What happens during a checkride for a private pilot license?

That's pretty much the checkride in a nutshell - for all the details on what's expected you should refer to the FAA Practical Test Standards for the rating you're pursuing.

Before your checkride

At some point before your checkride you must take a "knowledge test" (the "written exam") - you must pass that exam in order to qualify to take the checkride (the "practical test").
The results of the knowledge test are good for 2 years.

You will also receive instruction from your CFI specifically for "checkride preparation" (you must have 3 hours of this instruction within the 60 days prior to taking your checkride).

Usually your instructor or school will arrange for an examiner. Be sure to find out where he wants you to plan your cross-country trip to, and also ask for his weight (so you can do the weight and balance calculations), and the cost of the checkride (so you can have the money ready).

The Oral Exam

The day of your checkride1 you'll probably spend at least as much time on the ground with the examiner than in the air.

You'll start with the practicalities: making sure your 8710 is in order, verifying your eligibility, and paying the examiner.

Next, you'll go over your logbook with the examiner (do everyone a favor and bookmark all the things they'll need to see), and then you'll be given a thorough oral grilling2 by the examiner.

You'll be expected to know your aircraft's V speeds, it's useful load, and its fuel capacity (in gallons and hours), and you might have to be able to answer intelligently based on a scenario, like "supposed you want to take 3 members of your football team's lineup on a 300 mile trip..."

There will also be scenario-based regulatory questions ("You're taking your friends for a flight in the spring, but you haven't been in an airplane all winter. What do you need in order to be able to conduct this flight?")

You will also be expected to plan (or have planned, depending on the examiner3) a cross-country flight (including a weight and balance calculation using the examiner's weight, and possibly including one or more fuel stops), and be able to explain your decision-making process for things like the planned course (if you don't fly in an absolute straight line) and your proposed altitude(s) and en-route waypoint(s).

1 - Usually you do the oral exam, then go fly.  Sometimes you may do the oral one day and the flight portion another day - for example if the weather is lousy.

2 - This video is a little old, but a lot of it is still valid.

3 - You used to have to complete the flight plan the day of the exam, within 30 minutes, but that requirement has vanished from the PTS.

The Flight Exam

Every examiner conducts this a little differently - the tasks can be done in any order as long as they're all accomplished - but everyone I know has had the same basic sequence of events on their checkride.

After the oral you're going to get an update to your weather briefing (because you should), do a preflight inspection, get in the plane, and go fly your cross-country.

I've never met anyone who has actually flown the whole cross-country flight -- The examiner will typically have you fly through one or two waypoints to demonstrate that you can actually navigate, then you'll be told that something has gone awry and you need to divert ("The guy in the back is sick, take me to the closest airport before he hurls.").
When you've demonstrated your ability to navigate and divert, you'll usually cancel your flight plan (if you opened one) and break off to do the required air work.

At some point during your checkride the examiner will give you an engine failure, because aircraft engines are supremely unreliable whenever an examiner or CFI is in the right seat. You will be expected to pick a suitable landing point, establish a glide to that landing point, and run the "engine failure" checklist appropriate to your plane.  The engine usually "miraculously restarts" at some point once the examiner is confident you would have been able to put the plane down on your intended landing spot.

The air-work consists of all the require flight maneuvers, such as steep turns, stalls, slips, and slow flight, the required ground reference maneuvers, and basic instrument maneuvers.

Once the air work is complete you'll return to the airport (or maybe to the airport you diverted to) for the dog-and-pony-show landings (one go-around -- usually called by the examiner with something exciting like "There's a moose on the runway! Go around!", one normal landing, one short-field landing over an FAA-Standard 50-foot giraffe, and one soft-field landing).

If you mess up and the examiner has to fail you they will tell you immediately after finishing the maneuver that you busted on. You usually have the option of continuing the test and completing the remaining tasks unless you did something that made the examiner fear for his or her life (if you're comfortable continuing this reduces the number of tasks you'll have to complete when you re-take the checkride).

Assuming you don't screw any thing up too badly, scare the examiner, or hit anything taxiing back to the ramp you're a private pilot - the examiner will fill out the appropriate paperwork, sign your logbook, and issue you your temporary certificate.

Your specific questions that I didn't answer above

How long does it take?
My checkride took about 3-4 hours -- about 1-2 hours for the logbook review & oral, just over an hour in the plane, and about an hour of "miscellaneous bits" (re-briefing the weather, the preflight, securing the plane after the practical portion of the test, completing the IACRA paperwork to make your new certificate/rating official).

How are emergencies created/tested?
The standard engine failure is usually created by pulling the throttle back. Your examiner may throw other curve balls at you (like handing you the foggles and saying "You just flew into a cloud, get us out of it."), or create random distractions ("dropping" their pen during climb-out appears to be a favorite from reading other people's checkride stories).
What's important isn't how the situations arise, but how you handle them.  The examiner wants to see you fly the airplane safely, run the appropriate checklist(s), and handle the emergency in such a way that they're confident if it happened for real you'd be able to do the right thing.

Who makes sure the weather is suitable for flying?
You do! You are acting as Pilot In Command for your checkride, and you are expected to exercise sound judgment.
The examiner is not going to let you take off into a thunderstorm or gale-force winds (examiners have excellent self-preservation instincts. Most of them are or were flight instructors.), but if the examiner has to be the one to say "Yeah, I don't think we should fly in this weather" that's a guaranteed failure.

What if the checkride has to be cancelled for reasons not controlled by the student?
If you've already started (e.g. taken the oral, but can't do the flight portion because of weather, or the plane develops a mechanical problem) you'll receive a "notice of discontinuance" and reschedule the remainder of the exam.
Typically you can do this within 60 days, and you'll only have to do the portions of the exam you didn't do previously (though you can be re-tested on everything).
The same thing happens if you or the examiner have to cancel the exam for reasons not related to your aeronautical performance (that triple-breakfast-burrito on checkride day was NOT a good idea and you need to get back on the ground RIGHT NOW).

What else did I miss?
Probably a lot. I probably missed a lot too.
My checkride wasn't that long ago but I really don't remember much about it.

A common misconception is that the DE will bust you for one deviation or one wrong answer on the oral. That's simply not true. You must perform at an "acceptable level of competence," and only if you fail to perform at such a level will you be failed. The best way to avoid this is to acknowledge the deviation by saying something like "I'm low, correcting," and then correct. That way the DE knows you know what is happening in the plane, and that you are taking positive steps to correct it.

Also, don't think the DE can read your mind. Brief out loud everything that is happening in the plane: annunciate the checklist items, and say "takeoff checklist complete" when you're done; when you scan for traffic or make a clearing turn, say "clearing"; if you see a plane say something like "traffic, 4 o'clock low, opposite direction, no factor." The more you say, the more the DE knows how you think, and aeronautical decision-making is one of the most important skills a pilot must learn.


Where is the wing sweep angle measured from?

Taking the 747 example you mention, on Wikipedia the wing sweep is stated as 37.5°. Three references are given, checking one of them reveals that measurement was taken at 1/4 chord.

As you have noted, there are many angles, and in aircraft design they are all relevant to the designer.

The 'wing design' chapter from Hamburg Open Online University states:

  The sweep angle $ϕ$ depends on the % line on which it is measured. Normally the sweep angle of the leading edge $ϕ_{LE}$, trailing edge $ϕ_{TE}$, 25% line $ϕ_{25}$ (quarter chord sweep) and 50% line $ϕ_{50}$ are stated.

So normally in design 4 angles will be stated. Otherwise, e.g., when checking Wikipedia, the references used should typically be clear. Below shows two $ϕ_{25}$ angles, for example:


Try reading this article from businessweek.  It's going to give you an answer, but you're probably not going to like it.  Here a quote:

  “It requires an incredible level of precision flying,” Oliver says. “There are so many factors. Where’s the sun, which way is the wind blowing, where’s your crowd? You only learn that over time, after doing it enough. And you can’t go practice when skywriting fluid is 10 [dollars] a gallon and gasoline is 7 [dollars] a gallon.”
  It’s also difficult to learn the craft of skywriting when nobody is willing to teach it. Oliver and Asbury-Oliver won’t share any of their secrets. In fact, while Asbury-Oliver was employed by Pepsi, she was contractually forbidden from discussing her skywriting techniques with anybody, including friends, colleagues, and journalists. “In the ’30s and ’40s, there were a lot of skywriters trying to make a living,” she says. “So they shared nothing. They wouldn’t tell each other what kind of fluid they used to make the letters, what kind of exhaust pump they used. Everything was top secret.” While an air of secrecy might’ve made sense a century ago, why do they continue to be clandestine, despite their competition being essentially nonexistent? “We’re old enough and we’ve been around long enough that we’re both traditionalists,” says Oliver.


How does the target indicator on a jet fighter work?

There are two main questions here, mainly how does a fighter jet track a flying target, and questions about the symbols used on the Heads Up Display.
How does a fighter jet track targets
A fighter jet tracks its target(s) using its radar, which (as you are all aware) works by emitting EM waves and detecting the reflected waves bounded off by the target. The onboard computer processes this data and translates it to target information.
There are two modes of radar operation*. The first is a scan mode: the radar makes a sweep across a wide angle to look for targets. In this mode, the radar scope is wide, but target update rate is slow, and target information is coarse. The second is targeted mode: the radar focuses a narrow beam of energy at the target, which provides accurate readings with a high update rate. On the HUD, you can see "200Vc", meaning the jet is closing in on the target at a relative speed of 200 knots. Below that is "1000 FT", the distance to target.
* There are many modes actually, but to keep it simple, let's just focus on two.
A fighter jet does not identify a target optically nor using infrared. Neither of these two methods can provide accurate position information of the target. This may change in the future, but it is what the technology is now.
About the HUD
The HUD is from a F-18 (I am not sure which variant). Let's go over the symbols top to bottom and left to right:
Left column

On the upper left is a black square. It indicates that the trigger is pressed at this moment. It is displayed only on the recorded tape and is not visible to the pilot.
the boxed number is the indicated airspeed. It is reading 179 knots.
Going down is the angle of attack, or "alpha". It is reading 20.3 degrees.
Mach speed is 0.36.
G-loading is 1.7.
The max g-loading on this flight is 7.6 G.
Below that is the time in UTC.

Center column

On the upper center, the arrow pointing upwards "^" is the needle of the heading indicator. Above it is the ruler marked with heading numbers, which is apparently cropped off in this image.
The cross sign below "+" is gun cross. The cross is always displayed at the gun inclination angle as a backup.
The "w" sign is the attitude indicator. In the background we can see the numbers: the aircraft is pitched 26 degrees down and banked approximately 70 degrees to the right.
"GUN" indicates machine gun is the selected weapon. The cross indicate it cannot be fired, most likely because this is a practice mission and master-arm is not on.
"0" is the number of bullets left.
Near the bottom edge of the image, a bit to the right of center line, is the flight path indicator, a circle with three bars extending from its left, top and right respectively. It shows where the aircraft is travelling to, and it is useful for landing or flying low near terrain.

Right column

Current altitude is 15180 feet MSL.
Target closure rate is 200 knots.
Range to target is 1000 feet. If the range is longer than 1 nautical miles, it will display in nautical miles instead, up to the nearest 0.1 nautical mile (e.g. 2.3)

Symbol around the target

This particular circle is the target reticle for gun mode. A bigger circle is displayed if it is in missiles mode.
The center dot shows where the bullet will hit if the gun is pressed at this very moment. The circle moves around the HUD as the jet is maneuvered. For example, if the pilot pulls on the stick, the circle will move towards the bottom of the HUD because that is where the bullets are going.
Targets are identified by a square box on the HUD. The square is not displayed when the gun reticle overlaps with the target, which is the scenario in this image.
"IN LAR" means In Launch Acceptability Region. "IN LAR" is displayed instead of "SHOOT" because the target is designated as friendly. If the target is designated as hostile, "SHOOT" will be displayed instead.
Below the letters "LA", we can see a bold portion from 12'o clock to 1'o clock on the circle, and a mark at 1'o clock. This is the range to target. The mark rotates clockwise as target distance increases. For example, if the bold portion is instead from 12'o clock to 3'o clock, the target range will be 3000 feet.
There is a similar mark on the circle slightly pass 6'o clock, but the mark is outside the circle. This is the maximum range of the currently selected weapon. By comparing the bold portion of the circle to this mark, a pilot can tell whether the target is within range of the current weapon.
I have no idea what the "x" means.


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

Firstly, you did goof up by not checking what the refueler did. Your life depends on that fuel, and in light aircraft the gauges are notoriously unreliable. We've probably all done it but we shouldn't - always check!

However going off your figures you might have been what, 20 pounds overweight? That shouldn't cause such a massive decrease in performance. MTOW isn't an on/off switch. It's a point that has been selected as the maximum allowable limit - with a safety margin built in. You should never exceed MTOW even by a bit, but if you do you will (hopefully) live to see your kids birthday thanks to that margin.

I've flown a C172 right at MTOW (actually about 5kg under but close enough). Acceleration is slow, meaning you use more runway. Rotation actually feels normal thanks to ground effect, but once you leave that you notice a degraded climb performance. If you're over MTOW these effects are the same but amplified. If you are very overweight, you will climb in ground effect but will struggle to go much higher than 20-30ft.

As for your flight though, it could have been affected by a tailwind or high temperature/low atmospheric pressure. What was the temperature like on the second leg? Vy will theoretically get you the best climb rate even above MTOW so it doesn't make sense that you could climb below but not at that speed. Maybe there was something localised affecting the ASI, or, if I may be so bold, your technique on the day wasn't 100% :)


What is RTOW and how is it different from MTOW?

Google gives you the answer without even clicking any links:

https://www.google.com/search?q=RTOW

  MTOW is a hard limit regardless of other considerations and is tied up
  with the basic aircraft certification basis.RTOW is the limiting
  takeoff weight calculated for a particular runway under particular
  specified conditions

Maximum Take Off Weight - The maximum weight in which an aircraft can ever take-off, under any circumstances.

Regulated Take Off Weight - The maximum weight in which an aircraft can take off from a particular runway under specific conditions (winds, weather, specific aircraft configuration, etc,). For example, runway 29 at KXYZ airport with ambient temp of 20° C. This can get as specific as you wish.

Of course $RTOW \le MTOW$.


What crash does FAA SAIB CE-10-11 refer to?

From the details it sounds like the accident was N501N, a Cessna 310R that crashed on 10 July 2007 (NTSB Summary Report (PDF)).  This airplane had been previously written up for an anomaly with the weather radar and subsequently improperly released back into service.  The accident crew reported smoke in the cockpit and post-crash analysis revealed substantial electrical component damage, burned wire insulation, etc.


Considering all US untowered airports, what is the furthest distance that E2 airspace (dashed magneta line) projects from the airport?

Best candidate so far--

Sheridan County Airport-- Sheridan, Wyoming-- KSHR
Page E-92 in the "Airspace Designations" document

The E-2 airspace extends 17.6 (nautical) miles southeast of the airport-- and also 16 miles northwest of the airport  -- last amended 5/31/12

http://vfrmap.com/?type=vfrc&lat=44.769&lon=-106.980&zoom=10


Mainly because the short haul market needed to wait for the deregulation of the late 70s into the early 80s that resulted in the creation, by the early 90s, of the hub and spoke concept with small regional jets feeding hubs where the mainliners were.

The CRJ200 was the main pioneer of this market, as an up to date rendition of a smaller regional feeder jet. At the time it was expected to sell maybe a couple hundred units, even within Canadair.


What can I do on the ground in order to help my body acclimate to aerobatics?

The way the Air Force introduces people to the disorienting effects of aerobatics on the ground is to put them into smoothly spinning chairs called Barany Chairs.  And it doesn't just involve spinning in one direction, but smoothly and gently changing directions repeatedly.  Since I never suffered from airsickness, I don't know what they do (i.e. do they blindfold you, are there more than one axis of motion, do you have to tilt and move your head, etc.)

While an actual Barany Chair may be expensive, you could perhaps accomplish the same with  a friend and a nice heavy office chair.


Why would a pilot pick this military airport as an emergency landing airport?

Emergency landings often dictate landing at the safest airport, not necessarily the closest one. As I said in the comments, the flight was operating IFR and had turned the window heater on presumably for anti-ice. It could be that a line of weather was preventing VFR operation at closer airports and they diverted to the closest possible VFR airport.

When encountering an emergency there are things you don't want to do. You don't want to panic to get the aircraft down if the aircraft is perfectly flyable. You don't want to make major configuration changes, especially multiple ones, quickly. Pilots are taught to "Aviate, Navigate, Communicate" in that order. As a pilot you should prioritize flying the plane, work the problem, and determine the safest place to put down.

It is possible in this case that they could have continued IFR, but if they encountered icing below the missed approach point they would have been put in a situation with icing and no visual references.

It is also possible that the pilots recognized that some electrical problem was at fault, and even without icing conditions they would want to remain VFR because they didn't trust the electrical system would continue to function throughout the IFR approach and landing.


What's the reason for this frog finger shaped parking lots at Köln/Bonn airport (CGN)?

@Simon is right. The 'parking lots' are actually dispersal areas in the (previous) military airfield at that place.

The Cologne Bonn Airport started out as an airfield for Luftwaffe in 1938 in what was a former artillery shooting range. After war, RAF took over the airfield, with the first civilian flights in September 1950. The airfield was converted for full civilian use only in 1957.

"Koeln-Bonn-Airport14" by Borsi112 - Own work. Licensed under CC BY-SA 3.0 via Commons.

The original 1886m (32L/14R) runway is near the bottom of the image (near the dispersal area). The top runway, 3800m in length (32R/14L), was opened in 1961.

In military sirfileds, the parked aircrafts are usually dispersed in order to reduce vulnerability in case of an air raid. According to US Army Field Manual 5-430-00-2 (accessed via globalsecurity.org)

  If dispersal of aircraft is possible and consistent with active defense measures, varied parking patterns provide fewer lucrative targets for indirect-fire weapons.

It also gives some (conceptual) layouts for aircraft dispersal:

Source: globalsecurity.org

The aircraft are parked in such a way as to reduce the probability that more than one aircraft is hit simultaneously. These dispersal areas have banks of earth or small walls around them to reduce the aircrafts’ susceptibility to the effects of bombs landing nearby and to reduce collateral damage in case one of them blow up. It might've looked like this:

Source: portalnews.gq


Why are the colors of the MiG-15's attitude indicator inverted?

That attitude gyro reacts in the opposite manner to pitch movement (pitch down = horizon line rolls DOWN) compared to the "conventional" manner (pitch down, horizon line rolls UP). This is sufficiently confusing that on similar gyros of American manufacture, the words CLIMB and DIVE are printed on the "ball" inside the gyro case to remind the pilot what the instrument is telling him or her.

The "opposite" reading gyro horizons were commonly used in American fighter aircraft because their construction made them more resistant to tumbling than were the "conventional" reading instruments, which were used in civilian aircraft.

After WWII, those opposite-reading gyros wound up on the surplus market and a number of them were installed in civilian aircraft, including the Beech Bonanza that was carrying Buddy Holly, Ritchie Valens and the Big Bopper on the night of their crash. The pilot had trained in a plane with a conventionally-reading instrument in its panel and the accident report claimed that he was confused by that opposite-reading gyro in the dark, thinking he was trimming for an 800FPM climb when what he was really doing was trimming for a descent- and minutes after takeoff, the plane flew smoothly into the ground and everyone aboard was killed.

I have an example of both types of gyro horizon in my collection, and even when they are not spinning, simply tilting their cases in unison demonstrates the difference: one rolls up, the other rolls down when you pitch them both down.


Ducted fan designs like quadcopters are actually somewhat simpler in some ways to design and build than single-rotor helicopters, because the nature of the design means that the rotors don't need the complex mechanical linkages of a helicopter's main rotor; the four rotors can control pitch and bank simply by varying RPM, and so each one can be a fixed-pitch propeller. The design becomes more stable with a variable-pitch rotor design as the possibility of varying thrust with a constant rotor speed reduces unwanted roll moments from gyroscopic forces, but that throws the simplicity argument out the window (and helicopters have potential roll problems during throttle-up as well, some of which had to be solved before the thing could even take off).

Yaw is a little trickier, and one potential limiting factor to scaling up the design. The problem is that with all four rotors in a fixed vertical orientation, which is the simplest mechanically, there's nothing to produce lateral thrust to turn the aircraft around the Z-axis (straight up from the ground through the 'copter in level flight). Options include:

One laterally mounted fan. Simple to design, but you're adding one more fan to a design with a lot of high-speed spinning parts already, and the fan would either have to stop and start in opposite directions very often (easy with a little DC motor and plastic fan on a model, much more difficult when scaled up), or the blade pitch would have to be variable, to allow variable thrust to either side while the rotor turns in one direction) which increases complexity again.
Two lateral fans, one facing each direction; by varying their power (they'll probably both be spinning at a low idle while in flight) you provide yaw. Advantage is mechanical simplicity of each fan, disadvantage is having not four, not five but at least six fans, reducing "mean time between failures" of at least one of them increasing required maintenance that much more to ensure it doesn't happen in flight.
Arranging the main four rotors such that each rotor rotates the same way as the rotor in the diagonally opposite corner, and opposite the other two. By reducing the power of fans rotating in one direction and increasing the power of the other, you can induce yaw as the craft will yaw opposite the direction of the faster rotors due to the torque imbalance, without causing the aircraft to also pitch or roll as the total forces in those planes stays constant. The advantage is reducing the need for additional rotors; the four main rotors can provide motion in all three planes. The disadvantage will be slower yaw rates and increased maximum thrust requirements of each rotor basically allowing any two rotors to maintain required lift (a good requirement to have, not a great one to rely on everyday).
Putting the main rotors in tilt mounts and tilting them in rotationally-symmetric ways to induce yaw. It's an intuitive way to induce yaw, and the same tilt-rotor system would also reduce the amount of pitch required of the full aircraft to produce forward motion; just tilt the rotors and keep the fuselage level. Disadvantages include increased mechanical complexity, and the gyroscopic precession induced by trying to tilt a rotating mass which can cause the craft to tumble off its lift vector.

Other potential problems with the quad-rotor design include ensuring reliable power distribution (including maintaining some control if a rotor or an engine gives up completely), the lower inertia of the smaller rotors reducing the effectiveness of autorotation in an emergency, the need by many potential customers to fold the design up more compactly than its flight configuration, and the inherent fragility of the design with ducted fans on pivots in the corners of the aircraft, making it more vulnerable to fatal damage in "combat environments" (translated; everyone not on your side shooting whatever they have at you). Because the U.S. military has been a major customer of rotary-wing aircraft and a primary source of R&D funding, the survivability of the design against things like small-arms fire that a helicopter can typically take a few hits from is a definite point of consideration.

The last problem plaguing the quadrotor is more fundamental, and it is the lack of an answer to this simple question: what can a "full-size" quadrotor aircraft do that cannot already be done as effectively and cheaper with a traditional helicopter? The primary reason quadrotors make good UAVs is that it's easier for a computerized fly-by-wire system to keep them stable, but that is their only advantage to date compared to a single-rotor helicopter, so until the aircar becomes a serious legal and engineering possibility and people want a rotorcraft that is as easy to fly as a car is to drive (or at least easier than a helicopter where you pretty much cannot let go of the cyclic, ever), the quadrotor will likely remain small-scale.


What difference is there between stabilizers and stabilators concerning longitudinal stability?

There is no fundamental difference between them in such context. If you don't go to the extremes like 90° deflection (and generally stay in the linear range), you can mentally replace an elevator with a stabilator at a different equivalent angle. All-moving surfaces are typically a design solution when additional efficiency is required for whatever reason.

There are finer effects, especially at supersonic, but they don't change the overall picture for 'normal' aircraft. You can always find border cases when, say, elevator will stall but an equivalent stabilator will not yet, but they will generally be beyond the operational envelope.

Stability is primarily determined by derivatives, i.e. the way moments change with changing angles (of attack in this case). Absolute angles (tail vs wing) are less important and are usually the consequence of the desired derivatives.


What is the smallest manned aircraft with four engines?

I present you Yves Rossy's Jet wingpack, which satisfies your conditions (I know I'm pushing it, but couldn't resist).

Yves Rossy's Jet wingpack, By Rama - Own work, CC BY-SA 2.0 fr, Link

It is certified by FAA as an aircraft, powered by four Jetcat P400 turbojets, piloted by an individual, not a rotorcraft and used in show business.

According to the official site, it weighs 150 kg.

@ymb1's logic is correct. To get to lightweight four engined aircraft with, you have to go back when the engines were not powerful enough for large aircraft. So, I present you the Sikorsky Ilya Muromets, the World's first four engined bomber.

Sikorsky Ilya Muromets, By www.cultinfo.ru, Public Domain, Link

The Ilya Muromets Type S-23 V is reported to have an OEW of around 3700 kg, powered by four Sunbeam Crusader engines. Its predecessor, the Sikorsky Russky Vityaz, was still lighter, though it never saw service in numbers, sadly.

Of course they are not autonomous as per your requirement. Why would you want a manned autonomous aircraft anyway?


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

As is suggested in the original question, the answer appears to be "no".  This website gives some hints as to why a gear-driven supercharger would normally be used in addition to a turbosupercharger: http://www.rwebs.net/avhistory/opsman/geturbo/geturbo.htm

(Though the link may raise more questions than it answers: it doesn't make it obvious why a turbosupercharger usually injects air upstream of the carburetor, or why a gear-driven supercharger usually injects air downstream of the carburetor, or why only the latter prevents issues with valve cooling.)


Why are helicopters less efficient than planes?

The answer lies in the difference between energy and momentum. Both have to be maintained, but energy goes up as the square of velocity, while momentum goes up linearly. To impart a given momentum, you can either move a lot of air slowly, or a little air quickly -- but as you move the air more quickly, it requires disproportionately more energy.

In other words, the bigger the wing, the more efficient (from an energy/momentum perspective, anyway).

A rotor's size is limited, both because its fast rotation means it needs to be light (and thus can't be very reinforced, etc) and because the larger its radius, the faster the end spins. That means it has to touch less air, but move it more -- which requires more energy.

There's more detail at this question on Physics StackExchange (disclaimer: I wrote that question).


Were there any test flying incidents during which the pilots managed to escape the plane?

Do civilian space ships count?

In the VSS Enterprise crash  the captain survived. The plane broke up around him and he was able to unstrap his seat after which his parachute automatically deployed. The co-pilot died in the crash.


Surface deflection if loss of hydraulics on combat jet

Most of the ones that we measured without hydraulic pressure would just sit there. Moving the stick is possible within the servo valve deadband, but the surface does not move whatsoever, just stays in the last known position.

Hydraulically powered fighter jet surfaces are powered fully redundantly, by separate actuators and separate hydraulic systems. If pressure fails in system 1, opening the servo valve (by moving the stick) just connects pressure to return and its actuator becomes a passive damper that otherwise does not hinder the functionality of the remaining one. Yes the inputs to both servo valves are linked.

Most hydraulic power systems for fighter jets are irreversible, meaning the aerodynamic hinge moment cannot move the stick. But if the hinge moment becomes larger than the total force of the active actuators, the surface cannot be deflected anymore.

Info on military jets don't seem to be not publicly available. I could find this hydraulic schematic for a G450 elevator:

This set-up allows manual reversion: when all hydraulics are off the pilot can manually deflect the elevator, at higher forces than with hydraulics functioning. Note that the pink colour denotes "Hydraulic Lock". It means that when the servo valve is closed, back driving the actuator is not possible due to trying to compress the hydraulic fluid.

Over (a very long) time, gravity may slowly push the hydraulic fluid back through the circuit when unpowered. When all oil in the circuit has seeped back into the reservoir.


Why do we check Idle operation with carb heat on during a Cessna 172 run-up?

Because, in engaging the carburetor heat, you are decreasing the density of the air entering the engine with the same fuel flow, thereby richening the mixture.  At idle power, if the throttle idle set screw is not properly adjusted, there is a risk of an engine failure from too rich a mixture entering the engine.  The idle power carb heat check is a good way to verify the engine won’t do this in flight.


What's the minimum allowed flying height of a light aircraft over a town?

In Europe this is regulated by SERA.5005 Visual flight rules (source, emphasis mine):

(f) Except when necessary for take-off or landing, or except by permission from the competent authority, a VFR flight shall not be flown:
(1) over the congested areas of cities, towns or settlements or over an open-air assembly of persons at a height less than 300 m (1 000 ft) above the highest obstacle within a radius of 600 m from the aircraft;
(2) elsewhere than as specified in (1), at a height less than 150 m (500 ft) above the ground or water, or 150 m (500 ft) above the highest obstacle within a radius of 150 m (500 ft) from the aircraft.


Where do the forces exerted on flight yoke/stick comes from and how do they vary with flight conditions?

I've worked with control loading systems quite a bit. What you describe is a reversible system, where the flight crew feels the aerodynamic forces acting on the primary control surfaces (elevator, ailerons, rudder).

In the aircraft, the pilot pulls on the flying control, which is connected via a steel cable to the control surface, which then deflects. Airflow blows back on the deflected surface, with a force proportional to deflection of the surface. In the picture above $H_e$ is the hinge moment on the elevator, the aerodynamic part of which is $$H_{ea} = C_{he} \cdot ½ \cdot \rho \cdot {V_h}^2 \cdot S_e \cdot \bar{c_e}$$ with $C_{he}$ = moment coefficient, $\rho$ = air density, $V_h$ = airspeed at horizontal tail, $S_e$ = elevator area, $\bar{c_e}$ = mean aerodynamic chord of elevator.

The hinge moment coefficient is a function of trim tab deflection and angle of attack, and is measured in flight tests. Figure below shows $C_{he}$ for the Fokker F27.

On ground, at airspeed zero, $H_{ea}$ is zero but there is contribution of friction, bob weight and down spring.

In the simulator, the same flight control is installed as in the aeroplane, but now is attached to an active actuator that is programmed to push back at the stick with the same force that would be experienced in the simulated flight state in the aeroplane. The actuator features an inner (control) loop and an outer (force feedback) loop.

Force vs. position and position vs. time measurements are taken from flight measurements, which must be tightly reproduced in the simulator in order for the sim to be certified. Reversible controls of small, simple aeroplanes are much harder to simulate than the irreversible, hydraulically actuated flight controls of larger planes, since these do not change as a function of flight state.


The FAA treats large airplanes the same as any other airplane when it comes to VFR flight.  They are required to maintain the same distance from clouds, only fly with the same minimum visibility, see and avoid other aircraft, etc.

However, since only IFR flights are allowed above FL180 (without a special exemption), and large turbine airplanes are terribly inefficient at low altitudes, so it doesn't happen very often.

In the US, Part 121 flights have the most restrictions of any of the operating rules, and they have multiple regulations relating to VFR flight, including this one1:

  14 CFR 121.611 Dispatch or flight release under VFR.

  No person may dispatch or release an aircraft for VFR operation unless the ceiling and visibility en route, as indicated by available
  weather reports or forecasts, or any combination thereof, are and will
  remain at or above applicable VFR minimums until the aircraft arrives
  at the airport or airports specified in the dispatch or flight
  release.

So yes, even if it is operated by a 121 carrier, they are allowed to fly VFR by the regulations.  However, they must also comply with their Operations Specifications and Flight Operations Manuals which will have detailed procedures covering the conditions where it is allowed.

Outside of 121 there are even fewer restrictions on VFR flight.

1 There is also:

§121.347 - Communication and navigation equipment for operations under VFR over routes navigated by pilotage.
§121.349 - Communication and navigation equipment for operations under VFR over routes not navigated by pilotage or for operations under IFR or over the top.
§121.649 - Takeoff and landing weather minimums: VFR: Domestic operations.
§121.667 - Flight plan: VFR and IFR: Supplemental operations.


Why do some 2 seat fighters have side by side seating, while others have the pilots inline with each other?

The tandem arrangement (one behind the other) is used on aircraft that have single seat variants. The F-15, F-16, and F/A-18 are all primarily single seat aircraft. It's much easier to stretch the nose out a bit to add a second position than to make it wider. This arrangement is also more aerodynamic, requiring less frontal area.

Fighter aircraft designed for a crew of two will often choose the tandem arrangement for aerodynamics. If both seats need forward visibility, there are compromises available. Some aircraft like the F-15E can be flown from both seats even though there is less visibility from the back. It's possible to have a bubble canopy in side-by-side configuration (this is particularly seen in aircraft kits), though it will create more drag than a tandem canopy.

Having the crew sit next to each other can be helpful for crew interaction and sharing instrumentation. The F-111 is one such special case:

  The USAF wanted a tandem-seat aircraft for low-level penetration ground-attack, while the Navy wanted a shorter, high altitude interceptor with side-by-side seating to allow the pilot and RIO to share the radar display.

This may have also been easier to design the escape capsule. Of course the Navy changed their mind and went with the F-14 instead for better maneuverability.


Is there a list of CASA prohibited medications which would disqualify a pilot from flying or obtaining a Class 1 medical?

There is no all-encompassing list of 'banned' medications publically available for Australia. In the regulations there is a 'catch all' to the effect of "pilots must not take any medications which may inhibit their ability to fly safely".

If you want specific advice on a specific medication, why not give CASA a call? That or you can see a DAME (which is a GP qualified to do aviation medical assessments).

What you can find out there is general advice though. Although questions such as this on ADHD and this more generally refer to the US system, the Australian restrictions are not too dissimilar.

Broardly speaking, Ritalin and other 'depressants' are incompatible with flying. Bi-polar disorder faces many restrictions but stable depression is manageable. I did hear somewhere that you need to be off antidepressants for 12 months though. Diabetes and blood thinning medications are OK but subject to regular testing and scrutiny.

As an aside, sometimes CASA, instead of outright refusing the medical, will place restrictions on it instead. This can be things like you must fly by day VFR only, or you can only fly with a qualified pilot next to you.

EDIT: I found this page from the CASA website which has a list of medications to stay away from. It's not exhaustive but it's a start


Which atmospheric factors that can affect the performance of an aircraft while flying a circuit?

In short, all of them. Environmental factors that affect aircraft performance do so whenever that aircraft is flying, regardless of whether you're flying a circuit, a straight line, or anything in between. The most important environmental factors include:

wind speed
wind direction
air temperature
air density
air pressure


What trade-offs does an airline make when selecting an engine type for their aircraft?

Power

Some models are different in power, a consideration if you intend to operate hot and/or high, or heavy. Otherwise that extra power is mostly fuel-inefficient.

Competition

In situations where two or more alternatives are available, there's healthy competition. Engines are around 25% of the cost of a new aircraft, so there would be a big money to gain when airlines bulk order from a certain company.

Boeing took this a step further on the B787 where it's easier than ever to switch the type of engine to prevent this type of 'vendor lock-in'. Historically,  it was very difficult to switch due to the technical complexity in these systems.

Customer Relationship

If an airline has good contacts with a manufacturer and know how they work, they may prefer to opt for that comfort when considerable money is on the line.

Part Commonality

The more type of the same engine you operate, the better economies of scale you achieve. This is especially important as substantial maintenance work is concentrated around the engines.

This made for instance American Airlines store Boeing 757 aircraft that it got through a company acquisition that did not have the same engine type as the remaining fleet.

This thinking is not limited to your company, but for instance within a group of companies, as heavy maintenance is often centralized.
It can even apply across types. For instance, Korean Air ordered 787s and 747-8 both with GEnx engines. To quote GE Aviation on the two slightly different engine types:

  The -2B contains an identical core and similar materials as the -1B, delivering synergies for mixed GEnx fleets


Does the ARCA hoverboard violate known limits on small-diameter electric fans?

The key is that the Arca board only works in ground effect. Therefore, the pressure difference over the area of the board is the key for calculating its power needs.

From the video I would estimate the size to be 0.6 x 1.2 m thanks to @mins more thorough research we know that the board measures 1.45 x 0.76 m for an area of 1.1 m². To lift both the occupant and the board itself it claims to create 430 pounds of force, equivalent to 195 kg of mass in Earth's gravity, so the pressure increase between top and bottom is 1740 N/m² or just 1.7% of atmospheric pressure. This is not much when you consider that a turbofan compressor stage can create a pressure differential of 1.7, albeit at much higher speeds.

The concept is basically the same as the Hiller flying platforms of the 1950s, the first of which was powered by two 44 HP engines. Since the intake geometry of the Arca board is - how should I say - less than optimum, it can not fly as high as the Hiller vehicles and I find the claimed 272 HP hard to believe and the high power draw is due to the low efficiency of 36 closely coupled blowers.

Hiller VZ-1 Pawnee (picture source)

To calculate the exact amount of power needed I would need to calculate the mass flow from below the board at the given pressure, which depends nonlinearly on altitude. Then I would need to calculate the power to produce this mass flow at the known pressure differential with 36 small blowers. Sorry, but even my Hoerner books do not cover this. What is certain is that the thrust from the 36 blowers is not nearly sufficient to lift the 195 kg when out of ground effect. The board only works at very little altitude when the outflow cross section around the board is restricted. This gives it an automatic altitude limit of a few centimeters and makes it self-stabilizing in pitch and yaw.

It takes some thick skin to watch the full length of this platitude-filled piece of marketing for an obvious gimmick. The camera angles were chosen to make it look fly higher than it actually can, and in the one shot where it does fly higher you cannot see who or what is standing on top. Anybody spending 20 grand on this is going to regret it quite soon.

EDIT:

With the answer provided by Bruce Abbott to @mins' question on Electrical Engineering SE the question can be solved. Bruce approaches the problem from the electrical side and links to a 120 mm blower which creates 74 N thrust and consumes 7 kW of power. He calculates 65 kg for the batteries and 36 kg for the blowers, for an estimated mass of the board of 110 kg. However, in combination the thrust from closely coupled blowers will certainly be lower than that of an isolated blower with ideal flow conditions.

Conclusion: Looks possible, no limits are busted, but there is some potential for further optimization and badly needed mass savings on the board.


How do airlines train their pilots to deal with the stress of delays?

(My answer is limited to carriers based in the USA, things can be very different in other regions, many countries pay monthly salary and culturally have different view of company expectation verses safety expectation)
Pilots are paid per hour of block time, they are getting paid for all that time waiting on the taxiway after leaving the gate and starting an engine. The flight plan will usually include an extra hour or two for flying to an alternate airport if the weather turns bad at the destination airport, this is not commonly used with modern forecasting but it is part of the plan. So generally a pilot should not have a strong financial motivation causing delay stress. If a poorly timed childrens party is causing distraction then my opinion is that the company should consider strongly encouraging this pilot find a less safety critical career.
Pilots in the USA in recent years do tend to get a lot of general stress-management guidance during training, even a fair bit at the private pilot level.(depending on the school) Often this training is lumped under labels like "Human Factors" or "crew resource management", and FAA materials even include specific advice for avoiding situations just as described in your question they call it "get-there-itis". The free FAA materials tend to be a bit superficial but better than nothing in calling attention to a possible problem, industry training courses on the other hand have some good depth. This type of training has been growing since the late 1960s, but it got a large boost in the early 1980s after the 1977 Tenerife disaster where a KLM captain apperently hot to make up for delays started takeoff without full clearance and slammed his 747 into a Pan-Am 747 taxiing in the fog, just at rotation speed, killing over 500 people.


In the upper air, do pilots use flaps to generate lift as well slow down an aircraft?

It's a little complex, but here is a shot. Take a look at the following graph:

graph http://www.navlog.net/wp-content/uploads/2012/10/PowerAvailable.png

What you can see is multiple airspeeds. For a plane, the rate of cruise is maximised around Airspeed B is reached- this is when the difference between power available and power required is the greatest and therefore the most excess energy is available for climb.

The slope here indicates how much power is necessary for that airspeed- the steeper the curve, the worse it is. The value is really high for airspeeds all the way to left.

If you were to deploy the flaps, you would sort-of shift the power required curve to left- adding drag, reducing the difference between the power available and power required, reducing the maximum rate and in the process increasing the power necessary.

(source: ppl-flight-training.com)

In the equation above, you want to increase lift. Yes, you can do this with flaps- it would increase CL. As you yourself state, it takes a lot of drag to use flaps and slats. Another option is to increase velocity. This is more efficient and uses less energy.

The reason we need is flaps is since as the velocity drops for landing, we need to increase the CL to maintain sufficient lift for landing. Airspeed for B for landing though is much too fast, so you want to slow down to the left side of the graph. See this post on a little more detail on this relationship.

As for flap limitations, they appear to be 20,000 ft for the Boeing 737- Mostly because boeing found them unnecessary to use at higher altitude.


What are the weights of vertical and horizontal stabilisers of a Boeing 747-400?

From my time as an intern at the plant at Paine Field, I know that a 747-400 wing and center fuselage section weighs 42 tons.  That's just the structure itself.


How can I find out if a close encounter in flight would be classed as an airprox?

I've finally identified the flight you most likely saw out of the window. There was an oddity with Fligtradar24 where the data was missing for the flight, but I've straightened out that mystery.

First for the Flightradar24 oddity:
You were on B757 registration G-LSAE on from LBA to PMI. The previous flight that aircraft had taken was LS444/EXS4CX from HER to LBA. For some reason when your flight left LBA it was still showing on FR24 as LS444/EXS4CX. After it crossed into France over Le Havre it changed to showing as LS831/EXS81WF which is usually a flight from MAN to PMI. I can't explain this, but the registration, time and route matches exactly with the routing shown for LS257 on FlightAware, so this is your aircraft.

Now for the flight you saw:
There were only two RyanAir flights that you crossed paths with that might have been close enough to see. FR6462/RYR88FJ passed about 15-20 miles from you. But at 6:39 UTC over Lunay, a RyanAir B737, flight FR9052/RYR43EZ passed very close. I'm sure this is the aircraft you saw. According to the data, your aircraft was at 35,000 feet on a heading of 164° feet and the RyanAir was at 36,000 feet on a 12° heading. So, although the lateral separation was very close, the standard vertical separation of 1,000 feet was maintained.


Why is 3000 psi the most common hydraulic pressure used in commercial aircraft?

The linked article directly answers the question

  "Above 3000 psi, using aluminum as a pressure vessel becomes risky," says Galloway. "5000 psi systems almost exclusively rely on steel or titanium. To minimize stresses, the sizes of passages can be reduced. Computational fluid dynamics is also used to minimize pressure drop in critical areas."

3000 PSI was the best you could get with technology in the 1950s, when standardization occurred. Without economical titanium tubing and reservoirs, using steel would incur a weight tradeoff that doesn't make sense.

The A380 was a trigger to the development of 5000 PSI civilian systems because of both the high demands and the long run distances, both due to the size of the plane. I read somewhere that they took a look at the military 5000 PSI systems and realized it would never stand up to commercial use, so little technology was carried over.

Every new design large transport from the A380 onwards (787, A350) is 5000 PSI.


What is the maximum allowed difference between two altimeters for flying in RVSM airspace?

On the ground during the preflight check, the altimeters must be within 75 feet of each other.

In-flight the altimeters must be within 200 feet of each other.

I have been flying the B777 for about 8 years and I have never seen the altimeters disagree by more than about 10 feet, either on the ground or in flight.


The answer is stated in ICAO Annex 12 (Search and Rescue)PDF. (See Appendix I relevant to Chapter 5, 5.8 of the Annex.)

Ground-air visual signal code for use by survivors:

Ground-air visual signal code for use by rescue units:

  Note 1.— Symbols may be formed by any means such as: strips of fabric, parachute material, pieces of wood, stones or such like material; marking the surface by tramping, or staining with oil.


Why is the aiming point distance shorter in the US vs. Europe for long runways?

Good observation. It's often misquoted that the 1,000 feet is the [international] standard. The standards and recommendations for runway markings can be found in ICAO Annex 14. In particular section 5.2.6 for the touchdown zone marking (diagram shown below).

When a country decides it wants to deviate, it lists the differences in its AIP. In this case indeed the US AIP lists a difference from 5.2.6.4:

  The U.S. standard places the aiming point marking 306 meters from the threshold where it replaces one of the pair of three stripe threshold markings. The 306 meters location is used regardless of runway length.

(Note: 306 m is ~1,000 feet.)

The UK AIP does not list a difference in distance, but the reason why it's >400 m is in a note (missing from the 2016 edition of Annex 14) in the 2017 EASA guidance material, the 400 m is the standard, except:

  Where a PAPI system is provided for the runway, the beginning of the marking should be coincident with the visual approach slope origin.

The AP marker has always been (using Google Earth historic view) where the PAPI lights are at EGLL. Example for EGLL 27R:

When VASI is used instead of PAPI, like the 3-row VASI at OERK, it's 400 m on the mark:

I initially thought maybe it's because EGLL went through various lengths in its long history, but a new runway such as 05R at HECA that was built from scratch, is actually like EGLL 27R. There's more to PAPI than meets the eye.

So there is diversification indeed. As for 'landing short in the US', we are looking at ~100 m difference (306 vs. 400) for the aiming point, but don't forget the extra touchdown zone marking closer to the threshold in the ICAO standard.

Note: the figures apply to runways that are >2,400 m. Shorter runways have the aiming point brought closer to the threshold.

Trivia: Also still in the UK AIP is the unique aiming point, even though they are clearly no longer used at EGLL and EGCC for example (check historic view in Google Earth or current charts).


Do the FACs compute every speed value shown on the PFD speed scale, or only stall speed and maximum speed?

Yes. Kind of--the air data computers do some of the computations and display those based on hard coded limits.  For example, an ADC will compute current AOA and may have the AOA limits hard coded therein.

The air data computers also provide input to the FACs, which further limit the aircraft speed envelope based on altitude, speed, and configuration.  The FACs are necessary for configuration information and flight control positions.

A detailed explanation of the what the FACs accomplish is here.
There is a related question.

Other examples of ADCs and their respective displays appear here and here.  The first shows mechanical systems which compute a normalized AOA based, and later in the same article, a Gulfstream display shows feathers for Max AOA on the ADI, as seen here.


Who controls airspace and time in my area on helicopters?

Like others said, if it's military you're probably out of luck. If it's police, they don't fall under federal jurisdiction, so it'd be up to whatever department is operating the helicopter, city, county, etc. At 2am it's unlikely to be civil aircraft, but if it is and they are operating out of John Wayne Airport, their noise abatement rules are published here.


What is the optimal bank angle to accomplish a given turn in a glide?

The best bank angle is indeed 45°.

It can be shown relatively easily that that gives the tightest turn for constant angle of attack, where we assume that constant angle of attack results in constant angle of descent too. It would be pretty hard to show for constant speed, and it might not even be exactly true in that case.

However, this can't really be separated from the best speed. And the surprising answer is that the stall speed (which is ~19% ($\sqrt[4]{2}$) higher than in straight flight) gives smallest loss of altitude for turning given number of degrees.

The reason is that the drag (near the stall speed) is proportional to $\frac{1}{v}$, but the turn radius is proportional to $v^2$, so as you slow down, the radius decreases faster then the drag (and therefore vertical speed) increases.

References:

http://www.nar-associates.com/technical-flying/impossible/possible.html
Is it even remotely feasible to turnback a single engine aircraft with an engine failure?


Why do outboard spoilers deploy more than the inboard spoiler on the A320?

Airbus prefers simpler single-slotted flaps, which offer a weight advantage, but require higher-lift wing, which in turn slows the cruise speed. This is covered in a paper by an Airbus engineer, which I've used to answer a question about why the Airbus wide-bodies use different flaps when compared to the competition.

The single-slotted flaps are usually thicker as well, which in turn lead to thinner spoilers (so both can fit when retracted). Here's what the paper says:

  However, the reduction of the spoiler thickness increases the deformation tendency of the spoiler and the necessary higher stiffness would then result in higher weight of the spoiler parts.

The inboard flaps/wing generate more lift because the wing is thicker there, and the flaps are generally longer there. Which in turn is more suction behind the inboard [thin] spoilers. So a solution is to decrease the inboard deflection angle.

In comparison, this question about the 777 spoilers, shows that for all but one panel on each side, the deflection is uniform. This is a deductive answer. So kindly keep that in mind.

The following side drawing from an unrelated patent may help visualize the interaction better:


How does the less dense air affect the reciprocating aircraft engine performance?

Lower air density means less compression, hence less mean effective cylinder pressure during expansion, and thus less power, since shaft power is proportional to the product of mean effective pressure and angular speed...


Which country has the lowest flight time requirement for the issuance of a pilot certificate?

Here in the US you can get your sport pilot in 20 hours but that is a pretty heavily limited license, your basic VFR PPL will require at least 40 hours here in the US. You should note that this is flight time which is generally tracked on the hobbs meter (positive oil pressure or master switch on depending on configuration). There is a lot of other time in ground school, flight planing, pre-flight checks, and waiting for weather to pass that you will undoubtedly run into.

Looks like Canada requires 45 hours and thats day only. The UK also requires 45 hours.

These hours are for VFR only. An instrument rating, which is not a separate license but an additional rating on the pilot certificate, will take more hours. Some countries limit night flying privileges without an instrument rating, and if you intend on doing any serious flying its a good idea to have.

As mentioned by Ron in the comments, not all licenses are valid everywhere. Some are recognized with limitations, and some can be transferred depending on what you are trying to do. Some privileges may be recognized if you are flying to an area to visit etc. Other situations may require more training or filing different types of flight plans. Almost everyone is on ICAO format these days.


What is this hole on the tail of an MD-88?

That is the ram air intake for the air conditioning packs.


What is the meaning of the term "fly back only" in AMM documents?

(a) Accept with an inspection each 100 hours, cracks on the inner or outer shroud if there is:
A single hair line crack at the leading edge of the blade, possibly only on the coating on all blades (Area A1).

The statement translated means; Allow to continue in service with 100 hour inspection cycles the following defects.

(b) Accept for fly back only, cracks on the outer shrouds if they are:
A maximum of 0.08 in. (2.03 mm) long on up to 10 blades (Area A1).

Allow for One Time Flight Only, as described in the operators Op Specs and MEL, the following defects


What can airline pilots do if they are no longer in the position to fly, career-wise?

When I worked in the design department of an aircraft company, I had two types of coworkers: Those with and those without a pilot's license. You could easily spot the difference. In aircraft-related engineering decisions it was soon obvious. I mightily preferred to work with other pilots - they would have a much better grasp of "what looks about right" and not pursue hare-brained, outlandish ideas.

See it this way: All managers in car companies have a driver's license, so they have at least some contact with what their companies make. All higher managers where I worked had no pilot's license, and it made work outright awful. They were trained as beancounters, and that restricted their viewpoint. They were simply incapable of telling good engineering from bad.

If you have managed to get a CPL, adding an engineering degree on top is not hard. That is my advice to grounded pilots: Go to engineering school and enrich the workforce with your experience.


What is more environmentally friendly? An A320 or a car?

I'm going to simplify and assume that jets and cars burn the same fuel, and output the same exhaust, CO2, NOx and all. I'm going to compare only short-haul flights against cars.

According to Wikipedia, an A-320-NEO does 1.95L/100km per seat. Assuming flying at 80% capacity, that gives us 2.4L/100km per seat. According to
The Car Guide, a 2019 Honda Civic does 6.5L/100km. Assuming an average car carries 2 people, that gets 3.2L/100km. It would seem like flying is slightly better, using this simplistic measure.

Keep in mind that the longer you fly, the better the mileage, since the takeoff and climb are the fuel guzzling segments.


What do aviation agencies do to make waypoints sequences more easy to remember to prevent navigation mistakes?

Australia

Brisbane / Melbourne FIRs boundary
PUDYA SWEED LIPPS ALIDL CLOZA TOUDA PHONE
(Put your sweet lips a little closer to the phone, Jim Reeves)
Brisbane RWY19 STARs
LEAKY BOATS SINNK and
DRAIN PLUGG SINNK.
BLAKA MOOVI by the South.
Gold Coast (YBCG) SID 14/32
LUVLY MEETA MAIDS
(Lovely meter maids)

USA

Frederick, Maryland (KFDK) RNAV (GPS) RWY 5
PHILB DEFND GEEAY
(Phil Boyer, AOPA president, defends GA)
Kansas City, Missouri (KMCI) ILS/LOC RWY 1R
SPICY BARBQ TERKY SMOKE RIBBS HOTBI
Lebanon, New Hampshire (KLEB) ILS/LOC RWY 18
HAMMM HAANK BURGR FRYYS
Nashville, Tennessee (KBNA) ILS/LOC RWY 2C
LRETA JCKSN GRRTH
(Loretta Lynn, Alan Jackson and Garth Brooks)
Orlando, Florida COSTR THREE ARRIVAL
From LA BELLE Tacan: DOWNN MOANS BIGGR
From BOXKR ANDRO SETME
(I'm quite sure I missed some other)
Palm Beach, Florida (KPBI) Ivanka One Departure
The various departure paths include
UFIRD DONLD TRMMP IVNKA
(The FAA scrapped this procedure and some of the associated waypoint names in 2015.)
CRYER UTLEY FINNS PYRUT AHABB
(Captain Ahab is a fictional character in Herman Melville's Moby-Dick; Jimmy Buffett song: A Pirate Looks at Forty; Jimmy Buffett song: Fins; Michael Utley: musician; Jon Cryer(?): actor)
Portsmouth, New Hampshire (KPSM) RNAV (GPS) RWY 16
ITAWT ITAWA PUDYE TTATT - IDEED
(I thought I saw a pussy cat - I did!)
Salt Lake City, Utah (KSLC) RNAV (GPS) RWY 34L
HOAMR MARRJ BAURT LIEZA
(Simpsons characters)

Community wiki.


What is this little strake on Cessna 182 vertical tail?

It's one half of a VOR receiver antenna. There will be a corresponding element on the otherside of the tail.

The complete unit looks like this:

Source

Disclaimer: I have no affiliation with the the company from whom I borrowed the image - it was just a good image to illustrate the point.


What is the correct IATA airplane designator for the Boeing 787-10?

I looked it up in the corresponding IATA document and I can confirm it is 781.

Sadly I think I am not allowed to attach any kind of proof from the document but the source of my information is IATA document 8803 - Aicraft Types in version no. 28.


How does MCAS compare to stall protection systems installed in other aircraft?

MCAS is currently under scrutiny because it has apparently caused two crashes resulting in 346 fatalities. Other similar systems have undergone scrutiny in the past. For example, the flight control system in the Airbus A330 was under the microscope after suffering a number of very similar failures. On Qantas flight 72 the computer received faulty AoA data causing a sudden nose-down. They were fortunate enough to have enough altitude to recover, but it resulted in some serious injuries. It was determined that the incident was not completely isolated.

As to why the A330 was not grounded where the 737 Max was, that is probably due to the fatalities involved. Airbus just dodged a bullet in that the crews had sufficient time to recover. Timing was everything.


What is the table top runway maximum slope?

Most Part-25 certified aircraft have an operating limit of roughly +/-2% for runway slope, as most of the runways fall into this category.

It would be probably possible to certify aircraft for steeper slopes, however at a significant cost, as the flight test program would have to be extended to collect sufficient data.

It is also worth mentioning that anything over 1% upslope requires a bit of a different flare technique as opposed to a flat runway. Usually a bit earlier flare with a bit late thrust reduction does the trick. Extending the limit beyond 2% would probably require additional training, as the flare characteristics would be significantly different than that at a normal runway.


Can a plane with a thrust-to-weight ratio less than one fly vertically and perform loops?

With thrust/weight ratio above one, you can use the thrust of the engine to accelerate upward (at least at some point in the flight envelope).  As long as the engines can deliver full thrust, you can maintain that position.
Below one, vertical flight is still possible, but you will be losing speed in the maneuver.
Gliders are capable of loops without any thrust at all. The only energy in the maneuver is the speed of the glider on entry.


Do IFR / VFR weather minimums include ceilings?

The FAA does not define "LIFR" or "MVFR"
These are not terms that the FAA makes reference to.  Go look in the FAR/AIM, section 1.2.  You'll find VFR defined, and IFR defined, but not the other two.  Why is that?
Because those are terms used by the National Weather Service, not the FAA
That means that if you want to operate an aircraft, you obey the FAA weather minumums that are provided in your second link.
The information in the first link is about reading weather reports.  As far as the FAA is concerned:

VFR is VFR
MVFR is also VFR
IFR is IFR
LIFR is also IFR

So answer my question
Ok.  If you're departing from an airport, and you will be in class B airspace from the moment your wheels leave the ground, then as long as you have 3 miles visibility and you don't touch a cloud you can fly.
However, it's not likely that you'll be in class B airspace from the moment you leave the ground unless you're departing from the main airport (LAX, ORD, and so on) and if that's the case odds are you're on an instrument flight plan anyway.


What is the true top speed of the SR-71?

Based on the SR-71A operational envelope, the top Mach number was Mach 3.3 when authorized by the commander and Mach 3.2 otherwise. The top airspeed was 400 kts equivalent airspeed when supersonic and 450 kts equivalent airspeed when subsonic.


Radar Control; is it possible for ATC to instruct track instead of heading?

Radar controllers take wind into consideration when issuing headings - "Fly heading one six zero".

Issuing a track would not be practical. This puts the burden of figuring out what course to fly on the pilot. Not all aircraft have a glass cockpit or instrumentation necessary to easily, quickly, and accurately compute a heading to fly to stay on course. The radar controller knows real-time information, knows the 'big picture', and has practice issuing headings.

Actual position is used to provide separation. Heading doesn't matter for separation.


Can an aeroplane ever be so far away from an airport that it cannot land?

Can a commercial airplane fly outside the safety area? Yes, there is nothing physically stopping the plane from doing so.

Is it allowed to do so? No, precisely for the event should an engine fail then it will have enough range to get to the airport and make a safe landing.

Extending the allowable range of twin engine aircraft is what ETOPS (Extended-range Twin-engine Operational Performance Standards) is about.

By default commercial airplanes with 2 engines must remain within 60 minutes flying time of an airport in case of engine failure. This was decided at a time where engines were unreliable.

However as engine reliability increased airplanes could have that range increased with an ETOPS certificate.


First take a look http://www.erh.noaa.gov/cae/svrwx/downburst.htm for info on downbursts.

An aircraft encountering a microburst (the more localized form of a downburst and that which airline crews train for) can counter it in two basic ways:

establish, if possible, a climb rate through the descending air that is greater than the downward vertical speed of the air.
fly through the column of descending air to air that is not descending or is at least descending at a lesser rate

And, of course, do this without stalling the airplane, especially as you come out of the burst. A practical scenario is that your max climb rate through the descending air can at least reduce your descent rate toward the ground enough that you will be able to transit the burst before hitting the ground.

I was never in a full blown microburst for real, but I practiced recovering from them many times in simulators. For 747-100/200 aircraft in the 1990s the procedure was:

thrust levers all the way forward
raise the nose until you get the stick shaker
fly the aircraft straight ahead while keeping the speed solidly in the stick shaker range.
do not change the aircraft configuration, in other words don't mess with the flaps or the gear.

In simulators it's a wild ride. You can tell how far into the stick shaker range you are by the frequency of the shaker by feel and by its noise. The closer you get to an actual stall, the faster the stick shaker will go, so the idea was to keep the shaker on but not too fast. Since the airspeed will be varying rapidly, you have to do that with large pitch changes.

There was controversy back in the 1990s as to whether what we were trained to do was actually the best way, especially as to not changing the aircraft configuration and how deep to go into the stick shaker. Perhaps now the thinking is different.


How do partial- and full flaps compare for gusty approaches?

I’m not sure when it comes to large aircraft, but when you select partial flaps or opt for a no-flap approach and landing, it results in a higher speed on approach and landing.

If you then break down the wind components in vectors, the cross-wind component becomes relatively smaller, so it is as if you have less cross-wind and don’t need to have such a large cross-track angle upon landing (less crab) or less cross-control when touching down. Even though the effect is small, it is noticeable.

You can compare it with a small single-engine piston trying to stay on course with 30° of crosswind at 100 kts needing perhaps 15-25° of cross-track angle while a fighter flying at 450 kts only needs 3-5° or so under the same conditions.


Aircraft Emergency Evacuation slide inflation system: Why is a mixture of CO2 & N2 used instead of pure N2?

Let me first give some background information on the art of inflating an evacuation slide. There are two ways to fill them:

Expand gas from a high-pressure bottle: This will cool the gas as it expands, so ice may form at the aspirator outlets where sucked-in air and the expanding gas mix, blocking the flow of outside air into the slide. Also, storing compressed gas needs bulky and heavy steel vessels.
Pyrotechnic gas generators which use an exothermic reaction to create a large amount of hot gas. They are more compact and lighter than a pressure vessel for the same amount of gas produced, but their hot gas could scorch the slide material and will contract when it cools down after the filling process, so a slide filled by a pyrotechnic gas generator will sag after a while.

Because of the disadvantages of both pure stored gas and pure pyrotechnic inflation devices, current state of the art emergency evacuation slide systems use a hybrid inflator, which comprises a stored compressed gas together with a pyrotechnic gas generator. The pyrotechnic gas generator augments the stored compressed gas by providing additional gas as well as heat to counteract the effects of the expansion-induced cooling of the compressed gas as it expands out of the pressure vessel.

Operation of a hybrid inflator

The typical gas generator uses solid ammonium nitrate which is electrically ignited and produces nitrous oxide (N$_2$O) and water (H$_2$O) when heated. Nitrous oxide will exothermically decompose into nitrogen and oxygen when heated above 650°C or 1200°F, so even more energy and gas is produced. Note that the decomposition of two moles of nitrous oxide will produce two moles of nitrogen (N$_2$) plus one mole of oxygen (O$_2$), thus adding 50% more gas volume. This hot mixture of nitrogen, oxygen and steam is then piped into the pressure vessel and mixes with the gas flowing out from it, thereby heating the emitted gas.

The pressure vessel contains gasses like nitrogen or carbon dioxide. Other candidates are argon or helium, but their higher price has held them back. To increase the yield from the pressurized gas, the trick with the nitrous oxide can be repeated here: By storing nitrous oxide in the pressure vessel, again 50% more gas volume can be produced from what is stored, while the exothermic decomposition produces additional heat that offsets, to some extent, the heating of the stored gas.

Nitrous oxide is also attractive because it offers the best manufacturability, storage and handling of the possible decomposable gas source materials. Although classified as an oxidizer, in practice it is generally nontoxic and non-corrosive and is relatively inert up to temperatures of about 200°C. Also, nitrous oxide, as compared to gases such as oxygen, nitrogen and argon, liquefies relatively easily at ambient temperatures - helpful when the gas in the pressure vessel is stored in liquefied form to reduce its bulk.

Heated to its decomposition temperature, pure nitrous oxide will undergo a rapid disassociation chain reaction unless a coolant gas is added to absorb some of the heat generated by the exothermic reaction. Therefore, the mixture in the pressure vessel contains 50% or more of carbon dioxide which has a latent heat of vaporization of approximately 66 Calories per gram. As a three-atomic gas it is better suited for this task than two-atomic alternatives. Thus, it does not serve as a diluent (as aeroalias wrongly states), it absorbs heat and stabilizes the disassociation process.

Why a mixture of nitrogen and carbon dioxide

Now we can answer your question: Nitrogen is contributed both by the pyrotechnic gas generator and by the compressed gas and is produced from the dissociation of nitrous oxide (N$_2$O). Carbon dioxide is added to dampen the exothermic dissociation and absorb some of the heat produced. Without it, the gas generator would experience a runaway chain reaction! Its concentration in the compressed gas is between 50% and 75%, so the concentration in the gas generator mix is around 35% to 50%.

The high speed flow of gas from the pressure vessel is now piped through an aspirator, which sucks in ambient air by using the Venturi effect, and from there into the slide. This contributes up to three quarters of the total gas in the slide, so most of the nitrogen in the slide is from ambient air. In the slide, the concentration of carbon dioxide is diluted to around 10% to 15%.

Aspirator (from BF Goodrich's US Patent 4368009). High-speed gas from the gas generator (red arrows) enters from the angled pipe on the left and pulls ambient air (blue arrows) with it when shooting from the nozzles on the right. Contrary to aeroalia's claims, an aspirator is not just another name for a gas generator, it is an entirely different thing altogether.


The Concorde mainly transported fuel across the Atlantic so that enough was available to land safely. Passengers were just an extra on top. Also, being first-class only, it held fewer passengers than what low budget airlines have taken to cramming into their planes lately.
To look at the structure relative to passengers is a bit misleading. Let's look at the fuel load and the mass fraction of empty weight relative to MTOW instead:

747-100
Concorde

MTOW
333.4 tons
186.88 tons

Empty mass
162.5 tons
78.9 tons

Fuel
183,380 liters
119,800 liters

Fuel to empty mass
1.1285 L/kg
1.5146 L/kg

Mass fraction of empty to MTOW
48.74%
42.22%

If you compare passengers plus fuel to the empty mass of each airplane, the Concorde actually comes out well ahead of the 747 and looks like a prize of lightweight design. Having structurally efficient delta wings helped and should explain most of the difference.


Where can I find real-time flight tracking with the least amount of delay?

You can buy a DVB-TV USB stick for around €20, which will allow you to receive ADS-B data:

Up from that, you can get a high-end ADS-B receiver that costs about €750:

Finally, FlightRadar24 offers free hardware in selected locations:

Bear in mind that these devices will only allow you to receive signals within a relatively small area.

One thing worth noting is by contributing the data received by these devices, you get a free FlightRadar24 Premium subscription.

Lots more information is available at FlightRadar24 > Increase Coverage.


With radio not working, why it is more important to stay away from exactly class D airspace?

I think you are mis-interpreting the answer, you should remain outside Class-D until the flow of traffic can be acertained. If you lose comms outside of a Class-B or Class-C, you should not enter that airspace, instead divert to a Class-D or E airport if possible. If you are already inside the B/C airspace, continue, but don't enter. Class-A is different, as it is not surrounding airports and you can fly IFR after you've gotten your clearance with lost comms.

The original question links to the AIM, Chapter 4, Section 2-13, read that and see if it clears things up.


What is this Airbus A320 passager seat part?

That’s a credit card reader so a passenger can purchase either premium food products or spirits or inflight entertainment items.


Why would an airplane be approved for ditching?

I think that 14 CFR 25.801 might sum this one up. Aircraft that are approved for ditching under 25.801 have to meet several requirements:

(b) Each practicable design measure, compatible with the general characteristics of the airplane, must be taken to minimize the probability that in an emergency landing on water, the behavior of the airplane would cause immediate injury to the occupants or would make it impossible for them to escape.
(c) The probable behavior of the airplane in a water landing must be investigated by model tests [emphasis mine] or by comparison with airplanes of similar configuration for which the ditching characteristics are known. Scoops, flaps, projections, and any other factor likely to affect the hydrodynamic characteristics of the airplane, must be considered.
(d) It must be shown that, under reasonably probable water conditions, the flotation time and trim of the airplane will allow the occupants to leave the airplane and enter the liferafts required by § 25.1415. [emphasis mine] If compliance with this provision is shown by buoyancy and trim computations, appropriate allowances must be made for probable structural damage and leakage. If the airplane has fuel tanks (with fuel jettisoning provisions) that can reasonably be expected to withstand a ditching without leakage, the jettisonable volume of fuel may be considered as buoyancy volume.
(e) Unless the effects of the collapse of external doors and windows are accounted for in the investigation of the probable behavior of the airplane in a water landing (as prescribed in paragraphs (c) and (d) of this section), the external doors and windows must be designed to withstand the probable maximum local pressures.

Basically, the aircraft needs to have its hydrodynamic behavior while ditching investigated, and it must then float long enough for the occupants to escape. It sounds like the Learjet 60, if ditched, is not guaranteed to either a) remain structurally sound, or b) allow the crew and passengers to get out before it slips below the waves.
An aircraft that was certified for ditching, on the other hand, basically means two things:

The crew knows that they have at least a chance of doing it right (and will possibly change how the aircraft is configured or prepared), probably with an actual published checklist available to them; and:
If the crew screws it up, it's their own fault and the manufacturer might not be held liable; the aircraft met certification standards. This would significantly reduce their liability in a crash. It's probably mostly that one, honestly.


Can GPS be used in lieu of DME for instrument approaches?

Yes, the details are in FAA AC 90-108:

  7. Usage of Suitable RNAV Systems. Subject to the operating requirements in this AC,operators may use a suitable RNAV system in
  the following ways.

  (1) Determine aircraft position relative to or distance from a VOR (see first note in subparagraph 7b), TACAN, NDB, compass locator
  (see second note in subparagraph 7b), DME fix; or a named fix defined
  by a VOR radial, TACAN course, NDB bearing, or compass locator bearing
  intersecting a VOR or Localizer (LOC) course

And all fixes, procedures etc. must be loaded from the GPS database, you can't enter any fixes yourself based on lat/long or whatever (section 9(c)(1)).


What does "design-induced pilot error" means?

The phrase is basically saying that bad design causes people to make mistakes.

Design-induced - the interaction design or user experience is problematic.

Pilot error - the pilot made a mistake.

An example of this would be the placement of a flap handle next to a gear lever, making it possible to raise the gear rather than the flaps after landing.

Engine controls in modern designs now feature different shapes for each control knob for similar reasons. There have been many accidents where pilots have grabbed a mixture knob — and shut an engine off completely — when they meant to grab the throttle and reduce power. Different textures and shapes make that harder to do:


Could most commercial jet engines today run on ethanol without any problems?

Although turbines could be designed to run on ethanol it's actually a lousy aviation fuel (actually it's a lousy fuel in general). Petroleum-based jet fuel is high grade kerosene which has lubricant properties, which ethanol lacks, and ethanol has different characteristics which mean you can't pour it in and use it as a replacement.

Some problems with ethanol as a fuel are:

It's a solvent which dissolves some types of seals and hoses
It evaporates very easily, and can cause vapor lock
It is hygroscopic, meaning it attracts and mixes with water very readily. Water contamination would not settle to the lowest point, instead it would be suspended with the fuel
It has significantly less stored energy per unit of weight. Jet fuel has an energy density of 46 MJ/kg (megajoules per kilogram) and pure ethanol has 26.4 MJ/kg; that's only 57% of the energy density of jet fuel! Even if a jet was able to burn it at its maximum efficiency it would get just over half the oomph from it.

There are bio-fuel replacements for jet (and diesel) fuels based on oilseed crops like rapeseed (canola), palm oil, etc. These are processed to remove their OH atoms using transesterification to create fuels which are almost identical chemically. Modifying jets to use ethanol would be hugely expensive if it is even possible to do, so there's no point given there's a suitable replacement.

The point is actually moot though because crop-based biofuels are never going to replace petroleum. There simply aren't enough crops grown to feed people and engines at the same time, in fact even if we used all the worlds farmable land to grow bio-fuel crops instead of food crops we still would not have enough of it to replace fossil fuels. We have enough trouble feeding people already and the biofuels craze is not helping that. Bio-fuels based on non-food crops from marginal land may some day become economically viable and partially replace petroleum fuels.

After some searching I found a link to an article I wrote on biofuels for AOPA UK magazine which goes into more detail on biofuel issues.


What would be the impact of replacing the engines on the 737 MAX, not just reworking MCAS?

Possible? Yes.  Economically feasible, not even close.  To re-engine the plane, you would basically have to re-do a large amount of the FAR 25 certification.  Right now, Boeing has to re-do one thing, and it will take a few months.  To re-engine the plane would take several years at the least.  However much money it is losing right now, it is a drop in the bucket compared to the cost of what you propose.


Why would the fuel pressure decrease during a climb?

The most obvious answer is "Gravity".

To some extent this is "normal" in a low-wing aircraft with a nose-mounted engine and a fuel pump drawing fuel from the wing tanks into the engine: As the nose pitches up the fuel needs to run "uphill" to get to the engine - that's more work for the fuel pump, which might not maintain full "straight-and-level" fuel pressure.

You can see something similar in a Piper Cherokee in an aggressive climb, particularly if you are only using the engine-driven (mechanical) fuel pump: The fuel pressure typically drops when you pitch past ~15-20 degrees nose-up. The drop isn't much, but it's noticeable if you're looking for it.

If the pressure drop makes you uncomfortable turning on the electric boost pump(s) may reduce or eliminate it, but as long as the fuel pressure remains in the aircraft's normal operating range it's probably not a cause for concern. You should however become familiar with how much the pressure tends to drop in a climb: A larger drop than "normal" may indicate a problem with the (mechanical) fuel pump which you would want to have your mechanic investigate.


Is there other option than a Chinook to transport 2 cars simultaneously?

You could use an Mi-26 to transport your two cars, as seen here:

With a payload of up to 20 tons, it should be able to lift many useful combinations of two vehicles.


At what exact point in time should we be giving the 10 minutes to diversion call to ATC?

(I just came up with this, so it may not be the official solution - but it should be fairly simple this way)
You first need to know the fuel you need for the diversion with all safety requirements included. This is computed like normal using the MCDU, EFB, etc.. I'll call this your "bingo" fuel. You just need to add the fuel required a 10 minute period for your current flight situation. Once your FOB on the upper ECAM reaches that final result, call ATC.
The easiest way to compute the fuel required for the next 10 minutes is with the fuel flow indication.
On the engine display you have the fuel flow indication, which should be nearly constant during a hold at constant speed and constant altitude.

Add all fuel flow values together
Round up to the nearest 20 kg/hr or so to be safe
Then divide the total fuel flow by 6 (10 min = 1/6 of an hour) to give you fuel required for a 10 minute hold at the current conditions.

Example:
Let's say each of the two engines shows a fuel flow of 1000 kg/hr. Add together to get 2000. Then divide 2000 kg/hr by 6 to get roughly 340 kg fuel consumption for the next 10 minutes. Add this to your bingo fuel.
( 1000 + 1000 ) / 6 = 333 -> 340 ... (+ bingo fuel)
Quicker Alternative:
You could also take the higher of the two engine fuel flow values and divide by 3. Then round up:
1000 kg/hr divided by 3 = 333 kg -> 340 ... (+ bingo fuel)
Note: This works the same if you have fuel flow in pound per hour. The result will be in pounds of fuel required for 10 minutes.


It is the maximum speed in gusty weather. Aircraft designers and certification authorities make assumptions about the maximum vertical gust an aircraft will encounter and design the strength of the wing spar for it. Here 24 feet per second are assumed.

Depending on the mass of all parts not creating lift (fuselage, vertical tail, pilots, equipment ...) the load on the wing spar varies with the aircraft mass. For that reason, lighter aircraft can afford to enter a gust at a slightly higher speed. Here, the 800 lbs glider may fly up to 150 MPH, while the 40 lbs heavier glider should stay below 147 MPH to suffer the same wing spar bending loads when flying into this 24 fps gust.

Flying faster means flying at a higher dynamic pressure and at a lower angle of attack. Entering a gust will increase the angle of attack by the ratio between gust speed and flight speed. Since dynamic pressure is proportional to the square of flight speed, a linear wing lift increase due to higher flight speed will remain when entering a vertical gust. Also, at lower speed the angle of attack might be high enough that the angle of attack increase due to the gust will stall the wing, putting a natural limit on the load increase. Flying faster will remove this load limitation.

The maximum flight speed in gusty weather v$_g$ is a limit speed just like v$_{NE}$, but applies only in specific weather conditions (admittedly those which are most suitable for glider flying). While v$_{NE}$ might be determined by a minimum flutter margin, a formula in the certification requirements or structural loads in maneuvers, v$_g$ is determined by the maximum load factor the aircraft can tolerate.


You don't say which variant you're flying, but the C42B is perfectly capable of both taking off and landing with zero flaps on a reasonable-length runway. I've done it on several occasions with huge margin even for touch-and-gos on my home field's 1300 m asphalt runway. You do need to adjust the angle of attack (via pitch), but if you're flying the airspeed you'll basically be doing that anyway, so no big deal.

Extending flaps give you better flying characteristics at low airspeed, but increases drag. If you're flying the approach at reasonably high speed, then you likely don't particularly need the extra lift, and in fact it might even be detrimental especially once you're wheels on runway and trying to slow down. With flaps extended, you also need to monitor your airspeed more closely to make sure you aren't exceeding VFE.

On the flip (flap?) side, the C42 flaps lever manipulates the flaps directly -- it's just a cable going through the fuselage. Any time you're handling the lever, you are fighting directly against the airflow around the wing, with no help from e.g. elevator trim, let alone hydraulics or even electrics. I know that the effects of this came as a bit of a surprise for me the first few times I retracted flaps in flight; it's very easy to end up with a rough flaps retraction if you aren't prepared for the force involved.

You're supposed to be flying the airplane all the way to the ground, and only bleed off the flying airspeed very late during the landing, in the flare when you should end up at stall speed with the wheels just barely above the runway.

It's possible that your instructor feels that the added complexity of also handling the flaps lever (and the resultant drag changes) simply may risk being overwhelming at first. It's not like there isn't already a lot going on during a standard traffic pattern coming in to land; there's airspeed, altitude, auxiliary pump, carb heat, scanning for traffic, radio communications, keeping good tabs on your position relative to the runway, lining up for final approach mind the wind, making sure your turns are coordinated, during crosswind landings the final turn to align the airplane (as opposed to the direction of travel) with the runway, ...

Your instructor likely has a plan for how to introduce the use of flaps during landing; you are most likely going to need them by the time you're doing short-field work, if not before. You also can, and should, discuss with your instructor anything where you don't feel that you understand the instructor's rationale. Asking strangers on the Internet for advice is fine, and can provide additional insight (which can be quite valuable!), but should never be a replacement for asking your instructor.

  high incident rate that involve overshooting runways

If you're too far along the runway to land safely, just go around and make another attempt. (Landing long is fine, just annoying if you need to taxi all the way back; overshooting the runway is not.) It's good practice for everything except the flare, braking and taxiing, and it's good practice for go-around procedures. I've made the decision to go around in situations that very likely were perfectly fixable (things like being too high on final, or drifting to the side while still a moderate distance out on final) but I am of the opinion that it's better to go around and do it right, than try to press on when things are stacking up against you, especially if you're new. With experience, you'll learn what can be fixed in-place and what truly warrants a go-around.

Just make sure you tell the instructor what you're doing. Crew resource management isn't a big focus in single-pilot light aircraft, since you'll mostly be flying by yourself and certainly a lot of the time without another pilot in the other seat, but I find it's a good idea to follow the general principles anyway.

  Additionally, it doesn't seem to prep you well for the 'real world'. I can't imagine telling your F.O on a 737 'Don't worry about flaps today, it's too much to think about' :D

I know you added a smiley, but it's no joking matter. Don't treat, or think of, the C42 like a commercial jetliner. Don't think learning to fly a C42 will allow you to just drop into the cockpit of a jetliner (even a realistically simulated one) and fly the latter. It isn't, it will never be, it won't, and the C42 handles quite differently from the big iron. That doesn't make the C42 any less "real world".


Why does using carburetor heat increase fuel consumption?

I can think of two reasons:

The efficiency of heat machines depends on the difference between lowest and highest temperature in the cycle, relative to the highest temperature, as formulated first by Sadi Carnot. Simply put, the efficiency cannot be larger than $$\eta_{max}≤\frac{T_{max}-T_{min}}{T_{max}}$$
where all temperatures are expressed relative to absolute zero. If the entry temperature $T_{min}$ is raised by carburetor heat, the value of $\eta$ will drop. For the nitpickers: Piston engines are best described by the Otto cycle which uses an isochoric addition of heat and is a bit more messy to describe than the ideal Carnot cycle. If you want to include Diesel engines, use the Trinkler or Seiliger cycle.
With the higher entry temperature, all temperatures in the cycle are higher and you need to lean less in order not to exceed the desired cylinder head and exhaust gas temperatures. More fuel is needed for cooling, so the richer mixture will drive up fuel consumption.