, cabin air pressure at cruising altitude is lower than air pressure at sea level. At typical cruising altitudes in the range 11 000–12 200 m (36 000–40 000 feet), air pressure in the cabin is equivalent to the outside air pressure at 1800–2400 m (6000–8000 feet) above sea level.

Why aren't cabins completely pressurized, but instead to 6000-8000', seeing that many passengers wouldn't have to endure sometimes painful popping in the ears?


texts: How long can an average aerobatic plane sustain 0g?

texts: How long can an average aerobatic plane sustain 0g safely?


texts: How do test pilots determine an aircraft's capabilities?

texts: How do test pilots figure out an aircraft's capabilities (service ceiling, cruising altitude, etc.)? Do they simply take the plane to its limits to get that information?


texts: Is there a way to find out which runway is used by which flight on a particular day/date?

texts:
For example, i want to know which runway was used by NH 829 that flies from NRT to BOM (Narita-Tokyo to Bombay-Mumbai)

For flight tracking, I know and use these websites/apps - FlightAware, FlightRadar, FlightStats, Aviability, FlightMapper, Planefinder and Kvikr.

https://www.flightradar24.com/data/flights/nh829
https://flightaware.com/live/flight/ANA829
https://www.flightstats.com/v2/flight-tracker/NH/829
https://planefinder.net/data/flight/NH829
https://www.flightera.net/flight/All+Nippon+Airways/NH829
https://info.flightmapper.net/flight/ANA_NH_829
https://www.radarbox24.com/data/flights/NH829
https://www.airportia.com/flights/nh829/tokyo/mumbai/
https://www.planemapper.com/flights/NH829
https://kvikr.com/flight/nh829_ana

But none of them provide information about runway used for takeoff or landing at the source or destination airports respectively. I am looking for a publicly accessible, preferably free to use website/smartphone app/API or even a historical dataset (recent flights not those from the previous decade)

Is such information kept a secret (intentionally) or is it just that no one displays it, probably stored in the database. I understand that realtime information may not be available, but for past flights, such data should be available. I guess there could be country-specific restrictions too. But i want to see as much public data for any flight as available.

My ultimate goal is to find out which runway is used by LH717/LH716 and QF25/QF26 for takeoff and landing at HND (Haneda-Tokyo), so that i can get a better view of the Boeing 747 from as close as possible.


texts: Effect of gravity vs airmass on a falling object

texts:
Let's say you were drifting along in a hot air balloon at a ground speed of 50 knots at an altitude of roughly 10,000' MSL/AGL.  The airmass is uniform, moving at the same speed at all altitudes.  In your hand is a streamlined, very dense object.  Picture a 5 pound chunk of lead shaped like a torpedo.

If you were to drop this object (over an unpopulated area of course!) would it continue to track along the ground at the exact same speed as the airmass/balloon, or would the vertical acceleration due to gravity overcome the horizontal inertia, slowing the groundspeed and causing it to arc towards a trajectory more perpendicular to the ground?

In other words, would the lead impact the ground directly beneath the hot air balloon, or at some point "upwind"?

My gut tells me that it would fall almost straight down immediately, with only some slight sideways drift, but I don't know how to quantify that hunch.

FYI, this question has its origins in the discussion here:  Force Balance From Wind


texts: What's the use of so much torque on propellers?

texts:
(This question is closely related to this question)

A typical Cessna 172 has a 180 hp engine, with a max. rotational velocity of 2700 RPM. Even small 1 hp electrical motors can achieve that RPM, and therefore, I guess the rest of the power is converted into torque.

What's the use of so much torque, and what happens if there is less torque at the same RPM - i.e.

Can an electric motor perform similar to the Lycoming IO-360 with the same max. RPM, but with just half the torque of the latter?


texts: What turbine blade alloy did the Jendrassik Cs-1 use?

texts:
Wikipedia says that the first turboprop aircraft engine was the Jendrassik Cs-1 invented in Hungary by György Jendrassik.

It says it was supposed to run at 1000 hp but "combustion problems" limited it to 400 hp.

I would like to know what turbine blade alloy it used. Could not find this info online. I have a feeling the blade alloy limits were what limited the engine power, since that is the main limiting factors on gas turbines in general.

Note: The Hungarian version of the wikipedia article says the turbine ran at 550 C, and...

  A turbinalapátokat 50% reakciófokú csavart, szárnyprofil keresztmetszetű hőálló acélból gyártották precíziós öntéssel, és speciális beerősítéssel szerelték a rotorba.

Google translate:

  The turbine blades are made of 50% reactive twisted, heat-resistant steel with wing section cross-sections, and are specially mounted in the rotor.

Don't know what that means. 50% steel? Then what is the other 50%? Also, there is no citation for it.


texts: Can hydrogen gas be an alternative fuel source for a gas turbine engine?

texts:
I want to do research for an alternative fuel source for a commercial aircraft that will reduce the cost for flights.

Will the hydrogen gas be ignited in the combustion chamber and produce enough thrust to power the aircraft for flying? As for the problem that people had stated before for storing the gasses in a high pressure gas tank, can an increase in the aircraft weight be reduced by replacing the tank with usage of a hydrogen generator instead of a whole bulky tank that will weigh more?

By using a generator which converts water into hydrogen gas, we can just use water as our main fuel source which is more cost efficient?

In a flame of pure hydrogen gas, burning in air, the hydrogen (H2) reacts with oxygen (O2) to form water (H2O) and releases energy. If carried out in atmospheric air instead of pure oxygen, as is usually the case, hydrogen combustion may yield small amounts of nitrogen oxides, along with the water vapor.


texts: Why do budget airlines not use the jetbridge that's right there?

texts:
Related to Who decides whether an airline docks at a jetbridge or parks at a remote stand?, but I'm not asking about remote stands.

I recently took an easyJet flight (A319/320) from London Gatwick (LGW) to Malaga (AGP), and once through the gate, we walked down some stairs adjacent to the jetbridge and out to the plane. We didn't use a bus.

But the airbridge was right there. Why not use it?


texts: Why is taxiing super slow after an ILS CATIIIB landing in almost zero visibility?

texts:
I have experienced my very first ILS CAT IIIB automatic landing at my own home airport Lucknow (VILK). I'm super excited but also have myriads of questions related to many unique procedures I saw which I never seen in all my years of flying. Even though I was happy to have experienced such a magical landing, I was afraid how are we gonna park now because it was all white and the taxiing on this flight was the literally the slowest taxiing I have ever seen in my life.
After we landed and I could barely see the taxiway markings and even the runway borderline was hard to see. We crawled to the end of the runway to make a 180 degree and backtrack to vacate via taxiway C. The plane had already slowed down on its initial landing roll and at that time I didn't know about any special procedures or anything like low visibility conditions.
I was wondering why we did not exit via Taxiway B or C or even D or E when we had so many chances to do so and why we had to come all the way to the end of the runway only to go back and exit via C again and park at bay 13?
If any pilots here who have flown in CAT IIIB conditions, I wanna know how hard it is to find the taxiways in such a thick fog?


texts: What are the procedures for flying supersonic over international waters?

texts: Supposing I owned a supersonic aircraft eg a MiG-21 and wanted to fly the jet out into international waters for a supersonic speed run.  Are there any particular ATC procedures for doing so?


texts: How much snow can cover a runway while still allowing commercial airliners to land safely?

texts:
In regards to this question I thought about how much snow is shown on the runway and the exits in the movie.

So normally a commercial airport will have a fleet of snow plowers or heaters to keep runways, taxiways and aprons mostly clear of snow. But what is the safety limit on when the airport would have to close down due to too much snow coverage on the runway (not due to heavy snowfall, but due to the runway being covered completely in snow).

I think once the markers are no longer visible you would have a severe problem navigating on the ground or once snow piles up so high that the engines would take in a lot of snow it might also be a problem. But what are the actual limits during which one could safely land an aircraft on a snowy runway? And has it ever happend that someone landed on a runway covered in snow anyways?


texts: Are there any helicopter blades that fold in the middle?

texts:
Let's assume that, for some arbitrary reason, helicopter blades are too long for transport or storage. Folding them at the rotor hub, as is done with conventional folding helicopter blades, would still be too long and there is a need to fold them further. So, they are folded somewhere in the middle of the blade instead (or as well).

Do such folding helicopter blades exist? If not, has there been theoretical studies on how it could be done? What would be the impact on blade performance?

This is a question about the theoretical feasibility and difficulty of using such folding blades, and whether there have been existing studies or designs for it. As such, the practical applications and whether it would be worth it, or whether there would actually be a real-life scenario where this would be useful, should mostly be ignored.

(Bonus point if it is possible to deploy the folded blades simply by starting the engine, but this is probably too outrageously complicated to pull off anyway.)


texts: What is this thing sticking out in front of wings?

texts: I was wondering what this little stick on the wing was. My best guesses are an antenna or some sort of air speed measuring tube?


texts: What is the difference between the V-shape tail and the straight tail on the Beechcraft Bonanza?

texts:
In one of the answers to the question which aircraft is the oldest in production, the
Beechcraft Bonanza is mentioned. While reading the Wikipedia entry on this interesting plane, I noticed that there are some models with a V-shape tail and some with a more conventional tail.

What is the difference between the two designs?

 Source: Wikipedia

and

 Source: Wikipedia


texts: Why are the exhaust pipes design on the Ilyushin Il-2 not very popular?

texts:
This is a piece of this image from Wikipedia

Note the circled region. Movies often show exhaust fumes coming from those pipes when the engine is started. So I assume these are actual exhaust pipes.
This design doesn't appear very often, especially in modern piston engine airplanes. Why is this the case?


texts: Can a TCAS be alerted when the intruder aircraft has a transponder in stand-by mode?

texts: Can a TCAS give a TAs (traffic advisories) if the intruder aircraft has a transponder in stand-by mode?


texts: What is the relation between solidity and lift coefficients?

texts:
I've seen this graph in a couple of places. I'm not sure what it's supposed to mean, as the formulae I've seen in the papers cannot be found in any standard book or reference.
Please let me know if there is some solid reference for this, or if you could explain what exactly this graph represents.


texts: Would it be beneficial for the Boeing 777x to have a biplane wing design?

texts:
The Boeing 777x has huge wings to generate lift even to the point of having to have a hinge and being able to bend them.

Would it not be advantageous to have 2 wings like a biplane or one behind another? And what disadvantages would there be?

  A biplane wing of a given span and chord has twice the area of a monoplane the same size and so can fly more slowly, or for a given flight speed can lift more weight. Alternatively, a biplane wing of the same area as a monoplane has lower span and chord, reducing the structural forces and allowing it to be lighter.

This is from Wikipedia so possibly not reliable.


texts: What do winglets do to increase aircraft performance?

texts: It seems like a lot of the newer airliners have winglets or wing fences. How do they improve aircraft performance?


texts: Are there any 100% renewable energy aircraft in development?

texts:
There seem to be several options for aircraft R&D regarding cleaner fuels for the time when fossil fuels are no longer economically viable.

Some of these include:

Algae. A drop-in fuel. These fuels are being used and developed in co-operation with the USAF. They have had several successful test flights.
Batteries. Doesn't seem viable at this stage.
Nuclear reactor on board. Doesn't sound safe.
Hydrogen. This wiki page says they could be built by 2020. That's only a year away now...

I've found a few examples of test prototypes & flights using fuel mixtures that improve emissions and gasoline consumption, but are there any commercial aircraft in development, with an expected launch date that utilize 100% renewable energy?


texts: Are high bypass turbo jet engines suitable for tail and body mounted engines.  If not what are the drawbacks, danger if so, are there any anycraft with any such setup?


texts: What are the differences between "Off/On Time", "Total AC Time", and "Offset"?

texts: Can somebody please help explain to me the difference between all of these. I understand that "Off/On time" is probably the Hobbs time which is determined by the time my battery master switch is turned on - but I do not understand the total AC time and the Offset. I am assuming that one of these is the time that my plane is in the air. Picture attached for reference, and I fly a Cessna 172R.


texts: Where to find US airport weather Service Levels?

texts:
Where can I find an airport's level of service for weather services?
In other words, how do I know if a given airport's Service Standard is a categorized as Service Level A, B, C and D?

For background, the FAA has determined Service Standards to categorize the levels of detail in weather observation sites. See the following from Appendix D of FAA JO 7900.5C (p. 152):

The term Service Standards refers to four levels of detail in weather observations at sites where there is a commissioned ASOS/AWSS. The first category, known as Service Level D, is completely automated service in which the ASOS/AWSS observation constitutes the entire observation, that is, no additional weather information is added by a human observer.
The second category, known as Service Level C, consists of all the elements of Service Level D, in addition to a human observer, who adds information to the automated observation. This is referred to as "augmentation." [...] Service Level C is provided at all airports with a properly sited, fully qualified Federal facility during facility hours of operation. During hours that the facility is closed, the airport reverts to stand-alone ASOS or Service Level D as described above.
The highest category, referred to as Service Level A, includes major aviation hubs and high traffic volume airports with average or worse weather. The remaining group of airports (smaller hubs or special airports in other ways, that have worse than average bad weather operations for thunderstorms and/or
freezing/frozen precipitation, and/or that are remote airports) are referred to as Service Level B airports


texts: Does the FAA intend to discontinue domestic flight plans and switch to ICAO-only on October 1, 2015?

texts:
According to someone on the internet, the FAA intends to discontinue accepting domestic flight plans and switch to ICAO-only in October.  I've also heard this around the airport, but been unable to verify it.

The provided link says that the FAA is proposing to phase out domestic plans, but doesn't say that they've committed to it, nor does it give a date.

  The FAA is also proposing to implement flight plan filing for civil
  aircraft exclusively under the format used by the International Civil
  Aviation Organization (ICAO).

Is there an official FAA publication that verifies the FAA's intent to stop accepting domestic flight plans on October 1, 2015?


texts: How slow could the U-2 fly at 50,000 ft?

texts:
How slow could the Lockheed U-2 fly at 50,000 ft?

It was surely subsonic as its max speed is 500 mph.


texts: What is the official EASA definition of A, B, C and D checks, or where do I find it?

texts: Schedule Maintenance is divided into many different checks. What is the official definition (EASA website, not wikipedia) of A, B, C and D check, or where do I find it?


texts: How can a glider pilot add sport pilot privileges?

texts: If I understand the rules correctly, if one already has a Private Pilot rating, then one has Sport Pilot privileges but will need an endorsement for a new category/class of aircraft. What if one has a Private Glider rating? Would that person be able to fly a Sport Pilot power aircraft with just an endorsement?


texts: What are these lines on the fuselage of a 747?

texts:
Have a look at this picture:

It's from Airliners.net (though I've modified it a lot) and shows some lines on the fuselage. What are they? Are they Lightning Diverter Strips like in this question ?


texts: Is AMS (Schiphol) Polderbaan the runway furthest away?

texts:
I'm very interested to learn if there are (m)any (major) (commercial) airports that have runways further away from the terminal(s) than Schiphol's Polderbaan. Which airport is "in the lead" in this respect?

The northern end of the Polderbaan, the last runway to be constructed, is 7 km (4.3 mi) north of the control tower, causing taxi times of up to 20 minutes to the terminal.
[...]
Newest runway, opened 2003.
Located to reduce the noise impact on the surrounding population; aircraft have a lengthy 15-minute taxi to and from the Terminal.

Wikipedia


texts: What is the best method for an emergency takeoff?

texts:
(YouTube)

Before the collision at Tenerife the pilot of KLM Flight 4805 caused a 22-meter (72-foot) tail-strike by rotating early (I can't say that I blame him given the circumstances).

Is dragging the tail on the runway the best course of action in scenarios where a liftoff must happen as soon as possible?


texts: When does an instrument approach "begin" per §135.225(a)

texts:
§135.225(a) states that, "...no pilot may begin an instrument approach procedure to an airport unless—
(1) That airport has a weather reporting facility operated by the U.S. National Weather Service, a source approved by U.S. National Weather Service, or a source approved by the Administrator..."

Assuming that a part 135 pilot is operating to an airport where the weather reporting is out of service, and the pilot is not conducting eligible on-demand in accordance with §135.225(b). What portion of an IAP (if any), can be flown in this case without violating the intent? Is the IAP considered to "begin" at the IAF, IF or, for the intent of this regulation, at the FAF? Or, does it begin at the point ATC says, "cleared for the approach?" In a case such as this, the 135 pilot is needing a descent to VFR weather, since an IFR arrival (including visual or contact approach) is not authorized. Being able to descend to a the initial or intermediate segment altitude would obviously be an advantage.

If a local (or designated facility) altimeter setting is not available, terrain clearance would not be guaranteed when descending to the initial and intermediate altitudes. In that case I believe that ATC could not give a clearance for descent to those altitudes.


texts: Is it possible for squawk to change automatically in emergency situations?

texts:
It might be a silly question, but is it possible for an airliner to automatically switch the squawk code to emergency (7700) during a flight? (For example in case of losing all engines)

Thank You In Advance :)


texts: Why there are more requirements for being PIC of the airliner above FL200?

texts:
From another answer:

  Because there are first officers who legally can't be PIC of an
  airliner above FL200...

Why more experience is required to fly the airliner above I assume 6096 meters? I would expect, taking off and flying close to terrain should need more experience.


texts: How many Airbus planes have been destroyed in flight by severe turbulence?

texts:
Since a brand new A350 has literally the exact same design specifications / G limits as an airliner built in the fifties does (A 1955 F27 Fellowship will break up at 2.5 G-3.75G, same as a modern Airbus jet - anymore than 2.5 G it will start to break up), and there were quite a few airliners from the 50's and 60's era losing wings or being destroyed completely as a result of turbulence.

Are there any Airbus planes that have broke up due to turbulence or accidents that were likely due to turbulence, but covered up?

Do Airbus planes have systems to avoid Clear Air Turbulence, and avoid flying over mountains, since most turbulence related inflight breakups occurred due to mountain wave activity? (BOAC Flight 911 for instance was flying over the top of a mountain - it experienced G forces of +9 and -4, and broke apart and crashed).

https://en.wikipedia.org/wiki/Wien_Consolidated_Airlines_Flight_55

https://en.wikipedia.org/wiki/BOAC_Flight_911

https://en.wikipedia.org/wiki/Braniff_Flight_250

https://ral.ucar.edu/aap/turbulence

(scroll down the last link for photos of the DC-8 jet with half its wing and engine torn off due to turbulence while flying at 31,000 feet over the Colorado mountains)


texts: Do aircraft engine intakes require air filters?

texts:
I see helicopters which have air filters in their engine intakes, but jet fighters and commercial turbojet airliners don't seem to have any filters in their air intakes.

Isn't it true that even tiny particles can damage the turbofan's blades, especially since they rotate at such high speed?

What if the aircraft has to fly through a dusty area?


texts: Clarification on flight hours as compensation

texts: I've seen the phrase "flight hours as compensation" before, and would like some clarification on it. What I've read seems to generally concern operating an aircraft on a PPL for a commercial purpose, basically meaning if you fly an aircraft and don't cover "your share" of the aircraft expenses, then recording your flight time may be considered compensation by the FAA. What I'm wondering is, does it stop being considered compensation after you get a commercial license? If I have a CPL and fly for hire, paying no expenses of the flight, are my flight hours considered compensation in addition to my wage? Do I have a legal right to those hours? Is a company allowed to, as a condition of employment, require that I don't log hours while flying their aircraft? If a company suddenly and without reason sticks me behind a desk instead of having me piloting an aircraft,  would the loss of flight hours be considered a pay cut?


texts: How the antenna on the B737 Max fuselage doesn't disrupt the airflow?

texts:
As the title already say, how does the antenna on the Boeing 737 Max fuselage not disrupt the airflow?

(Boeing) 737 MAX antenna.


texts: What is the difference between an RPL and a PPL licence?

texts:
I am looking forward to starting my training to get my RPL license and I was wondering what the difference was because on the website it looked like you have to do 2 different pieces of training for each license. If I was to get my RPL in Australia what would the difference be between the two?

Thanks,


texts: Is it likely that an aircraft could have been near 10° 08' north at local midnight August 26/27, 2003?

texts:
Edit: The astronomical data turned out to be different. I'm keeping the constraints below as they where, but those are not relevant to finding the closest person to Mars.
This is part of an effort to determine which human has been closest to Mars. As Apollo astronauts and ISS space station crew are ruled out, this someone must have been on Earth
That's why I'm turning to you. Planes are frequently flying 10km or higher, much higher than any mountain on Earth, and passengers and pilots are therefore higher up than any people on the ground.
There are some rather delicate restrictions:

The aircraft must have been very close to 10° 08' north. There's a quickly growing altitude penalty for being far from this..

The aircraft must have been at this latitude at local solar midnight

The longitude is not overly important. For the western hemisphere, the date is August 26/27, for the Eastern hemisphere, it's August 27/28. Africa can be either, but has a 700m altitude penalty be default.

Is night-time air traffic dense enough for this place to exist?
From initial research, busy airports such as Singapore and Kuala Lumpur are south of this line


texts: Do all aircraft need to have horizontal and vertical stabilizers?

texts: Are (or were) there any operational aircraft that don't have horizontal and vertical stabilizers or canards? If so, what's the effect on how they fly?


texts: Would it be viable to use jet blast deflectors as a power source?

texts: From an environmental point of view would installation of windmills just before jet blast deflectors provide enough power to power up all machinery at airports? How much of a reduction in reliance on fossil fuel sources of energy would that be? By how much would that reduce landing fees and could the energy provided at least power a mechanism that could tow All aircraft (including the Airbus A380 and the Boeing 747) during the entire taxi phase pre flight and post landing along with ALL airport machinery in busy airports like Heathrow


texts: What is the typical voltage and frequency of the electrical generator in an airliner?

texts:
How many volts does the typical airliner CSD (Constant Speed Drive) produce?  I've read the CSD's output is typically 3-phase 115 VAC @ 400 Hz. Is that correct?

I've also read the typical airliner generator puts out "in-phase 28 VAC". Is that correct?

Does the CSD provide more voltage than the generator needs and the generator reduces the voltage via a transformer?


texts:
Regarding the 1902 Wright glider. Why is the airspeed, Va, calculated adding the ground speed, Vg, and wind speed, Vw?

In August 1903, Octave Chanute published in L'Aerophile a table (see attached) showing the measured quantities:

(1) distance traveled along the ground (col. 2),

(2) flight time (col. 3),

(3) wind speed (col. 5),

(4) glide angle (col. 7),

corresponding to a few flights performed on Oct. 8, 1902. From these parameters and the total mass of the machine and pilot, O. Chanute calculated that the 1902 glider lifted about 62 kg/hp (see the last column).

It is not quite clear for me why Va = Vg + Vw (see col. 6). The airspeed should be constant, independent of the headwind speed, as long as the glide angle is the same because the thrust is the same. It is true Va = Vg + Vw but if Vg added to Vw does not give always a constant Va, for the same glide angle, then something is wrong with the measurements.
The water speed of a boat traveling upstream depends only on its thrust and is independent of the river speed.

The lift in the table (~62 kg/hp) is quite big in comparison to the lift of the best gliders of the time, mentioned by O. Chanute a few lines below the table, that lifted only 45 kg/hp.

The precise value of the airspeed, Va, is essential in calculating the lift. If ones takes it only 1-2 m/s lower, due to miscalculations, then the evaluated lift grows artificially.

Source: http://gallica.bnf.fr/ark:/12148/bpt6k65534693/f190.item.r=wright

Update

There are a few sources of errors that could have altered substantially the results in the table.

(1) O. Chanute wrote, above the table (see the link), the Wrights did not drift, more than 1/4 in a arc of a circle from the straight line, to always have good headwinds. This drift increases the traveled distance.

(2) The glider was first lifted as a kite to a few meters above the ground with the help of two men. This height made the glide angle to be higher than that of the slope, which can be estimated from a picture (see the attached image where the glide angle appears to be 9.01 deg).
If instead of 7 deg 20' the slope angle was 9.01 deg and the 1902 machine started from a few meters above the ground then instead of 58.1 kg / hp it would have lifted less than 114.4 kg / (114.4 kgf * sin(9 deg 20 minutes) * (54.7 m/12 s + 5.68 m/s) ) = 47.4 kg/hp.

(3) The third factor of incertitude is the wind speed that varies with altitude being stronger a few meters in the air than close to the ground.

Wright glider, 1902. Undated picture.

Question: Do you know a modern replica of the 1902 glider that lifts ~62 kg/hp?
If such a thing exists then the 1902 machine could have lifted 62 kg/hp.


texts: Is drift and sideslip angle the same in the accompanied figure?

texts:
Consider the following figure:

Initially aircraft is moving along dotted line. But due to wind, aircraft ground track is changed to solid line but body still pointing parallel to dotted line. I've the following questions:
(1) What is sideslip angle in this case?
(2) What is direction of relative wind?


texts: What does the German AZF radio license test comprise of in the oral examination?

texts:
I understand you're required to have an AZF-license, on top of a BZF-license to do IFR radio transmissions in Germany; I also figure the test is similar to the BZF license with a written and an oral part.

What's a typical sequence of radio calls in the oral test? Are there any particular gotchas one should be aware of?

I've read through a list of phrases (out of something called NfL), so I'm vaguely familiar with the differences from US phraseology, but I got from the BZF test there are other differences, like you tend to get a question "Are you ready to copy", rather than the "advise ready to copy" I'm used to.


texts: How can a passenger determine airspeed without a handheld GPS?

texts:
This question is in the context of being a passenger on a commercial airliner, where you're in the cabin and the cockpit door is locked.

In another question, someone posited that if an airliner had reduced its airspeed by 60%, he'd be quite concerned.   I asked "How would he even know?"

How would a passenger on a commercial airliner, who is reasonably technically savvy but not a pilot, be able to discern airspeed?

This is old school. The person does not have any modern smart devices.  Or does, but their battery ran down.  (Not looking for a product reco for a gadget or app, there's another answer for that.)  The person could probably improvise a plumb bob, stuff like that.

Would anything change if the passenger has a clear view of the ground, relevant maps with scales, and a stopwatch (but not any wind data)?


texts: What has been done to provide security for remote wireless updating of in-aircraft software components?

texts:
Is it true that in the latest generation of Boeing aircraft some software components / Electronic Flight Bag data can be pushed to the flight remotely via a Wireless link?

If so, what sort of safeguards are in place to preserve the integrity of such an update? How does the aircraft authenticate that the data sent is indeed legitimate?

I'm curious to know the details. e.g. Are these conventional Ethernet networks over which the update gets pushed at the airport end? Is the final wireless transmission done by a COTS WiFi router? Does the update travel via the internet from (say) Boeing till the airport?


texts: Is more cargo loaded if there is less passengers than expected?

texts:
When pre-flight weigh in is done, if the plane weighs less than expected because people don't turn up, is more cargo added?

Conversely - if the plane is over the estimated weight - does cargo get removed?  Passenger bags removed?  Passengers removed?

Is it within the airline's strategy to achieve 100% seat capacity utilisation?


texts: Why do helicopter rotors have constant section and angle of attack?

texts:
As I understand it helicopter rotor blades keep a constant aerofoil section along their length, and are not twisted. Other rotating aerodynamic devices such as propellors, turbofan fans and wind turbines thicken and get a steeper angle towards the hub due to the lower incident airspeed (in the direction of rotation).

I'd guess it'd have something to do with variation of airspeed on the advancing and retreating sides maybe?

Edit: some are pointing out that this may in fact not be true, and that rotors can in fact have twist, just that it's less visually apparent. The chord at least would still appear to be constant

Edit 2: Since posting this I've taken a module in helicopter aerodynamics at uni, and the question is indeed wrong, blade twist is most definitely a feature of helicopter design.


texts: What is the diameter of a Trent 900 engine?

texts: What is the diameter of a Trent 900 engine, i.e the diameter of the fans, from one fan tip to the one that is directly opposite it? What is the radius of the fan or the the length of each fan blade?


texts: Is the nose cone of the MiG-21 adjustable in-flight?

texts:
In some of the photos I saw of the MiG-21, the nose cone was extended and in others it was shortened. So, is the nose cone of the MiG-21 adjustable in-flight to allow for increased/decreased air flow?

I noticed on a video yesterday from another question regarding the nose cone of the MiG that the SR-71's engine cones are adjustable, so that led me to believe the MiG's might be as well, though nobody mentioned it specifically in that particular question.


texts: What is an easy format for giving pilot reports?

texts: Is there a technique anyone has to make it easier to give PIREPs (mnemonics, etc?)  I'd like to be able to give them while I fly but I can never find the expected format handy, so it ends up being a hassle.  If there's a trick anyone has to make it easy to give one, please share!


texts: What, if any, would be the most correct term for the aerodynamic flight control surfaces of SpaceX's Starship?

texts:
SpaceX's Starship uses a unique flight control scheme during descent that I have not seen anywhere except with skydivers: it falls straight down belly-first using four aerodynamic control surfaces at the nose and the bottom to induce drag and thus provide pitch, roll, and yaw control, somewhat like a skydiver uses their four limbs.
 [Time lapse by @asy on Twitter, original source footage by LabPadre.]
This is a pre-flight actuation test of the aerodynamic control surfaces. The Starship is in its launch attitude, i.e. tail-down / engines down. On descent, it would be falling belly-down, where the belly is the side facing away from the camera, i.e. if the vehicle were falling right now, we would be looking at it from the top.
These aerodynamic control surfaces have been called lots of names by the spaceflight community: fins, flaps, wings, flings, wing-dings, flippety-flappety-bits (yes, really). Tim Dodd, the Everyday Astronaut, sometimes jokingly calls them Elonerons. SpaceX themselves only name them once on the Starship website, where they use the term flaps. Elon Musk uses both flaps and body flaps in tweets.
They are, however, different from many of the concepts mentioned above, in that they act perpendicular to the airflow. The closest analogy I can think of, other than a skydiver's limbs, is how the Northrop Grumman B-2 Spirit uses differential speed brakes for yaw control instead of a rudder.
Given that we have so many names for so many different types of control surfaces (e.g. flap, slat, spoiler, aileron, elevator, rudder, speed brake, horizontal and vertical stabilizer) as well as combinations of them (spoileron, flaperon, stabilator (all-moving tail), "ruddervator" (V-tail)), etc., there must be some term we can apply to these?
What I am looking for is a term that concisely conveys what these control surfaces do, in much the same way as everybody knows what an "aileron" or an "elevator" does. Or, alternatively, an answer could be that such a term does not exist.


texts: Advantages to doing an initial instrument rating training in a Cirrus over a conventional aircraft?

texts:
I live in Australia and I'm in the process of choosing a school for my instrument rating. I need feedback from the many of you out there with IFR experience willing to share their thoughts.

I'm going to do a single engine instrument rating because I am a just private pilot with no immediate plans of doing a CPL or flying multi engine aircraft at the moment. I have CSU and RU endorsements, have flown VFR to this day on a basic and complex aircraft. There are a few schools that I'm considering, with the only real difference among them boiling down to aircraft and, of course, total training costs.

1. Towards the top end, I could train on an SR20 and brand new full
    motion simulator in a posh school.

2. The middle range would be on an C182 or a PA28R and standard
    simulator.

3. The lower range would be on an IFR rated C152 + time on a complex
    aircraft, and again standard simulator.

All up, the costs would go from simple on the C152 to (almost) double on the SR20.

Here's my call for advice: Other than the fanciness of flying in an SR20 over a C152 and learning in a shiny school,

What are the real, concrete benefits of doing an IR in an SR20 over a more conventional aircraft?

On the one hand, the C152 has analog instruments while the SR20 is all glass and has autopilot which, I understand, comes down to personal preference. Another key difference is speed. I'd say that flying more slowly might be an advantage to stay "ahead of the aircraft" but then again, that might be beside the point of IR training. I'm the super lucky position to be able to afford both but I still want to make a financially clever decision as I'm not the kind to spend money unnecessarily. In hindsight, that's how I did my PPL and it served me well.

A great many thanks for your much valued answers.

PS. Another factor that does play a role is obviously instructor experience and their availability.

PPS. A definite minus for the SR20 is the "requirement" to do the CSIP endorsement which puts the total costs just shy of that of a multi-engine endorsement on the Seminole or on the DA42 + IR.


texts: Is it ok to use an iPad (or similar consumer hardware) and electronic charts for GA in Europe?

texts:
I'm wondering if it is it ok to use a consumer tablet and electronic charts (e.g. within the AirNav Pro app) instead of the paper version for recreational VFR single-piston flights?

Edit: to clarify, my question is indeed about official, up-to-date charts, accessed with consumer hardware (I mention AirNav Pro, but it could well be any pdf reader for that purpose) as opposed to paper medium.


texts: How do airlines handle uncertainty in passenger weight for weight and balance calculations?

texts:
When commercial airlines calculate the mass and distribution of passenger load, in the cases where they do not weigh the passengers directly, they use standard weight measures which have been approved by the appropriate aviation authority.

The standard weights can be broken down by passenger type (adult/child), by sex (male/female) and by other factors such as season or business/economy class. To obtain these figures a survey is carried out at an airport and appropriate measures are taken to ensure the sample is representative.

The result is a single value that represents the standard weight for a male/female/child/etc. Whilst the standard weight may have a minimal bias (i.e. a small deviation from the population mean), it does not represent the variance of the observed passenger weights. That is if the sample mean is 90kg with a std deviation of 10, the there is a ~15% chance that a passenger has a weight more than 100kg (assuming normal distribution, for the purpose of this example).

Given that airline operators have to be extremely careful and conservative with their weight management how do they account for this uncertainty in their calculations? Using the example above, if there were a flight with 100 passengers each >100kg, there would be an underestimation of mass by over 1 tonne (relatively small in comparison to total loaded aircraft mass, but still a large figure in itself).

Are accommodations for this variation incorporated into the standard passenger weight (say use mean + x std. dev.) or does this get included in the operational limits that the airline set for their max weight allowances in their various forms, for example reduced Max Zero Fuel Weight (MZFW) or Max Take Off Weight (MTOW)?

Edit: This is a slightly different question to a similar one about how a commercial aircraft has its mass determined. The focus here is more specific in looking at how the standard passenger weights are calculated and what are the assumptions around using that data.


texts: Is it possible to get permission to fly in the DCA “no drone” area?

texts:
The entire immediate Washington D.C. area is in a “no drone zone”, in a 15 mile radius from DCA.
Are there ways to get an exemption for activities such as film making, property inspections, etc?


texts: What is the difference between Boeing 73G, 73H and 737?

texts:
I found a data source, where Boeing 737 could be encoded with the following values - 733, 734, 735, 738, 73G, and 73H; Boeing 767 with values 762, 763; Boeing 777 - 772, 773, 777.

Any idea why such coding is used? Is it some standard to encode them with such values? Can I get more details from such codes (for ex., full aircraft type incl. customer code like Boeing 737-808)?


texts: Is spin recovery possible in an airliner?

texts:
During initial flight training a lot of emphasis is placed on stalls and spins and how to recover from them, but is it possible to recover from a fully developed spin in an airliner? Do these large aircraft have enough rudder authority to pull it off?

Has it ever been done? And is it part of the training for specific type ratings? (in a simulator of course)


texts: What's the shape and place of the tip vortex in a propeller, depending on propeller sense of turning?

texts: If the propeller vortex is placed and has changing features depending on the propeller sense of turning, both in traction and pusher configuration, knowing about this may have an interest for the design of multi-propeller airplanes.


texts: What are the effects of headwind strength on landing?

texts:
Assuming a direct headwind with zero crosswind component, what are the effects of landing into say a 10kt vs 30kt vs 50kt headwind? Are there any specific advantages or drawbacks to a stronger headwind when landing? Are there any specific procedures that kick in when the headwind exceeds a certain number for a certain aircraft?
I don't know if aircraft type matters much in answering this question, though I realize that small aircraft could potentially encounter a headwind that is faster than the recommended landing speed, thus making it difficult to reach the runway in the first place. Let's leave that situation out of the answers - assume that the wind is slower than the recommended landing speed.
I understand that landing into a headwind is the preferred option, and that tailwind landings are possible up to certain limits.
I understand that crosswind makes the landing more challenging and that there are limits to the crosswind component. Assume a direct headwind for this question.
I understand that a headwind makes ground speed slower for a given quantity of lift, but that's irrelevant to anyone but the passenger anxious to make his connection.
Assume a fairly steady wind with minimal gusting - at a level most pilots wouldn't be concerned with. (Unless, of course, gusts make a more or less significant difference based on steady-stream speed.)
Update:
This seems to be a fairly difficult question. I get the fact that, in practice, the above conditions are likely never going to be met, this is more of a theoretical question - assuming a direct headwind, assuming near zero gusting, assuming "significant" differences in headwind (in relation to the aircraft's landing speed - a C152 with one on board will land slower than a fully loaded A380). These are combinations that will probably never happen outside a wind tunnel, but I'm sure someone, somewhere has thought about them.


texts: Exactly where can a stowaway hide in a wheel well?

texts:
My question is exactly where a person could contort their body so as not to be mangled by the gear retraction system and very limited space. Some lived and died in the nose well and as I remember it, most aircraft at least provide half the nose wheel diameter (for several feet) to the nose strut (between strut and gear doors). The nose doors suddenly opening would explain why they fell to their death.

Presumably most people attempt to stow in the main gear and I just don't understand how?

WIKI lists approximately 150 known wheel stowaways. A cursory review shows about 20% percent lived through the ordeal. Most die of hypothermia, hypoxia, trauma from falling on the ground or in the air, but a few are crushed or mangled. Despite my knowledge as a pilot and A&P, I could not make an educated guess what a person would need to do as the gear retracted to keep from being crushed.

Medical issues are not part of this question and were covered by WIKI and reviewed in a  related question that asked "How can a stowaway hide in the undercarriage?" on SE. No precise aircraft volumetric space capability was given or the "aerobatics" (I could not resist) needed as the gear retracted.

I am particularly impressed that stowaways survived DC-3, DC-8, and most surprising is the B737; these are all aircraft I have worked on and can not imagine how it is done. No one listed attempted B757 but there is a somewhat spacious 12-18in in front of the retracted main gear for cables, fuel lines and valves that could possibly allow a human space.


texts: Should "Thrust Reduction" and "Acceleration" heights be the same for the Boeing 737 NG?

texts:
Should the Thrust Reduction height be the same, lower or higher than the Acceleration Height?
In other words, what is their "correct" sequence.
I am referring specifically to the B737NG, if it makes a difference.
And I am assuming no Noise Abatement procedures are in place, nor any obstacle clearance requirements.
Just assume one takes off towards the open sea.
I have already read the thread What determines the "acceleration" and "thrust reduction" heights? but it did not answer my above "simpler" question.
I always thought one does not reduce thrust before cleaning up but reading some posts I am in doubt now.


texts:
On aircraft with 2 crew placed one in front of each other (tandem) equipped with ejection seats, the rear seat is ejected before the front one (described here for the F-14).

Why is the rear seat ejected before the front one?
Is an aircraft without ejection seat (e.g. glider) evacuated in the same order and why?


texts: Why is the empennage of some aircraft not placed on the centerline?

texts:
Check the MD80's empennage below.

Can easily tell it's not built on exactly centerline by naked eyes.

Is that because aluminum joint or consider aerodynamics?

I don't think it is manufacturing defects or imprecision.

Some of the small aircraft have the same construction like this.

Couldn't find the similar discussion online though.


texts: Helicopter flight: Does the rotor disc plane and hub plane rotate along axis perpendicular to rotational axis?

texts:
In many pieces of literature, diagrams as below are shown to explain the directional flight of Helicopter. I have the understanding that the cyclic input will only change the pitch angle of the blades and hence the amount of lift forces acting will vary around the disc. BUT the disc-plane (more specifically, the hub plane), will remain parallel (to the reference plane, for example, the skids, or the top surface of the helicopter). I mean, the disc plane shouldn't pitch down or up as shown in the diagram.

Am I correct? Also, I am finding hard to give a suitable name to the "reference frame", I tried to define above. Is there any standard name for that?


texts: Does DO-178C require static code analysis for level A software?

texts:
Does DO-178C have any guidelines on using static code analysis for level A software?

As per Do-178C:

  Section 6.3   Software Reviews and Analyses
  Reviews and analyses are applied to the outputs of the software development processes. One distinction between reviews and analyses is that analyses provide repeatable evidence of correctness and reviews provide a qualitative assessment of correctness. A review may consist of an inspection of an output of a process guided by a checklist or similar aid.

  An analysis may examine in detail the functionality, performance,
  traceability, and safety implications of a software component, and its
  relationship to other components within the system or equipment

Can this achieved by Static analysis ? Some of the tools like polyspace which has misra standard checks


texts: Is there an additive that can lower the freezing point of jet fuel?

texts: Does an additive exist to decrease the freezing point of jet fuel? I have found an additive that decrease the freezing point generated by drops of water (appears between 0 and -10°C), but I'm needing to reduce the freezing of the fuel (-45°C).


texts: Do you need type ratings for private flying?

texts:
This question popped into my head when I learned some Citation X series have shared (?) type ratings.

So a theoretical situation:

I am a happy person with PPL and IFR ratings and then I decide to rent a 737-800 to give a birthday party to a close friend.

Can I just charter a private jet (assuming I am lucky enough to find a company that will give one to me) and fly? Do civilians need type ratings? I have heard you need a type rating to be the pilot in command. (It wouldn't be hard to find a pilot if that is the case.)


texts: Does currency in one C172 model apply to other models?

texts:
If I am current on one model of a Cessna 172, am I also legally meeting the currency requirements for a different version of the same aircraft model? For example, if I have many hours in a Cessna 172M, but have lately been flying a Cessna 172S, would I also be able to take passengers in the 172M?

This could be the case for a flying club that has many different versions of the same aircraft model. Perhaps on a nice day of flying the aircraft that you have been flying more recently has already been booked. You would still like to perform the flight with a different aircraft also offered by the club. However, it has been more than 3 months since you have last flown that specific aircraft.


texts: What are the consequences of an airline pilot deviating from a flight plan to perform a random maneuver?

texts:
What are the consequences of a pilot flying a scheduled airline flight with passengers deviating from a flight plan to perform a random maneuver?

Say during a normal landing procedure, he spots something interesting not in his normal flight plan nor in the normal landing procedure, and decides to do a fly over, then returns to land the plane normally.

I imagine he would be fired from his company, but would there be legal action against him? If so, what would be the severity of the crime? (We can assume the US or Europe).


texts: What did a maintenance person put into the engines after landing?

texts: I was recently flying on a A320-251N and directly after landing & coming to a halt at the gate, a maintenance person approached the engines carrying a box of something that looked like paint cans, opened some lid on the side and apparently put some of the content of the cans into the engine or so. What was it probably? (It was on an cold & icy airport, if that plays a role)


texts: What are concrete examples for class G up to 14500?

texts: It is said that there are some places where class G goes up to 14500 and then class E starts. However, I find they all overplayed with some special use airspace by looking at NorCal and SoCal Sectionals. Can anyone point me to some non-trivial 14500' Class G places? It is best to see some civilian airport within it.


texts:
I will soon be retiring from my first career as an electrician on large construction projects. Planning on becoming an active private pilot again and I am
basically an aviation nut. I am curious as to what certifications are needed to be employable at an avionics shop ? What would be the best/quickest route to get there?


texts: Say a seaplane has ditched onto ocean or a very large lake due to engine failure. Is it possible to sail the plane to the shore using wind alone, similar to sailing a boat?


texts: Does Air Force One (VC-25) have retractable staircases on all its exit doors?

texts:
While going through an article on AFO, I came across this little piece of info:

So, does it have retractable steps on all its exit doors? How does it manage doors like these?


texts: How much would it cost to fit and maintain every passenger life jacket with personal beacon?

texts:
About a year ago one sailor showed his fancy life jacket. It included EPIRB or also known as personal beacon.

To date, the smallest personal beacon I managed to find is Fastnet 220, which weights 150 grams and has battery life of 6 years.

Given the scale of airline industry, how much would it cost in installation, maintenance and fuel, to fit each passenger life jacket with such device, excluding the device cost itself?

Edit: Total weight per 200 seat airplane is 30kg. Perhaps someone can translate to fuel/$ per year per whole industry?

From Thomas Cook PDF, I found that life jackets are audited every 12 weeks and takes up to 40 man-hours per aircraft although they've implemented RFID tags now.

Regarding points outside the original question scope:

The device cost can also decrease to few dollars if they are manufactured in mass scale.

Certification is also a factor. Feel free to estimate it as well if you are familiar with the industry.


texts: What's the difference between Rotation speed vs takeoff speed?

texts:
My aviation teacher told us to memorize some speed values among other things before our flight training:

$V_R$ = 40 kt
$V_S$ = 39 kt

According to wikipedia:

Vr:
The speed at which the pilot begins to apply control inputs to cause
the aircraft nose to pitch up, after which it will leave the ground.

But I'm somehow confused with the values, since the takeoff speed (according to what I was taught) should be 10-25% greater than Vs, in this case around 43 and 49 kt.
If Vr is the definition mentioned above, which should be takeoff speed? does it have a definition within V speeds? Isn't takeoff speed the speed at which the aircraft leaves the ground?
Thank you


texts: Why do we have to check the speed brakes during GPWS memory items on an A320?

texts:
Just out of curiosity, I want to ask why do we have to check that the speed brakes lever is retracted during a GPWS (Ground Proximity Warning System) maneuver using the A320 memory items?

It clearly says in the F/CTRL SYS that the SPD BRK is inhibited if the thrust levers are above the MCT detent.


texts: How can we design a wing for cruising at very low speeds?

texts:
I was thinking about a simple super-light aircraft powered with a little low-power piston engine. Is there any way that we can design a wing so the aircraft flies very slow (like 25 km/h as minimum speed) without stalling?
I mean a suitable wing design for this kind of aircraft. (slow one) Other questions:

Which parameters in designing wings must be considered for lowering stall speed?
My thrust power is low so I accept lower cruise speeds.whats the effects of this on my design?
Can we choose thicker airfoils for wing and ignore the drag issues due to low speed?


texts: Smoking in the cockpit - how is this tracked?

texts:
A finding in the final report of US-Bangla Airlines Flight 211 crash is that the captain was smoking in the cockpit during the flight (page 46, section 3.1.2 e of the final report). My questions are:

Are all occupants of the aircraft breathing second hand smoke
including the first officer? Smoke detectors do not work in the
cockpit?
More importantly, how would this kind of behavior be tracked and
corrected in the airline industry? Are the Cockpit Voice Recordings
reviewed? Are there systems/policies in place?


texts: Why is air mixed with bypass air on the A/C of an aircraft?

texts: Air is taken from the compressors, then it is cooled by the air that comes from the ram air inlet. After that, it is compressed and cooled again by an expansion turbine. When finally air is condensed, it mixes with bypass bleed air. What is bypass bleed air?


texts: Can I compute the lift coefficient based on the NACA airfoil?

texts:
I would like to know whether it is possible to compute the lift coefficient $C_l$ based on the NACA airfoil? Usually I look up the values on airfoiltools.com.

Eg: If I have a 2412NACA airfoil and would like to know the lift coefficient for an angle of attack $\alpha$ = 3°. What would be the corresponding lift coefficient?

Thanks


texts: Which FAA regulations require compliance with TCAS II Resolution Advisories?

texts:
I've always heard that complying with a TCAS II Resolution Advisory is a required action for pilots qualified and operating an equipped aircraft. I am not familiar with the regulatory basis for this, though. I'd like to get a bit more specific with the context. For aircraft operating under 14 CFR 91, is there a regulation that can be referenced?? For aircraft operating under 14 CFR 135, is there a regulation that can be referenced? And what about for 14 CFR 121?

I'd also like to know if there are exceptions to any regulatory requirements.

This answer mentions that aircraft must respond within 6 seconds. I believe the source is AC 120-55C but I'm not totally sure.


texts: What is the difference between a 'live' NLG axle and a 'fixed' NLG axle?

texts:
What are the advantages / disadvantages of a live and fixed nose landing gear axle and how do they work? Maybe certain aircraft need a particular type fitted?
I can't see the need of a moving axle (assuming that's what 'live' means) unless it is somehow powered by a motor or something similar for push back..

Or..
Maybe on an aircraft a live axle is one where it rotates with the wheel and a fixed one is where the wheel rotates around the axle?

The reason I ask is that I saw in a textbook that nose wheels are either on a fixed or live axle and nose wheel shimmy is prevented by using a twin nose wheel set up attached to a live axle.

I'm now not sure if the terms live and fixed axle are in relation to the vertical component or horizontal component of the nose gear.


texts:
I have a strange naming difference for a SID in a route. The route is:

  DOME4W DOMEG Y841 ANAVI DCT NVO UM170 KENUM UM615 IDOSA UN857 RESMI
  UN491 DITAL UN872 DIDAK UZ15 ARDOD A5 VALAX VALA1A

I am bothered by the DOME4W departure (Paderborn Lippstadt, EDLP). The actual name is DOMEG 4W.

Is it allowed to have shortened SID names? In the FMS, I see this as well as DOME4W, but the SID description name it DOMEG 4W. Why this difference?


texts: When is the autopilot engaged and disengaged?

texts: When does the pilot engage the autopilot during a flight? And when does he disengage it - e.g. at what height - during the descent?


texts: Why are the minima for Cat A higher than for other categories at KSEA ILS 16L?

texts:
I was looking at the KSEA ILS 16L approach (depicted below) and was wondering just why the minima are bumped up for Cat A aircraft (64 feet on both DA and HAT, as well as 200 feet of RVR).  Thing is, I've already checked Chapter 10 of the TERPS, and nothing in there says anything about approach-category-specific adjustments to ILS minima, nor does the Form 8260 for this approach say anything about the cause.  (This also makes the SA CAT I and CAT II/III procedures Cat A NA, which matters for aircraft that have a small aircraft CAT II ILS authorization IAW FSIMS 4.2.3.)  Furthermore, neither 16C nor 16R's ILS approaches have this feature, which is even stranger because you'd think that 16L and 16C are close enough together that their ILS OCSes would overlap, and they also use highly similar MAPs (climb to 900 on a heading, then intercept the SEA 161 radial, then proceed to TEBNE along that radial -- the only difference is the initial heading of 160 for 16C vs 165 for 16L).

What is doing this? Is there an obstacle there that is doing this only to small aircraft?  Is there some vagary of the TERPS I'm not finding? Is this an error?


texts: When are pressure-swirl atomizers and airblast atomizers used?

texts:
I am a little confused as to when (during T/O, cruise, etc.) and how the combined pressure-swirl atomizer and airblast atomizer is used.

Lefebvre writes that "the merits of the pressure-swirl atomizer at low fuel flows, namely, easy lightup and wide stability limits, are combined with all the virtues of airblast atomization (notably a soot-free exhaust) at high-fuel flow rates."

From this I understood, that if a combined pressure-swirl and airblast atomizer is used, then the swirl atomizer would be more used during cruise (lower fuel flow rates) and the airblast more during takeoff (higher fuel flow rates).

However, it is also stated by the author just before that for an airblast atomizer "The major practical disadvantages are rather narrow stalobility limits and poor atomization quality at startup, owing to the low air velocity through the atomizer."

At takeoff isn't the air velocity lower? And if that is the case, then this for me puts into question the use of the airblast during takeoff.

So are the conditions for the airblast atomizer: high fuel flow rate and high velocity and for swirl atomizer: low fuel flow rate and low velocity?

If so, how do they interact during engine operations?

All citations are taken from Chapter 1 of Gas Turbine Combustion by Lefebvre.

I know I am wrong and I would love to know why. Thank you for your help!


texts: How do you calculate the maximum distance to communicate with tower control?

texts:
I'm stuck on the following riddle found on the geocaching web site:

A helicopter pilot is flying at an altitude of 1981 meters. He is heading inbound an airfield 335 meters high. There are no particular obstacles (such as mountains, ...) between the helicopter and the airfield. What maximal distance (in nautical miles) can the pilot expect in order to be able to communicate with the airfield control tower?

Unfortunately I don't know anything about air control rules and multiple Google searches came to no avail.

Please could you give me a clue (not the answer as it would spoil the fun) how to answer this riddle?

Edit

For those who are interested here is the link to the geo-cache


texts: How does an RMI respond when tuned to a VOT station?

texts:
I know that a VOT station for testing VORs broadcasts a 360 radial signal, so on a VOR, the indication would be 360 with a 'FROM' or 180 with a 'TO' indication, but how does an RMI respond if tuned to a VOT station?

Would the RMI simply home to the station because it points to the direction signal is coming from, or would it point at the 180 position because it detects that it is on a 360 radial 'FROM' the station?


texts: How do exhaust cones affect the performance of turbine engines?

texts:
I've seen explanations stating that it creates uniform stream of exhaust gas towards the exhaust duct, however without the cone wouldn't it still be considered a uniform stream?

Also since a divergent duct is formed between the outer duct, and the exhaust cone, does that slow the air down so it reduces turbulence?


texts: Are there "Introductory flights" available to see if I want to pursue training?

texts:
Through endless sources available it's possible to learn the rules of flying without undertaking formal training: I can take practice tests, study flying rules, laws, altitudes, speeds, controls, etc., however, I'd like to try out actually flying (preferably for free) before considering the option of paying for a full license.

Basically I'd like to take a trial flight - I don't care if someone has to sit with me, but I'm not keen on the idea of spending a lot of money before at least having one flight under my belt.

Teens often drive before getting licensed in private; any options for me to do the same with aircraft machines?


texts: How can I estimate the required T/O power for propeller aircraft?

texts:
How can I estimate the maximum required take-off power for a propeller aircraft with the following available data?

Wing surface S
Max. lift coefficient in T/O configuration cL
Take-off distance available d (regardless of obstacle clearance etc.)
MTOW
Airfield altitude (let us assume MSL)

Is the data available even enough?


texts: How would you brief passengers who will try flying your plane?

texts:
Following up on this question about pilots letting passengers fly the plane, suppose you’re in a Cessna 172 with passengers and you have your PPL. If you want to let a friend try flying the plane, you might climb to 3,000' AGL and get clear of other traffic. You’d probably get to $V_A$ or a little less and trim for level flight. Then, you might let them try some shallow turns. You’d probably say:

Don’t fight me on the controls
If I say let go, let go immediately
Don’t move any of the controls very rapidly
Don’t move any of the controls to their limits

What else might you say? Are these things correct? What else might you let them try?


texts: When the brakes are checked, what do the firemen actually do?

texts:
Watching this video (at 06:58 mark), this plane had just made a mayday landing, due to a bird-strike. Because of the right engine being shutdown, it was forced to land immediately, with a full load of fuel. The added weight of the fuel, combined with loss of the additional stopping power of reverse thrust, caused the pilots to bear down on the brakes harder and longer than would be normal in an end-of-flight landing.

The pilot requests to hold on a taxi-way after vacating the runway, during which time the firemen come up to the plane to "inspect the brakes."

What do the firemen actually do when inspecting? Are they looking for fire? Glowing brake pads? Do they use an infra-red heat gauge?


texts: Would a gimbaled, always horizontal cockpit be beneficial to fighter jets?

texts:
Would it be possible to have a spherical cockpit that was gimbaled in jets such as fighters so the pilot was always upright. With all controls in the cockpit wirelessly communicating with the rest of the jet?

Wouldn't this be an advantage as it would be easier to aim and the pilot wouldn't get disorientated and could see anywhere by maneouvering?


texts: What are the aerodrome services SRE and CEV?

texts:
eAIP in France list two services on AD-2 (aerodromes) for which I have no clue what they stand for. They are not known to AIXM neither.

SRE found on eAIP of aerodrome LFOA
CEV found on eAIP of aerodrome LFBD

Any idea what these services are? Thanks a bunch!


texts: Is aluminum electrical wire used on aircraft?

texts:
Aluminum electrical wire got a bit of a bad reputation in household wiring due to reacting badly with terminals not properly rated for aluminum.  Properly handled, it works fine, but it's so distrusted for small branch circuits that distributors won't even stock it.

Aluminum is a worse conductor than copper, by almost half. But that only considers it by volume (e.g. Wire diameter).  By mass, the advantage swings back to aluminum.  Nearly twice the ampacity for the same weight.  Where would that matter?  Aircraft.

Transport class aircraft are increasingly electrical, like the bleedless 787 where electrical does much of the heavy lifting.

Is aluminum wire actively used in aviation?  Or is it "taboo" like it is with houses?


texts: How does altitude affect the speed of sound?

texts: I read once that the speed of sound decreases as altitude increases.  I wonder if that's true and, if so, are the pressure waves made at high altitude lesser than the ones at low altitude because of the difference in air pressure?  And, lastly, does that mean that lower speeds at higher altitudes will be subject to the problems one encounters when approaching mach speed?


texts: What are the ICAO GNSS waypoint naming conventions?

texts:
I'm curious about ICAO naming conventions regarding GNSS and RNAV waypoints. Would I be correct in assuming that all GNSS area waypoints are 5 letters, and RNAV waypoints are 6?

What about waypoints like CB401? Do these represent a reference to a VOR/DME? If so, why are they included in GPS waypoint databases?


texts: What are the names of the antennas which I have marked in this picture of a Boeing 737?

texts: I have taken the picture from PMDG 737NGX Microsoft flight simulator X. I am really curious to know what this antennas are. These antennas are behind the nose gear.


texts: How much force can the landing gear of a Piper Arrow withstand?

texts: I'm currently working on my CFI-A in a Piper Arrow and i was wondering if anyone knows how much force the landing gear can withstand? The reason I ask is because I have never been asked this question and I know there has to be a concrete answer out there. For example, aircraft in the Navy that need to land on a aircraft carrier have to go through a series of landing gear stress tests.


texts: What causes a taildragger to lift its tail during the takeoff roll?

texts: The rear of a taildragger is closer to the ground than the front. As the aircraft moves forward (I guess at its stall speed), its tail rises up and the aircraft moves with the fuselage level before takeoff (As seen here). But why? Does the pilot change the elevator?


texts: I've been wondering this for a while. I understand how planes detect electromagnetic waves with it's radar but I don't get how they detect if missile has locked to the plane using laser. Only ways I can figure are some kind of tiny receptors all around the plane but it sounds very impractical way.


texts: How does a TACAN signal change with bearing from the station?

texts:
In the TACAN system , how does a change in bearing , would translate to a change in the time (or frequency) domain.

I'll try to elaborate:

I'm aware , of the TACAN operation in general.

let's say that I'm 270 degrees (referance to north) and 180 degrees (referance to north) , how would this change reflect on a Scope or on a spectrum analyzer if at all (of course I mean in the analog signal).


texts: What would happen if the elevators were set to opposite angles?

texts: For example left elevator angle = +30 deg, right elevator angle = -30 deg. Would these settings be able to induce a rolling moment on the aircraft? What would happen with the pitch?


texts: How do you calibrate the compass of an aircraft on a compass rose?

texts:
A follow-up from this question; one of the answers mentioned that the compass rose in the picture was used to calibrate an aircraft's compass.

But how does that actually work? Do you park the aircraft on top or something?


texts: How much do the fan blades of a GE90-115b stretch when the engine is spinning at maximum RPM?

texts: I've always wondered what kind of stresses and resulting deformations jet engines are subjected to when running.


texts: Why didn't the EASA enforce the 2 man cockpit rule BEFORE the Gemanwings accident?

texts:
International numbers state that planes downed by pilot or co-pilot due to suicide are a rare but still possible occurrence.

In the United States such a safety procedure is standard (as of 9/11 - if I remember correctly). Why didn't the EASA think of that earlier?


texts: Delta plane looked like it was landing on Atlanta freeway

texts:
Yesterday a few minutes after 4:00pm ET (2020-01-04 21:00 UTC) I drove my car out of Park-Ride Lot C of Hartsfield-Jackson Atlanta International Airport in Atlanta and took 85 South to 285 West/North.

When I reached the 285 N part of my drive, a southbound airliner was descending straight toward me, and since Hartsfield doesn't have north-south runways, I immediately felt like something was "off".

Having lived in San Diego for many years (which has an airport VERY close to the city) and also Atlanta for many years, I'm used to seeing jets come in for landings.

But this felt different.

So I thought "Maybe it's a military plane, and maybe there is an Air Force base nearby with a north-south runway"... I was grasping for an explanation.) But I clearly read Delta on the belly of the plane, so Hartsfield must have been its destination.

It felt so much closer than any other jet in my years of living in the Atlanta area that I went home and felt certain I'd find news stories about a Delta jet landing on an Atlanta freeway, but I haven't found any.

I can think of 2 possible answers:

Maybe I was still on the parts of 85 S and 285 W that travel west, and the plane was flying east and landing on the southernmost runway (10). And maybe this particular plane just happened to be coming in lower than any other I've ever seen but within their own expectations for minimum altitude.

But I really think that I'd already made it to the part of 285 N that travels nearly due north (shown on the left side of the map).

Maybe there are tiny stretches of 285 N/W that travel due west for a long enough time that an aircraft landing on one of the other runways would have been facing me head-on.

But I think Google Maps is really accurate, and even when zooming in, I see no part of the 285 N freeway west of the airport that would have taken me due west.

Would there be any other explanation?


texts: Did CNN correctly state that AirAsia flight stalled and crashed?

texts:
CNN reported that the cause the crash of AirAsia Flight 8501 is:

  ... it stalled and fell out of the sky ...

The reality is that when an airplane stalls it does not fall out of the sky. Why did CNN report such a statement?

The aircraft was at 36,000 feet when it stalled. According to the flight recorder, it was descending at 6000 feet per minute. Stalling an airplane at 36,000 feet means there is plenty of time to recover from any stall, unless the airplane was loaded tail heavy. But that was not reported.

Am I missing something here?


texts: There are very few articles as to what wing stiffeners are on the internet, so my question is what are wing stiffeners?


texts: Would a 2nd row of distributed props on a 2nd staggered wing of a biplane increase its efficiency?

texts:
Would a 2nd row of distributed props on the rearward wing of a biplane with 25% gap and 150% negative stagger increase the efficiency of a biplane ULTRALIGHT, 25MPH, Re 500K? ( rear wing is 25% lower than forward wing, 150% rearward)

Both wings would have distributed propulsion from several props along their span in tractor configuration.

Forward wing props see a prop inlet speed of V1, or aircraft speed.

Forward wing sees V2 ( exit speed of prop), (assume an increase in speed of 50%, based on prop size, Hp using prop formula) V2=150%V1

Calculate forward wing size based on 150%*V1*k1

k1= efficiency/coverage factor of Wing1

Props of 2nd (rear) wing would have a inlet speed of V2, but an exit speed of V3 ( assume another 50% increase)

2nd wing sees a speed of V3=150%V2=150%(150%V1)=225%V1.

Calculate rear wing size based on 225%*V1*k2

k2=efficiency/coverage factor of Wing2

An interesting note: average leading edge airspeed over wings is (150%+225%)/2=190% of aircraft speed!! ( if this proposed theory is correct)

Is this correct, at least conceptually? See side view of configuration below.


texts: What is the moderate dihedral angle for a low wing airplane?

texts:
An increase in dihedral results in a decrease of the total lift produced by the wings. I would like to know the moderate dihedral angle (in degrees) for a low wing airplane, especially the amature built kind( for instance the rv-3).

Also, is there a recommended angle of attack for such category of airplanes.


texts:
Is there any type of relation that limits yaw rate of a multi-rotor (i.e quadcopter)?
Something like this relation for fixed wing aircraft: $R = \frac{v^2}{g \tan(b)}$, where $R$ is the minimum turning radius and $b$ is the maximum bank angle.


texts: What type of variation in temperature does the wing undergo?

texts: Generally what is temperature variation does the wing of the commercial aircraft like A380 undergo , flying at mach speed of 0.8 and how does it affect the aircraft other than icing , what type of literature can one go through to study the temperature effects on aircraft


texts: Why are movable rocket thrusters not used in airplanes?

texts: If an engine fails in a passenger airplane, why can't it have movable rocket thrusters in the wings to help safely land the airplane?


texts: Do any countries besides the USA accept Basic Med?

texts: Are other countries accepting Basic Med for flights through their airspace, for example the European Union?


texts: Longitudinal stability of airships: How is the critical speed defined?

texts: Airships are unstable in pitch above a certain speed, called the critical speed. What causes the instability, how does it manifest itself for the pilot, and how is the critical speed defined and determined?


texts: Was the oxygen mask, on this flight, out of order?

texts:
Recently I was on flight where the panel for the oxygen mask, above my seat, looked like on the picture: the "button" in the middle of the panel was extended, turned and was showing a red tag on the side.

I asked a member of the cabin crew if this indicated a problem and the response - after he had tried to turn and push it in - was "I don't know, I don't think so". The fact that he couldn't turn it, or push it back into the panel, makes me think that it is more than just a locking mechanism, that it might have indicated that the system was out of order and I should've moved to a different seat.

Was my hunch correct, does this indicate a faulty oxygen mask?

The plane was an Embraer 190.


texts: Which source to use when reporting the current altitude to ATC?

texts:
While flying from KSNA to KVCB VFR at night, Norcal Approach asked for my current altitude.  I was somewhere between 12.0 and 12.5 depending on which reading I was going to use.  ATC had me confirm.  My GPS altitude was 12.5, my transponder was showing 12.3, and my altimeter indicated 12.0.  I am assuming, since altimeter settings are based on the barometric pressure on the ground, that the thinner air above 12,000 feet would make my altimeter the least reliable of the three and the GPS the most reliable.

When ATC asks, should I give them the altimeter indicated altitude?  Also, is the transponder altitude that I can see derived from secondary radar and isn't that what ATC is already seeing?


texts: What happens if an aircraft is only stable at higher angles of attack?

texts:
Does anybody know what will happen to an aircraft, if it is stable (in longitude) for let's say: -8° > angle of attack > 8° ?
So for angle of attack 4° the aircraft is not stable (centre of pressure is in front of centre of gravity), so the angle of attack will further increase until 8° where it becomes stable (centre of pressure behind centre of gravity).
So except that my aircraft will oscillate a bit, it should always return to a stable position, right?


texts: What are the dimensions of the A320's wingtip fences?

texts: Does anyone know the size (relative to the wing) or have a schematic draw of these wingtip fences?


texts: Are there any precision approaches that use only GNSS/LAAS?

texts: Is there any airport which has a precision instrument approach using only GNSS (augmented with LAAS) for guidance?


texts: Minimum length required for the runway landing and takeoff of ATR 72-600?

texts:
What is the minimun length required for the runway landing and takeoff of ATR 72-600?
obs: altitude of 1000ft at 30 degrees


texts: Why is training regarding the loss of RAIM given so much more emphasis than training regarding the loss of SBAS?

texts:
I've noticed a lack of subject matter on the loss of SBAS as compared to RAIM.
In the ACS there is mention of RNP, SBAS (WAAS), and RAIM, which are all related, but the available content for RAIM and WAAS is much heavier on losses of RAIM than losses of WAAS.
This really became apparent to me when I was searching Garmin G1000 documentation to find annunciations regarding the loss of SBAS, and I noticed that there essentially isn't one other than "APR DWNGRADE" which loosely translates in the manual to, "you lost WAAS capability".
However, the loss of RAIM has a much more clear and direct annunciation, "RAIM UNAVAIL": that needs no translation and is immediately clear that you've lost RAIM.
Why would Garmin not have an "SBAS UNAVAIL" or "WAAS UNAVAIL" annunciation in the same manner as they do for RAIM?  It's almost as if the industry as a whole largely discounts the possibility of SBAS failures.

Here's a list of G1000 NAVIII Annunciations
Here is where WAAS is mentioned in the annunciation list.  Note that the column on the left is the annunciation displayed on the flight deck, but the column on the right is the manual's referenceable extrapolation:

Notice above that neither of the flight-deck-displayed texts on the left which have extended explanations on the right that include "WAAS" also contain "WAAS" or "SBAS" in their in-flight annunciation messages' texts.

Here is where RAIM is mentioned in the annunciation list:

Notice above that the flight-deck-displayed text does contain "RAIM" (twice) for a RAIM loss.

I included the above information to demonstrate my point, and I essentially have three closely-related questions:
Why is Garmin so indirect about the loss of SBAS in their annunciations?
Why do pilots not also perform SBAS predictions like they do for RAIM?
Why is the loss of RAIM given so much more emphasis in training than the loss of SBAS?


texts: In wing design, how is factor of safety related to G-limits?

texts: What does factor of safety mean with regard to the maximum G force an aircraft is rated for? Does a rating of 3Gs mean the same as a safety factor of 3? Or is there some extra margin?


texts: How A330-200 or 243 would be much safer under the ETOPS terms?

texts:
I am flying this week to France in an Airbus A330-200. I have a phobia of flying I have several questions here on the aviation forum. The plane is A330-200 is the one we're going with and I am reading about it. It works under the term ETOPS.

I read this part and now I am scared more than ever and I didn't understand it correctly:

  In aviation vernacular, the colloquial backronym is "Engines Turn Or
  Passengers Swim", referring to the inevitable emergency water landing
  of a twin engine aircraft after a double engine failure over water
  outside gliding range of land. But ETOPS operation has no direct
  correlation to water or distance over water. It refers to flight times
  between diversion airports, regardless as to whether such fields are
  separated by water or land.

The company I am flying with, its fleet has an average age of 5.6 years in 2016, making MEA one of the youngest fleets in the world.


texts: What is the use of wing root seals? What kind of leaks are possible without having wing root seals, and if the seal is broken what kind of issues can airplanes face?


texts: Are you allowed to do your entire PPL on a medium-sized jet aircraft from day one?

texts: I'm wondering if say, hypothetically, I had a friend who had a large aircraft (e.g. Learjet), could I do my PPL hours on it from day one, or is there anything stopping this?


texts: How do internally carried IR missiles acquire a lock?

texts:
On aircraft that carry their IR missiles on external stores, like the F/A-18, an IR-missile acquires a lock by having its seeker being directed to the target heat source by whatever means and the missile then locking on the the heat contrast with its own seeker. The missile only gets fired once the seeker has a positive lock.

How would this work in an aircraft that carries its IR-missiles internally?

Would the weapons bay doors have to be open to let the missile acquire a target with its own seeker or would the missile just be given an approximate position where to search and it would then acquire a lock on its own once it's out of the weapons bay?