What is the correlation between RNP level and the CDI indication?

The Performance Based Navigation concept allows to optimize the instrument procedure design with the aircraft navigation performance.
This concept is used en route, to reduce aircraft separation, and in terminal area to optimize arrival and departure procedures. The utmost development of Performance Based Navigation for approach, missed approach and departure is known under different names.
FAA initially referred to RNP SAAAR Operations, SAAAR standing for Special Aircraft and Aircrew Authorization Required.
ICAO now refers to RNP Operations with Authorization Required (RNP AR).

The estimation of the aircraft position is performed by the Flight Management System based on different sensors: Inertial (ADIRU), GPS, radio navigation (DME and VOR).
The FMS computes the best aircraft position estimate based on the following hierarchy of navigation modes:

GPS/inertial,
DME/DME/inertial,
VOR/DME/inertial,
Inertial only.

The RNP capability depends on the availability of GPS/IRS integrity.

The GPS integrity mainly depends on the number of received satellites, the FMS will calculate the GPS estimated error as a function of the number of received satellites and which satellites among the most appropriate for the aircraft position.

The ADIRUs are capable to evaluate their own estimated error that they send to the FMS, similarly the FMS itself is able to calculate the ADIRUs  drift error based on previous ILS landing(if any)  as he compares the ADIRU position to the real aircraft position while on the ILS, This error is reduced to a mean average drift per hour of flight.

The FMS therefore is able to calculate an Estimated Position Error (EPE), thus allowing the CDU to display both the Required Precision, and the Estimated precision

With respect to the HSI, it displays a route as well the approach calculated by the FMS, within the estimated precision which normally is better than the required precision, the pilot is supposed to be on the route and not one dot  or 2 dots apart. When the CDI is centered you are within the Estimated Error;  However indeed if the CDI is not centered the error is augmented as you say in the question, but you should not add the RNP but the Estimated NP that shows on the CDU, because the FMS calculations are normally correct.

Of course if your equipments are faulty and mysteriously the multiple faults are not detected you may be neither within the RNP nor within the ENP.

Please refer to the following website for more details:

https://www.theairlinepilots.com/forumarchive/aviation-regulations/rnp-ar.pdf


What does the "BA/" stands for in this ATIS?

I think the BA/ references "Braking Action" in the ICAO D-ATIS sequence. Since the example report from LBTA (Istanbul Ataturk International Airport) does not suggest that a Braking Action value would be assigned (no rain, etc), it appears to be a placeholder for that information if it was provided.

Below is an excerpt from Annex 11, to the publication - Convention on International Civil Aviation (Air Traffic Services), showing the sequencing (where it would normally appear in the D-ATIS report) of a Braking Action report (if provided/available).


Does the FAA have risk targets for specific activities?

"We rate passenger airline flights as 'safe' if there are fewer than X casualties per million flying hours"

I am not aware of any official FAA document that states such sentence. However, something similar can be deduced from safety requirements related to the development of aviation systems.

ARP4761 is a well-known standard for conducting safety assessments on civil airborne systems and equipment. A probability of failure occurrence associated with the severity classification can be found on page 14, which shows the following table:

As it can be seen, the maximum allowed occurrence of a catastrophic failure is 1.0E-9. Playing a bit with the numbers, this could be translated in:

  Commercial aviation flights are considered as 'safe' if there are fewer than 1 catastrophic condition per billion flight hours

One could assume that a catastrophic condition can lead to fatalities, and this seems reasonable. But I'm afraid that this presumption is not written in official FAA publications (I might be wrong).

P.D.: Now, where these probabilities of occurrence come from is another interesting (and un-official) story, but I think is out of the scope of this question for the moment.


Can light aircraft be equipped with yaw damper?

Yes.  The Garmin Perspective avionics suite for the Cirrus SR-22 is equipped with a yaw damper in its GFC-700 AFCS.

The King KAP140 autopilot also offers a yaw damper function for aircraft with a servo controlled rudder trim.


How does leading edge flap increase camber?

Leading edge flaps and droops do increase the camber because when they move, the leading edge actually droops, and with it the leading edge extremity of the chord line, while the mean camber line remains in place for most of the airfoil length:

Droop

The airfoil is dramatically bent down to the point the bottom side is now concave and the top side has a larger convexity.

Effect on the lift coefficient:

For the same angle of attack α, CL is decreased, but it is now possible to reach larger α and with them larger CL. It also means lower speeds are required to generate the same amount of lift.

LE flaps are usually found at the outboard portion of the wing.

More: Aircraft Design, a conceptual approach, Daniel P. Raymer (around page 278 - view it)


Why don't helicopters always takeoff from a hover out of ground-effect?

Forward flight is much more efficient than hovering.  As airspeed builds, lift increases from "translational" lift as the air moves more horizontally over the disc.  Since the relative airflow is more horizontal, the angle of attack for a given pitch angle is increased.

The vortices and turbulence move behind and down from the helicopter so undisturbed air is drawn over the disc to be accelerated downwards to produce lift.  Lift is more efficiently produced by accelerating a large mass by a small amount rather than a small mass by a large amount.

It is more efficient to remain in ground effect and slowly increase speed to gain translational lift than to increase power to HOGE (Hover Out of Ground Effect) and attempt to translate.

The problems you refer to are where an unwary pilot attempts to transition from HOGE whilst allowing the aircraft to climb or attempting to maintain height.  Without enough power, the loss of ground effect before the benefits of translational lift are gained will result in a rapid descent back to earth (as vortex ring state or settling with power is pretty much impossible to avoid) or you overpitch and drag the RRPM (rotor RPM) down so low that you cannot produce lift or even worse, stall the blades.

Bottom line, it takes more power to establish positive climb out of ground effect than to gain translational lift in ground effect.


How do I find the magnetic bearing to the station in this question?

I think the figure is just intended to illustrate the bearing to the NDB relative to the aircraft, and not the magnetic heading of the airplane. So when they give you your magnetic heading of 160, you're still using the bearing of 045 relative to your aircraft, which gives 205 magnetic.


Can you help me ID these two helicopters?

My guess is an AW139 on the left and the AS355 on the right. Both are very widely produced models.


How to navigate onto VOR RWY 18 approach at KDEC?

I would expect to receive radar vectors to final if I was coming from the north into Decatur, IL.   However, we do not plan on radar vectors when we flight plan because we could lose our ability to communicate with ATC.
I would fly the victor airways to AXC.  I might plan on coming in on the 029 radial (V191) to AXC.  I am hoping for a clearance for the approach by the time I get to AXC.  When I hit AXC, I would them make a right turn and proceed outbound on the 349 radial on the approach plate.
With a proper clearance, I would maintain my cleared altitude till TRACS and then descend to 3100 FT and finish the approach using the procedure turn to line up with the runway.
You are more than welcome to fly off routes provided you remain within the service volume of the navaid you are using.  For AXC the service volume is from 1000' AGL to 40NM (for low altitude flight).  There are no restrictions to the service volume in the Chart Supplements.  If you are going to do this (and ATC clears you), you will fly the OROCA as a minimum altitude.  The off-route obstacle clearance altitude (OROCA) for this quadrangle is 3200 FT MSL.  You could file BLM direct AXC and only be one degree off the final approach course.  (See AIM 5-4-7(f))
However, you are still required to cross an IAF before you start the approach.  You will fly over AXC and then turn around to fly the procedure turn... you cannot just cross TRACS and descend for the landing.
A procedure turn is always required if it is depicted on the chart with four exceptions (AIM 5-4-9)

Receiving radar vectors to final approach course
On a route marked "NoPT" on the approach plate
Received a clearance for a straight-in apporach from ATC
Performing a timed apporach


Why are contra-rotating jet engines so rare?

If the low-speed and high-speed spool rotate in the same direction, the relative speed between them is low. Contra-rotating means you need to double the individual speeds to arrive at the relative speed, and this will increase bearing losses greatly. Both friction and wear will go up with little benefit in regular operation. A notable exception is the Rolls-Royce Pegasus engine for the Harrier jump jet.

Stators between the rotating stages ensure that air flow inside the engine is mainly in axial direction, so aerodynamically a different rotation direction between two spools will make little difference. However, contra-rotation will indeed make the stator between the last stage of the high- and the first stage of the low-pressure turbine obsolete. The video linked by @Moo cites a 10% reduction in part count as the advantage. Additionally, the first stage of the low-pressure turbine should show improved efficiency (like the second propeller of a contra-rotating propeller).


What do the Thunderbirds pilots do when they can't fly?

I would imagine they do the same thing all pilots do when they go to the airport expecting a nice day and wind up grounded by weather: Sit around at the airport with the other pilots and complain about the lousy weather. (In this case, since they're all sitting in position waiting for the weather to clear up any griping was probably done over the radio.)

There are of course other things they can do, being a fairly well-known demonstration team and an important component of the public relations arm of the US Air Force, for example signing autographs and talking to spectators at the airport.


Can airline ignore or get exception from V1 and other safety rules?

To answer the question as asked, no I've never heard of an airline "ignoring" V1.

To address the implicit question, I have no idea what the story is behind that IL-76 operation shown in the video, but I could creatively come up with all sorts of possible explanations for the takeoff roll that essentially matched the available runway: power not set correctly, takeoff data computed incorrectly, poor pilot technique, unexpected tailwind, aircraft loaded heavier than expected, or maybe that crew DID decide that it was so important to get home that they were willing to accept an absurd risk.  But I wouldn't take ONE video without explanation of "what really happened there" as any indication of what airlines in general will do.

At its most basic, V1 is simply the point at which you transition from a "stop" mentality to a "go" mentality: if something goes wrong PRIOR to V1, we'll stop; if something goes wrong AFTER V1, then we'll go.  Now, there are LOTS of things that complicate that discussion... not everything that can "go wrong" is the same: at 80 knots, getting an "anti-skid fail" light is probably not worth aborting for; at 80 knots, getting a loss of all generators probably IS worth aborting for (assuming that V1 is well above 80 knots).  Just below V1, losing an engine IS something you'll stop for; losing one generator or one hydraulic system might not be.  And this is all dependent on the aircraft... in the C-130, we were pretty stop-oriented, and we'd stop for all sorts of things immediately prior to V1 that in the 737 -- a much more go-oriented aircraft -- we'd take airborne.  The difference being, you can stop the Herk pretty quickly & with a comparatively low risk of problems; a high-speed abort in the 737 (as in many jet aircraft) is much more of a big deal.

All that said, though, there is always a speed below which you'll stop, and above which you'll go.  If an engine flames out at 20 knots, you'll stop in nearly any scenario I can think of (that doesn't involve bad guys storming the airport).  In the Herk, it was common that your accelerate-stop speed was above your rotation speed, so V1 was essentially at rotation.  But there was always some speed where your default choice between stop/go changed over.

You might "ignore V1" by simply saying that once takeoff power is set, we're going to continue regardless, but that's just bad decisionmaking by the crew, and not the sort of policy that I could envision ANY airline ever making.  (Again, the case of mortar shells falling closer & closer to the aircraft & bad guys overrunning the airport might be an exception to this... take our chances with the ground rather than with the bayonets.  But the outlandish nature of this exception illustrates how rare it would be to "ignore V1" in any considered scenario.)

Airlines tend to accept far fewer risks than other forms of aviation.  The mission of an airline is to make money, and nothing interferes with that mission like the bad publicity & loss of assets (and potentially, certification) that comes from a crash.  In the military, there can be a mindset of accepting lots of risks because troops are counting on us completing this mission. In general aviation, there tend to be individual decisionmakers, with little institutional guidance & corporate wisdom to back them up.  But the airlines tend to be entirely willing to postpone a flight if it can't be performed safely, so for "airlines" to ignore V1 or other safety rules seems highly unlikely.  (Which isn't to say that an individual crew might not do so, although at least at US carriers, they aren't likely to continue to be employed if they're found out.)

--- EDIT, added in response to updates/edits in the original question:

What you're asking is, in essence, can "they" get permission to take off knowing that takeoff roll = available runway, and if anything goes wrong after the point at which stopping takes all of the remaining runway, then they're dead.  If takeoff roll = available runway, using all engines, after you've reached the speed at which you can no longer abort the takeoff within the remaining runway, and then you lose a motor, you now

Don't have enough runway left to stop, but also
You don't have enough runway left to accelerate to takeoff speed with the remaining thrust (less than the original case)

That's more or less the "bad guys storming the airfield" scenario, where you know that you're dead if you stay, so it makes sense to take off & hope that the motors keep running through the takeoff roll.  Given that the risk of staying is so high, the risk of losing an engine during those seconds of the takeoff roll is the lesser of the two evils.  And yes, in Viet Nam there certainly were times when C-130's would accept those sorts of risks to get the badly wounded out of dirt strips in combat.

Now, is that a reasonable thing to do in peacetime?  Not in my simple mind.  If we are assuming that the IL-76 crew did their performance computations correctly & their long roll was a known & accepted risk, then maybe they reached the opposite conclusion.  It's not something that I'd expect an airline to ever approve with passengers on board, and we'd have to get creative to find a scenario where they'd approve it for a ferry.

Can a crew make that sort of choice on their own?  Well, yeah, at least once.  Would an airline approve that option?  Hard to imagine.


What does "With One Minute Weather" Mean?

It's used at uncontrolled airports to tell approach controllers that you've got the AWOS/ASOS there. I believe the tower at KMCC is temporary (probably for firefighting).

The AIM 4-3-26 is snappily titled Operations at Uncontrolled
Airports With Automated Surface Observing System (ASOS)/Automated Weather Sensor System(AWSS)/Automated Weather Observing System (AWOS), and says:

  If ATC service is required for IFR/SVFR approach/departure or
  requested for VFR service, the pilot should advise the controller that
  he/she has received the one−minute weather and state his/her
  intentions.
  EXAMPLE− “I have the (airport) one−minute weather, request
  an ILS Runway 14 approach.”

It's also in the Pilot/Controller Glossary:

  ONE-MINUTE WEATHER− The most recent one minute updated weather
  broadcast received by a pilot from an uncontrolled airport
  ASOS/AWSS/AWOS.

And this from the ATC Orders 5-10-2:

  Automated weather observing systems may be set to provide one minute
  updates. This one minute data may be useful to the pilot for possible
  weather trends. Controllers provide service based solely on official
  weather, i.e., hourly and special observations


What is this open panel at the rear of this airplane?

It is the Auxiliary Power Unit (APU) inlet door.

Image from Boeing Aero Magazine


Can anyone Identify this FLY FAIR seaplane?

That is a Sikorsky S-38B
I am not sure about the registration. My guess is NC196H, but it is one out of this list:

NC158H,
NC159H,
NC195H,
NC196H,
NC197H,
NC198H,
NC199H,

See aircrafthistory.org.uk
The FLY FAIR marking may be a reference to the 1933/1934 Chicago World Fair / "A Century of Progress International Exposition". Jamiec found this photo album by George Buivid on auction that documents a trip to the Chicago World Fair in Sikorsky's own S-38 aircraft:

Picture source: Flyingclippers.com Artist: Mike Machat

source: Wikipedia original source: NACA Aircraft Circular No.79


Is there a real temperature change along a streamline when its velocity changes?

Don't know what you mean by real temperature. You will certainly experience a change of static temperature in an adiabatic flow if the velocity changes.
Stagnation enthalpy describes the total energy contained in the fluid which comprises inner (thermal) energy, kinetic energy (and potential energy which is often neglected). Stagnation enthalpy is constant for an adiabatic flow with no energy exchange. Thus, thermal and kinetic energy are antagonistic in the sense that increases of the kinetic energy need to be countered by reducing thermal energy in order to keep a constant value of total i.e. stagnation enthalpy, and vice versa.
The stagnation temperature of a fluid is a virtual entity, temperature entities that are observable i.e. measurable are static temperatures. However, in a stagnating point the static temperature ideally features the value of the stagnation temperature.
Back to your question: If you measure temperatures in an adiabatic flow at points of different flow velocities, you will experience different temperature readings. Your measurement setup has to ensure that your readings are not falsified by slowing down the fluid at the points of measurement.


Was the Space Shuttle aerodynamically neutral while piggybacking, or did the combination act like a giant biplane?

This podcast with one of the pilots answers just about every question on the shuttle carrier you could have and it's worth a full listen. But to cover the flight dynamics, I would skip to 50:33 minutes, where the pilot states (please note there is no official transcript of the podcast and I typed this as I listened to it, please see the official podcast for the actual verbiage, but this is close):

  Markus Voelter (Interviewer): Let's talk a bit about the flying characteristics, did the wings of the shuttle add some extra lift or
  was it mounted with essentially 0 angle of attack?

  Arthur C. “Ace” Beall (Pilot): It was mounted with some angle of attack, you can see that as it's sitting. At the speed we were flying,
  the carrier itself was about 5 degrees nose high. The shuttle was creating lift, but
  how that affected it aerodynamically is hard to say, it was always
  mounted the same way so we had no basis of comparison. It did, however,
  create a lot of drag and made the aircraft very top heavy so bank
  angles were limited.

So some lift was generated but at the speeds they were flying, other limitations came into play that were more of a concern. It's also worth noting that when in transport no one was in the space shuttle and the control surfaces were not used in any way.


How do you check the correct operation of the rudder when it's tied to the nose wheel?

Every small airplane that I've flown that uses the rudder pedals for nose wheel steering uses bungee cords or springs so that they will stretch when pushing the pedals without the aircraft moving.  This allows the pedals to move without requiring the nose wheel to do so as well, and you can check them in the normal manner.

Larger airplanes that use the rudder pedals for nose wheel steering have a method of turning the nose wheel steering on and off, so the check could be done before the steering is engaged.  That being said, most larger aircraft do the control check during the taxi (that's when most airliners are doing it) and there is nobody out there to make sure that the rudder is actually moving the correct direction.  In my airplane, the response for the flight controls is "free and self-centering" (since we have hydraulic flight controls) and we don't verify the actual direction of rudder movement.  That's a maintenance function.


How does a circulation control helicopter work

A quick scan of the linked document suggests that they're referring to controlling the relative amount of engine exhaust directed into each rotor, which (due to the downward direction of the exhaust jet that drives the rotor) controls how much downward deflection each blade gives its airflow.  By making this differ from one blade to the other, the rotor can be tilted without twisting the blades at the root as would usually be the case with large, heavy lift rotor designs (the effect is somewhat like the Bell-Hiller paddle system often seen on small helicopters).

The resultant rotor tilt gives pitch and roll control, which are used (directly, or by mixing rudder effect) to move forward, aft, or sidewise in hover, and to control speed and climb/dive, plus turn, when in forward flight.


Can a normally poorly handling airframe with high moments of inertia actually have superior flight dynamics under autonomous control?

The underlying assumption of your question seems to be that a higher control bandwidth always leads to better disturbance suppression. Since a higher control bandwidth is easier to achieve with low-inertia systems, aircraft with low inertia would have better disturbance suppression.
This assumption can work in theory, especially for SISO (single-input, single-output) systems. However, for aircraft, we are essentially dealing with MIMO systems. While we can achieve near-perfect disturbance suppression for one degree of freedom (e.g., zero variation in altitude), this will inevitably lead to large excursions of other degrees of freedom. For example, disturbance suppression in altitude will lead to large variations in pitch as we try and keep AoA constant with every gust. So, for a MIMO system like an aircraft, we have no choice but to formulate a cost function of what we consider a 'smooth' ride, and balance the control scheme across various degrees of freedom.
Since we are considering a balancing act, it then makes sense to tune the internal dynamics of the aircraft such that a smooth ride is naturally achieved. So that means: high inertia for degrees of freedom experienced by the passenger, and low inertia for degrees of freedom not felt by the passenger. In practice: larger fuselage inertia and smaller control surface inertia.
Unsurprisingly, this is how it works in practice: larger aircraft are generally more comfortable, whereas at the same time, degrees of freedom not felt by the passengers are exploited in modern aircraft for gust suppression. For example, wings are more and more dynamically decoupled from the fuselage by highly flexible composite wings. Ailerons are split in smaller sections for gust suppression, you may find videos of "dance of the ailerons" for modern aircraft.


Translation

Seal means sello mecánico.

While the answer could stop here, we wouldn't know what seal types are used in turbine engines, and how some are pressurized to prevent contaminants entering the aircraft pressure vessel.

Need for bearing compartments and seals

  I've read phrases like "All gas turbine engines use pressurized seals
  for their shaft bearing compartments..."

In turbine engines, there are one or more shafts holding the rotating parts of the compressors and turbines (rotors). Bearings are inserted between a shaft and its stationary supports to limit destructive and heat-generating friction. Bearings also bear the large axial load transferred by compressor and turbine rotors to the shafts.

In turbine engine bearings, solid friction is replaced by fluid friction using an oil film between balls or rollers and races. Bearings are enclosed in a cavity and oil is injected into the cavity. This cavity is known as a sump.

The following drawing is taken from  an answer to In a turbofan what holds the spinning axis?. You can see the five bearings within their sumps:

(Source)

Oil must be circulated from the oil tank to the sumps and back, and cooled before being reused. As oil quantity is limited, oil must be prevented from leaving the oil system. This is where seals enter into action. In particular, seals are used to prevent leakage between a rotating shaft and stationary sump apertures.

High speed seals

Turbo engines' oil seals are specially selected to bear the high rotation speed of the shafts (wear), and the high operating temperature of the engine core (adjustment and bending). They are of two main types: Carbon or labyrinth. Both reduce oil pressure while it travels in the interstice between the shaft and the sump wall.

Carbon (source) and labyrinth (source) seals

Air sealing

  All gas turbine engines use pressurized seals

As one would think, these seals are not perfect: a small quantity of oil will be able to make its way across the seal, and this quantity will increase with seal wear. Unfortunately, burnt oil releases hazardous fumes which could enter the aircraft air conditioning system as cabin air is tapped most of the time into the engine compressor.

To limit the leakage further and to recover leaked oil, a second cavity is built around the first seal and pressurized air is injected into it. This has two effects:

Air pushes oil back into the sump.
The second cavity being also sealed, any leaked oil can be drained and dumped overboard.

For example, the forward sump (on the left of the first picture) encloses 3 bearings (from left to right: #1, #2 and #3). Oil must be contained within the sump near bearings #1 and #3. Let's look at a CFM56-7B engine mounted on Boeing 737 NG. This is the lower half of the forward sump:

CFM56-7B forward sump, based on drawing from CFM56-7B Familiarization Manual

Oil enters the sump and is directed to bearing races using tubes and oil nozzles.
An oil seal prevents oil from escaping the sump in large quantity.
As some oil would nevertheless cross the seal, compressed air is injected on the other side of the seal, to counter oil leakage. Air entering the sump is then dumped overboard by the centrifugal air-oil separators.
The space where air is injected is closed by a cap on the sump with a air seal on the shaft.
Air and a small quantity of oil able to cross the oil seal are eventually drained and released overboard.
Oil crossing the bearing is scavenged and returns to the oil tank after air has been removed.

Metal particles in scavenged oil are captured by magnets to detect abnormal wearing of bearings. From time to time oil is added to the oil tank to compensate for small leakages in the bearing sumps (and in the gearboxes).

See on Youtube: Carbon Seals - Turbine Engines: A Closer Look.


Did WW2-era aircraft have constant-speed or variable-pitch props?

Variable pitch (with feathering) was virtually universal on (at least American) multi-engine fighters, bombers, and transport aircraft even early in the war: the DC-2 had feathering variable pitch, and it entered service in 1934.  The P-38 had feathering and variable pitch, and was in service before the US entered the war.

Constant speed propellers were also found on many single engine combat aircraft -- one was the Hellcat, which entered service in 1943, though it's very possible the technology was introduced earlier.  The P-47 Thunderbolt also had this feature.

When you're talking about aircraft that weigh several tons and need to deliver thousands of horsepower through a propeller, especially for combat operations, the weight and cost of variable or constant-speed propellers became negligible by comparison to the cost of the aircraft or the cost of fielding a losing design.


Do fighter jets have a traditional inverted fuel system?

I don't know for certain as I'm not military, but I imagine that they pressurize the fuel tanks using bleed air, much like jet airliners do. It's also likely that they make use of boost and ejector pumps to provide positive pressure directly to more centrally-located tanks which the engines then feed from.

(from FAA AMT Handbook [pdf])

The F-15 has both wing & fuselage tanks; according to a site of dubious accuracy (F-15E.info):

  The left and right engine feed tanks contain baffles in order to provide a limited amount of fuel to the boost pumps during inverted flight or during negative G maneuvers

  Left wing tank
  Auxiliary tank
  Left engine feed tank
  Right wing tank
  Right engine feed tank
  Tank 1 (main tank)

Baffles are dividers in the tank itself that limit the speed at which fuel can flow from one end to another, usually to prevent fuel sloshing and screwing up balance.


Can I find out why an aircraft squawked an emergency code (7x00)?

This FAA webpage has a list of the various transponder codes and what they are used for, which will give you an idea of what the problem is.  Unless there is an actual aircraft incident or accident which requires the FAA to investigate though, you won't be able to find a record of it.  In fact, pilots aren't even required to file a report unless requested, and those don't go into a public database.

For actual incidents or accidents, you can look at the NTSB Accident Database & Synopses.

For pilot reports to the NASA ASRS self-reporting safety system, you can search their database.  If the pilot filed a report then you will see it show up there.

Commonly used emergency codes are:

7500 - Hijack Code
7600 - Loss of Radio Communications Code
7700 - Emergency Code

Also, some countries use the code 7000 for VFR traffic (which is not an emergency code), but the US uses 1200 instead.


If a SID chart says "GPS... required", can the plane use a different GNSS?

The FAA's standards require the use of GPS, i.e. the American satellites. This is covered in AC 20-138D, Airworthiness Approval of Positioning and Navigation Systems. It defines GPS:

k. Global Positioning System (GPS). GPS is a U.S. satellite-based radio navigation system that provides a global positioning service.

It also says that GLONASS and other non-US systems are not supported:

GLONASS is not yet approved for IFR operations in the U.S. National
Airspace System
[...]
No FAA TSO exists for GLONASS, GPS/GLONASS, multi-constellation or
dual-frequency avionics. Therefore, adding capability for any other
constellation or dual-frequency capability must be accomplished as a
non-TSO function until appropriate TSOs are available.

Apparently there is some kind of working group looking into using non-US GNSS but it's not possible yet. See Appendix 8 of the doc for full information.


Why do the CRJ700 window shades open in different directions?

Judging by an exit photo here, you're right.

When there is an opening in the fuselage (e.g., where the emergency hatch would go) the surrounding area needs extra strengthening. Below is a high-res example for an Airbus fuselage:

(source) Notice the extra and deeper stringers to the left of the door, and the lack thereof away from the door where the windows would be (yet to be cutout, but you can make out one).

(gettyimages.com) And here's a CRJ700 fuselage (first fuselage actually).

While that's the front service door, not the overwing exit, note the white stringer above the first window to the right. Its depth is clearer on its mirror on the left by the shadow it casts.$^a$

And since a sliding hard blind needs to go somewhere, they typically go into a hidden tray, which takes space. Here is an example from a McDonnell Douglas patent from the 70s.

An upside down unit flanking a hatch could very well be installed that way to make way for a structural element, or to make way for cables/pipes/tubes in the area, especially that the CRJ700 is a narrow plane.

$^a$: It won't affect the first row seats though. Note that the passenger entry door (port side) is taller, so the topmost stringer is already well above the windows. As for the right side, depending on the configuration this area will have either a galley or a lavatory. I tried to check for photos from inside the lavatory, but it didn't have a window (on the outside, the window is there, it's just blocked by the interior panels from the inside – photo below).

(thepointsguy.com)


Yes, squawk codes are still used and required with ADS-B.
It's possible that in the future this may change, but because of the bifurcated implementation the FAA has chosen for ADS-B I don't think it's likely.

ADS-B operates by giving additional information beyond the Mode A (squawk) code - this is either encoded on the 1090MHz transponder frequency (Mode S "Extended Squitter" - what most of the world uses) or sent on a separate frequency (the 987MHz "Universal Access Transceiver" frequency, which is a US/FAA only thing mainly intended for light GA aircraft).

The Mode S and Extended Squitter data includes things like the aircraft's unique Mode S address (a 24-bit number assigned to the aircraft by its national registry, in the US this is linked to the N number), and may also provide the tail number or flight number. The ATC radar system will accept and display this information for the controller.
At the moment the Mode S/ES data is not used as a substitute for the Mode A transponder code, but because Mode S data is coming through the ATC secondary radar system it's all immediately available with the secondary radar return the same way a Mode A squawk code is, and it's possible that the FAA may use the Mode S ID in place of the Mode A squawk code for these aircraft in the future.

The 987MHz UAT transmissions also include the Mode S address (because it's a useful unique identifier for a given aircraft) and flight ID/tail number can be sent as well. Information from UAT transmitters is received through separate ground stations and recombined with the radar return in the ATC radar back-end.
There's some magic to that recombining which is out of my depth, but my limited understanding is that since the UAT data isn't directly correlated with a radar return squawk codes are part of how the two are matched up (the radar computer knows your N number by your discrete squawk code, the UAT ground station knows it from your Mode S ID - if they match and the position data is within reason the ADS-B information can be associated with your radar data block).


How to understand "Stage length, for payload calculations includes 85% wind"?

The document AEA Requirements Long Range Aircraft is related to airline fleet planning, and the calculation of the fuel needs. Note that it is dated Dec. 1987. More on airline fleet planning.

85% wind

For this planning the document from the airlines association recommends to assume the wind that has a probability to occur of 85%. That means: assume you will find this wind on your route 85% of the time. The wind force itself is determined talking into account statistics for the regions overflown.

Stage

The flight profile is provided on the document itself, defining "stage" as start of climb to end of descent, excluding initial climb:

Planning profitability

Knowing how much fuel will be required and by deduction how much payload can be transported allow airlines to estimate the airline costs and revenues on a given route with a given aircraft. This is important for planning aircraft acquisition and replacement, as well as the route catalog.


How can I calculate the relationship between propeller pitch and thrust?

The geometric pitch ($p$) is simply the distance that a point on the prop would move forward in one rotation, if it's gripping in a solid medium. You can derive the pitch speed via this geometric relation if you wish, but I would caution against inferring performance from this number. Instead, you should consult propeller, engine and aircraft performance in their entirety.

Using your provided data, let's see if everything fits. We assume:

Prop RPM of 2200
Top cruise speed ($V$) of 125mph
Prop diameter ($D$) of 2.36m (from Wikipedia on SE5a)
Prop pitch ($p$) of 1.75m
Wing area ($S$) of 22.7 sq.m (from Wikipedia on SE5a)

From this reference, the reference pitch angle/blade angle ($\theta$) by convention is measured at 3/4 of the blade radius, and can be related to pitch via:

$$\theta=\tan^{-1}{\frac{4}{3} \frac{p}{\pi D}} \approx 17.5deg$$

The advance ratio is calculated, with $n$ being the prop rate of rotation in round per seconds:

$$J=\frac{V}{nD} \approx 0.65$$

Using the plot below as a rough reference, which is predicted for the McCauley 7557 propeller, gives a thrust coefficient ($C_T$) of 0.06.

Ref: http://webserver.dmt.upm.es/~isidoro/bk3/c17/Propellers.pdf

Now the thrust coefficient is defined as:

$$C_T=\frac{T}{\rho n^2 D^4}$$

where $rho$ is the air density and $T$ is the propeller thrust.

For level flight, thrust equals drag, and we can back calculate the drag coefficient:

$$C_D=\frac{2C_T n^2 D^4}{V^2S} \approx 0.07$$

This is high enough to be well within the realm of possibility for a biplane (if it's too low, then it's an indication that the performance numbers do not jive). For reference, Cessna 172 has a total drag coefficient of 0.032 at 122kt at SL. In conclusion, I would say that your numbers check out in the back-of-envelope sense.


Can helicopters land in a poor visibility scenario?

Can helicopters fly IFR?  Yes

Do they use ILS?  Yes.  The only tricky part of it is the need to be slow at the end of the glide slope.

An IFR helicopter can use any of the navigation and landing aids available to any other aircraft.

This PPRuNe discussion is interesting.


Wind speed over which a Canadair fire fighting plane cannot safely fly?

The problem is not the wind speed per se, but the combination of factors.

Let's start from the data; this is the METAR for Athens on the 17th of July, the day of the fires:

  METAR LGAV 171220Z 03026G38KT CAVOK 32/10 Q1016 NOSIG=

I have highlighted the wind speed data. It says that the wind at Athens airport was on average at 26 kts, with gusts up to 38 kts

26 kts of wind at high altitude would not be a problem for a CL-215
26 kts of wind near ground (to drop the water it has to do low passes) and at low speed (it has to go as slow as possible to be precise) can be highly dangerous, as proximity with the ground increases turbulence. Let's also consider the mountainous terrain around Athen (and the fires were on the side of a mountain), windshear and turbulence were probably quite strong. (See also this question: When crossing a mountain ridge at low height above terrain what consideration is given to turbulence? )
26 kts was the average wind speed, gusts were up to 38 kts, increasing the risks of such operations.

In addition to the above, let's remember that these aircrafts have to fly over fires, that will create additional turbulence through the rising hot air column that they generate. (thanks to David Richerby)

I do not think that a hard limit for such operation exists, as said above is the combination of windspeed, terrain configuration and mission that determines if an aircraft can perform it or not.


I'm not sure if you're asking about flying such an aircraft (e.g. renting one) or owning one. But either way the answer is yes.

I've flown a Hawker Hunter at a (now-defunct) location in Cape Town on a mixed low-level/acrobatic flight along the coast. There were no restrictions on who could fly in the aircraft apart from the obvious ones (no kids; must have reasonable height/weight and general fitness) but they didn't let non-pilots take the controls. We did some aerobatics (up to 5G, from memory) and I had the controls in cruise flight for about 10 minutes. There was absolutely nothing that a civilian couldn't learn: it's 'just' another aircraft.

As for owning one, it's not uncommon at all. Privately owned ex-military aircraft are often referred to as "warbirds" and in the US there's even an EAA organization for owners. The aircraft are usually considered experimental (or the local equivalent) for the purposes of regulation and airworthiness.

The barriers to owning these aircraft are (as always) money and training. Buying and maintaining them is very expensive because there are so few parts or mechanics available, and insuring them is (almost) impossible so most owners have to self-insure. The operating costs are also usually high, especially if the aircraft systems need 'exotic' fuels, gases, lubricants or other consumables. You may need to include explosives on the list, in the case of ejection seats.

Training is a similar issue because so few people can instruct you in how to fly a military aircraft, but obviously this isn't a total barrier and I assume that if you're involved in that part of the flying community then you'll find the contacts you need.

So in general, if you can buy a military aircraft legally in your country, if you have enough money for operations and maintenance, if you can find someone to train you, and if you can comply with your local regulations on non-type (experimental) aircraft then you can absolutely do it. But for most people that's a lot of 'ifs' :-)


Bugs simply make instruments easier to read with a very quick glance.

If I need to steer exactly 162 degrees, which is easier?  To read where the needle is pointing or just see if the needle is pointing to the bug which I manually set to 162 degrees?

The bugs are set by rotating knobs on the gauges.  Here, the heading bug knob is in the lower right corner.

The way I often use it is to turn onto the next heading required according to my plan, then set the bug to that heading so that I can simply glance at the needle (still pointing to the bug, good) to keep me on course.

Other uses:

If ATC gives you a "next heading", you will read back the instruction, then you can set the bug to that next heading so that a), you don't forget it and need to call back and b) can simply turn onto the bug when it's time to turn.
Set it to the departure runway heading on take off.  To "fly runway heading", just keep the bug at the top of the gauge.
On arrival, set it to the landing runway heading.
As a "gross error" check.  You would not believe how many inexperienced pilots set off in entirely the wrong direction.  As well as setting the heading bug to "first leg of the plan", you check this along with "and the road should be on my left with the river on my right".

On some simple autopilot systems, the autopilot follows the altitude and heading bugs rather than having controls for these settings on the autopilot itself.


Is it legal for a passenger to sit on the jump seat in Part 135 operations?

Lets start with 14 CFR 135.125, which defines security requirements for part 135 flights:

§135.125   Aircraft security.
Certificate holders conducting operators conducting operations under this part must comply with the applicable security requirements in 49 CFR chapter XII.

We pass the ball to 49 CFR 1544 and make sure we're in the right place:

§1544.1   Applicability of this part.
(a) This part prescribes aviation security rules governing the following:
(1) The operations of aircraft operators holding operating certificates under 14 CFR part 119 for scheduled passenger operations, public charter passenger operations, private charter passenger operations; the operations of aircraft operators holding operating certificates under 14 CFR part 119 operating aircraft with a maximum certificated takeoff weight of 12,500 pounds or more; and other aircraft operators adopting and obtaining approval of an aircraft operator security program.
(b) As used in this part, “aircraft operator” means an aircraft operator subject to this part as described in §1544.101.

For brevity, I'm not posting 1544.101 which defines a host of paragraphs you must comply with depending on your operation.  If we assume a charter operation in an airplane weighing over 12,500 lbs, we get (1544.101(e)(1)):

(1) The requirements of §§1544.215, 1544.217, 1544.219, 1544.223, 1544.230, 1544.235, 1544.237, 1544.301(a) and (b), 1544.303, and 1544.305; and in addition, for all-cargo operations of §§1544.202, 1544.205(a), (b), (d), and (f).
(2) Other provisions of subparts C, D, and E that TSA has approved upon request.
(3) The remaining requirements of subparts C, D, and E when TSA notifies the aircraft operator in writing that a security threat exists concerning that operation.

From here the one we care about is 1544.237, which says:

§1544.237   Flight deck privileges.
(a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its security program.
(b) This section does not restrict access for an FAA air carrier inspector, an authorized representative of the National Transportation Safety Board, or for an Agent of the United States Secret Service, under 14 CFR parts 121, 125, or 135. This section does not restrict access for a Federal Air Marshal under this part.

Which brings us to our answer: YES, a passenger may occupy the jumpseat if you do not have a door, and also if you do have a door as long as your company security program allows it.


Under what conditions would a helicopter be allowed to fly at low altitude over populated areas?

I have no idea about the specific flight you saw, but the general answer to your question about operating legally below the minimum safe altitudes in 14 CFR 91.119 is that the FAA can grant a waiver allowing lower flight. The waiver process says that to get a waiver to 91.119(b) (flight over congested areas) there must be a public interest reason but aircraft can't be lower than 500ft unless lives are at stake:

  When issuing the waiver, the altitude requested should be an absolute
  minimum, but may not be less than 500 feet from persons or property,
  unless necessary to safeguard human life

There isn't enough information about the helicopter you saw to say what was going on but assuming that it really was a Chinook at at 100' AGL then it was too low even for a waiver, according to the FAA's process. But the most obvious explanation is simply that it was taking off; helicopters take off in a range of attitudes and airspeeds and some of those takeoffs are probably relatively low and fast. It might have been a medevac flight (they're often brightly painted) or perhaps something to do with logistics or construction; if you got the N number then you could look it up.


Do 121.5 MHz ELTs have to be replaced with 406 MHz models?

I can't speak for the other countries, but at the moment (December 2013), at least in the United States, the answer is no.

The FAA and the FCC have been engaged in a bit of a regulatory battle of wills on this subject, (most recently in March of 2013, and covered by AOPA, EAA, and AvWeb pretty extensively) - Basically the FCC wants us to take our 121.5MHz woop-woop boxes and make them go away, because they're pretty lousy for search-and-rescue, and the FAA is, for the moment, telling the FCC to get stuffed because regulating aircraft is the FAA's job.

Now just because you don't have to replace your ELT doesn't mean you shouldn't -- to be honest a 121.5MHz ELT is not much better than having no ELT at all (COSPAS-SARSAT doesn't monitor 121.5 anymore), so you should consider the type of flying you do, and the likelihood of an incident where the ELT might be useful.

The new 406MHz ELTs are vastly superior to 121.5MHz units for search-and-rescue performance, and if I were running a commercial operation, or flying regularly in an area were search-and-rescue help may be hard to come by if I had an emergency (like say Alaska) I'd fork over the cash for a GPS-enabled 406MHz ELT to replace the ancient 121.5MHz unit in my plane in a cold second.


What is the purpose of including sea level pressure and temperature in a METAR?

The sea level pressure allows pilots to calibrate their altimeters to make sure they are accurate. KGOK is 1069 feet elevation, if a pilot were to set their altimeter to 1020hpa (or 30.11 inches of mercury as used in the US, that's the A3011 in the METAR) then their altimeter would read 1069ft at ground level.


Does hypoxia affect pilots differently from people on the ground?

The analogy that if someone can become acclimated to working at high altitudes and therefore should not need supplemental O2 in an airplane is flawed. While flying - at least straight and level - does not require strenuous exertion, it is very cognitively taxing. It's a constant process if taking in a deluge of incoming data, be it instrument read outs, navigation information, external stimuli, radio chatter, the grunt work of flying the aircraft etc.

Unfortunately, the conscious and cognitive centers of the brain as well as the eyes require an oxygen rich blood supply in order to operate fully; if this is denied or reduced, serious deterioration of these abilities will occur and can happen rapidly within seconds.

Night vision is also severely impaired by hypoxia as the rods in your eyes require a lot of oxygen as well. I did an experiment one night in C172 where I took off at sea level and climbed to 12,500 feet. Looking outside the aircraft at those altitudes I could see a few bright stars but after I had landed back at close to sea level, I looked up at the night sky while tying down the airplane and could see a sky filled with stars as well as the bright gaseous strip of the Milky Way. The effect was dramatic; you really are affected by hypoxia at night.


What are the advantages/disadvantages of a forward-folding propeller?

The problem has traditionally been that if you wanted to minimize propeller drag on a cowled tractor motorglider engine you had to go with a feathering prop.  Expensive, and a bit heavy because you have to have a hub with blades that can rotate on their axes to change pitch, with a passive or active pitch change system, so the hub needs a blade root retention structure with bearings that allow the blade to rotate on its axis and a control mechanism of some kind.

With an aft folding prop it's a simple job to hinge each blade on a bolt to passively trail, and when it's spinning the blades naturally move out and rest against structural stops or just sit in the proper position from centrifugal force.  You don't even need an actuating system because the wind blows them back for you when you're done.

This design tries to achieve a similar benefit but needs an active method to drive the blades forward against the air flow, so it adds an internal gas spring mechanism in the hub to push the blades into the forward position against the air flow when not spinning, and when spinning centrifugal force is enough to keep the blades from coning too much from thrust loads plus the gas spring (the VW based engine spins pretty fast, 3000 rpm, so there is plenty of centrifugal force).

So the main advantage is you get most or all of the benefit of a feathering prop (the only other option), without the elaborate hub/bearings required for feathering, just a simple pivoting bolt or pin and a spring system to push the blades forward.  The spring system is the only add-on relative to a super simple aft-folding prop.  Pretty elegant.

As a main disadvantage, it's easy to imagine that the blades when folded will be a little bit destabilizing either in yaw or pitch or both by adding surface area forward, depending on where the flat surface is oriented when it stops (like the way floats are mildly destabilizing in yaw and usually require extra fin area).  No doubt that is taken into account when sizing the tail surfaces and perhaps the blade surface area is too small to be noticeable.

The other problem is the engine can't be made to windmill, but that's also a problem with an aft folding prop as well. and in any case the VW based engine this airplane uses won't windmill even with a fixed prop (if the engine quits in your VW powered homebuilt, it'll stop at just about any speed you can fly at and you need a starter to get it going again).


If an A320 loses an engine why does the landing category go to CAT3 single?

According to the forums PPRUNE, for A320, taken from here:

  The power supply split function that monitors the electrical segregation of the FMGC's does not consider the APU generator as an independent electrical source. As a consequence, when an engine generator is lost the capability is downgraded to CAT 3 Single.

  The electrical power supply split function monitors......
  -The two BUS TIE contactors
  -The DC TIE contactor (between DC BUS 2 and DC BAT BUS)

  When one of the above contactors is closed, the FMGC considers that the power supply split is lost (independently of the APU generator)

  The A330 does not have this restriction and can be CAT 3 Dual capable even with one engine generator failure as APU is considered an independent electrical source.

Also- if you dig in the FCOMof the plane, you would find that if you perform dual engine cat3 approach, and an engine fails- the buses remain split to prevent the failures from reaching the other side, and it degrades to SINGLE.

If you perform an approcah with the APU online- the electrical system is built that if a failure occurs- the bus ties close and power is managed to the whole aircraft from 1 source only- meaning the buses are not split. Hence the single.


What is the actual air speed over and under a wing due to Bernoulli's Principle?

If you know the pressure coefficient of the flow, the rest is easy. The equation for the pressure coefficient $c_p$ is:
$$c_p = \frac{p - p_{\infty}}{q_{\infty}} = 1 - \left(\frac{v}{v_{\infty}}\right)^2$$
$q_{\infty}$ is the dynamic pressure and contains air density $\rho$ and the flight speed $v_{\infty}$:
$$q_{\infty} = \frac{\rho}{2}\cdot v_{\infty}^2$$
The equation for the local speed, relative to flight speed, is:$$\frac{v}{v_{\infty}} = \sqrt{1 - \frac{p - p_{\infty}}{q_{\infty}}} = \sqrt{1 - c_p}$$
Now you need to know the pressure coefficient. At Mach 0.85 the local Mach number of the 747 wing, which has a wing sweep of 37.5°, is 0.674. Since I do not have the airfoil of the 747-400, I used one from the same family (BACJ), found here. If you are interested, many more can be found in Michael Selig's immense airfoil database.

The plot is from a TSFOIL calculation of the 2D flow around BACJ at Mach 0.8, so it needs to be taken with a grain of salt. Note that it shows a stagnation point, and, therefore, Mach = 0 at the leading edge. The leading edge of the 747 wing is swept by 45°, so it will only slow the orthogonal speed component to zero. Consequently, the 747 wing has a stagnation line where the lowest speed will still be Mach 0.6.

On the suction side, the airfoil reaches Mach = 1.2 quickly and even Mach 1.3 near the trailing edge. Modern, so called supercritical airfoils can tolerate mildly supersonic speeds on their suction side, and the Boeing 747-400 makes use of them. However, since the wing sweep reduces Mach effects, the top speed will be Mach 1.2 or slightly lower, and the TSFOIL calculation shown here is not exactly correct for flight at Mach 0.85, but gives a general idea what happens on the wing.

To answer the many questions you posted directly:

The shape of the airfoil is immensely important. Thicker airfoils need to displace more air, and higher flow speeds are created on both sides. Camber will increase the pressure (and speed) difference between both sides.
Changing the angle of attack will add a roughly triangular difference, which is highest at the leading edge, to the difference between both sides. Lower side pressure is increased slightly, and upper side suction goes up by a lot at the nose.
Good wing designs have a triangular lift distribution over wing span, with the highest lift at the root. Since the displacement effect of the fuselage is added to the flow effects, the highest speeds will be encountered at the wing root.
Just look at the pretty pictures ...


What is decalage and how it affects airplane performance?

This article from flying magazine has a nice definition (including some history)

  Decalage — a French word meaning “shift” or “offset” — is, broadly
  speaking, a difference between the incidences of any two lifting
  surfaces. It was originally applied to the two wings of a biplane: In
  the usual arrangement, the upper wing was farther forward than the
  lower and had a larger (can’t get away from that term!) angle of
  incidence — called positive decalage — so that it stalled first,
  shifting the center of lift aft and providing an automatic nose-down
  moment for recovery.

  In a monoplane, the term refers to the angles at which the wing and
  the stabilizer (or canard) are attached to the fuselage. For an
  airplane to be longitudinally stable, it must have positive
  aerodynamic decalage; roughly speaking, the forward surface must be at
  a greater angle of attack than the aft one. This principle applies to
  conventional airplanes and to canards alike.


Why are there extra restrictions on constant-speed propellers?

The engine is the same, not simpler. There is one additional level of complication to the system -- the constant speed propeller has a number of extra parts.

The pilot needs to handle one more lever, selecting the speed. And needs more training in order to remember to put it at the right setting in various flight conditions -- not to mention how to handle an emergency when the constant speed unit falls (you need to prepare for every possible situation).

All in all, more training and more complicated systems sets up the requirements for restrictions.


Why might a moving map Android app consistently record altitude off by 120 feet?

While I think it would be unusual in 2016, it is possible that the unit is recording altitude as distance from the ellipsoid rather that distance from geoid (model of MSL on the earth used by the receiver).

If you use this NOAA calculator, you can find the geoid height for a single spot.  At the location you show, it's 37m or 122feet.  That's suspiciously close to the difference you're seeing.

Output from GEOID03
                                         latitude        longitude       N
Station Name                            ddd mm ss.sssss ddd mm ss.sssss  meters
USER LOCATION                            33 24 15.77000 119 24 57.49000  -37.259

If this error is constant over time (multiple recordings), then I think it's more plausible than random error sources.


Why does the U-2 use a chase car when landing?

It is to help the pilot land the aircraft (the chase cars are also used during takeoff). The U2 is considered notoriously difficult to fly in low altitudes- a tradeoff in an aircraft optimized for very high altitude flight:

Because the U-2 was so specialized, it was amazingly difficult to fly. ... the lower the U-2 flew, the heavier its unassisted controls got, to the point where pilots literally had to brute-force the plane around during take-off and landing.
... landings were the biggest problem. The replacement for Johnson's cart-and-skid ground system was a compact setup — two centrally located landing gear in the fuselage and one detachable "pogo" gear on each wing — that turned the U-2 into little more than a 30,000-pound bicycle. Because of the high-lift wings, pilots didn't so much land the plane as fly it really close to the ground (usually about two feet), stall it, and then fall out of the sky.

The decreased visibility of the pilots, combined with the highly efficient wings and bicycle landing gear meant that unassisted landings are difficult (but certainly possible, as has been demonstrated)- thus the chase cars.
On of the chase car drivers (themselves U2 pilots) describes the drill:

... the objective is ensuring that the pilot safely landing the aircraft... calling him down to two feet... holding them off there and then the plane will just kind of settle down on the ground.


Why do some turbofan blade have forward swept tips?

Increasing performance of the fan means making it rotate faster. Tips of the fast-rotating fan travel at supersonic speeds. This design of fan blades is to overcome blade stall and to increase effectiveness of the fan. The design is probably patented and that's why it doesn't show up on engines of other manufacturers.


Do we need to know the true track to a VOR?

The short answer is no, you don't need the true bearing to the station if you have magnetic bearing.  Presuming of course that your airplane has a magnetic compass to fly that bearing, there is simply no reason to convert to true.


What are the pros and cons of vacuum and pressure gyros?

Inspired by this question, I would like to know what the pro's and
  con's of the mostly used vacuum-gyro and the less used
  high-pressure-gyro is.

It is largely related to the instruments in your aircraft but in reality its all about air pressure and the systems are really doing the same thing in the end of the day.

Lets look at the evolution a bit, early aircraft that lacked an electrical system generally used a small external venturi to generate low pressure suction for the early gyro instruments. Note the venturi tube in front of the door about half way up the body on this early Cessna 170.

(source)

Since it was easy to generate low pressure this way early instruments were built as suction based. As planes got faster and external (drag educing) things were removed these systems went internal. Since the instruments were already suction based it was logical to make engine (or electrical) suction pumps to drive them.

When pumps moved into the engine compartment they came with some issues. Wet suction pumps have an oil issue that can seep into the system and cause issues with the instruments. That was solved with the advent of the dry pneumatic pump however that was a bit more susceptible to debris clogging but could provide both positive and negative pressure.

This paper outlines both systems as well as their pros and cons in depth and answers the question quite well. However the end result is that both systems provide the same outcome and in the view of the instruments there is no real difference.

  Gyro Instruments Within the case of the gyro instrument the air flows
  through the air seals of the gimbalsʼ bearings and across the rotor,
  spinning the rotor on its axes. The exhausting airflow from the rotor
  housing applies precession forces to maintain a reference to earth in
  the attitude gyro and the attitude of the aircraft in the directional
  gyro. The mechanics of the gyro instrument remain the same, whether it
  is driven by the airflow in a pressure or vacuum system. The air- flow
  through the instrument is a result of the differential pressure
  between the instrumentʼs air inlet and the air outlet ports. In a
  vacuum system the pressure at the air outlet port is lowered below
  atmospheric pressure. The differential pressure between the atmosphere
  and the pump now forces air to flow through the instrument. In a
  pressure system the pressure at the air inlet port is raised above
  atmospheric pressure and the airflow is in the same direction.

So what are some pros and cons,

In a vacuum system the filter is upstream and air is pulled through it and it does a good job of keeping the air clean.

  ...filtering the air entering the instrument. This filter will remove
  most contaminates from the air, but moisture is not one of them.
  Periodic replacement of this filter will ensure clean airflow through
  the instruments.

While in pressure based systems the air filter is generally mounted in line but has a similar effect

  In a pressure system there is an inline filter in the line between the
  outlet port of the pump and the inlet port of the gyro instrument.
  This restricts, but does not completely stop, the flow of all
  contaminates to the instrument.

However pressure systems have a moisture problem since the compression of air creates moisture, this may add moisture while a suction system will only draw ambient moisture.

  Unfortunately when air is compressed, moisture is created. Although
  the pressure is extremely low (approximately 2.5 to
  4.5 PSI), this system is no exception. Moisture is the No. 1 contaminate, contaminating the gyro bearings in a pressure system.

The paper also outlines that both systems are susceptible to downtime due to pump inspections and system maintenance. Which is a con of both systems.

  Side-question: Are there any other ways to make the Artificial Horizon
  work?

Yes, electricity

(source)


What can I learn before I actually go to flight school (Austria)?

Get hold of a simple simulator to familiarize yourself with the basics. I enjoyed Microsoft FSX . It's not intimidating. You can follow along just getting the basics, and you can hear generic pilot talk. It's not going to guarantee you a jump start hours wise, but at least when you get to flight school, you may have heard some of the terms and even messed with certain controls.

Don't expect to skip ahead without serious time investment. A few hours playing on a simulator(emphasis on PLAYING) will help with familiarity and maybe confidence, but be prepared to spend a lot of time listening to your instructor.

Another good thing, though it sounds silly could be to invest in some training videos. I personally enjoyed the courses offered by sporty's pilot shop. It was $200 when I bought it, but I would argue that it paid for itself, since I needed less time paying instructors and renting planes to practice things.

On the other hand, sometimes you hear instructors say they prefer blank slates as opposed to people coming in with bad habits. Maybe be patient and wait until your instruction begins. That way you start off with the habits that your specific school likes to train.

Good luck!


What are the aerodrome services SRE and CEV?

When in doubt, check GEN 2.2 for a list of abbreviations.

  CEV
  Centre d’essai en vol
  Flight test centre
  SRE
  Elément radar de surveillance du système radar d’approche de précision
  Surveillance radar element of precision approach radar system


Why does a stall decrease lift, rather than increasing it?

For a parcel of air to generate a lift force as it flows over the wing requires the wing to tip that air parcel's momentum vector downwards slightly; the reaction force that the wing experiences as it does this is what we measure as lift.

In the case where the airflow over the top of the wing separates from it, the parcels of air flowing by do not get their momentum vectors redirected downwards anymore and the wing hence "stops flying".

Meanwhile, the region of separated flow constitutes a zone of turbulent air which forms a stirred-up wake in the rear-facing "shadow" of the wing at its high angle of attack and the only work performed by the wing in this case is to stir up that wake- and that constitutes lots of drag.


(flightaware.com) Return flight.

AI 140 (the return flight) arrives closer to the Pakistani FIR border. The south route when flying westward can be explained by jet stream avoidance.

Apart from the recent exceptions given to Air India by Saudi Arabia and Oman, the countries shown below do not permit flights to enter their airspace if their destination/origin is Israel (flightservicebureau.org, March 2018).

This is also briefly covered on FR24's blog.


What angle of deflection / pitch on the rotor blades can the controls generate?

Maximum pitch angle would totally depend on the type of helicopter you are flying. Each helicopter has its own set of limitations and pitch angles depending on the blade, rpm, etc. The controls include a mechanical stop, and you would hit that limit sooner or later if you put in an overly aggressive control input on the cyclic, or full collective up or down. Think of it as the same way you would hit the outside edge of the control on a video game joystick.

In "real life", the pitch angle numbers are irrelevant to a helicopter pilot. During
autorotation, the RPM of the spinning blades is maintained by reducing the pitch angle allowing an upflow of air from the descent to maintain the rotors spinning - similar to blowing air on a fan in order to keep the fan blades moving. The rotor RPM can be adjusted through up and down collective movements, which will in turn increase or reduce the RPM required.


Why doesn't the aviation industry use SI units?

Non-SI is only used for altitude, distance and speed except in US and some other American countries.

Altitude is in feet because 1000 ft happens to be reasonable vertical separation and 1000 ft is easier to calculate with than the corresponding SI figure 300 m. Also the procedures for instrument flying were first developed in the USA using feet.
Distance is in nautical miles because it is related to the unit used for measuring latitude and longitude. 1 nautical mile corresponds to 1 minute latitude (and longitude on the equator), which makes it easier to calculate distances from navigational maps using the grid lines as scale (large area navigation maps need to preserve angles, so they can't have constant scale). If angles were converted to decimal, 1 km would be 1/100 gradian. Alas, angles and time were never converted to decimal.
Speed obviously based on the distance unit in use.

Nevertheless if it was not for the prevalence of US-built planes after WWII and more advanced state of aviation in the USA at that time, we would probably be using metric in Europe too as continental planes before WWII usually had instruments in metric.


Does clearance delivery assign VOR or GPS-A approaches?

No.  Normally you don't know which approach you are going to be using at your destination because you can't be sure which runway will be in use.  The STARs at larger airports are to provide standard routings for all/most the of airport's approaches/runways and each STAR is based on a different arrival direction, so the STAR in your clearance will usually be based on where you're coming from and you usually include one in your filed flight plan, that you've picked because its initial waypoint links in nicely to your route.  The actual routing within the STAR you will be using, you find out when you listen in on the destination ATIS to find out the approach in use as you plan your arrival.

Once you get there, you may only fly one or two legs of the STAR before ATC gives you a heading and now you are on radar vectors to get lined up for the approach and you just do what you're told and the rest of the STAR routing goes out the window.

The key thing in IFR is accommodation of communication failures. Comm failure procedures are intended to allow you to complete your flight by following your most current clearance and observing SOPs that allow ATC to predict where you're going to go and when, with reasonable confidence, so that they can work traffic around you.  If you've declared a comm failure (7600) enroute, you would fly the STAR routing and altitudes as published and use as much common sense as possible.

For example, a lot of STAR routes kind of drop you off at a Downwind Termination Waypoint for a particular runway and indicate radar vectors beyond that.  In a comm failure situation you are expected to fly the published route to the DTW and from there you are expected to find your own way to the approach by the most logical, predictable routing that causes minimum disruption.

If the destination has no STAR, your clearance will be to the last waypoint in your route that gets you close to the airport, and that will be your clearance limit and from there you would get radar vectors to line up with whatever approach is in use.  In a case of a comm failure, you are supposed to proceed to your clearance limit, hold there if you're early, then proceed to fly the appropriate approach at the time specified in your flight plan by the most logical routing, so that ATC can predict where you're going and when.


What geographic reference system do airport towers use?

I've only done passing research on the matter before, so if anyone knows more please chime in.  As far as I know the FAA uses NSRS (National Space Reference System), and the NSRS currently uses NOAA GEOID models, although this is expected to be changed in 2022.  I'm not sure which regulation covers airport surveys, but you can reference AC 150/5300-18 (pdf). ICAO Annex 14 doesn't seem to mention a specific vertical datum for MSL, but specifies that, independent of the method, surveyed altitude for precision approach runways has to be accurate to "one-quarter metre or foot".
Interestingly, some airports and navaids aren't even using the WGS-84 lat/long coordinates, much less a recent international geoid model for MSL.  This is increasingly rare, but you can check a list of waypoints excluded by Garmin for non-WGS-84 compliance here and see a list of overall compliance by country here.
While it's always nice to have higher resolution MSL altitude models, we have to keep in mind their limited usefulness. Since airport's charted elevation is the reference point for barometric altitude in aviation, the only issues with an inaccurate airfield elevation are seen when comparing to elevation measured elsewhere. As a result airplanes a few miles from the airport may indicate less accurate elevation relative to the airport and local sea level (but would indicate accurately relative to other altimeters at the same location). An inaccurate survey would also affect GPS's geometric or "GLS" altitude, but that's basically only used as a cross-check.
I'd guess that in practice temperature and pressure variations over an area are greater than the variations in geoid elevation error over the area, and regulations already account for those inaccuracies, for example by requiring higher MDA when using an altimeter setting from a different airport. Additionally, some of the tools for measuring altitude on an aircraft have much lower accuracy than the <1 m accuracy of these geoid models and surveys.  Even an ideal radio altimeter can only measure 1.5 ft accuracy and then only when close to the ground (according to Arinc 707-7), and un-augmented GPS and barometric altitudes are frequently off by several dozen feet. Aviation is designed with imprecise altitude measurements so sub-foot precision isn't necessary or practical away from an airfield.


What is the purpose of the extra horizontal and vertical surfaces on the tail of the Beechcraft 1900?

Yes that is what is the most cost effective solution after flight testing has demonstrated that the vertical tail surface has to be increased for instance. The little winglets at the end of the horizontal tail do increase aerodynamic efficiency of the stab - plus they just look cool.

The BAe 125 stuck a bit of fin on top of the original fin design, the Beech 1900 added the extra vertical tail surface underneath the aft fuselage cone, in the form of 2 v-shape surfaces which also help the total horizontal tail area.


Which of the pilots flies when it gets dangerous?

In the end it's all up to the Captain.  If the FO is PF, which with most airlines alternates with each leg of a block, and something exciting happens, the capt may let the FO continue flying if the capt feels the FO has things under control.  Or the capt may say "I have control" and take over.  Depends.

The Pilot In Command is pilot in command.  He/she commands, but with modern CRM rules, there is expected to be some mutual consultation and decision making, so the command authority has to take all that into account.

AF447 was an unusual situation where the capt didn't realize early enough what a clusterfark the two FOs sitting in the front seats had gotten themselves into, who were both mentally overloaded into a tunnel vision state, and especially the right seater, who appeared to lack basic fully internalized flying skills, sitting in panic mode with the stick full aft for almost the entire ride down.


Is there any country that requires window blinds to be open for takeoff and landing?

There is a regulation which indirectly covers it. Certainly in the UK and I'm pretty sure in the US and EASA land, it is an offence to not comply with the lawful instruction of a member of the crew. Therefore, if you are asked to raise the blinds, it is a legal requirement for you to do so.

Failing to comply with an instruction which is not itself illegal is an offence. Rarely used but it has been. Usually, the cabin crew will just mark you down as "idiot" and do it themselves. But, if it is clear that you understand and that you are able to comply, you might be removed from the flight and prosecuted. Generic laws like this, e.g. "dangerous driving" are there to provide for reasonable action when a specific law does not apply.

A valid defence would be to demonstrate that you were unable to comply to the extent that the prosecution is unable to convince a jury of your peers to find you guilty "beyond reasonable doubt".

So, in summary, albeit indirectly, it is a legal requirement for you to raise the blind when asked to do so in the UK.


What is the "off-side engine generator" on an A320?

Offside simply means opposite, and it's to do with the AC bus supply priority.

For the A320 the priority is:

Onside, e.g., left engine IDG for AC BUS 1
External power
APU
Offside, e.g., right engine IDG for AC BUS 1, meaning the left engine's IDG has failed or taken offline.


What happens when an airline pilot decides not to fly at the last minute?

There would be a great deal of variability on what happens depending on the airline, whether or not it was unionized, what country it was in, who the pilot was, and the specific situation of the flight involved.

The scenario of an hour or less is a truly rare occurrence. The system is set up to prevent such happenings. The last two carriers I worked for had a 2-hour showtime. If a pilot hadn't checked in or been picked up by that time, the search immediately started for a replacement.

The only occurrence of an approximate one hour replacement need that I'm personally aware of was when a captain failed a breathalyzer test at his 2-hour show time. Given the confusion of the moment, it was well less than 2 hours when they started the search for a replacement. There was no ready reserve, and no management pilots available that were current, so they had to start stealing captains from flights due to depart later. I was due to operate JFK to AMS around 2 hours after the JFK to TLV flight they needed a captain for, so they stole me off my flight, which meant they had to get someone else for that, etc.

There is good reason for a 2-hour showtime other than just making sure a pilot is there. There is work to be done, and that work has to be done by someone. In this case, a non-current management pilot did that work, including my cockpit flow. I went directly into cockpit, sat down, and called for the before start checklist.

There was in this instance a good reason to do what could be done to avoid taking a delay. Numbers of flights leave JFK for Europe and the Middle East in the evening. If you take a delay, you may well get a lower altitude than planned because someone ahead of you has grabbed it; everybody's going over the North Atlantic track system. If that happens, you need more fuel, which is more cost, etc.

What would happen to a pilot causing a one-hour replacement depends on so many things I won't even try to address that other than to say that it could range from no penalty whatsoever to immediate termination. In the case above, the captain was terminated, and since he was in his late 50s back when the age 60 retirement rule was in effect, it was the end of his airline career insofar as U.S. airlines were concerned.


Can pilots tell if a cloud or fog is made out of water droplets or ice crystals when flying through it?

Boeing provides some decent notes on this in their powerpoint which you can find in full here. Their sections on pilot reports and the summary section have some good notes for identifying ice crystals in flight/clouds/fog

  Pilots have reported rain, sometimes ‘heavy rain’ on the windscreen, Sometimes at impossibly cold temperatures. This is
  believed to be the result of these small ice crystals melting on
  impact with the heated windscreen
  No observations of significant airframe icing
  Turning on landing lights at night and seeing reflective precipitation .It is likely they were seeing the larger particles even
  though they make up a smaller fraction of the population
  Hearing a different sound from rain. Ice crystals hitting the airframe sounded different than rain or hail
  Light to moderate turbulence
  No significant airframe icing
  TAT probe frozen
  Ice detector not detecting ice (when installed)
  Appearance of rain on the windshield

The same powerpoint also discusses that satellite imagery can be used to see ice crystals. A lot of planes even small stuff have the ability to receive feeds of this data which can be used to identify sections of ice crystals in flight.

According to various sources the threat is particularly dangerous due to the fact that there is no hard and vast way to visually identify the crystals and in many cases the effects are similar to other events and may lead the pilot to belive something else is happening.

For pilots we can only go by look, unless you are flying slow in a 172 you cant exactly pop the window open at altitude and feel the cloud. Simply put pilots can not reasonably tell if a cloud is vapor or crystal prior to flying into it and observing the above noted actions.


Is tungsten a good metal for jet engines, besides the weight penalty?

No, tungsten would generally not be a good choice for jet engines.

Some of the parts that would need to be the most heat resistant, such as turbine blades are subjected to rotational forces that increase directly with the mass of the part. Thus a high mass material such as tungsten would increase the forces the part would have to withstand. These forces are already measured in tons per blade.

If you discount the high-mass quality of Tungsten, the biggest problem is that Tungsten is also brittle. If a turbine blade failed, as does happen, it would be very difficult to contain. Tungsten is used in armor piercing projectiles; the results of a tungsten turbine blade failure would not be good.


What is this plane and what are the rockets on the back used for?

As the source linked next to the image in the other question says, it is a C-130 performing a "rocket assisted takeoff".

These are performed to safely achieve V1 on short airfields, where the aircraft would not be able to take off otherwise.

The rockets (or "bottles") use solid fuel, so they are usually single-use.

I have no data on the thrust provided by one of them, but the wikipedia article mentions that a "smaller version" made for the civilian market, could deliver "250 pounds of thrust for 12 seconds", so it is reasonable to expect that the thrust provided by the larger bottles would be larger.


How effective was WWII bombers self defense anti-air armament?

The only figures I could find were the 60 bombers out of 300 lost by the USAAF in the Schweinfurt raid, most of those losses from German fighters. That convinced the generals that the onboard gunners weren't all that effective, and bombers couldn't defend themselves from a determined fighter attack. Major air attacks on Germany were postponed until the long range P51 could be deployed to protect the bombers better.

Gunnery from a bomber is far more difficult than from a fighter, that fires straight ahead. In a bomber, the gunner might be firing to the side, which means they have to factor in the bomber's speed that will propel the bullets sideways, and actually aim slightly behind the approaching fighter. The closer to the nose or tail, the less one aimed behind... bomber gunnery is very complex. This wartime training film illustrates the problems of firing on fighters approaching from the side. Try to calculate those ever changing angles when you're being shot at...

The same difficulties were experienced by ships being attacked by aircraft... very difficult to shoot down a small, fast moving aircraft approaching a ship. The Bismarck couldn't stop slow moving Swordfish biplanes from knocking it's rudders out. In the last major naval action of the war, eight Japanese warships (including the Yamato) were attacked by around 400 aircraft from US carriers. Seven of the eight ships were sunk, while only 14 aircraft were lost in the action, despite those ships having had quite a few extra AA guns added.

So, why arm the bombers? That was a question asked by Curtis LeMay in 1945. He devised a plan to take most of the guns out of B29's and operate them at night, because the Japanese hadn't demonstrated much in the way of night interception. He reduced the attack altitude to 12k feet from 30k feet, because that put the planes above small arms, but below the effective range of large anti-aircraft cannon. And, he used the weight saved from armament removal to carry extra incendiary bombs, to ignite the largely wood buildings of major Japanese cities.

The result was the fire raids, the most destructive bombing campaign of the war, even more destructive than the atomic bombs.

Guns on bombers have been dwindling since then, with the B52 having only one tail gun, while the B1 and B2 have no guns. Still, during Linebacker II, two MIG21's were shot down by B52 tail gunners, so the guns weren't completely useless.


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

As an automotive engine mechanic with 35 years of performance oriented experience and 29 years of that with ASE Master Certification and about a dozen other engine specific certifications.  Twenty or  so years ago I trained to be a piston engine aviation tech.
So I think I can say with some certainty that I know a thing or three about how engines work and what sort of things can have a detrimental effect on them.
"Thermal shock" is definitely bad for an internal combustion engine.  That said, touch & go's will not cause thermal shock to occur in a piston engine, here's why.
Thermal shock is what significantly rapid and drastically uneven temperature change in an engine is called.  This means if one or the other isn't occurring then there's no thermal shock occurring.

(To be accurate, it's more a degree of severity, as these conditions happen during normal operation and always will.)
The minimum operating temperature called for by the engine manufacturer is to avoid thermal shock.  It is important enough for the manufacturer to stress because it is the only reasonable condition the pilot can produce enough thermal shock to damage the engine.  When the engine is below the minimum, applying full power causes the pistons and rings to heat up and expand much more rapidly than the cylinders. This in turn reduces the clearance around the pistons and can dramatically increase the friction.  The increased friction compounds the problem by adding to the heat and expansion of the piston.  More expansion -> more friction -> more heat... This quickly becomes a deadly self reinforcing loop.  Because the pistons can't shed heat to the cylinders fast enough the cylinders don't expand and very quickly there's no clearance and the piston seizes up inside the cylinders.
Rapid temperature change in part of the engine without a matching change in the rest. This is the part of thermal expansion that breaks things.  The piston to cylinder heat transfer is very inefficient. But the transfer of heat, to the air from the engine, is even slower. So, once the engine is warmed up, it stays that way till it's parked in the hangar and you're headed out. That's just physics 101.

The alternative situation is not likely to happen and if it did, your last worry would be the thermal shock to your engine as the engine wouldn't be running long enough to get damaged, from heat shock that is.  What I'm talking about is full submersion of the engine in water. Given this scenario I am doubtful "thermal shock" would really be on your mind.  To be honest, I'm not sure if even the coldest water you could keep liquid is cold enough to chill the cylinders to the point of interference.

The belief that touch & go's cause too much "thermal shock" probably comes from mechanics understanding the cumulative effect of dissimilar thermal expansion caused by repeated full throttle application during the touch & go's, but being unwilling or unable to explain that it is really only an issue during the run-in period of time when the new rings are seating in freshly honed cylinders.

The only other way I can see touch & go's being an issue is if a freshly built engine is put together with too little clearance between the pistons and the cylinders.  In the extreme, repeatedly heat stressing the engine could scuff its way to a seized piston.  None the less, that wouldn't be thermal shock anyway.  That would be builder error and the probable source of stories that say "Touch & go's will blow your engine up!"


How does fuel flow and altitude affect the compression ratio of jets?

the compression ratio of a conventional gas turbine is a strong function of the rotating speed of the engine; note that at near-zero speed, the compression ratio of a gas turbine is essentially 1:1 and the engine will not run- even if some means is provided to alter the pitch of the compressor stage fan wheels.

density altitude also enters into the picture, inasmuch as beyond a certain altitude, there is not enough oxygen available to allow the engine to develop full rated power- and beyond that point the engine's power rating falls off with increasing altitude.


Is it possible to celebrate a holiday twice by flying from one point on Earth to another?

Technically, yes. As I right this, it is half past midnight at London, Heathrow. It is half past eight at New York Kennedy. And, it is half past five at Los Angeles. If it were not Daylight Savings Time, it would be half past seven in New York. On New Years Eve, you would have between 4 and 5 hours to celebrate in London, fly and land, before you started celebrating again In New York. Hardly any time for even a celebratory drink (as a passenger) and kiss. I have come very close to landing before I took off  when traveling from the US to the Asia. So far, I have never made it. I’ve always missed it by an hour or three.

It would be easier to celebrate New Years in somewhere like Lubbock, TX (Central Time, USA), then flying to Roswell or Clovis, NM (Mountain Time, USA).


I think your premises are wrong. If an airport has a runway 16/34 then either both landings and departures take place in direction 16 (runway 16 is open) or both take place in direction 34.

In most cases both directions are not used at the same time. Which direction is chosen usually depends on the current wind direction so planes depart and arrive with headwind (not tailwind). Which one is open (16 or 34) can change from day to day, even during a day. Usually one of the directions is used most of the time because the wind usually comes from a certain direction. For example, London Heathrow has two parallel runways and in approx. 70 % of the time the wind comes from the west (westerly operation). Hence, they use runways 27L and 27R most of the time for both arrivals and departures.

There are, however, runways that are restricted to either take-off or landings, like runway 18 in Frankfurt, for example (only for take off), or 07L/25R (only for landing). But again, 07L/25R means: either all planes land in direction (on runway) 07 (towards the east) or all land in direction (on runway) 25 (towards the west).

See also:

What determines in which direction a runway is used?
Why is tailwind during final approach and landing so dangerous?


Are there common standards for aviation graphical user interfaces?

I think your best bet might be going through the Instrument Flying Handbook [PDF, Large!] by the Federal Aviation Administration. It has plenty of nice graphics, if you're fine with a lot of other irrelevant stuff in the document. There's also the Chapter 8, Instruments, of the FAA Pilot Flying Handbook [PDF], which is a bit more compact.

I'm not sure there are any exact specifications how these things have to look. I suspect the minimum requirements are given in the certification specifications, and how they are then presented may be up to the manufacturer.

For instance, in EASA CS-23.2600B:

  The  applicant  must  install  flight,  navigation,  surveillance,
  and powerplant installation controls  and displays  so  that  a
  qualified  flight  crew  can  monitor  and  perform  defined  tasks
  associated  with  the intended functions of systems and equipment. The
  system and equipment design must   minimise  flight crew errors, which
  could result in additional hazards

I'd interpret "minimise  flight crew errors" to not do anything overly ambitious with the instruments that deviate from the norm, i.e. what everybody else is doing.

In EASA CS-23.2610A:

  Each aeroplane must display in a conspicuous manner any placard and
  instrument marking necessary for operation.

It does happen that this stuff can be different- while the military is generally more flexible, the U-2 reconnaissance aircraft has a speed indicator that goes the opposite direction.


As Timothy already mentioned, most trainers do not have flaps, but when a glider is equipped with flaps, it would be most commonly in form of flaperons where full-span ailerons are coupled with flap control allowing common-mode motion both upwards and downwards. In contrast to the powered airplanes, flaps in gliders are used not only for landing, but also (maybe more importantly) to adjust optimal glide ratio for the speed currently flown. Thus upward turned flaps are common configuration during fast gliding between thermals for example.

Finding information for particular gliders, especially such mentioning flaperons explicitly turned to be quite hard. Pilot operating manuals usually just describe how to manipulate flaps handle without going into the details on actual construction. Typical placecard for flaps handle (from DG-400 manual) does look like this. Ranging from landing configuration to negative flaps.

Particular gliders equiped with flaperons include (maybe not the most modern ones, but those I was able to find some more info about, good enough as examples IMO):

DG-800 and LS-10 has full-span flapperons. Mentioned explicitly in the flight manual: The wings feature single piece flaperons, which are driven at two places. The mixing of aileron and flap deflections takes place in the fuselage. (The same formulation exists in LS-10 flight manual.)
DG-600 -- according to the wiki.
ASW-20 (and probably some other Schleicher gliders too) -- there are two distinct surfaces on each wing, sometimes referred as "flap" and "aileron", but both of them actually moves according to the mixed inputs of both controls, the ASW-20 flight manual contains nice table of deflections:

Eta has three flaperon sections on each wing, each with different mix ratio between control inputs
... and many others, I believe