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

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

I'm unaware of any regulation that requires a minimum number of hours to be a captain or first officer above FL200. That doesn't mean there aren't such, just that I don't know of them.

It's not that that taking off and flying close to terrain requires more or less experience, but that safely operating at high altitude typically involves a different set of knowledge and experience than operating at low altitude. A seasoned bush pilot who does only that would be ill equipped to suddenly become the captain of a 747 at 35,000 feet, just as the 747 captain who had never been a bush pilot would be ill equipped to scud run through a valley to land on a remote airstrip.

Part of the difference between two such pilots is, of course, a matter of a propeller airplane versus a jet, a slow airplane versus a fast, and the differing complexities of their aircraft. In addition to those differences, though, the environment that they typically operate in and indeed the altitude itself makes things different. The nature of the emergencies they can possibly face are also different.

Offhand I can think of three things the typical low altitude pilot doesn't have to contend with that the high altitude pilot does. There are certainly more.

Oxygen considerations, in other words what you need to do if you suddenly don't have it at a breathable pressure. Probably never going to happen, but the high altitude pilot trains for it.
Regular operation in or close to the coffin corner. If you're unfamiliar with the term,  Wikipedia has a reasonable explanation as well as
this question.
A whole different situational awareness environment than the low altitude pilot. For example, I used to do a flight from Sao Paulo to Miami. Two other carriers had flights scheduled that went out immediately before us, also 747s. Everybody was always heavy, which meant the first guy out got the highest cruise altitude available for the weight we were all at approximately, the second guy 2,000 feet below that, and then us sucking fuel 4,000 feet lower than the first. However, I knew that if I could open up the distance between myself and the second guy, I could get a clearance through the second guy's altitude to the first guy's altitude since there was enough time/distance between us. So what I would do was to climb at best angle rather than best rate. Then, if the weather was good (i.e. no turbulence) and I had the engines for it, it took very little fuel burn before I would able to get 2,000 feet higher if I was willing to accept slightly lesser protection from the top of the coffin corner. Sometimes that would work out, sometimes not, but it always got us at least up to the first guy's altitude. And on rare occasions, it meant we reached Miami before either of the other two.


How is a flight routed from the last waypoint of a STAR to final?

Look more carefully; says it right at the bottom. At the STAR's termination waypoint, LGA, expect radar vectors to final.

If you had comm failure, and couldn't talk to ATC, you would fly the STAR in your clearance and if it is an open STAR like that, at the termination waypoint you would find your own way to the ILS/LOC and shoot the approach, taking the most logical path to get there and avoiding any unusual maneuvers or turns.

A lot of the procedures you see in SIDs and STARs are not followed exactly as depicted when ATC is giving instructions (the controller may put you on vectors long before you reach the termination waypoint for example), but are there in case of a communications failure, to ensure that an arriving or departing aircraft has obstacle clearance and so that ATC can predict with reasonable certainty where you are going to go as you arrive with no way to talk to them.


What causes aircraft to swerve during takeoff?

I know you said that you don't think it's a crosswind, but honestly it most likely is.  As the plane speeds up and the wings start to generate more and more lift the plane is more easily affected by cross wind.  So, as you speed up, it gets harder and harder to keep the plane straight.  Throw in some gusts, and you're going to get some jerking motions as well.  Especially if that gust decreases the lift of the aircraft, the wheels suddenly catch the ground more and the craft is suddenly tugged harder than the pilot anticipated...

Here's a video of a Boeing 777 taking off in a heavy crosswind that should illustrate the point more.


Are there any drawbacks to requesting progressive taxi every time?

Apart from appearing really unprofessional, the obvious drawback is a significantly higher workload, both for the pilot but especially for ATC. You're not the only aircraft moving around at the airport, and even if you are, the controller most likely has other things to do than focus entirely on you.
As a pilot, you will also have a lower situational awareness, since you are not actually keeping track of where you are, but just following turn-by-turn instructions. Are you 100% sure you are at the right runway? And that the runway is long enough? What was the departure procedure again? Is the aircraft correctly configured for takeoff? I guess you didn't have time to check the charts, do a departure briefing and run through checklists since you had to focus on the radio all the time.
A more subtle drawback is that the controller will trust you less and as a result may very well choose to delay you in some situations. This is not written in any books, but controllers do establish sort of a mental picture of a pilot's competence level while talking to them, and if someone repeatedly requested progressive taxi, that would certainly raise a red flag. If you're waiting in line for takeoff, and there is a gap between arriving aircraft just large enough to get you going, the controller is more likely to let you wait for a better opportunity if they do not trust you fully. What's to say an (apparently) inexperienced pilot won't line up and spend 30 seconds on the runway before applying power - forcing a go-around for the aircraft on short final? Best wait another few minutes until there is a larger gap.
Ultimately, if you are in doubt about where you are, PLEASE DO ASK the controller for help! But, if you plan on making a habit of it just for convenience, please know that you are abusing the system, potentially reducing ATC capacity and causing an unsafe situation for yourself or others.


There is no regulatory guidance on how fast (or how slow) an aircraft must move during the pushback. Furthermore, there are many opinions (see below) on how fast an airplane moves during pushback.

If you watch a pushback, you will notice that ground personnel known as wing-walkers* will walk alongside the aircraft, at the wingtip, during pushback.  The normal speed of humans walking is 3-4 mph, which can surge to 5-6 mph for short distance.

The speed is not fixed. It is dependent on all the factors you mentioned plus the experience of the tug driver and ground crew as well as size of the airplane and its weight. It takes longer to accelerate a large airplane to this speed, and it is harder to slow down a large airplane.

* ICAO Annex 2 Volume 5 (Appendix 1-5) and SA CATS 91.05.1 (5)

See also:

airliners.net / Pushback-speed Limitations?
pprune.org /  Pushback and Towing - Time


Will the steep beta descent mode become illegal for new aircraft?

I wouldn't call it a "descent mode from altitude".  It's considered to be a dangerous and foolish practice to operate an engine in ground beta (generally coming back into DISCING - blades flat) while in flight to get steep descent rates.  If the prop doesn't want to come out of ground beta, you are dead meat.

When the Twin Otter was in production, it was an open secret that demo pilots were using DISCING to get crazy steep approaches to impress customers.  After a couple exciting events, flight ops finally put an end to it.

Some airplanes already have ground beta lockout systems.  Is this a proposal to mandate a system for the PC6 specifically?


What are the differences between the MiG 31 and MiG 25 (if any)?

The MiG-31 is an all new design with higher strength for low-level flight and new engines. The reason it looks just like the MiG-25 has to do with the structure of the Soviet aviation industry. The basic shape is first defined by the Central Aerodynamic and Hydrodynamic Institute (TsAGI is the abbreviation of its Russian name) and then given to the design bureaus which do the mechanical design. Production is then relegated to dedicated manufacturers which build the designs of different bureaus in parallel.

Both aircraft were designed as interceptors. The main difference is the advanced radar, digital data links and the more powerful engines of the MiG-31 which made a longer fuselage necessary. The MiG-25 radar, a development from the 1960s, could only detect high-flying targets, while the Zaslon radar of the MiG-31 can also detect and track low flying aircraft (look-down/shoot-down capability); a necessity after NATO changed its strategy to nap-of-the-earth flying to avoid detection.

If you need to tell both apart on pictures, look for these features:

While the main landing gear of the MiG-25 has a large, single wheel, the main gear of the MiG-31 uses two smaller wheels in a staggered arrangement.

MiG-31 main landing gear (picture by Burkhard Domke source)

While most MiG-25 were single seaters, the MiG-31 has two occupants, a pilot and a weapon systems officer behind him. Two-seater versions of the MiG-25 can be easily distinguished because the two cockpits are separate units, the front cockpit replacing the radar.

MiG-31 on the ground with canopies open (picture source)

The wing root of the MiG-31 has a small strake added while the wing of the MiG-25 is a pure trapeze with a straight leading edge. The picture below shows the MiG-25 in black lines and the MiG-31 overlaid in red.


Can a pilot rated in one category solo in another category without a current flight review?

You do require a flight review, per the Beard (2013) interpretation:

  Finally, you have also asked whether a person operating in solo flight
  under a § 61.31(d) endorsement must comply with the flight review
  requirements in § 61.56(c). With a few listed exceptions, no person
  make act as pilot in command of an aircraft unless within the previous
  24 calendar months that person completed a flight review with an
  authorized  instructor. 14 C.F.R. § 61.56(c). Section 61.56(g)
  provides an exception for student pilots provided the student pilot is
  undergoing training for a certificate and has a current solo flight
  endorsement as required under § 61.87. Because this exception applies
  to student pilots, a pilot who holds a higher level pilot certificate
  and has an endorsement for solo flight under § 61.31(d) must comply
  with the flight review requirements in § 61.56 before acting as pilot
  in command of any aircraft.

Regarding the student pilot exception, others have suggested in comments that you are in fact a student pilot because you're new to the category/class. However, the interpretation says you are not:

  Section 61.81 states that subpart C "prescribes the requirements for
  the issuance of student pilot certificates, the conditions under which
  those certificates are necessary, and the general operating rules and
  limitations for the holders of those certificates." As such, by its
  express language, subpart C to part 61 applies only to those persons
  who are seeking or hold a student pilot certificate.

So, since you will be acting as PIC and none of the exceptions in 61.56 apply, you need a flight review. As for a checkride, the person taking the checkride is acting as PIC (61.47(b)) so again, you would need a valid flight review.


Can the thrust reversers still be activated if the landing gear won't extend?

(Source) LOT Polish Airlines Flight 16
All Boeings, minus the 717 and 727, have wing-mounted engines. A belly landing will already damage the engines and potentially rupture fuel or hydraulic lines, so no. Some reverser types employ target doors, which require clearance to the ground.
In case of tail-mounted engines, the answer will depend on the flight manual and the extent of the gear extension failure (partial, all, main, nose).
An MD-80 manual notes:

IF Nose Gear Unsafe, Both Main Gear Extended:
Idle reverse thrust may be used with caution for deceleration.


How can the radar range for ATC be estimated based on stated maximum radar range?

A radar system designed to track artillery shells is likely to be entirely useless as an air traffic control system.

To improve their utility radar systems reject signals outside their design parameters. This means that stationary elements (buildings, landscape features, etc.) are ignored, as are objects with velocities well outside the target range. There may be other optimisations.

The muzzle velocity of an artillery piece is typically well in excess of the speed of sound (Reference) A radar system designed to handle artillery shells may reject many subsonic traces, and thus ignore most aircraft that you might want to have some control over.

Of course, you could reprogram or repurpose the electronics, but then you wouldn't really have a naval radar anymore.


Would supersonic bi/tri/multiplane wings have less lift interference drag than a subsonic version?

Amazingly, at supersonic speeds it can work the other way. In the Busemann biplane the shock waves interfere in such a way as to actually reduce drag and also to reduce the sonic boom. Wide enough separation to avoid interference would actually increase supersonic drag.

See for example:

Wu, Jamieson and Wang
Kusunose, Matsushima and Maruyama


What is the definition of “airport boundary”?

It's effectively a reporting point consisting of the point at which the controller expects you to cross the perimeter fence line around the airport property.  If the controller uses that term, I would expect that there is a pretty obvious perimeter fence, and the controller isn't too concerned with the precise location at which you cross it, within reason.


What are lateral, longitudinal and directional stability?

The answer here is found in the Pilot's Handbook of Aeronautical Knowledge (and probably elsewhere) and is as follows:

The longitudinal axis of an aircraft is more or less a straight line through the aircraft's nose cone or prop hub and the endpoint of the fuselage (the aircraft's center of gravity will usually lie along or just slightly above/below this line as well). It is the axis around which the aircraft rolls, controlled by the ailerons. The lateral axis is parallel to the wings and passes through the aircraft's center of gravity. It is the axis around which the aircraft pitches, as controlled by the elevators. Finally, the vertical axis is "normal" (perpendicular in all directions to) the geometric plane formed by the longitudinal and lateral axes, parallel to the aircraft's primary lift vector and (in level flight) its weight vector. It is the axis around which the aircraft yaws, controlled by the rudder.

Rotation about any one axis is the job of one linked set of control surfaces as mentioned above. Stability in that same axis, roughly defined as keeping that line passing through your aircraft pointing in the same direction, is the job of the other two surfaces in concert, but primarily the one that would move the endpoints of that axis up or down relative to the aircraft. So, elevators provide lateral rotation to achieve longitudinal stability, and vice versa for ailerons.

It differs slightly for the vertical axis, as if your plane is both longitudinally and laterally stable, it's also "vertically stable", however the plane is longitudinally and laterally stable, but completely out of control, in a "flat spin". Stability in the vertical axis therefore is secondary to "directional stability", which keeps the longitudinal axis pointing in a particular direction along the geometric plane formed by the lateral and longitudinal axes. In this case the rudder both controls yaw and provides directional stability.

In addition to control surfaces, weight and especially the aircraft's center of gravity is important in stability. Ideally, most small planes are most stable in level flight when the CG of the aircraft is exactly on the centerline of the aircraft (between the tip of the nose and the tip of the tail) and slightly forward of the aircraft's center of lift (which depends on the wing's angle of attack but is usually close to the thickest point in the wing's cross-section). In this configuration, while the aircraft is travelling forward normally, downwash from the wings flow over the top of the horizontal stabilizer, keeping the nose level. In a stall, the slight nose-heavy configuration along with the stabilizers in the rear will cause the nose to point downward gently, restoring normal airflow and allowing the pilot to recover.

If the CG is too far forward, the pilot will need to apply upward pitch or trim to keep the nose level. This will reduce the amount of travel he will have available to pitch up, and in a stall, the plane will nose down sharply and the elevator may provide insufficient force for the pilot to pull out of the dive.

If the CG is too far aft, the plane will want to nose up constantly, and the pilot will have to apply downward elevator or trim. In a stall, a plane with an aft CG won't nose down, preventing the pilot being able to restore normal airflow over the wings. This is especially dangerous in an uncoordinated stall aka a spin; the aft center of gravity in combination with the forward thrust of the engine will "stabilize" the plane in the spin and make it impossible to recover.

If the CG is off the aircraft's centerline, the plane will tend to roll towards its heavier side. This is compensated for with ailerons or aileron trim, and for most everyday flight it's the easiest to compensate for, but it can cause unfamiliar roll behavior and a tendency to spiral down, which the pilot must be aware of and correct for.


Do helicopters have an auto hover system?

Yes, advanced flight directors and autopilots for helicopters can control the aircraft in all axes, and often they have modes for hovering built in, including maintain altitude, lateral veloctiy hold, hover, and/or autolevel.

Hovering is difficult because it requires more complex controls than maintaining altitude in an airplane.  Helicopters have a different set of control axes than fixed-wing aircraft.  Fixed wing aircraft are controlled in pitch, roll, and yaw, with thrust as an extra variable.  On a helicopter the flight path is controlled through cyclic (roll and pitch), collective, and throttle, with the anti-torque pedals as well to control yaw.  Hovering the aircraft requires controlling of the cyclic to keep the aircraft over its target with no lateral movement, and collective and throttle to maintain constant altitude, although the exact procedures are a little more complex.

While not present on low-end helicopters due to a combination of complexity and lack of necessity, advanced autopilots for helicopters do exist.  Like on other aircraft, there is a wide variety in autopilots between simple functions to maintain attitude (often called one or two-cue guidance depending on the number of axes used) to complex FMS-integrated three-axis modes (which would be "three-cue" guidance). The FAA Helicopter Flying Handbook states, for example, that  "The most advanced autopilots can fly an instrument approach to a hover without
any additional pilot input once the initial functions have
been selected."

On the Agusta AW139 helicopter that I'm familiar with (although I'm not a pilot), they have several modes that provide this functionality:

an altitude mode to maintain a given altitude
an altitude acquire mode to smoothly reach a desired altitude
an autolevel mode to level off at the end of an approach segment
a lateral velocity hold mode to maintain slow lateral motion or no lateral motion
more exotic search and rescue modes providing capabilites to transition to a hover, mark-on-target descents to predefined altitutdes, etc.

A traditional hover would be achieved by combining a low lateral velocity mode with a zero vertical speed mode like altitude or autolevel.


How can I tell how far I am from a cloud?

The answer, as best I can discern it from my training & my own experience, is "You can't!" -- every instructor I've flown with has said that cloud clearances are the most inadvertently-busted regulation, even when pilots are doing their best to obey the requirements.
Our eyes and brain are really good at judging distance relative to landmarks and objects of known size (that's how we can tell we're on a "3 mile final" or "8 miles out"), but without known references our ability to estimate distance quickly falls apart, and there simply aren't that many useful landmarks in the sky.

Judging lateral distance to clouds is, at least in my experience, generally easier than vertical distance - as long as you're a fair distance away from the cloud anyway.
You can roughly estimate the ground position of a cloud pretty easily (and if you can't you can always use its shadow and be pretty close). You can also usually find features on the ground of known size (runways, for example: You can get the length of the longest runway at a field from your handy VFR sectional), and figure out how many of those are between you and the cloud's ground position.
Also if you're doing this whole pilotage-and-navigation thing right you know where you are on the chart, and you can visually estimate the ground position of a cloud pretty easily (again if all else fails use its shadow and you'll be close). Break out your plotter and you can figure out how many miles away you are from the cloud (but inside about 3 miles this is going to get pretty difficult, and with your head in the cockpit mucking about with the chart and plotter you may wind up inside the cloud by the time you're done working up your estimate!).

A final close-in technique for clouds at your altitude is to use your wing. You know your aircraft's wingspan, and you can also say that roughly half that value is the length of one wing. Figure out how many "wings away" the cloud is, and do the math -- of course if you're at a distance where you can do that kind of visual estimation you're likely to be close to the cloud clearance limits.

Judging vertical distance is harder.  The usual advice if you're below the clouds is to get the cloud heights from a local airports ATIS or AWOS and use that as a guide.  If you're above the clouds PIREPs for cloud tops serve the same purpose.

Visually if you're above the cloud the same skills you use to judge your height above a runway will work. The catch is those skills really only work when you're within about 1000 to 2000 feet (i.e. "By the time you can really judge the distance you may already be too close!").
Coming up from below a cloud you're basically relying on judging your closing speed to an object of unknown / nebulous size: As you approach the cloud it's going to get bigger, but you don't really know how big it's going to get before you wind up inside it.

As a final visual cue in any direction, remember that clouds aren't clearly-defined boundaries - Often you'll see little wispy streaks of cloud around you as you're getting closer to the cloud you're trying to avoid (particularly when approaching from below). This is a pretty definitive indication that you're probably closer to the cloud than you should be, and you should start heading away from the cloud before you wind up inside it.

I think the best bottom-line practical advice I've ever gotten on cloud clearances, loosely paraphrased from a couple of the local CFIs: "Just stay way the heck away from clouds until you're instrument rated and on an IFR flight plan." and "If you think you might be too close to a cloud, get further away!" -- the latter probably being what the FAA is getting at with their statutory distance requirements.


Having declared a mental health condition in the past, how will this affect my plans to work as a pilot, and what should I do about it now?

This answer is inspired by best-practices in dealing with immigration officers.

I shall not dance around your feelings.  You picked the right industry to tell that lie, because the airline industry in particular is extremely familiar with fraudulent "support animals" - people slapping a vest on Fido to sneak them where pets do not belong.  The airlines have struggled with this and its consequences, and the FAA is certainly well aware of it.

Simply Tell The Truth about your mental health.  Which is to say, tell the truth now.

But you can't tell the truth if you don't know what is is. At extremes, stating a fact you don't know is lying, because you imply that you know it.

The form asks if you were diagnosed with a mental disorder.  Note those words.

The origin of the question on the matter is the "doctor"'s letter.  Review it.  If it plainly claims "diagnosis" and "mental disorder", then that is that: you must tick "yes". However if it is ambiguous on the point, then you don't know -- you should ask the "doctor" for clarification. I would write them and say you are applying for an ATP license, and ask them a) Did you diagnose me?  If so was the diagnosis of a mental disorder in the meaning of this form (attached)?

And the doctor will write you back and state definitively a) whether it was a diagnosis and b) whether it was of a mental disorder or other reportable thing on that form.  She will surely give you the most helpful answer possible within her medical ethics. You may rely on that because she is a licensed professional.  There may be an ethical issue there, but that's between her and her medical board: not your problem.

"Ah, but she can't recant the diagnosis since she's not a bona-fide doctor!"  Well then, she also was incapable of issuing a diagnosis, so you were not diagnosed after all.

If FAA asks about the contradiction between your FAA claim and your support animal letter, show them this second letter.  Of course they will suspect your goal was to cheat your landlord, but that does not violate any FAA regulations (except perhaps the "morals" rule, but therein, they are concerned about serious arcs of behavior that indicate disrespect for the duties of pilot, e.g. lying to FAA about mental health, not lying to landlord about a cat).


Yes.

What allows you as a pilot to fly large aircraft (legally under the FAA) is a type rating. As long as the two Captains hold proper type ratings for the aircraft they suffice for the required two crew members needed to fly the plane. However one of the two of them will be performing the duties of the first officer and that should be decided prior to the flight.

First Officer and Captain are rankings given by the airline not any governing body. Both the FO and Captain cary the type cert required to fly the aircraft (as far as I know).

The limited (and quickly dwindling) exception to this is aircraft that require a crew of 3 where the third is a flight engineer. The Flight Engineer position does hold its own certification.


Does Lift/Drag generally improve at higher Reynolds numbers?

Yes, the boundary layer that surrounds the airfoil is known to decrease its thickness as the Reynolds number increases; its relative thickness to the characteristic length (the cord for example) scales as $Re^{-1/2}$ in steady flow, and the polar curve becomes more horizontal when Re increases. Meanwhile, lift coefficient increases just a little bit (check this post).

In result, lift-to-drag ratio increases with Re.


How do tyre pressure sensors in aircraft work?

On a Boeing 777, a tire pressure sensor/fill valve is installed on each of the 12 main gear wheels and two nose gear wheels. There is an in-axle transformer in each of the axles.

The tire pressure sensor/fill valve is made of an air fill valve and three independent pressure sensing channels which provide accurate tire pressure.

The tire pressure sensor/fill valve is installed in the wheel.

A relay transformer hubcap assembly connects to the tire pressure sensor/fill valve. The left 28V DC MAIN bus supplies the electrical power to operate the tire pressure indication system.

(Image source: 777 AMM)

You can see the sensor in these images:

(Source: airliners.net)

(Source)


Why did flight NH175 divert back to Los Angeles?

You're already aware that the flight crew followed ANA's security protocol.
Yes the flight was closer to PANC, for example. Approximate location based on average ground speed and time it took to return to KLAX is shown below (to make sure there weren't any map projection antics).
(gcmap.com)
Security protocols are not public, but we can deduce from the timeline of the events what had happened.
The cabin crew became aware first (not the airline ops), which means the passenger was likely to be the one to bring the issue to them. Boarding a different painted airplane nowadays than the one on the ticket is no biggie with code-sharing and whatnot, honest mistake.
"While" on the way back, the airline ops discovered it was a mistake, when exactly, no reporter says. Maybe it was soon after.
Let's flip the question.
Why not KLAX?

Does this passenger have their [perhaps suspicious] checked-in luggage on board? Probably not.
Can we search them and their carry-ons? Yes.
Did they come forward? Possibly.
Do we have handcuffs on board? Yes.
Can we overpower this one person? Yes.
Are we willing to arrange (logistics) for their accommodation and ticket back to KLAX? No.
Do we have different flight and cabin crews to takeover the plane in PANC if needed (duty hours)? Hard to arrange.

How about arranging for the whole plane accommodation until said crew arrives? Harder to arrange.

Then proceed with protocol. Reacting and overreacting are different. In conclusion, there was no rush to quickly get rid of the passenger.

Addendum: Here by coincidence Alaska is also part of the US, a different route means you're going to burden another country with unneeded trouble, and as the police confirmed, there was no security risk (while the plane was headed back).


Why do stealth aircraft generally lose in maneuverability?

Radar stealth is achieved by carefully designing the aircraft to reflect radar waves in specific directions. It helps to keep the aircraft shape as simple as possible.

External weapons make this more complex: each missile adds a large number of surfaces that can reflect radar. The missile can also interact with the airplane fuselage to reflect radar waves several times. And once the missile has been launched it leaves an empty pylon behind with yet more surfaces capable of reflection.
It's much easier to maintain stealth if the missiles are stored inside the aircraft.

Some aircraft (e.g. the F-117) also try to achieve IR stealth by hiding the exhaust, mixing the exhaust gases with air etc. This is difficult to combine with vectored thrust.

Still, an aircraft like the F-22 has pretty good maneuverability, thanks to good aerodynamics and huge amounts of engine power.

The Su-37 uses vectored thrust and canards (again, extra reflection surfaces) to achieve high maneuverability.

So, there's a tradeoff going on. Do you want to blow your enemy out of the sky before he's seen you (which requires stealth)? Or do you focus on close combat (where maneuverability is most important)?


Why do some multi-engine aircraft have accelerate-go distance in their performance charts and some don’t?

It depends on the aircraft in question.  This isn’t required for the certification of a light twin and is solely up to the OEM’s discretion to publish said information.


Why do buses at some airports differ from conventional ones?

Apron buses are dedicated to transportation in the airport area, the one your show is located near the air museum at Salzburg airport / LOWS) in Austria. Similar buses are very commonly seen at airports:

Apron bus. Source.

The bus is traveling on short distances, it's maximum speed is 40 km/h, the price is lowered in proportion of the simplified design (more technical data).

Regarding the hidden wheels, considering the speed and the apron flat surface, this is possible for aesthetic reasons (many additional advantages come for free, e.g. fuel savings, protection against debris and stowaway). More importantly, the bus is a kneeling type type designed to accelerate passenger transfer. The floor can be lowered to:

To board and leave the bus more rapidly (no or small step).
To be accessible to everybody with no help, including when seated in a wheelchair (no lift required).

Protecting the wheels also keeps clear the space needed to lower the bus, and prevent accidents. This may be of some particular interest in a region subject to important snow falls, like in Austria.

Wheel access is provided by a panel:

Aero ABus

But this type of buses also exist with some or all apparent wheels:

Source.

Airport buses may be wider than regular road buses, they are not subject to public road regulation:

Source.

The model shown in the question can carry 100+ passengers in standing position (5 seats).

Source.

Apron buses can also have a bridge included (see also mobile lounges):

Source.

Unrelated comment: Salzburg, in addition of being the birthplace of Mozart and a famous ski resort, got an airport well known for its difficult approach during winter snowstorms, with the aircraft flying close to the mountain sides.


Why does U.S. airspace revert to class E above flight level 600?

You ask why doesn't it go all the way up... but all the way up to where? It's somewhat of an arbitrary limit, but FL600 tends to generally be the top of the troposphere, so it seems like a good choice if we're picking numbers.

One reason could be that the FAA AIM (Airman’s Information
Manual) says that the top of the service volume for the high-altitude
VORs is 60,000 feet above the VOR facility, so it seemed like a good altitude to end the restriction of Class A, that all aircraft must be on an IFR flight plan.  If you're tooling around above FL600, perhaps you don't want/need to be on an IFR flight plan (think experimental planes, rocket launches, etc.)

It could also be that when they set up the airspace, there wasn't a whole lot going on above 60,000 feet, and given that survivability at that altitude without a space suit is low, so there weren't a lot of aircraft that high, plus the top of the troposphere is around that altitude, it just seemed to be a good number. Most commercial aircraft have a service ceiling well below FL600 (the Boeing 777 ceiling is FL431), and since Class A is positively controlled airspace with everyone having to be on an IFR flight plan, aircraft above FL600 are not as common, and so it didn't make sense to spend resources (at the time) to force things that high to go through some kind of waiver process, or put the effort in maintaining the services required to provide IFR separation services for aircraft that high.

However, as we look to the future, there is a great report from Embry-Riddle about Safe Operations Above FL600 that sheds some light on what goes on above FL600 and considerations that should be taken into account going forward as the airspace starts to get more crowded with drones, and planned spaceflight and supersonic transports.


Could flight MH370 have suffered decompression due to a high altitude bird strike?

would such a scenario fit the known facts about MH370?

The evidence presented by the team searching for the aircraft includes

No voice communications using any of multiple radio systems available to cockpit crew.
Transponder ceased responding to secondary radar.
ADS-B transmissions ceased.
ACARS transmission ceased.
Aircraft made a change of course back across Malaysia
Malaysian military tracked an aircraft believed to be MH370 apparently following waypoints in the Malacca straights (suggesting another change of course)
Satellite data appears to show MH370 then flying to the south for many hours on autopilot until it ran out of fuel.

It isn't clear how a bird strike could disable the pilots and also cause the failure of all automated communication systems whilst allowing the autopilot (presumably) to make several turns and then fly the aircraft into the southern Indian ocean.

People have advanced many ideas about MH370. It isn't immediately obvious that this idea fits what is known any better than many of the other ideas.


Can you fly a helicopter without a driver's license?

Here's a a video where a CFI discusses this very question. There's no rule that says you need a driver's license to obtain a certificate to fly in the US. The real question is why you can't obtain a driver's license. If you have a medical problem that disqualifies you from driving, that will likely pose a far larger issue getting a medical to fly. Similarly, any drug or alcohol problem or conviction must be reported to the FAA. If your driver's license was suspended or revoked due to drug or alcohol, that must be reported as well. These issues are reviewed on a case-by-case basis, as the FAA wants to be satisfied that you will not try to fly while impaired. Beyond those types of problems, if you simply don't own a car and never wanted to learn to drive, nothing is stopping you from getting a license to fly.

Note that you will need some sort of government-issued photo ID. A passport or state-issued non-driver ID should be fine. You might also run into the practical problem that it may be difficult to get to/from airports in many regions without driving, so you'd have to find alternate transportation.

Finally, there is one sort of connection between driver's licenses and flying in the US. Pilots with a valid driver's license can fly Light Sport Aircraft without obtaining the otherwise-required third class medical certificate. A few rotorcraft (like this one) qualify as LSA. There are, however, significant restrictions on these operations, such as the requirement that they can't fly at night or carry more than one passenger. This rule does not override the medical requirements to fly, but requires the pilot to certify him/herself able to fly safely instead of receiving that certification from a Aviation Medical Examiner. In other words, if there's a reason you wouldn't be able to obtain a third class medical, then you are not allowed to fly a LSA using only a driver's license.


Why don't airport have heated runways to deal with winter conditions?

Removing snow from runways is not the biggest problem. Snow can be ploughed from the runways pretty quickly. The problems occur:

When it is snowing, especially in snow storms with strong winds and poor visibility. The wind and visibility are bigger problem than the snow laying on the runway and when the snow fall rate is such that the snow becomes a problem itself, the heating system would not be able to keep up melting it anyway.
Due to snow and ice accumulating on aircraft preparing for take-off. Obviously heating runways would not help in this regard.
Due to fog, which is much more common in winter. Again, heating runways would not help in this regard.

So runway heating would probably not help very often.

Also the runway has to be extremely strong, because aircraft have much higher weight on each tire than cars. A heating system with adequate durability would therefore be really expensive.


Is air to air refuelling possible at "cruising altitude"?

The main limitation is that the receiver needs to have enough excess thrust available to be able to precisely maintain formation on the tanker. Near the service ceiling, you typically don't have a lot of excess thrust, so refueling happens somewhat lower than that.  Since fighter generally have more excess thrust at a given altitude than a transport will, they can refuel at somewhat higher altitudes.
Other than wanting to have enough excess thrust available to accelerate forward in the event of a "breakaway" call, tankers don't have particular limitations that I'm aware of, though I've not flown those. (I'd assume being right at the limits of IAS / TAS isn't particularly comfortable for a tanker, so at least something below their service ceiling, but I don't know what that limit is.)
Pumps, rather than differential pressure, move the fuel, so that system is unlikely to drive any altitude constraints.
It's common to hear refueling happening in the mid-20's over the U.S.  How much that's driven by airspace availability vs by performance, I don't know.


Does a hold-entry count as a hold for instrument currency?

The entry of a hold is sufficient for the holding procedures task on the instrument rating practical test in the US and for execution of an instrument approach procedure that begins with a hold, so it follows that it would also be the appropriate standard of completion for currency purposes regarding the required holding procedure.
I think the text you quoted in the question serves as a sufficient source by itself.


Why isn't airport relocation done gradually?

Gradual relocation essentially mean having to staff and equip nearly two full airports during the transition period. It is also annoying for the travelers that want to transfer planes and need to relocate to the other airport. They would then need to get transported to or from the new location and through security again unless a small short hop flight is established during the transition. In IST's case it's 35 km distance between the old and new location.

Having two busy airports close to each other is also a bigger challenge for air traffic control than a really busy one and a calm one.

The solution to the issues you mention can be solved by thorough preparation. Like making sure all the old badges work (or having the new ones passed out as they come in for their first day at the new location), make sure everyone knows where they need to report for work in the new location. Perhaps having some extra trouble shooters on hand to fix teething issues.


One of the best reasons to unload before using your ailerons is to make sure you are not
stalled.  If you are, using ailerons could reverse and make you roll the opposite way.

Ailerons can be evil when used uncoordinated with rudder, yet very helpful rolling out of an inverted dive.  The danger increases if the aircraft is yawing and near stall.  So it is much safer to recover in 2 steps, unloading first.


When will Europe allow phones (to communicate) on planes?

There is a similar ruling since last week.

The use of electronic equipment as long as they are in "flight mode" during all phases of flight was already allowed in Europe by EASA since November 2013.

Since last week (26 November 2014) EASA also allows phones to be on and connected throughout the flight. This allows for WiFi services, phone services and Bluetooth battles during the flight.

Before allowing the use of these electronics in flight, airlines have to assess the impact of the signals transmitted by the mobile devices on the aircraft, ensuring aircraft systems are not affected. For this reason mobile communication will not be allowed by all airlines on all flights at once.


What are the benefits of a 'cranked arrow' delta wing?

The main benefits are:

High root thickness, so the wing can be made stiffer and stronger where the loads are highest.
Better pitch stability in the post-stall region, so no AoA limit needs to be observed. The X-31 could maneuver with thrust vectoring only because its cranked arrow delta wing was more or less neutral in pitch over the full AoA range. A simple delta wing produces strong pitch-up moments in the post-stall region wich would quickly overpower the moments possible with thrust vectoring.


What are the minimum hours required for private instrument fixed-wing plus commercial helicopter?

The 150 hours is flight time which is not category or class specific so hours in both airplanes and helicopters would count towards the 150 hours.  You are missing an instrument helicopter rating.  It is in addition to the instrument airplane rating.

Below I try to sum up the minimum hours required for each certificate and rating if obtained under Part 61.  Part 141 schools require different hours.  You actual experience will vary considerably.  I would first get a private pilot airplane and helicopter certificate and then work on the instrument ratings concurrently.  Afterwards, work towards the commercial helicopter rating.

To get a private ASEL certificate:  You need a total of 40 hours
flying time to that meets 61.109 experience.
To get an private helicopter certificate addon:  An additional 30
hours of training is required.  You will already have more than 40
hours total time.  Total time at this point would be 70 hours minimum plus the flight time for the practical tests.
To get an instrument rating for both airplane and helicopter: You will need 50 hours of PIC cross country time plus 40 hours of simulated or instrument time.  The 3 hrs simulated time required by the PP ASEL should count towards that 40 hours.  You must have at least 15 hours each with a CFII in both airplane and helicopter (total 30) and if they are all cross country flights that will help your cause.  You already started with a minimum of 8 XC PIC hours from your private certificates.  The remaining 12 hours along with 7 hours of simulated time can be accumulated in either airplane or helicopter.  Total time up to this point should be 120 hours plus the flight time for the instrument rating practical tests.
To get a commercial helicopter certificate:  A total of 150 hours total time (all the above counts) and 50 hours of helicopter time.  (You should already have 45).  35 hours of PIC helicopter time (Already have 20) to include 20 hours of training on commercial maneuvers, 10 hours solo and 10 hours of helicopter cross country time.  The way I see it, is the commercial will add an additional 30 hours to your total time giving you exactly 150 hours.


When receiving a TCAS RA, DESCEND DESCEND, and starting the descent, if a pilot received GPWS warning, TERRAIN, what would they do?

TCAS (II) does not give the descend RA below 1200 ft AGL while climbing or below 1000 ft AGL while descending.

Image from FAA Advisory Circular 20-151A Table 2

In case such an unlikely event happens (and is not an equipment malfunction), the best possible maneuver is to climb away from the incoming aircraft i.e. turn and climb to the side of the previous route.


The 737-800 is not grounded (and never has been). The aircraft type has an excellent safety record. Since 1997 over 5000 have been produced.

The 737 MAX 8 is its successor. The aircraft is very similar to the 737-800. One of the differences is the placement (more forward and higher) of the slightly bigger engines. This changed the stability of the aircraft under certain flight conditions, causing Boeing to introduce the Maneuvering Characteristics Augmentation System (MCAS). The MCAS played a crucial role in two recent crashes of the 737 MAX 8, leading to the grounding of the aircraft type.

The 737-800 does not have such a system and is therefore not affected.

Airlines typically use IATA aircraft codes (3 letters) or ICAO aircraft type designators (4 letters) to indicate the aircraft type used on the flights.

For the Boeing 737-800 the ICAO type designator is B738, while the IATA codes are 738 and 73H.

The Boeing 737 MAX 8 has the ICAO type designator B38M and IATA code 7M8.


How can a helicopter show up at 29000ft, 547kts at Flightradar24?

@mins answer contains good information, however the conclusion that the mistake is in the Flightradar 24 database is not correct.

It is not Flightradar 24 that has a database error:

  30040D IS I-PTFT it is NOT I-MOFI F2TH I-MOFI is miscoded on one box
  and using 30040D incorrectly. I-MOFI is 30047D please change it back!
  Why was it changed in the DB when I-MOFI was correct in the DB, I
  thought miscodes were not allowed anymore?

What this says, is that the 24 bit Aircraft Address (a.k.a. the Mode S address) 30040D belongs to the aircraft with the registration I-PTFT.

The registration I-MOFI has the 24 bit address 30047D, but the quote says it is miscoded on one box (transponder).

Flightradar 24 receives the Aircraft Address with the ADS-B messages from the aircraft and uses the database to find the aircraft associated with the address.

From the screenshot it can be seen that the address they receive is 30040D. In their database, this is correctly linked to the I-PTFT helicopter.

The fault is with the aircraft with registration I-MOFI; it transmits the 24-bit address 30040D while it should have transmitted 30047D. The transponder has the wrong 24-bit address encoded into it.


How do altimeters cope with varying lapse rate?

Yes, but it doesn't really matter.

The error that seems to be an underlying assumption in your question is that you're treating the pressure altimeter as measuring altitude. It doesn't.

Rather, it measures the difference between the static pressure and a reference pressure (the latter being the "altimeter setting").

That difference is expressed as an altitude, but it really is a difference in pressure. It could just as well be expressed as just ρref−ρstatic, the value of which would also increase as the aircraft climbs, but that would be less intuitive (and likely less precise, if not necessarily less accurate) especially when close to the ground.

(This isn't much different from how an airspeed indicator doesn't really tell you speed, it tells you the difference between static and dynamic pressure, but the scale is such that this difference in pressure is expressed as a speed. That's why the ASI acts up when the pitot tube is blocked.)

To be airworthy, an altimeter is required to display the correct value to within some margin of error which I don't know the exact value of. Vertical separation is then chosen such that the minimum difference in actual altitude, given the same altimeter setting, between two aircraft is sufficient to ensure vertical clearance between them even if both have instrument errors that are maximally unfortunate.

IMC minimum safe altitudes are also selected in a similar manner, to ensure obstacle clearance even if the altimeter is maximally out of calibration.

Since every aircraft within an area is supposed to be on the same altimeter setting, or (above the transition altitude) on the standard setting of 1013.25 hPa, as long as everyone sets their altimeter properly, the errors will all be very similar and everyone at, say, "5000 ft" or "FL310" is flying at very close to the same static pressure level, even if that level doesn't correspond exactly to 5000 ft AMSL or 31000 ft AMSL. Thus, while you're correct in theory, it is not a problem in practice.


Why do wings prefer laminar flow if cd is lower for turbulent flows?

Laminar flow and turbulent flow are not directly linked to Reynolds number, even though Reynolds number is a heuristic indicator of when the flow may transition from laminar to turbulent. However, the transition is actually not well-understood and is difficult to model/predict. That's why you will see cases where, for the same Reynolds number, one flow is laminar and another is turbulent.

Let's take a flat plate for an example. The flat plate boundary layer in laminar flow actually has a closed-form solution; the skin friction drag is given by:

$$C_{f}=\frac{1.328}{Re_c^{1/2}}$$

As you can see, as Reynolds number increases, the drag coefficient decreases.

Turbulent flow, on the other hand, has no closed-form solution. An approximation for a smooth plate is given by:

$$C_{f}=\frac{0.074}{Re_c^{1/5}}$$

The two lines are plotted in the figure below (cited from this Penn State course, which has a pretty good summary of boundary layer results for flat plate). As you can see, at the same Re, laminar flow has less skin friction drag than the turbulent counterpart.

From a skin friction drag perspective, if you can keep the wing in laminar flow, then all the power to you. In practice, however, this is very difficult. Any un-eveness on the wing (e.g. rivets, steps and gaps) could transition it to turbulent flow downstream. Any contamination, such as insects, could potentially ruin it.

Another consideration is whether staying laminar for the whole wing is desirable from a flow separation perspective, since laminar flow separates easier than turbulent flow. There will be a trade-off amongst stall speed, high AOA handling and drag.


Are fixed wing aircraft with gimbal thrust feasible?

Could you create an aircraft using an jet engine/propeller/ducted fan on a gimbal?  Sure you 'could'; it is feasible by the laws of physics.  But just because you can does not mean that you should.

Setting up multiple points of lift on a manned aircraft seems like a good idea with a lot of advantages but is a Pandora's Box of problems, the not the least of which is the grave risks of single point failure.  Lift and control is totally reliant on balanced lift between multiple engines.  Lose one engine and the craft departs from controlled flight and crashes.  You better hope you have an ejection seat and/or parachute on board.

Some solutions to these problems come in the form tiltrotor designs like the Agusta Westland 609 and the V-22.  But these aircraft have multiple redundancies in their design including a common transmission system between the rotors; in case of a single engine failure, the good engine has enough power to drive both rotors.  Tiltrotors can also glide like regular airplanes and utilize control surfaces during this and cruise flight.

As a final note:  Be careful in putting too much faith in Musk and other Silicon Valley whiz kids speculating about other design endeavors.  The skills required to run a successful software company are often very different from that required to develop other artifacts like aircraft and automobiles, etc.  Musk was a genius with PayPal but nearly went bankrupt starting an electric car company and his development work with SpaceX has been punctuated with a series of spectacular failures.  He also quietly withdrew from his proposed 'Hyperloop' project, I suspect, because he really didn't understand what he was getting into there.


What was the speed limitations for droop nose on the Concorde?

After checking the systems chapter on the nose, it turns out a dual uplock failure would limit the drop to 5° (see updated answer). If it is just one uplock that failed, the nose/visor should hold, but reducing the speed is out of caution.

As for the speed limits, here they are from the aircraft limitations section of the manual:


How does the idle speed adjustment in a Stromberg NA-R9B float-type carburetor work?

The idle speed adjustment in any engine is to control the minimum RPM that an engine reaches, in other words how quickly it will run with the throttle all the way off. You want the idle speed to be high enough that the engine will not stop running when the throttle is pulled back, but not so high that it wastes fuel. On a carbureted engine the idle speed is typically adjusted using a set screw which allows a mechanic to quickly adjust the idle speed. This would be done when the airplane is serviced as part of its regular maintenance, or out of the service cycle if there's a reported problem.

The idle speed adjustment is unrelated to the mixture control and is not adjustable in flight.


Do all Bombardier jets have manual reversion?

Can't speak for the Lear, which I believe has manual controls anyway, but the CRJs DO NOT have manual reversion.  The RJs are designed to a technical level similar to the Boeing 767.

The control surfaces are purely hydraulically operated.  For elevator and rudder, which have 3 PCUs each, you'd have to lose all 3 hydraulic systems to lose the surfaces.  For the ailerons, which are 2 PCU and split one of them on each side to Hydraulic System 2 and 3 while the others run on System 1, you have to lose 2 systems to lose one aileron, and all 3 to lose both ailerons.

The probability of this kind of multiple failure event is below the 1:1,000,000,000 risk threshold for catastrophic events, so it's good to go.

It's been discussed before how the hydraulic PCU can kind of be driven manually by hauling on the controls to lever the PCU piston about the bottomed-out servo control valve, but this would only give a bit of movement at the limits of control travel in any case and is not a practical consideration for trying to control the aircraft in flight.


Manu H has given what, to me, sounds like as close to a textbook answer as you can get.
Crosswind is always 90° to your direction of travel. You base crosswind off of your track instead of your heading. Regardless of your track or heading, or the wind direction, the crosswind intensity would be a percentage of the total wind intensity ranging from 0% to 100% coming from 90° to your direction of travel. You can find the numeric value of the crosswind using Pythagorean’s Theorem. The headwind/tailwind component and the crosswind  component make up two of the legs of the mathematical 90° triangle. The actual wind bearing from your direction of travel and its intensity make up the hypotenuse.
Or, you can use the graph, below:


Can hours logged training to be a Sport Pilot apply toward the Private Pilot Certificate?

Absolutely, you can log just about any flight time in an aircraft!

The definition of flight time is in 14 CFR 1.1 and says:

  Flight time means:

  (1) Pilot time that commences when an aircraft moves under its own
  power for the purpose of flight and ends when the aircraft comes to
  rest after landing; or

  (2) For a glider without self-launch capability, pilot time that
  commences when the glider is towed for the purpose of flight and ends
  when the glider comes to rest after landing.

However, the instruction logged towards a sport pilot rating by a flight instructor certificate with a sport pilot rating (61.413) may not be used toward the requirements of the private pilot certificate.

If the instructor is a CFI certified under 61.181 then the instruction may also be used towards your private pilot certificate but you will need to be proficient to the higher standards, which may require additional training.

For those who already have their Sport Pilot Certificate, take a look at this question: What does a sport pilot have to do to get a private pilot certificate?


How can dynamic and static pressure be explained?

You are very close. Your explanation of static pressure is correct, but not your dynamic pressure. Ram air pressure is what the pitot tube measures, in other words the total pressure experienced. It is your airspeed gauge which measures dynamic pressure by mechanically (in the case of a traditional pitot-static system) subtracting static pressure from ram air pressure.

If I was explaining this to a layman I would say that ram air pressure is equivalent to sticking your hand out the window of a moving car, while static pressure is the pressure inside the car. That's a bit of an over-simplification as the pressure inside the car will be lower than outside due to the movement through the air, but it gets the point across.


What are the differences between Lycoming and Continental engine designs?

Lycoming engines have the camshaft above the crankshaft, and Continental engines have the cam below the crankshaft.  This seems to keep the Conti cams better oiled and therefore less susceptible to corrosion.


Is there a good reason to have a handheld Aviation Microphone in GA?

According to the 172 Minimum Equipment List from Cessna (S and R models)

these are both Category C items which the MEL states

  Category C: Items in this category shall be rectified within ten (10) calendar
  days, excluding the day of discovery.

So it looks like you may need to fix it but in the event you are flying it looks like you need an alternative (headset should do that) and or a backup headset on hand.

However the 4th column states that zero are required for dispatch so you can fly without it.

As people are noting in the comments in a lot of planes these mic's go more or less unused or are inop these days. I know I have never personally used one in any of the archers I have flown.


What does the letter "D" next to the VOR frequency and name mean?

Since you're specifically referencing a Jeppesen chart, we'll go right to the source.

Jeppesen's "Introduction to Jeppesen Navigation Charts" has a glossary and explanation of all terms and symbols.

The answer to your question reads as follows:

  1 — VORDME. Low and High/Low charts include a Compass Rose with VHF
  Navaids. Shadow box indicates navaid is airway component, with
  frequency, identifier, Morse code and INS coordinates. Small "D"
  indicates DME/TACAN. Class indicated by: (T) Terminal, (L) Low, (H)
  High.

So, the D indicates that the VOR has a co-located DME radio.

(and, no need for correction to your assumption: the H and L in brackets do, indeed, refer to a High or Low class of VFR)


Shouldn't there be ATIS/sign information on sloped up runways?

FAR 91.103 says (emphasis mine):

  § 91.103 Preflight action. Each pilot in command shall, before
  beginning a flight, become familiar with all available information
  concerning that flight. This information must include -

  (b) For any flight, runway lengths at airports of intended use, and
  the following takeoff and landing distance information:

  (2) For civil aircraft other than those specified in paragraph (b)(1)
  of this section, other reliable information appropriate to the
  aircraft, relating to aircraft performance under expected values of
  airport elevation and runway slope, aircraft gross weight, and wind
  and temperature.

The most "reliable" place to find this information is the FAA Chart Supplement, which says this for KAVX (emphasis mine):

  Rwy 04 final 2,300´ steep 2.1% downslope, Rwy 22 upslope preferred
  ldg. Pilots cannot see acft on opposite ends of rwy due to gradient,
  must announce taking acft rwy on unicom prior to dep.

Any time you see mention of runway slope, you should be aware that something strange (and likely dangerous) is going on there.  Ditto for the cliffs on the diagram, which you are expected to know would create a downdraft on short final.

Since you were legally required to become familiar with this information when you planned a flight there, no additional notice (such as signs or NOTAMs) was required.

If there had been changes to the airport not yet in the CS, there would be NOTAMs for the airport until the next update cycle--and you would be responsible for knowing those as well.  However, with the airport being closed five months for construction in this case, they had plenty of time to get the CS updated before it reopened.


Is a helicopter ride unsafe for young children?

A few notes of update.

Evidence from other operators that there is no hard age limit

  There is no upper or lower age limit for pleasure flight however we recommend that children under 12 are accompanied by an adult.
  Central Helicopters T&C

  Generally anyone can be a passenger on a pleasure flight. Young children should be accompanied by an adult.
  Hields Aviation FAQ

GUIDANCE FOR EVENT ORGANISERS
AND HELICOPTER OPERATORS AT SPECIAL EVENTS covers Local flights (They call it A to A) and makes no special mention of minimum or maximum age limits. You can be fairly sure this document would be where any such specification would be made. Along with CAP 789, which is linked below, which also has no special mention of age limits for flights on helicopters

It is very hard to prove a negative, but I hope this is enough to convince you. Operators are under no obligation to justify their rules.

Original answer follows:

There is nothing inherently stopping an infant taking a flight on board a helicopter.

I suspect this has everything to do with the operators of these flights do not have the equipment to properly ensure the security and safety of infants.

Airlines typically provide extender belts for infants on laps. They also have provision for dealing with emergency situations with infants on board. This is because it is what their customers require and makes commercial sense to provide those services.

CAP 789 (which is guidance for operators) has something to say about this (emphasis mine)

  EU-OPS, JAR-OPS 3 and the ANO require the aircraft commander to ensure that at
  certain times each passenger on board occupies a seat or berth with his safety belt
  (or harness where provided) properly secured. These regulations also require the
  aircraft commander to ensure that multiple occupancy of seats does not occur except
  by one adult and one infant who is properly secured by a supplementary loop belt or
  other restraint device.

The clientele of helicopter pleasure flights probably do not regularly require bringing infants aboard. So there is little requirement or commercial pressure for them to do so.

The "must be 4 years of age" is quite possibly entirely arbitrary - in that they are probably large enough to use the standard harnesses/belts/noise protection provided. Operators probably do not routinely carry things like infant noise protection, and helicopters are noisy environments.

Some child restraint systems used in cars are appropriate for use in aircraft, and some operators may have allowed you to bring your car child seat on board for use with your infant (More info is available here). You would need to call around a few operators to find out.


Has Air Traffic Control ever had to talk a first time pilot through a landing due to an emergency?

The answer is yes.  One example was on April 2, 2012.  Helen Collins, an 80-year old Grandmother was forced to take the controls of her husband's CE-414 and land it at Door Country Cherryland Airport (KSUE) after her husband had a massive heart attack at the controls and died.  She managed to circle the airfield and call 911 on a cell phone.  The emergency dispatcher contacted the FAA who got in touch with ATC.  A KSUE based private pilot named Robert Yuksonavich took off and joined her in formation, talking her through what was about to happen and flew her wing on several practice approaches prior to the landing attempt.  On landing the Cessna 414 skidded off the runway and came to a stop in the grass, breaking the nose gear off.  Helen survived with only minor injuries; her husband was pronounced dead on the scene.

A brief piece by the CBS morning news featuring commentary by Capt Chesly Sullenberger about the incident.

This is the full ATC of the accident


This is an issue on airline passenger safety that has been debated since a very long time, and there are various arguments for and against the use of smoke hoods.

A classic example which showed the requirement for smoke hoods was the British Airtours Flight 28M, which had an engine failure during its take off roll at Manchester International Airport in August 1985. The ensuing fire and black smoke made the evacuation very difficult, and as a result 48 people died from smoke inhalation. Perhaps, the presence of smoke hoods could have saved many more lives. But at the same time, the subsequent investigation revealed there were other factors which contributed to the tragedy, such as the restricted access to exits and standard operating procedures which did not take into account the wind direction before turning.

From what I have read and researched, smoke hoods might involve unnecessary time wasted in wearing them. After all, airline crews are trained to evacuate a passenger aircraft within 90 seconds with half the emergency exits blocked. This time is considered sufficient to escape toxic smoke related fatalities. Secondly, the passengers might require some detail as in how to use them. Surely, space, weight and cost issues are secondary and can easily be overcome, but these are other issues which prevent their use.

In case of a fire upon crash landing, the immediate action is to evacuate and go as far away as possible from the aircraft. Since the passenger will not be staying in the smoke, it does not seem logical to provide smoke hoods. A water landing on the other hand might require passengers to float on the water surface for some time till emergency services arrive. This necessitates the need for a life jacket, otherwise lives can be lost due to drowning.


Why do airlines retire the flight number after a crash?

consider if you Google a flight number you can see the flight status, imagine if the number was from a past crash, you might for a moment think the one you're looking up had crashed


What happens if a seat belt is found broken, before flight take off?

Options would be to either move the passenger to another seat & placard that seat as unusable, or go back to the gate and have maintenance fix what's broken. In the former case, the seat would most likely be fixed by a mechanic at the next station.

The seatbelts used in the F/A demos are seatbelt extensions, which still need the installed seatbelt itself to be intact. They are fully functional as such, though, unlike the demo life vests & O2 masks, which indeed are "demo only" and of no use at all in a real emergency.

For a mechanic, the seatbelt is quick & easy to replace, although without needle-nose pliers (and a spare male or female belt), rather difficult for the crew -- who wouldn't be allowed to anyway.

The FAA requires that every passenger has a seatbelt and has been told how & when to use it, and that the crew has verified that they have it on before takeoff.


Why are the VHF and UHF airbands directly adjacent to frequency bands used by vital radionavigation aids?

The most obvious reason is that the ITU allocated the VHF and UHF bands for aviation purposes generally, and then aviation authorities had to split those limited bands into adjacent comm and nav sub-bands.

If aviation had gotten separate ranges for nav and comm, then that would double the risk of interference from adjacent non-aviation users, plus it would have made designing radios and sharing antennae more difficult.

So, we got the lesser of two evils.


What are the structures on the sides of and aft of the canopy on Israeli F-16s?

They're conformal fuel tanks, a type of external fuel tank designed for a specific aircraft type to reduce drag and other effects.

In general, they increase fuel load and free up stations for weapons or even more fuel.

In particular, the F-16 is a small platform with a modest fuel load and thus has a moderate radius even when clean. But when it's combat loaded with sensors and weapons, the additional weight and drag quickly eat into its combat radius, so one or two drop tanks are semi-permanently hung from its wings and/or belly. Don't quote me, but the CFT's almost double the F-16's internal fuel capacity.

The F-16 wasn't originally conceived for ground attack, carrying bombs for many of its missions, but it quickly grew into the versatile multirole platform it is today.

The USAF can better accommodate the F-16's short range because it flies a huge fleet of ~450 aerial tankers to service 2000 fighters, whereas the IAF operates just 11 tankers for 400 fighters. (Obviously other USAF a/c also require tankers, not just fighters.) Also, the IAF doesn't have the luxury of other nearby friendly air bases it can fly out of. Thus, they use CFT's.

With the benefit of hindsight, the original F-16 design team would probably have enlarged the internal fuel tanks from the start had they known how the F-16 would be used.


Ferry Permit for aircraft outside the U.S

If the aircraft was taken off the US registry and registered in Brazil, the answer is no. You have to reverse the process to put it back into the US registry, and until it is, you can't ask for a ferry permit from the FAA.

For the benefit of those who may not know the process:

A request is made in Brazil to deregister the aircraft, with a note to send a copy of the deregistration certification to the FAA. The seller needs to request this in Brazil; the buyer cannot make the request, neither can the FAA. Processing of this request can take anywhere from two days to several weeks, particularly if the aircraft is registered to anything other than an individual and/or if there are any registered liens on the aircraft.
The Brazilian government sends a notification to the FAA that the aircraft has been deregistered.
A registration form with either a previously reserved N-Number or by default letting the FAA assign one is sent to the FAA, along with a valid bill of sale. If the bill of sale is from Brazil, it must be notarized by a Brazilian notary and apostilled (certified) at at any public notary office (cartório). If it is in Portuguese, it must be translated by a certified public translator, a list of which may be obtained from the Junta Comercial of any state in Brazil. If you don't do these last two steps the application could be rejected. Better to use the FAA form for the bill of sale.
Once the FAA receives the registration request, it verifies that it has received the deregistration confirmation from Brazil. No registration will be issued until that happens.
A registration certificate is issued and mailed to the person or entity on the registration form.

You can then make arrangements for a ferry permit, but keep in mind that the procedure to request a special flight permit (the official name for a ferry permit) has other requirements, including sending a copy of the current airworthiness certificate, portions of or all of the logbooks, etc.

Also, if the aircraft has any outstanding AD's that have not been complied with, and the AD notice makes no allowance for ferrying the aircraft to a location for the purpose of achieving compliance, the ferry permit will not be issued. You will have to bring the US mechanic to the airplane (or find a local FAA-licensed mechanic, possibly an IA as well depending on the nature of the AD) to take care of it.

Bottom line is talk to your local FSDO first before any money changes hands to avoid any unpleasant surprises. The process above can be applied to an aircraft in any country, just change the references to Brazil.

(If you see an error in this explanation, or something that needs clarification, please add a comment so I can correct it or further clarify it.)


Absolutely you can use a fabric for covering and airframe.  I used to build large scale R/C aircraft much like they used to build real world aircraft. I used fine silk to cover the wings, elevator, tail, and fuselage. I used epoxy to adhere it to the wooden airframe and then later apply some kind of lacquer, which serves to shrink and pull tight the silk and also makes it airtight. This can then be painted or not.  Silk is a very strong lightweight material. The performance is actually probably better than many modern materials, but probably would not hold up to the elements as well over time.


Three reasons:

The B-52 stayed useful by taking on "easier" roles as it aged.

It actually started life as a high-performance penetrator, relying on speed and altitude to stay safe. Think Early Cold War, shortly after WWII.
When ground-launched missiles improved, the B-52 was forced into flying low-altitude penetration underneath radars (a role for which it was NOT designed and rapidly wore out the airframe) accompanied by a host of other aircraft to protect it and help it penetrate defenses. Despite their escorts, we lost low-dozens of B-52s in Vietnam.
Later in the Cold War, the B-52 was completely outmatched by air defenses (fighters, SAMs, etc), and had little hope of penetrating defenses (at either low or high altitude) to drop nuclear bombs. Instead, it was relegated to flying in friendly/neutral airspace, lobbing long-range nuclear cruise missiles into the Soviet heartland (a tactic they feared more, as it turned out, than manned low-level penetrators). It was basically a missile bus.
In the Gulf War, the B-52 only flew after air defenses had already been defeated by other aircraft (F-16s, F-15s, F-111s, etc). It was basically a bomb truck.
During ALLIED FORCE (1999), "B-1Bs and other conventional (non-stealthy) aircraft could not survive in the face of double digit SAMs, even when employing advanced decoys and other countermeasures."
The B-1 program, btw, went through a similar progession, starting out as a high-performance penetrator,  then forced into even lower-altitude penetration, then also relegated to bomb/missile trucking, pushed back by AAA, MANPADS, SAMs, look-down shoot-down radar, improved Soviet interceptors, and Soviet AWACS. In fact, the B-1 and B-52 fly largely* the same missions today.

*There are some important differences. The B-1 is no longer nuclear capable (START compliance), leaving that mission to the 20 B-2s and ~40+ ALCM-armed B-52s. The B-1 can also reposition more quickly, lending it to CAS role: it dropped 37% of the then-total ordnance on ISIS (2x that of the A-10)(see source) in OIR before they returning stateside for upgrades and were relieved by B-52s. (And, yes, the B-1 does CAS.)
Overall, the B-1s fly ~330-450 hours/yr, the B-2 ~230-290 hours/yr, and the B-52s ~200-220 hours/yr (2008-2012). The B-1 and B-52 cost roughly the same per hour (the B-1 has higher fixed costs but lower operational CPFH).

In 40 years, the B-52 went from being the US' primary strategic tool against another superpower to being outclassed by small nations.
Bomb/missile trucking is an "easy" job, but far from ideal. You can't bomb your targets until the air defenses have already been defeated---after the "first week" of a war, the most critical phase, when you need them the most. In other words, the B-52 (and B-1) are relatively easy to shoot down, so they're not nearly as useful as they used to be. You can't fly them unless many of the toughest enemies are already dead. So you can't use them as often as you want.
@MSalters phrased it quite nicely: the reason the B-52 (and B-1) hasn't changed is because other aircraft are doing the hard work for them (tearing down enemy defenses), and such aircraft have advanced immensely. But that amount of support is quite resource intensive, so if you wanted to fly B-52s in the "first week" when enemy defenses are still effective, you'll need a lot of help: (Image source: Beyond the "Bomber": The New Long-Range Sensor-Shooter Aircraft and United States National Security - Lieutenant General David A. Deptula, USAF (Ret.), 2015.) The same was true with strike packages during Desert Storm, eg only a third of the aircraft dropped bombs while the rest provided support (jamming, anti-radiation, top cover, etc).

We didn't build enough B-1s and B-2s to replace it, so we kept some B-52s to fill in the gaps (we don't have any other suitable heavy bombers in inventory, this is the only choice).

The 100 B-1Bs were just a stopgap until the B-2 showed up, of which we meant to build 132 (cut to 21 airframes). Had the Cold War continued, the B-2 would have comprised the bulk of today's bomber force.

We were busy buying new fighters and cargo planes.

The official, stated goal is to recapitalize the entire bomber fleet (less the B-2) because it's increasingly obsolete. That's worth repeating: the B-1 and B-52 are near obsolete. They're not nearly capable enough. The next bomber isn't another B-1, B-52, or modded 747 because we don't want to maintain the same capabilities. We want more capability--much more--than what we currently have. We've only waited this long because replacing the airlift and fighter fleets took priority.
The LRS-B (new stealth bomber; formerly NGLRS) will replace the B-52 starting around next decade. The contract is expected to be awarded very soon. The Pentagon briefed a select group earlier this month. Looks very promising---well managed, on budget, very capable, and surprisingly mature.

UPDATE: The B-21 (ex-LRS-B, ex-NGLRS) was indeed awarded 27 Oct 2015, a month and a half after this post was originally written. Very little is known, but it is indeed a stealthy bomber (the official render closely resembles the outer mold line of early B-2 iterations before the redesign). And it is indeed on time and under budget by ~9% (APUC = \$511M vs. the \$550M requirement, FY10\$).

In short, we still fly the B-52 today because we don't have a choice, not because we want to.

Parting thoughts:

I want to emphasize that the B-52 did not remain effective in its intended role (penetrating the USSR on Day 1), upgrades notwithstanding.

Yes, the B-52 survived multiple replacements (eg XB-70, B-1A), but not because it was more capable (it wasn't; the B-70/1A went higher/faster/lower/with more payload), but because those potential replacements couldn't outpace Soviet defenses either and so were cancelled in favor of ballistic missiles and cruise missiles... except the B-2, which could outpace Soviet defenses but was curtailed when those Soviet defenses disappeared. The B-52 survived basically because of luck: against the XB-70 and B-1A, it was the incumbent, already bought and paid for; against the B-2, history smiled.

Also, the B-52 did not "survive" the B-1B. The B-1B was never meant to replace all B-52s in the first place. The B-1B was meant to fill an urgent requirement as a stopgap from ~1985-1995 until the B-2 could enter service. Unlike previous B-52 would-be replacements, B-1B production was not cut short: 100 were ordered, and all 100 were delivered, essentially on time and on budget (though that was actually partly the problem).

Thankfully the B-52's range and payload kept it productive during its long service.

Some background.

The USAF operates ~160 bombers:

76 B-52s
63 B-1s
20 B-2s


Why does the SR-71 Blackbird sometimes have dents in the nose?

The SR-71 had a detachable nose (photo #2), and could change between three different nose cones depending on the mission. I haven't found a lot of information on the three, other than what this site and this site mentions:

Training nose with dead weights
Radar nose containing a Side Looking Radar. This is probably the bulge you saw on the photos.
Photo nose containing the optical bar camera, taking very wide photos of the ground.


What happened with flight AC692 to St John's?

Why return to Toronto and not stop on the way:

Generally speaking the most probable cause for reverting back to an airport that seems an unlikely choice is that the airline has a base there. From a base airport the aircraft is readily available for other use, and crew rotations are easily managed. In addition to that, if the "unsafe to land" condition was due to a technical issue with the plane, maintenance is secured at a base airport, but not necessarily elsewhere.
As Verandaguy pointed out in his comment, Air Canada does have a base at Montreal, which would have been closer to the aircraft at the time of diverting. This being the case, the reason for returning to Toronto is very likely to get the plane and crew to a position that best suits  the following rotation of each.
We do not know about the flight hours the crew had on them, so diverting to a non-base or non-scheduled airport might have caused serious trouble with continuation of the flight: You might have to fly (or if diverted to a base, call up) a relief crew to the divert airport  to fly the plane onward, and the crew with rest period limitation would have to be flown to their "home" base airport. This situation might have arisen at St. Johns after a stopover enroute.
While I at first did not think that weather was the reason (ref. METAR posted by Federico), it turned out that runway conditions were not suitable for landing in high and gusting crosswind (comment below by Mike Sowsun, kudos for that). We do not know the weather trend, so flying to, say, Halifax might prove problematic if the weather and/or runway conditions did not get better fast enough (see previous bullet point)

Fuel: too much to land at destination, too little on arrival at Toronto?

The reason for not carrying extra fuel is pretty much solely economical: it's a huge waste of money to fly fuel around instead of cargo or passengers. However, while it is true that airlines do not like to ferry extra fuel, an aircraft has all sorts of reserve fuel on board: you carry extra juice for trip to alternate airport, holding at destination or alternate and so on. When a crew decides to divert to an alternate airport, they make sure they choose one that does not result in fuel emergency.
It is therefore extremely unlikely that the plane was running on fumes when it arrived at Toronto.
Nor is it likely at all that the plane would have been over fueled by mistake. If it had been so, you would most probably just have circled at St. Johns for a while to burn the excess off, or dumped on the way there.
The observed use of flaps and/or speed brakes cannot be used to determine the fuel situation of the plane. These are more likely dictated by traffic situation.

As for the reasons for not landing at intended destination: As Mike Sowsun commented below, runway conditions were less than satisfactory, and the captain made the only possible judgement call: high gusty crosswind + slippery runway is a big no-no. A roadside observation cannot be used as a reference when judging what conditions are at an airport, even nearby. I know by experience that local variations in weather can be huge at places such as St. Johns. Also, changes in weather at these latitudes in coastal regions are very hard to predict, sometimes even for such short periods of time as the duration of this flight.


What vintage aircraft was registered as NC7210?

My step grandfather, Roy Danischefsky, purchased the Ryan B-1 Brougham #157 NC 7210 in Sept 1928 from Mahoney-Ryan Aeronautics for Midwest Airlines (Wisconsin). He flew it for Mid-West as a private charter and to promote flight as a new transportation option. Here is a photo of him in front of the plane.
Also - Here a photo of the plane from San Diego Air and Space Museum Archives
https://www.flickr.com/photos/sdasmarchives/5684139991/in/photostream/
Where is this plane now? I would be VERY EXCITED to know that it is still exists. Many of these planes did not survive.


What would be the safest way to drop thousands of small, hard objects from a typical, high wing, GA airplane?

Funeral homes sell gum bags for ashes. They dissolve in the ocean, releasing the ashes. You could make satchels and drop them in bundles with the teeth wrapped in kelp.


KC-130: What are the four tanks/tube on the wings in between the engines used for?

The tanks between the engines on each wing are external fuel tanks. The pods outboard of the #1 and #4 engines are aerial refueling pods which house the hoses and drogues that are reeled out when refueling other aircraft.

This page has several examples of the outboard pods trailing drogues for refueling.  These pods are unique to KC- and MC-130 variants. One example:

The inboard external tanks (between engines 1 & 2 and 3 & 4) are found on most variants of the C-130.


How do you choose engine placement for under wings engines?

After having read aeroalias' picture collection, I feel an urge to chime in.

Longitudinal position

The main reason to place them ahead of the wing is flutter suppression. Flutter is an oscillation caused by the interaction of elastic and aerodynamic forces. In case of the wing, it is an up-down bending motion. Since air takes its time to flow over the wing, at a certain airspeed the air pressure change on the wing is so much out of phase with the motion that it amplifies the elastic motion of the wing. By placing the center of gravity of the aircraft part ahead of its elastic axis, flutter can be suppressed. This is true of flaps (where a mass balance is added ahead of the hinge line) as of full wings (where engines take the part of the mass balance).

Imagine the wing bending up, and now add the inertial forces of an engine connected to this wing and also moving up. If it is placed ahead of the elastic axis, it will induce a torsion moment into the wing, such that the local angle of attack is reduced, which in turn will reduce lift and the forces which cause the wing to bend upwards. The same happens in opposite direction when the wing bends downwards. Since the biggest thickness of the wing is in its forward section (which shifts the elastic axis forward) and the heavy flap mechanism is in its rear section (which shifts the local center of gravity back), a wing without an engine mounted forward of it needs a much heavier structure or less heavy, but otherwise unproductive, balance weights.

Placing the engine ahead of the wing brings some more benefits:

Airflow at the intake is less influenced by the pressure field of the wing, so the variation in local flow direction is smaller, resulting in a better-performing intake.
An uncontained turbine failure is less likely to damage the wing.
The engine can be mounted higher relative to the wing, such that the landing gear can be shortened.

Why engines are not placed on top of the wing is discussed in this answer.

Lateral position

In two- and three-engined jets you put them at the wing station where the inner wing ends. The main reasons are:

There is a major rib anyway to support the wing's skin, so the structure for attaching an engine is easier to add.
There is a gap between inner and outer flaps (at least in Boeing designs), so the engine blast will not hit the flaps.
They are still relatively close to the center of the airplane to not require an excessively large vertical tail to cancel the yawing moment in single-engine flight.

Boeing 737 bottom view (picture by Adrian Pingstone). The inner wing section has an unswept trailing edge while the outer wing has less taper and a swept trailing edge. The engines are exactly where both meet.

Aircraft like the DC-8 had their inner engines at the wing rib which supported the inner flap tracks of the outer Fowler flap, because they had no gap between inner and outer flaps. On the DC-10, Douglas placed the wing engines at the break between inner and outer wing, however.

In four-engined jets the inner engines are placed like those on two-engined jets, while the outer engines are placed at the end (or slightly outside) of the outer Fowler flaps, about midway between the inner engine and the wing tip. Note that again a rib is needed where the aileron cutout starts - this rib doubles as the engine mount. There the engines can contribute a lot to bending relief, and since a single engine contributes only 25% of the total thrust, the yawing moment of the outer engine in the engine-out case is roughly equal to that of a single engine of a two-engined jet.

Airbus A340 bottom view (picture by Adrian Pingstone).

Why it is better to separate the engines and spread them out over the wing instead of collecting them in a single nacelle is explained in this answer.

In some cases, the engine location is dictated by other requirements. On the Antonov An-70 the inner engines need to be far enough out to allow to drop paratroopers from the front door, for example.


Well, going beyond just judging from the Electra's itty bitty stubby wings, digging around for Electra performance data I found a page that gives a takeoff distance of 1290 meters, or 4200 feet, which would most likely be the distance at sea level, standard day, max gross.  Which is what I would expect with such itty bitty stubby wings.

Even allowing for more power in the military versions, I'd say it's safe to go with no.


Why are there two red lines on the G-meter in the MiG-29?

@George already gave a correct answer, but I'll expand it a bit and show the source.

Indeed, the lower load limit is for trans- and supersonic flight (formally M > 0.85) and the higher limit is for subsonic conditions.

The AoA redline at 15° also relates to M > 0.85. At subsonic speeds, the max AoA is 26°. I can only speculate why it is not shown on the gauge. Normally, the control system will enforce these (AoA) limits automatically.

Here are the load and AoA graphs from the MiG-29 flight manual (or more precisely, its 'Practical aerodynamics' part).

One might notice that the official supersonic load limit is 7 rather than 7.5. I'm not sure why is the gauge showing 7.5.

The curves indicate loads and AoA that are actually achievable at different altitudes (in km). The boundaries are labelled 'structural limits' (on the top) and 'control system limiter settings' (for alpha).

The text explains:

The load applies to the mass 14200 kg, whether with or without missiles. For higher mass, the load limit is reduced by 1 g.
The lower supersonic limit is explained by the lift losses for trim. (MiG-29 is marginally stable at low speed, but (like nearly any aircraft) is highly stable at supersonic speeds, and part of the wing lift must be used to counteract the strong tail downforce).
At M > 0.85, the leading edge droop flaps are stowed, which limits AoA at 15°. At lower speeds, the flaps expand the AoA limit significantly. (There may be further limits; e.g. 13° with a failed SAS (stability augmentation system)).


How long to receive FAA wings lapel pin?

I requested all three FAAST WING lapel pins around, but not at, the same time. I think the first two pins were at the same time. It took over three months to receive the first one. When I enquired about the others, I was told that Avemco Insurance (the sponsor of the awards program) orders them in bulk. They ship out the awards only when they have them in stock. So, your experience my vary depending on Avemco’s ordering cycle.


1.VRB02KT: Is it varying more or less than 180°? 2.VRB03KT: Is it surely varying more than 180°?

Based on these criteria, is there a way to identify if a variable 2KT wind is varying less or more than 180° when the indication is just VRB02KT?

No, there is no way to tell. And you don't need to tell. The wind velocity is too small to have any operational impact.

If the wind intensity following a VRB indication is 3KT or more, can I assume it is varying more than 180°? Since this excessive variation in direction (not the relatively low intensity of 3KT) is the reason why the station can't measure the mean direction precisely.

Yes, that is safe to assume, as per the definition you quoted.
Remember the values you see in a METAR are average values over a period of time. If you need the immediate wind, ask the tower.