Since when did European regulations require the ability to suppress alerts?

Since June 2011.
EASA first proposed a change to CS 25.1322 in NPA 2009-12 (Notice of Proposed Amendment) in November 2009:

CS-25 contains a certification specification (CS 25.1322) that dictates the colour of
warning, caution, advisory, and other message lights that are installed as annunciation
displays in the flight deck. As presently written, CS 25.1322 addresses visual alerts only in
the form of coloured lights installed in the flight deck. No specifications are stipulated to
cover new technologies or the use of alternate media, such as aural tones/voice that can
be more effective. CS 25.1322 is therefore considered outdated and does not address the
safety concerns associated with today’s display systems.

EASA then included these changes to CS-25 (the Certification Specifications for Large Aeroplanes) in Amendment 11 on 27 June 2011. The version of CS 25.1322 before (last amendment of 16 December 2010) shows this text:

CS 25.1322 Warning, caution, and
advisory lights
If warning, caution, or advisory lights are installed in
the cockpit, they must, unless otherwise approved by
the Agency, be –
(a) Red, for warning lights (lights indicating a
hazard, which may require immediate corrective
action);
(b) Amber, for caution lights (lights indicating
the possible need for future corrective action);
(c) Green, for safe operation lights; and
(d) Any other colour, including white, for lights
not described in sub-paragraphs (a) to (c) of this
paragraph, provided the colour differs sufficiently
from the colours prescribed in sub-paragraphs (a) to
(c) of this paragraph to avoid possible confusion.

(EASA CS-25 Amendment 10)
Afterwards, the text is very similar to the one in 14 CFR:

CS 25.1322 Flight Crew Alerting
(a) Flight crew alerts must:

provide the flight crew with the
information needed to:
(i) identify non-normal operation or
aeroplane system conditions, and
(ii) determine the appropriate actions,
if any;
be readily and easily detectable and
intelligible by the flight crew under all
foreseeable operating conditions, including
conditions where multiple alerts are provided;
(3) be removed when the alerting
condition no longer exists.

(b) Alerts must conform to the following
prioritisation hierarchy based on the urgency of flight
crew awareness and response:

Warning: For conditions that require
immediate flight crew awareness and immediate
flight crew response.
Caution: For conditions that require
immediate flight crew awareness and subsequent
flight crew response.
Advisory: For conditions that require
flight crew awareness and may require subsequent
flight crew response.

(c) Warning and Caution alerts must:

be prioritised within each category,
when necessary;
provide timely attention-getting cues
through at least two different senses by a
combination of aural, visual, or tactile indications;
permit each occurrence of the
attention-getting cues required by sub-paragraph
(c)(2) to be acknowledged and suppressed, unless
they are required to be continuous.

(d) The alert function must be designed to
minimise the effects of false and nuisance alerts. In
particular, it must be designed to:

prevent the presentation of an alert
when it is inappropriate or unnecessary;
provide a means to suppress an
attention-getting component of an alert caused by
a failure of the alerting function that interferes
with the flight crew’s ability to safely operate the
aeroplane. This means must not be readily
available to the flight crew so that it could be
operated inadvertently or by habitual reflexive
action. When an alert is suppressed, there must be
a clear and unmistakable annunciation to the flight
crew that the alert has been suppressed.

(e) Visual alert indications must:

conform to the following colour
convention:
(i) Red for Warning alert
indications.
(ii) Amber or yellow for Caution
alert indications.
(iii) Any colour except red or green
for Advisory alert indications.
use visual coding techniques, together
with other alerting function elements on the flight
deck, to distinguish between Warning, Caution
and Advisory alert indications, if they are
presented on monochromatic displays that are
incapable of conforming to the colour convention
in paragraph (e)(1).

(f) Use of the colours red, amber and yellow on
the flight deck for functions other than flight crew
alerting must be limited and must not adversely
affect flight crew alerting.

(EASA CS-25 Amendment 11)


The instrument they are using is not certified, hence the ESTMD.  When they get a certified one, the ESTMD will drop off the METAR.

Technically, the primary certified instruments are inop or unavailable, so backup equipment, believed to be reliable, but not certified, is being used.


What range or variation should we expect from gyroscope in a helicopter?

3-DoF magnetic gyroscopes are a dime a dozen nowadays, together with 3-DoF accelerometers, magnetic field sensors, and GPS position transducers. These are in mobile phones now, tiny and frugal with electricity. A google search for "9-dof position acceleration gyroscope" results in a lot of options.

For the sampling rate: this needs to be at least twice the frequency of the fastest vibration - more is better, since a frequency at half the sampling rate shows up as a triangular wave.

For the frequency range of angular displacement, this article might be of interest. It shows vibration data of a car driving over the road, using an iPhone to measure the vibrations. The article mentions a sprung frequency (inside the vehicle) of 1 - 5 Hz. A helicopter usually has higher inertia than a car, so sprung frequency should be lower. If you take 0 - 10 Hz as a baseline for the range, you should be safe. The ground reaction angular frequency range is always higher than the airborne one: responses in the hover are measured in seconds, not in Hz.

Above graph shows pitch response of an example helicopter, from Prouty, Helicopter Performance, Stability and Control. A helicopter with a rotor mounted on top is unstable in the hover, but in order to still be controllable for human pilots the response frequency may not be too high - it turns out that humans can comfortably control instabilities with a time period in the order of around 10 sec. The military have requirements for the stability response in MIL-H-8501A


How does density altitude affect Taxi-Out Time?

The time between takeoffs on a given runway is a function of wake turbulence separation from the preceding aircraft, though wake turbulence avoidance times can often be waived by the pilot in command (depending on operating procedures).  Takeoff separation time is calculated based on aircraft type/weight.

An increase in density altitude could determine whether or not the aircraft can do an intersection takeoff, which in some cases could increase taxi time.


What are capabilities of small Airplane in general?

You have a few questions and the answers to them vary greatly based on the plane in question. It's often said you should chose the plane for your "mission" which means you should think about what you would like to do with the plane and then chose the plane that best fits that "mission". But anyway let's address some of the questions at hand.

  What is usual range of that kind of planes

This depends on the plane. Small planes can get anywhere from 500 nautical miles to upwards of 1500 nautical miles depending on fuel load and optional tank configuration. But the middle of that range seems to be the average. I have found that range is more dependent on how long you can sit in the plane not now much gas you can carry. Remember there is no bathroom on these little planes and some are not the most comfortable things in the world.

  What is the worst weather under which it's ok to fly that kind of
  airplane?

Although this is changing most small aircraft are not certified to fly in ice. Some can be modified to do so and some come with the option when you buy it. That being said I don't know if I would fly a small plane in ice but IMC is possible and done all the time. Remember also that fancy equipment does not always mean you are safer, you are still flying a tiny plane in bad weather.

Rain is possible but keep in mind rain on the ground could mean ice in the air depending on the temperature. Some small airplanes will be able to climb above this but that depends on plane.

Wind is limited by the airports you are flying to and from. If the wind is blowing down the runway you are good to go but every small plane has a maximum demonstrated crosswind component that will limit your ability to fly in high winds at some single runway airports where a crosswind landing is the only option.

  How expensive is to fly internationally with that kind of plane.

Again this changes from plane to plane and country to country. Small pipers can be flown for (from what I have read) under 10K(USD) a year and less if you don't fly very often. With older planes you will pay more in maintenance and less in up front cost while with a new plane you will pay more to buy it and less to maintain it as its fresh. You will also have to factor in gas and insurance. Insurance depends on YOU and your flying time so its hard to say what that will fall in. Gas here in the US (100LL) is around 4.56-6.00 where I am so figure in that based on fuel burn etc.

  What is the procedure and usual cost for example if I fly from Rome to Prague, how the border control checks me, how and what kind of taxes related to that particular flight do I pay. Please, don't miss anything.

I don't fly in the EU so I will refrain from commenting here.

  If a plane is declared to have range of 1900 km, what is practical
  range in practice?

Here in the US you are required to flight plan with enough fuel for your flight plus 30 minutes of reserve. I don't like when companies put range because this is very much based on the winds and your course. If you get a 40 knot tail wind you will very quickly increase your range, while a 40 knot headwind will bring the number back equally as much. I would calculate range based on usable fuel and fuel burn of the engine. but if they are saying 1900KM I would plan for the 1750KM range to be safe.

  If regular service for an airplane is declared to be after 7000 km of flight or X hours of flight, what has to be done usually in those services? Changing of oil, changing of filters?? How expensive usually is that?

Aircraft service is (as far as I know) done on hours not miles flown (although they are related in a way. Here in the US you need a yearly inspection which includes lots of things like testing gear and other components and ever XXXX hours when your engine hits TBO (to be overhauled) you need to overhaul it. This overhall can be costly but is very dependent on the engine. It can range anywhere from 15K to (insert large number here). You are also responsible to have anything fixed should it break obviously.

  Cost to park

There are 2 things here your storage cost and the cost when you actually go somewhere. I fly out of KPNE and have spoken to a few people about the cost of a tie down/hangar. It seems I can keep an airplane in a tie down for less than $100 a month but it would be outside all the time. Hangars get pricy and can be rented or bought. There are lots of small airfields where I am and I'm sure its possible to store a plane for cheaper than at KPNE.

As for going somewhere that depends on ramp fees. Here in the US these fees are sometimes waived if you buy gas or very nominal in the first place. Some airports also have a small landing fee (KPNE is $5). I don't know about EU (although I'm sure they have it) but here in the US you can get the AFD (airport facilities directory) which has lots of info on these kinds of things. Most airports/FOB's now have websites that list their prices as well.

  Anything else you think is important to know about possessing and airplane of that type.

It seems you are looking for a fixed number to a question that does not have an answer like that. You must first identify your mission then you can find a plane to fit the mission profile. You can then look at the prices of other people who have owned that plane and you may find what you seek but you will also find that there is a HUGE deviation in the prices as no two planes are alike.


How does VFR work in countries other than USA? What does hi and lo mean?

The "hi" and "lo" represent en-route high altitude and en-route low altitude.  The difference between the two is the transition altitude when switching from flying with reference to height to referencing altitude

The transition altitude varies from country to country (e.g. typically 18000 for the US and 3000 in the UK unless varied - 6000 in the London area for example) and can be found in various publications and on the en-route charts themselves.

The structure of airspace is consistent world-wide with some variations which are always marked on the relevant charts. There are far too many small variations to go into any detail here.

Finally, the charts themselves. Because the structure is consistent, the charts are also consistent although there are cosmetic differences such as the symbols used, colours used and certain pieces of useful information which may or may not be printed upon them.  The differences are easy enough to  learn quickly.  I've flown VFR in the  UK and the US and the charts look different, but are fundamentally the same. Within an individual country, charts may even differ cosmetically if the airspace is particularly busy when the chart makers may choose to omit less important information.


Can instruction be given during a flight conducted under 14 CFR 135?

It took me a little bit to figure out the underlying reason for asking this question and it has to do with logging flight time.  For example, in a single pilot operation with an autopilot, the second pilot is not required and therefore cannot log the flight time at all even though their company may want them there.  The FARs don't allow the second pilot to log the time.

The regulation that governs logging of flight time is 61.51.

  61.51(h) Logging training time. (1) A person may log training time when that person receives training from an authorized instructor in an aircraft, flight simulator, or flight training device.
  (2) The training time must be logged in a logbook and must:
  (i) Be endorsed in a legible manner by the authorized instructor; and
  (ii) Include a description of the training given, the length of the training lesson, and the authorized instructor's signature, certificate number, and certificate expiration date.

So the question becomes what training was given during the revenue Part 135 flight and were you an authorized instructor?

The term Authorized Instructor is only found in Part 61.

  61.1. Authorized instructor means—
  (i) A person who holds a ground instructor certificate issued under part 61 of this chapter and is in compliance with §61.217, when conducting ground training in accordance with the privileges and limitations of his or her ground instructor certificate;
  (ii) A person who holds a flight instructor certificate issued under part 61 of this chapter and is in compliance with §61.197, when conducting ground training or flight training in accordance with the privileges and limitations of his or her flight instructor certificate; or
  (iii) A person authorized by the Administrator to provide ground training or flight training under part 61, 121, 135, or 142 of this chapter when conducting ground training or flight training in accordance with that authority.

Since it is a Part 135 revenue flight I would believe the CFI would have to comply with section 135.338 and 135.340.

  135.340(a) No certificate holder may use a person nor may any person serve as a flight instructor unless—
  (1) That person has satisfactorily completed initial or transition flight instructor training; and
  (2) Within the preceding 24 calendar months, that person satisfactorily conducts instruction under the observation of an FAA inspector, an operator check airman, or an aircrew designated examiner employed by the operator.

If the authorized instructor has complied with 135.338 and 135.340 they are also bound to the training program for the 135 company.  If that training stipulates you can give dual given during revenue flights than you are more than welcome to do so.  If there is no provision in the training program to provide instruction during revenue flight then it should not be done.

The best option is to request a legal interpretation on the validity of what you are wanting to do.


This document describes it nicely. They are also known as inertial seperators:

  The nacelle inlet of many aircraft models includes an inertial separator
  provided by the aircraft manufacturer to prevent heavy particles from
  entering the engine inlet. Most installations incorporate two moveable
  vanes, one upstream of the engine inlet and the other blocking the bypass
  duct. For bypass operation, the inlet vane is lowered and the bypass
  duct vane is opened permitting maximum separating efficiency. In some
  installations, the vanes are fixed in the bypass mode.

  As shown in the sketch, air entering the engine inlet must turn sharply past the inlet vane (shown in the lowered position). Particles heavier than air are carried straight through, by their own inertia, into the bypass duct and dumped overboard.

  The aft radial inlet design provides many advantages such as superior
  anti-icing utilizing the principle of inertial separation, low noise levels and unequalled protection from FOD.


What are the conditions under which one would normally switch on the Engine and the Wing Anti Ice?

In general the cowls get operated way more than the wings, because the operating requirements are more stringent, because ice can form on cowl inlets more readily than the wings in conditions near freezing (temperature drop from inlet flow) and the consequences can be worse when the ice is shed.
Can't speak for the 737, but on the CRJs at least, the cowls have to be on in conditions where the wings don't, such as flying in visible moisture above 230 kts (above which the wings only have to be on if you get an actual detection of ice on the airframe).  So when you depart in real icing or "technical icing" (visible moisture below a certain temperature) conditions, both wings and cowls will be on, but during the enroute climb you don't need the wings on without an ICE caution message, whereas you still have to put the cowls on pretty much any time you are in cloud.
In the CRJ program the duty cycle of the cowl AI system was several times higher than the wing AI system because of this, and I'm sure most airliners are similar.


Which aircraft can fly at FL600 or above?

Commercial Airliners:

Both Concorde (service ceiling FL600) and the Tupolev Tu-144 (service ceiling FL660) could reach FL600. Most airliners have a service ceiling of around FL410 though.
Business Jets:

According to this article the highest service ceiling for various business jets is at FL510, so none can reach FL600.
Military Reconnaissance Aircraft:

The Lockheed SR-71 Blackbird had a service ceiling of FL850 and routinely operated above FL600. Many other aircraft in this category (e.g. MiG-25, Tsybin RSR, U-2, RB-57F, M-17 and M-55) can also fly above FL600.
Military Fighter Jets:

Most fighter jets have a service ceiling below FL600, but there are a few that can fly higher (e.g. F-15 and F-22 with service ceilings of FL650, the MiG-25 again, and  MiG-31 with the highest service ceiling of FL820+ for a fighter).
Experimental Aircraft:

Wikipedia has a list of altitude records, often by experimental craft. The 60,000 feet limit was surpassed around the end of the second world war with the advent of rocket and turbojet engines. Two notable achievements:

The rocket powered X-15 reached space twice. In 1963 it climbed to 67 miles, nominally corresponding to FL3530. Note that the X-15 did not self-start.

The glider (!) Perlan II has a service ceiling of FL900 and actually reached 76,124 feet. It utilizes standing waves forming at mountain ranges which under certain conditions can extend into the stratosphere. From wikipedia: "A sailplane at 90,000 feet altitude flies in approximately the same aerodynamic regime [...] to be experienced by a moderate size aircraft flying near the surface of Mars."

High altitude balloons and rockets can of course fly higher.


What is the relationship between power and fuel efficiency?

Unfortunately, the cause and effect in this question is really muddled up. Peter Kampf's excellent answer should explain most of what you need, but it might be that you find his answer difficult to understand because you're still operating under the idea that the stick only manages speed and the throttle only manages altitude.

If this is the case, please consider this analogy: imagine that there are three buckets of energy available to any aircraft: chemical, potential, and kinetic.  (note for the pedantic: yes, chemical energy is potential energy.  Go away.)

Chemical energy is stored as fuel (dead dinosaurs).  It is released by the engine and can be converted into either altitude or airspeed or both.
Potential energy is altitude below you - the energy which is stored in the aircraft as altitude.  It can be converted into airspeed, but not back into dead dinosaurs.
Kinetic energy is airspeed - the momentum of the aircraft.  It can be converted into altitude, but not back into dead dinosaurs.

As long as the engines are operating, the chemical energy "bucket" is always pouring energy into the other two buckets.  The throttle determines how much energy is poured out per second.  The yoke (stick) determines the distribution of that energy - whether the kinetic bucket is pouring energy into the potential bucket, or vice versa, or neither.

What this means is that if you want to ascend, it's not enough to say that you simply have to pull back on the stick, or that you simply need to increase throttle.  Merely increasing throttle with the nose pointed at the ground does not help you ascend.  Merely pulling back on the stick with the airplane already at the critical angle of attack does not help you ascend.  To ascend, you need to "fill the altitude bucket", which (as Peter says) is always a combination of pitch and power.

As to your actual question regarding fuel efficiency, since it's based on false assumptions I will only say that it depends on the circumstances of the flight, but it is certainly not correct to say that increased fuel consumption is always the result of the greater throttle setting necessary to achieve a higher altitude.


How much extra drag does landing gear incur?

Since drag equals thrust in level flight, we can work out an approximation for any aircraft that has a counterpart in MS Flight Simulator or similar software.

Before you fly away, real values would require renting a CFD / wind tunnel facility, or access to the 747 flight test data.

To compare the drag before and after, fly at the required altitude/speed, and notice the fuel flow with and without the gear extended.

Write down both fuel flow values, look up the jet engine model from jet-engine.net/civtfspec, note the number of engines, and use the SFC value (lb/lbf hr) to find out the force differential in lbf, then convert to Newtons.

I ran the test in a reputable 737-800 add-on, and with the values for the CFM56-7B27 engine (SFC 0.380), the difference was 67 kN at 250 knots IAS and 3000 feet MSL.

Source—CFD visualization of the turbulent structures around a landing gear.

Fuel flow figures (per engine) were 1.1 and 2.4 (x1000 kg/hr), angle of attack remained constant.

The drag (thrust) values were 57 kN and 124 kN. The landing gear more than doubled the drag at 250 knots (460 km/h).

In other words, the landing gear alone consumed 2600 kg/hr of fuel in those conditions.

That agrees with Terry's experience:

  It's enough drag that in flying a 747-100 gear down the 600 nautical miles from Yokota Air Force Base near Tokyo to Osan Air Force Base a bit south of Seoul, we burnt more than twice the projected fuel burn. Had we not been tankering fuel to avoid refueling at Osan, we would not have been able to do it when we couldn't get the gear up. It was all we could do initially to stagger up to FL190, and we never got higher than FL220.—Terry

A 747 has two bogies more than a 737, they're also bigger and tilted, so the drag penalty for a 747 is likely triple that of a 737, or even more.

At approach speeds the landing gear drag should be much, much lower.

  [The] drag depends linearly on the size of the object moving through the air.

  [The drag varies] with the square of the relative velocity between the object and the air.

  —NASA


Does official source of data about air routes exists?

Such information is not available, for free, on a world wide level.

If you are willing to spend some money, you should have a look at Navigraph, which provides such information on a world wide level, for hobby use.

However, most countries now make their AIP publically available on the internet. Simply search for "[country name] AIP" to look up an AIP for a specific country.

In any AIP, you want to look at part 3 of the ENR section. Usually ENR 3.1, ENR 3.2 or ENR 3.3. Here is an example of from AIP Denmark: AIP Denmark ENR 3.3 - RNAV routes

This information is digital, official, up to date, free and in WGS84 format. However, you will have to look it up for every country.

If you are looking for a visual overview of airways and RNAV routes in Europe, a good place to start is the Eurocontrol regional charts.

You should also check out SkyVector


What will be the immediate action by the pilot and ATC if any plane blocks the runway while landing?

ATC will tell the landing plane to go-around. The pilot will then execute the go-around by flying the missed approach procedure as published in the airport charts.
Go-arounds happen daily and are pretty much a routine action.

In any case, if the landing pilot feels that the runway is not safe for landing, he can decide to go-around by himself without ATC order (if the controller missed the issue or if the airport is uncontrolled for example).

For reference, the missed approach procedure can be as simple as:

Stopping descent
Climbing back to a published altitude
Flying a published pattern
Trying a second approach


Do the CAA's recent changes to medical requirements mean I wasted my time getting a medical?

No, I don't think so.  I believe there is a distinction between a UK PPL and an EASA PPL.  UK PPLs are defined purely by the CAA and only permit flying of aircraft outside the scope of the EASA licensing regime, such as some vintage and home-built aircraft.

The CAA proposal applies to the UK NPPL and PPL licenses not to the EASA PPL (with the exception that it may apply to pilots flying non-EASA aircraft in the UK only).

As it stands it is still necessary to have a class 2 medical to use the full privileges of an EASA PPL, although as footnote 1 says the CAA "aim to influence EASA in considering reviewing the medical requirements for EASA Private Pilot licence holders flying EASA aircraft".


Has research into the aerodynamic properties of non-smooth surfaces suggested any promising directions for future aircraft design?

Non-smooth surfaces are already used, particularly in some Military Aircraft. If you've ever run your hand down the fuselage of an FA-18 Hornet you will find the surface is quite rough, much like the skin of a shark. At lower speeds very little is achieved, however at higher speeds small bubbles of air buildup in the indentations of the skin thereby creating an extremely slippery surface.

Take a look

Take a look here too

I'm certain my terminology is not correct, sorry about that. I would have put this all into comment, but I'm not allowed yet.


The excerpt you posted mentions a further modification of the Oswald efficiency/taper ratio curve which is not applied to the graph in the excerpt. With that modification (which I believe is included in the following pages of the book), the optimum point may move to 0,45. For an assignment, the other places you found 0,45 from and the BAe wings are sufficient motivations to set it at 0,45 IMHO.
I'd like to mention that taper ratio is not the only way to adjust spanwise lift distribution, you can change the airfoils (which you mentioned you have excluded from your design) or you can add twist to the wing so that the wingtips work at a lower AoA. This has the added benefit of making the wing root stall before the wingtips where the ailerons are located.


What should I look for / check during an oil change?

First, a word of caution - Don't attempt your own oil changes on an aircraft unless you're familiar with the process, and have both the tools and skills you'll need to get it done right.
  It's probably a good idea to have your mechanic supervise you on your first oil change, and check your work on the next few until you're sure you've got the hang of  it.

  This isn't an oil-change how-to - just a list of stuff to look at to judge the general health of an engine.

Disclaimers and warnings out of the way, here's what I look for (or ask the shop to check) during an oil change:

Draining that dirty old oil

First, don't forget to grab a sample for oil analysis while you're draining (I'll talk about that a little later!).
Now, while the oil is running out of the drain you're really looking for big chunks of metal coming out with it (or heaven forbid blocking the drain hole) You also want to make sure there is no nasty sludge coming out (that's a car in the video, but the principle is the much same).
Basically what's coming out of the drain should look like oil. It'll be dirty (dark to black, rather than the pretty clear-ish liquid you poured into the engine all those hours ago), but it should still be flowing nicely.

  Obviously chunks of metal here would be bad. If you're noticing them in the drained oil you've got some serious mechanical damage in your engine and you need a mechanic to check it out.

  Sludge generally means you need to talk to your mechanic too - often it means a bunch of low-time oil changes to clean out the gunk from the engine, but if it's severe it could indicate other engine problems that need attention

Checking the Oil Screen

If your engine has an oil suction screen that can be removed and cleaned (as on most Lycoming engines), remove it and inspect it for any pieces of metal, then clean it and reinstall it.

  As with chunks in the drained oil, bits of metal in the screen are often a sign of a serious mechanical problem - if you find any you're going to want to talk to your mechanic.

Inspecting the Oil Filter

As part of every oil change the filter should be cut open and inspected for fine metallic particles in the pleats. There are a few of ways to do this (one is to simply stretch the pleats out under a bright light and look at them, another is to wash the filter in a solvent and strain the used solvent through a coffee filter to see if any particles are left behind).
EAA has a great video on inspecting an oil filter - it's worth the 10 minutes to watch.

  If you find any bits of metal  in the filter you already know what I'm going to say -- you're going to want a mechanic to check things out. A very small amount of metal may not be a serious issue, or it might be the beginnings of an engine on a path to self-destruction.

Run an oil analysis

Some people do an oil analysis every oil change, some people don't ever do one.
Smarter people than me say it's probably a good idea to do them, so I consider it to be cheap insurance and a good window into where those "bits of metal" I keep talking about above might eventually start coming from.
There are plenty of companies that do aviation oil analysis and for an idea on what's in the report check out Blackstone Labs' interactive report explanation page.
There's another EAA video that talks about oil analysis which is worth the 3 minutes to watch too...

  Note that a single oil analysis won't tell you much (unless things are REALLY out of whack) - it's the long term stability or trends that matter here, so if you're going to do an oil analysis be prepared to do them at every oil change from now on...

Do the things that aren't oil-related

An oil change is a good opportunity to do some other regular maintenance - Since the cowling is off anyway why not clean/gap/rotate your spark plugs (which is another mind-numbing task the FARs allow owners with a private pilot certificate to do)?
In fact since the cowling is apart and your engine is naked now's the time to give it a good once over for any loose parts, chafing wires, etc. that might have come up since the last oil change or service that had someone under the cowling.

It's probably also a good opportunity to check all your lights (interior and exterior), and break out the manufacturer's lubrication chart to see if there are any other things that need to be oiled, greased, cleaned, or sprayed.

So what's all this fuss about metal?

You've probably noticed above that I'm really harping on all the ways you can find metal in your oil in this answer.  The simple fact is that all engines wear, and eventually they wear out. That wear shows up as microscopic bits of metal relatively harmlessly suspended in the oil (what the oil analysis picks up), but if that wear suddenly accelerates bigger pieces of metal start getting torn off of the moving parts in your engine, and showing up in other places like the oil filter and screen, letting you know something is wrong with your engine, and hopefully letting you know on the ground rather than in the air.

I don't want to give the wrong impression here though: Not every bit of metal that turns up in an oil filter will be a death sentence for the engine that produced it! In fact brand new engines sometimes produce a few bits of metal during break-in as parts wear in to each other, and they stop after the first oil change or two. The thing to remember is any metal showing up where it shouldn't be during an oil change is definitely something to have checked out by a mechanic.


What is the groundspeed history of an aviation of such as a Boeing plane?

If what you're asking is to see groundspeed history of a certain type of aircraft, you can choose a type here:  aircraft type airborne now

Then follow the links to see its flight track history as shown here: Flight Aware Track History


Can a holder of a G4 Visa legally receive flight training and/or acquire a Private Pilot Licence?

You would need an M-1 (for training at a flight school) or F-1 (for training at a college & some flight training academies) Visa to receive flight training.

More information here.


What is the time before an alarm is given after a fire sensor perceives a fire?

The fire sensor's time to give the alarm is customizable depending upon the fire safety alarm being used. Two widely used types of continuous-loop systems are the thermistor type detectors, such as the Kidde and the Fenwal systems, and the pneumatic pressure detector, such as the Lingberg system. (Lindberg system is also known as Systron-Donner and, more recently, Meggitt Safety Systems.). A typical delay of 10 Seconds is quite common. Here is the Source for your further reading


What's a stepdown fix in a non-precision approach procedure?

From the FAA's Pilot/Controller Glossary:

  STEPDOWN FIX − A fix permitting additional descent within a segment of an instrument approach procedure by identifying a point at
  which a controlling obstacle has been safely overflown.

In other words, a step down fix tells you "you've passed an obstacle, so you can now descend further".


Is it possible to have the laminar flow above $Re=10^7$?

The airfoil always starts with a laminar boundary layer; at some point on the airfoil surface, the boundary layer may transition to turbulent. In a uniform free-stream, two modes of transitions dominate:

Natural transition
Forced transition

a. Natural transition

Natural transition is the transition mechanism that we typically associate with Reynolds number. As flow moves along the airfoil, the local Reynolds number increases and any initial disturbances amplify. When the amplification increases past the maximum threshold that a laminar boundary layer can tolerate, the flow separates locally (laminar separation bubble) and reattaches as turbulent boundary layer.

The following graph (Ref. Drela, Flight Vehicle Aerodynamics) shows the growth of the local Reynolds number ($Re_\theta$) and the instability parameter ($\tilde{N}$) for a flat plate. Once $\tilde{N}$ increases past the critical value ($N_{crit}$), then laminar-turbulent transition occurs. Notice also how the point of transition is affected by the free-stream Reynolds number ($Re_\infty$): the higher the free-stream Reynolds number (which is what your OP is asking), the earlier the natural transition.

Image ref: Drela, Flight Vehicle Aerodynamics

Since the shape of the airfoil affects the pressure distribution, it also affects the boundary layer shape. You can modify the airfoil shape to delay the transition as much as possible in order to minimize skin friction drag. This is the design objective of Natural Laminar Flow (NLF) airfoils. But even on NLF-0215F at a $C_l$ of 0.65, for example, transition occurs at 61% chord on the upper surface, at a free-stream Reynolds number of 5 million.

b. Forced transition

Forced transition occurs when there is irregularity or protuberance on the airfoil surface. This can be due to manufacturing tolerances, contamination, or by design. Contamination can be due to rain, ice-buildup or even collision with insects.

Thus in practice, actual transition would occur much earlier than predicted via natural transition.


What was the forensic process underlying the recent news regarding MH370 debris?

If you bring an NTSB investigator a piece of 2024 sheet aluminum with zinc chromate primer and a urethane topcoat all they can tell you is "It's 2024 sheet aluminum, with some paint on it." - BUT if you bring them a piece of 2024 aluminum riveted to a  structure that looks like this:

and tell them "I found it on an island in the Indian Ocean" they can infer  lot more.

In this particular case they've found some debris, and they know a few things:

The debris was found in an area where it's reasonable it could be part of MH370.
The location isn't conclusive in and of itself, but it's certainly a factor that strongly implies this could be part of the missing aircraft.
The part LOOKS like it came off an airplane.
It's aircraft aluminum, riveted to a skeleton that gives it an airfoil shape. That warrants further investigation by itself (even if we didn't lose an airplane in that area recently it's clear that some part fell off some airplane at some point in time, and investigators generally want to know which airplane had bits falling off).

That leaves us with the question Could this part have come from the airplane we lost?  which is the stage we're at now, and there are many ways to make this determination.

You might get lucky and recover the aircraft ID plate, or a chunk of the tail with the N number.
There's confirmatory testing to be sure it's not a well-perpetrated hoax, but these are pretty definitive identification elements. Unfortunately that's not the case here, so we move on.
If you recover what appears to be a control surface you'll usually find a manufacturer stamp somewhere on the part, or a serial number plate. They'll certainly be inspecting this debris to look for that kind of data tag. (The data tag below is from a Piper control surface but Boeing probably uses similar plates).

If you don't find a data tag maybe there's airline livery on the debris.
This at least lets you know whose plane you've found, but that's not applicable here as the debris in question appears to be painted basic white.
Failing all of that you compare what you've found to manufacturer's drawings of the aircraft you think it came from and see if the dimensions match any parts or sections of that aircraft.

There are other possible steps and confirmatory testing involved (metallurgy, mass spectrometry on the paint, etc.) to determine if it's likely this part came from the aircraft you think it did, but that's getting into the territory where you'd be better off signing up for training courses in accident investigation.


What is the point of having lots of different flaps settings?

1a. On take off, with a light airplane you may select less flaps to reduce the additional drag and save some fuel. Max takeoff flaps are reserved only for short runways and high loads. Fuel savings are very important nowadays.

1b. On approach, less flaps produce less noise and may also allow a higher approach speed (VFE is the maximum flaps extended speed and may be different for different flap settings). Maximum flaps are set only later in the approach when the plane has stabilized at the final approach speed.

1c. The flap setting has an effect on the airplane's pitch angle. A certain flap setting may help to minimize the tailstrike risk. The longer B787-9 has nine settings, while the shorter 787-8 has six.

I learned the Boeing numbers are not true angles either. For example, settings 1 and 5 may only affect the leading edge slats. At higher settings they approximate the actual angles (which are anyway somewhat misleading in the case of today's multi-part Fowler flaps, which move both down and backwards).

https://www.flightglobal.com/news/articles/farnborough-aero-secrets-of-boeings-new-dreamliner-401784/

http://www.boeing.com/commercial/aeromagazine/articles/qtr_4_08/pdfs/AERO_Q408_article05.pdf


Can large airliners be operated without ground support?

There's a good example which is the A319 LR which flies scientists down to Antartica. They utilize (very) little ground support, except for the stairs (they seem to have inbuilt ones in the front as well, although these are not used on site) and the trucks to offload the cargo. APU provides the power on the ground, and the aircraft has sufficient juice in the tanks to make the round trip without refuelling.

(source: smh.com.au)

You can read up on it here. She does weekly flights from Hobart to Wilkins aerodrome in Summer. 4 hours and 30 minutes of flying right into the uninhabited :)


Do horizontal stabilizers on airliners have varying angle of incidence in the span-wise direction (washout or negative twist)?

There is little to be gained by twisting the horizontal stabilizer in terms of efficiency.

First, the span of a typical horizontal tail is much smaller than the wing (see A320 illustration below for example). Apart from the small outboard portions, the downwash behind most of the wing is fairly constant. This makes the simplification of a uniform downwash on horizontal tail valid.

Second, the lift and drag contribution of the horizontal tail on the overall aircraft at cruise, during which aerodynamic efficiency is paramount, is fairly small. Even assuming a large static margin of 30% (smaller static margin equates to smaller tail contribution), improving the tail span efficiency from 0.8 (typical) to 1 (elliptical) only reduced the total induced drag by half a drag count using some typical aircraft parameters.

These are the parameters I used if you want to verify yourself:

$C_{L_{trim}} = 0.4$
$\alpha_{wb} = 4.8$
$\frac{\partial\epsilon}{\partial\alpha} = 0.43$
$\epsilon_0 = 2.8$
$C_{m_{ac_{wb}}} = -0.12$
$\overline{V_H} = 0.6$
$a_t = 4$
$\frac{S_t}{S} = 0.25$
$h_{n_{wb}} = 0.22$
$C_{L_{0_{wb}}} = 0.4$
$e_{wb} = 0.85$
$e_t = 0.8$ (typical, compared to fully elliptical of unity)
$A_{wb} = 8$
$A_t = 5$


How does a normal aircraft exhaust nozzle (the base model) generates a lot noise?

Those "chevrons" are vanes that modify the air and exhaust flow (those are turbo-fan- engines in those two images) and create air vortexes that quiet the noise but also create some drag. They are engineered to maximize noise reduction with a minimum of drag.

(popularmechanics.com) Quiet engine air brake.

There is a company called ATA Engineering that is now developing a product called a "quiet engine air brake" that create more drag but is stowable during cruise flight. The R&D work was commissioned by NASA.  They use the same vortex flow concept. Because most of the noise from airliners during approach comes from things that stick out in the airflow, like flaps and spoilers, landing gear doors, etc., this allows the aircraft designer to generate drag to slow down the aircraft while at the same time reducing noise.

Its a pretty nifty concept, if you ask me. Over time I think we will see the design of exhaust systems on jet engines become stranger and stranger! 8)


In a nutshell, the aircraft had enough energy to climb without exceeding its stall AOA.  The expert stated the plane should have "immediately stalled", but the incredible amounts of mass and velocity associated with a plane that large demand a closer analysis to the physics.
When the nose breaks free, lift and weight are out of balance. When an aerobatic plane applies full up elevator, lift and weight are out of balance.
There are two "bookends" to what happens next.  The upper is G limits are exceeded and the wings tear off.  The lower is stall AOA is exceeded.  In between is an attempted loop.
Apparently, the rugged 747 had enough velocity to climb, sans nose, for a while.  Really a testament to its design.
Even after stalling, its momentum would have carried still higher, so it is difficult to determine when exactly it stalled.
Factors which determine "stallability" include wing loading, wing configuration, and tail volume. A very high wing loading with a very thin wing (as seen on many supersonic fighter aircraft) will stall much faster.  Deploying slats and partial flaps greatly helps a plane tolerate higher angles of attack.  Large tail volume also increasingly inhibits higher and higher AOA.
Essentially, it is a race between change in flight path and change in AOA within the G limits of the aircraft.


Why were the ailerons of the Fokker Dr. I (Red Baron) located on the top wing?

The top wing is always the most efficient, as the lower ones suffer reduced lift due to interference from the air flowing beneath the one above. Ailerons will therefore be most effective on the top wing. If they do the job OK then there is no need for any more.
Reasons for adding more below include:

The upper set are likely to be (or found to be) inadequate.
Making both wings identical to simplify production.

The outermost part of the wing is also the most effective position. So if a short aileron is inadequate then the designer faces a choice of two less efficient additions, to widen it inboard or to place another one underneath. Another issue is which brings more drag or weight penalties, a small aileron which must be sharply deflected or a larger aileron which needs more subtle movement.

Such decisions were often based on the designer's personal experience and preference rather than firm knowledge. They would stick with what they knew rather than take arbitrary risks. Historically the Sopwith came first, following their earlier successful biplanes such as the 1 1/2 Strutter and Pup in having identical upper and lower wings with short ailerons. Fokker responded in his own equally successful house style, with a single aileron on the top wing only, having a long span and outboard balance tab.

Which design is better depends on how you define "better" - less weight, less drag during turns, less cost, optimal distribution of aerodynamic forces through the structure? The basic technical tradeoff is between a single large and strong upper aileron vs. several smaller and lightly-built lower ones. I doubt if anybody has ever crunched realistic numbers.


Fine for operating not single-pilot certified jet with one pilot

According to FAA Order 2150-3B in Appendix B (penalty guidelines) the recommended penalty for "Failure to comply with operating limitation" is a 30 to 90 day license suspension. That is what I would expect would happen in real life if the FAA investigator thought that the pilot had no good reason for operating without a co-pilot. If there was some good reason and the pilot's record was clean otherwise, they might change it to a warning.

I disagree with the other answers that claim it would be quickly reported. Unless an informed passenger noticed it and reported it, I doubt it would get reported by anyone else. The fuel guys have no idea what operating limitations are or who is operating the plane. In many cases, crew and passengers are long gone by the time the fuel truck pulls up. For the fuel truck to deal with just one guy or to fuel an unoccupied aircraft is commonplace. For all the fuel truck guy knows, there could be crew inside the aircraft doing stuff. He has absolutely no idea what the operating situation of the aircraft is.


What make and model are these two small propeller planes?

They're a couple of Cessna 210s. I can't tell from just looking whether they're Turbo 210s or normally aspirated. You can tell they're not 172s or 182s because they lack wing struts. Cessna 177s also do not have wing struts, but their front windshields are considerably different.


How does a failed turn and slip indicator behave if the gyro isn't spinning at all?

It depends on how it fails, there are lots of possibilities on what caused it to stop spinning and they can all lead to different outcomes. In this instance it just kind of bobbed around as if it were free floating. But if something is jamming the mechanics it may simply stop moving altogether so it really just depends on how it fails.


How is RVSM approval obtained for a properly equipped airplane?

You can find lots of information on RVSM at this FAA website.

From This MSWord document found on that site:

  Operational Approval or Authorization.   The FSDO or CMO will grant operational approval or authorize the operator to conduct RVSM operations by issuing Operations Specifications paragraphs B046 and D092 to air carriers or issuing a Letter of Authorization (LOA) to general aviation operators, as appropriate.  Individual operator RVSM-compliant airframes are listed in D092 or on the LOA, as appropriate.  The FSDO or CMO will take this action after it has determined that the operator’s aircraft are RVSM compliant; it has approved the operator’s RVSM maintenance program; a CMO has approved or a FSDO has accepted the operations programs and the office has accepted the operator’s plan for participation in the monitoring program.

This Excel spreadsheet lists points of contact at various FSDOs.


Do pilots have the ability to bypass customs when utilizing jump-seat privileges?

Just to put down as an answer what has been pretty well covered in the comments...

All pilots, jump-seating or not, will still clear customs.  They may have a separate line, but there will still be the normal record of their entry.

Beyond that, the airline absolutely knows who they let on the jumpseat for each flight -- so "no record" won't really happen in any event.


Those are METAR flags. From the G1000 manual:

  METAR flags and their associated text are displayed on the Active Flight Plan Page on the MFD. METAR flags appears next to waypoints in the flight plan with an associated METAR. A solid light blue METAR flag indicates the METAR observations are available for a specific waypoint; a hollow light blue METAR flag indicates an off-route METAR near the waypoint is available. When off-route METAR text is displayed, the system provides additional information as to the origin, distance, and direction of the report in relation to the selected flight plan waypoint.

The ones you have are the 'hollow light blue'.


What does it mean for a ATC to say a flight's callsign followed by "in disguise"?

The controller was probably referring to an airplane in a different livery but operating under the American call sign.

A likely example is US Airways. After the two companies merged, from October 2015 all flights were operated under the American call sign, but re-painting the US Airways planes took at least a couple years.

This is not standard phraseology but "Kennedy Steve" is known for trying to inject some humor into his work. See also: What does Top 1% mentioned by ATC refer to?


How does a remote pilot land a fixed-wing UAV?

There's a wide range to techniques. In the hobby world, it's much like landing a full-size plane under VFR, you fly a circuit and glide path. Flaps, side-slip, cross-wind, retractable undercarriage, etc can all be used. The difference is that you have to judge the runway centre-line from some distance off to one side, which requires a lot of skill and practice. Also wind-sheer, gusts and unevenness in the runway surface are magnified by the scale. Fortunately the light weight allows models to handle landings that would wreak the full-size.

At the other end of the spectrum, large UAVs can land autonomously, similar to an airliner auto-land, using all the electronic aids of a modern runway.

In the middle are small UAVs, operated away from a runway. Small, slow UAVs can just circle a GPS position with the motor off, gliding until they reach the ground. Faster UAVs fly into nets or a vertical arrestor wire - again autonomously.

For completeness, I should mention that there is a specific branch of model competition for landing on a simulated carrier deck, with an arrestor wire.


Can the Safety Pilot log an approach if acting as PIC?

No, a pilot may not log an approach that he or she did not perform as the sole manipulator of the controls.

According to the FAA, in order for a pilot to have performed a loggable approach, that pilot must have performed that approach as the sole manipulator of the controls. A required SIC may not log an approach that the PIC flew, nor may a PIC log an approach that was flown by the SIC. Likewise, a safety pilot, though he or she may be a required crewmember for a flight, may not log an approach that was performed by the other pilot.

This hinges on the FAA considering the word "performed" in 14 CFR 61.57 (c) to mean fly the approach as the sole manipulator of the controls. See the FAA's leter of interpretation Carpenter (1999) which addresses this issue:

  As the SIC you have not "performed" the approach as contemplated by FAR 61.57(c) because you were not the sole manipulator of the controls during the approach.


What is this strange cutout in Class B of Kansas City International Airport?

There are in fact two airports in the cutout:

An unmarked field (A in top map) just east of Platte City (see below) that corresponds to the NW limit of the cutout. Note that this edge of the cutout appears to parallel the main runway at MCI.

The private Elton Field (B in top map). In the image below, field is boxed in red and runway in blue.

And there's also the VFR reporting point over north Platte City


How do hot air balloons get started (without burning the fabric)?

The balloon is spread out on the ground and rigged to the basket.
Then, a cold air blower is used to do the initial inflation, blowing air into the envelope through the bottom aperture. This gets the balloon about 75% inflated, but still horizontal.
Lastly, the burners are lit to heat the cold air already inside the canopy, expanding it and raising the balloon to vertical and full inflation.

You can find any number of videos on YouTube that show the process. Here's one:


What materials form the structural elements of the Boeing 737?

Most of the Boeing 737's structure is made in aluminium. Composites are used for smaller parts like the ailerons, the wing-to-body fairings and the tail cone.
It looks like all of the control surfaces are composites.

Medium capacity airliner series. Aluminium alloy wing structure, upper skin and tail plane, with graphite composite elevator, rudder and ailerons. Glass or carbon fibre-reinforced plastic nosecone, fairings and fin tip. Single or split-scimitar double winglets.

more composite components:
The nosecone, wing and fuselage fairings, fin tips, the fairings of the flap actuators and other non-stressed components are constructed from glass and carbon fibre reinforced plastics (GFRP and CFRP). The rear of the engine nacelles are constructed of graphite, Kevlar and glass fibre composites.
In February 2000 an advanced carbon graphite winglet developed by Boeing became available as an option on the 737-800.


Why does the spool speed increase with altitude for a turbofan engine (single spool & double spool)?

As you note - as altitude increases, air density decreases.

The work done by the compressor stages therefore also decreases at any given rotational speed. If we assume constant power applied to the compressor stages (not entirely correctly) then the speed will increase until the work done matches the power input.

The overall work done by the engine will still decrease, due to decreased combustion, but the spool speed is going to increase a certain amount.


What are these openings around the Comet's engine intakes?

Short answer

Top (Comet 1)

1: Air conditioning -- 2/3: Engine cooling -- 4: Likely fuel venting -- 5/6: Engine cooling

Bottom (Comet 4)

1: Engines cooling

Details

The De Havilland 106 (DH 106) "Comet" was a UK airliner, the first commercial one with jet engines, introduced in 1952 under the colors of BOAC. The last aircraft was retired in 1997. The Comet 1 is known as a great engineering achievement, but also for its initial series of catastrophic failures. These accidents led to the understanding of metal fatigue caused by decompression cycles (after a famous structural test) and the generalized use of openings with rounded corners by all airliners. Beside technical achievements, the aircraft and other of the same era are also remembered for their beautiful shapes.

Cutaway, showing how engines are buried in the wings:

Source

The Comet 1 was an interim version until the more powerful Rolls-Royce Avron engine development was complete. The Comet 1 engines were Halford H.2 Ghost aka De Havilland Ghost 50 Mk1 or simply Ghost.

De Havilland Comet 1XB - From photo by Ruairidh MacVeigh, Flickr

From left to right:

I cannot definitely identify the smaller hole near the fuselage, it might be the ram air intake used for fuel venting. A system which was used quite frequently for emergency landing until the engine bearing overheat problem had been fixed. In some description this hole is completely on the right of the outboard engine.
Ram air intake below inboard engine intake is for cabin air conditioning. Ram air goes to the heat exchanger which cools cabin air circulated in the heat exchanger. The Comet was one of the first aircraft to use bleed air from the compressor and the turbine to provide comfortable cabin pressure at high altitude.
Ram air intakes on each side of the outer engine are used for engine cooling.

On the top of the wing, there are scoops, more visible in the Comet 4 picture below.

De Havilland Comet 4 -- From photo by edk7, Flickr

The Comet 4 engines were Rolls-Royce Avon AJ.65 with twice the thrust of Halford H.2 Ghost.

The engine cooling intake between the two engines has been enlarged and the second one (outboard) removed.
The four air scoops over the wings are additional intake for engine (e.g. to ventilate fuel vapors) and accessory cooling (e.g. for alternator).

Additional information:

DH 106 Comet 1XB at Canada Aviation and Space Museum
Airliner Tech Series 07 - De Havilland Comet
De Havilland 106 Comet presentation


Why aren't 757 scimitar winglets flush with the ailerons?

No prior knowledge of this design choice, but the design direction seems pretty clear here.
The original design reduces load towards the wingtip for efficiency. The textbook spanwise loading for maximum efficiency is the elliptical loading, however when tip devices, as in the original design, are employed, the tip load should not be zero. With a tip device, it is possible to maintain a pressure surface <> suction surface pressure differential. Therefore at the wing tip (just before the tip device), there is still significant lift being generated.
The scimitar winglet design that you have shown must be more efficient than the original design (otherwise why else would they retrofit it?), which therefore means that it can isolate a greater pressure differential from the outboard pressure surface to the outboard suction surface. Because this tip device is designed for a greater pressure <> suction surface pressure differential, but the original design was designed for a lesser differential, more load can now be generated outboard for the same drag penalty. As can be seen in the picture, the chord extension is at an incline to the trailing edge. This gives more camber to the outboard section of the wing, and therefore more lift on this portion and nearby.
Of course, the designer could have just tilted the trailing edge down for the same chord length as the inboard section of the wing. This would create the increase in outboard wing loading, but due to the abrupt change in camber from the aileron to the cambered outboard section, there would be a significant vortex formed. To decrease the effect of the vortex formation (it will still generate, but will be weaker), the surface follows the original design, but is extended with significantly more camber after the original wings trailing edge. The trailing edge camber (extra downwards curve) is very apparent in the first and second images. This device therefore allows an increase in outboard load without having to affect the inboard section geometry.
Obviously just creating more lift outboard, and therefore more overall lift, doesn't necessarily help an aircraft. During cruise, we only need sufficient lift to overcome the weight force. Because the new tip device creates more lift for the same amount of drag at a particular incidence, and because the drag polar is relatively unaffected, this means that we can create the same lift at a slightly different incidence angle, and therefore can cruise at a lower drag penalty.


Why did the altimeter in an F-16 jump suddenly as it passed through Mach 1?

The altimeter doesn't measure static air pressure, it measures actual air pressure. So, to get an accurate reading of the static air pressure, the static port has to be carefully placed so that the ram air pressure (caused by the forward motion of the plane ramming into the air) and the slipstream pressure (caused by air rushing past the static port opening) cancel each other out (or nearly so).
So, Destin is correct: The actual air pressure after the shockwave is lower, causing a jump in the displayed altitude.


What can be expected in an airline interview?

The Delta Interview Process

I interviewed about three months ago at one of the several regionals that uses the Delta interview process.  It goes a little something like this:

Company Introduction

You arrive in the morning, somebody meets you, shakes your hand, and you usually hear a little speech or presentation about the company.  If your prospective employer uses AirlineApps, they'll have you verify that all of your information is still current, and gather your paperwork.  Then, it's off to Computer-Based Testing!

Computer Based Testing

CBT in the Delta interview is divided into three segments: cognitive, personality, and job knowledge.

Cognitive

The cognitive test is essentially reflex and memory games, of the sort you'd see on lumosity.com.  Some examples:

You are shown a horizontal line, with a pointer in the center.  The pointer will move from side to side at random along the line.  It is your task to counteract this random movement using the arrow keys to keep the pointer as close as possible to the center of the line.

Measures:  Focus and concentration

You are shown two words, such as DF3ET and DEFET.  It is your task to determine as quickly as possible if they are the same or different, and to click the appropriate same or different button on screen.

Measures: Attention to detail?

You are shown a table of six numerals paired with six simple shapes.  This table remains on screen.  You are shown a series of these shapes.  Decode, as quickly as possible, the series of shapes into the numerals they represent.

Measures:  Matching, working memory.

You are shown a graphic of a man holding a flag in one hand.  The man is either facing towards or away from you.  The man is either right-side-up or upside-down.  No matter his orientation, determine as quickly as possible whether the man is holding the flag in his right or left hand.

Measures:  Spatial awareness

A line wavers back and forth in a white area between two red zones in a random fashion.  When the space bar is pressed, the line will instantly be reset to the center of the white area.  It is your task to press the space bar as quickly as possible after the red line leaves the white area, but not before.

Measures:  Attention, reflexes.

You are shown the horizontal line with the pointer as well as the white area with the line.  It is your task to keep the pointer centered with the arrow keys while simultaneously using the space bar to reset the line when and only when it moves outside the white area.

Measures:  Division of attention, reflexes

You are shown a series of six simple shapes.  It is your task to recall the six numerals that were paired with these shapes from earlier in the test.

Measures:  Recall

A series of simple mental math problems is presented.  "Which would you rather have, 1/4th of \$200, 1/5th of \$300, or 1/3 of \$250?"

Measures:  Mental math skills

You are shown four rectangles.  One has a thin border, one contains a filled in arrow pointing left, one has a shaded arrow pointing right, one has a thick border.  There are multiple exercises to the test.  During some portions of the test, you are asked to click the rectangle whose arrow matches the direction of the one you are shown.  In others, you are asked to click the one whose shading matches.  In others, the border.  These criteria change at random.  Your task is to match the proper criteria as quickly and accurately as possible.

Measures:  Attention to detail, adaptation to changing conditions.

Listen through your headphones.  A series of notes will be played.  Then a second series of notes will be played.  Touch SAME or DIFFERENT.

Measures:  Whether you were good at Simon as a kid.

Personality

You are shown approximately 130 statements, one at a time.  Your task is to determine how much you agree or disagree with them on the following scale:

Strongly Agree
Agree
Neither agree nor disagree
Disagree
Strongly disagree

The statements are similar to:

I think the new morality is no morality at all.
Over the years, I have done some pretty stupid things.
I have literally jumped for joy.
I have a hard time resisting temptation.

Job Knowledge

This test measures technical knowledge.  It contains questions concerning:

Turbine engine theory
Descent planning
DME arc degree-to-nautical-mile calculations
Stall recovery procedures
Mach-to-TAS conversion
Transport category systems knowledge
Emergency procedures
Aerodynamics
and more!

Thank Wright that's out of the way, next up is lunch!

Then comes the interviews:

Tell me about a scary time in the cockpit
What would you do if you were an FO and the captain arrived smelling like alcohol?
Which is colder, -40 C or -40 F?
I see that you failed a checkride, tell me about it.

And so on.

The conclusion

You made it!  Someone comes out and shakes your hand.  Now it's time to fill out PRIA paperwork and pee in a cup.  If all goes well, you're given a conditional offer of employment!  Congrats!  You're a regional FO!

(If you can make it through training)


Why do some military aircraft use variable-sweep wings?

By sweeping wing backwards, you essentially make the air 'see' another airfoil.
Look at these two diagrams:

When the air meets the wing, it travels along $V$. This 'seen' airfoil is a lot thinner than $V1$ (which is perpendicular to the leading edge).  As the aircraft experiences less pressure, the aircraft experiences less drag. However, this also reduces the velocity of the air. This is good if you're looking to delay things such as shockwaves as the air goes supersonic, since spreading the force out more delays this effect and the flow separation which comes with it.

Unfortunately, for all the advantages, It would have a very high landing speed. So the wings are swept forward, the aircraft has a more effective aerofoil for lower speeds, and the minimum airspeed decreases correspondingly. There is now more drag, but also more lift which you need for the slower speed.

Wikipedia puts this nicely in not all too-complex terms:

If we were to begin to slide the wing sideways (spanwise), the sideways motion of the wing relative to the air would be added to the previously perpendicular airflow, resulting in an airflow over the wing at an angle to the leading edge. This angle results in airflow traveling a greater distance from leading edge to trailing edge, and thus the air pressure is distributed over a greater distance (and consequently lessened at any particular point on the surface).
This scenario is identical to the airflow experienced by a swept wing as it travels through the air. The airflow over a swept wing encounters the wing at an angle. That angle can be broken down into two vectors, one perpendicular to the wing, and one parallel to the wing. The flow parallel to the wing has no effect on it, and since the perpendicular vector is shorter (meaning slower) than the actual airflow, it consequently exerts less pressure on the wing. In other words, the wing experiences airflow that is slower - and at lower pressures - than the actual speed of the aircraft. One of the factors that must be taken into account when designing a high-speed wing is compressibility, which is the effect that acts upon a wing as it approaches and passes through the speed of sound. The significant negative effects of compressibility made it a prime issue with aeronautical engineers. Sweep theory helps mitigate the effects of compressibility in transonic and supersonic aircraft because of the reduced pressures. This allows the mach number of an aircraft to be higher than that actually experienced by the wing.

Is there a performance gain? Depends on your definition:
Having fixed swept wings would imply that:

The landing speed might be unacceptably high, and with that, long runways would be required.
You could design a fast and light aircraft.Take the F104 Starfighter for example, which had thin, short wings for the same effect but couldn't move them, and was extremely dangerous at slow speeds.

Having variable wings:

The F14 was intended for carrier operations, where you would want a
slow landing speed. Making an aircraft go that fast would probably have been impossible otherwise. It was also designed for long range operations, adding weight of fuel.
Adds weight and mechanical complexity to the airframe, which increases maintenance cost and fuel burn.

If I understand it correctly, today aircraft today rely more on system such as high-lift devices like for instance slats and flaps.


Is it hard to hover a coaxial rotor helicopter?

The difficulty in hovering a helicopter lies in the fact that hover is unstable. Any tiny divergence will increase over time, so you have to keep adjusting the controls all the time. And this does not differ between single rotor with anti-torque and dual-rotor.


How many variations are there of the Avro Lancaster?

There were twenty-three different variants, according to Wikipedia:

British-built variants (13)

Ten combat variants (B.I, B.I Special, B.I (FE), B.II, B.III, B.III Special, B.IV [Lincoln B 1], B.V [Lincoln B 2], B.VI, B.VII)
Two reconnaissance variants (PR.I, GR.3/MR.3)
One SAR variant (ASR.III/ASR.3)

Canadian-built variants (10)

Two combat variants (B.X [later 10S/10U], B.XV [Lincoln XV])
One dual-purpose combat/reconnaissance variant (10BR)
Three dedicated reconnaissance variants (10AR, 10MR/10MP, 10P)
One SAR variant (10S&R)
One trainer variant (10N)
One drone-mothership variant (10DC)
One jet-engine testbed variant (10O)

Plus the Avro Lancastrian, a commercial airliner derived from the Lancaster B.X (the first few Lancastrians were direct conversions of existing B.Xes, although later batches were built as airliners from the start).


How does maneuvering affect radar detection of stealth aircraft?

RCS depends on the aspect presented to the radar source, so an aircraft can offer a low radar return from one angle and a large one from another. How much the RCS changes by depends on how much work went into optimizing the airframe from all sides.

Since reduced RCS tends to be at odds with aerodynamic performance, not all sides of an aircraft will be optimized, which will affect mission planning: with proper intel, an aircraft can plan its ingress and egress vectors in such a way to present its "best profile" to any hostile radar installations.

As an example, compare the F-22 with the Su-57. Both airframes have had some low observability built into them, but to different degrees. In particular, the rear aspect of the Su-57 is pretty conventional, suggesting that for whichever reason (funding, time limits, serial production costs, contract requirements, etc) it was deemed acceptable to have a larger RCS from behind.


Is it possible to define a "good landing" in terms of pitch angle and vertical speed?

A "good" landing with a 737NG as described in the Flight Crew Training Manual (FCTM) is flown with a pitch that has increased by 2 to 3 degrees during the flare. The resulting vertical speed is not specified, but will only depend on the airspeed at a given pitch increase. Remember, that a good landing requires a stabilized approach first, so you should cross the runway threshold at Vref + wind correction and at the correct height (usually 50 ft for typical glideslope).

Initiate the flare when the
main gear is approximately 20 feet above the runway by increasing pitch attitude
approximately 2° - 3°. This slows the rate of descent.
After the flare is initiated, smoothly retard the thrust levers to idle, and make small
pitch attitude adjustments to maintain the desired descent rate to the runway.
Ideally, main gear touchdown should occur simultaneously with thrust levers
reaching idle. [...]

Typically, the pitch attitude increases slightly during the actual landing, but avoid
over-rotating. Do not increase the pitch attitude after touchdown; this could lead
to a tail strike.
Shifting the visual sighting point down the runway assists in controlling the pitch
attitude during the flare. A smooth thrust reduction to idle also assists in
controlling the natural nose down pitch change associated with thrust reduction.
Hold sufficient back pressure on the control column to keep the pitch attitude
constant.
Avoid rapid control column movements during the flare. If the flare is too abrupt
and thrust is excessive near touchdown, the airplane tends to float in ground effect.
Do not allow the airplane to float; fly the airplane onto the runway. Do not extend
the flare by increasing pitch attitude in an attempt to achieve a perfectly smooth
touchdown. Do not attempt to hold the nose wheels off the runway.

(Boeing 737NG FCTM 6.10 - Landing, emphasis mine)
Typical touchdown vertical speeds are then between 60 and 180 ft/min as explained in this answer.


Which country started the tradition of naming aircraft?

I think the answer has to be that it has always been a tradition.

Since time immemorial - in the most ancient of mythologies and legends, across a very wide range of cultures (in fact I'm not aware of a culture that didn't name water-going vessels - boats of all sizes have been given names.

I don't think it's possible to say which country, or even which culture, started the practice of naming boats.

Many if not most of the traditions, names, roles and structures in aviation were inherited from navigation (including the term navigation of course).

Aviation, in many senses, is simply navigation translated to the sky.
Given this, it would be pretty remarkable if it hadn't always been a tradition to bestow names upon vessels in aviation too.

The Wright brothers' first powered aircraft was named (Flyer, I guess they were too busy pioneering to expend much energy on naming), but really,  it goes back longer than that, to navigation.

What I think is interesting is that now not all aircraft are named, whereas just about every boat that can be painted on still has a name painted on it.


As the comments have explained, "airside inspection" is tasked with addressing issues "airside," which means pretty much everything inside the airport perimeter, and outside of the terminals.

Just about anything airside will affect the safety of aircraft operating at the airport. For this reason, there are generally many regulations and rules that apply to operations here. Airside inspection involves making sure all of these rules and regulations are followed. This can be anything from addressing security issues to removing FOD (foreign object debris) and ensuring markings and signage are in working order.

Since they are responsible for managing activity on the airport apron, they absolutely have the authority to stop anyone that is in the wrong place at the wrong time. Although there may not have been any apparent issue, there could be regulations or dangers that not everyone is aware of. If the flight crew sends passengers out onto the apron when they shouldn't, this is an issue that the airside employees would want to address.

There are various descriptions available for positions that involved airside inspection, including some of the duties involved.

  Maintains safety and security on airport premises; ensures TSR 1542 compliance; patrols,inspects, searches and escorts as necessary; conducts identification checks and permits access only to authorized individuals; provides security training as necessary.
  Patrols and inspects airport operational areas for potential hazards; ensures compliance with FAR 139 and other federal and local rules; monitors and controls vehicle traffic on taxiways and runways; patrols all airport facilities, airside and landside.
  Monitors and controls vehicular traffic on taxiways and runways and public roadways and parking lots; checks for proper ID on vehicles and personnel entering the Airport Air Operations Areas (AOA).
  Ensuring compliance with all safety/security regulations and standards within our activities and ground handling operations.
  The management of a safe and efficient airside operation by carrying out Airside Inspection Audits and Flight Turnaround Audits.


Is the "effective wing span" reduced in a turn?

Your understanding is correct.
"reduced effective wing span" is just an analogy to help some people understand the concept of lift in a turn. The Total Lift is not reduced, it is just applied in a different vector in relation to gravity. The vertical lift component (in relation to gravity) is reduced and you can then imagine that the effective wingspan is also reduced by the same amount.
Banked turn (from Wikipedia)


What is the difference between BHP (brake horsepower) and HP (horsepower)?

For machinery that involves power transmission via shafts and gears, they are the same- and the actual term is brake (not "break") horsepower, because the apparatus used to measure the horsepower output of a machine is called a brake dynamometer.

For turbomachinery like jet engines where thrust is generated by movement of air, the concept of brake horsepower can't be applied- except in those cases where the turbine drives a propeller on a shaft. In these cases, the turbine's output shaft can be attached to a dynamometer and its horsepower output measured- and the result is quoted as shaft horsepower.


Dimensional analysis with wingspan length?

In page 38 of the book you're quoting, the derivation goes on replacing $c^2$ with $S$,   the planform area of the wing, implicitly introducing the wingspan...


What is the purpose of a walled area in the vicinity of Heathrow Airport?

It allows them to do a run-up test of the engines without blowing debris at other parked aircraft, people, or things on the ground.

[Credit to Ralph J]
The walls have a structure that allows the noise of engine run-ups to be absorbed as well. Engine run-ups, especially multi-engine run ups, can be very loud.

You can read more about IAC-Acoustics ground run-up enclosures here.


Can a safety pilot acting as PIC also log cross country time?

The safety pilot cannot log cross-country time.

The FAA has issued a Legal Interpretation (Gebhart) that clarifies the FAR.

  Section 61.65(d) contemplates that only the pilot conducting the
  entire flight, including takeoff, landing, and en route flight, as a
  required flight crewmember may log cross-country flight time. Because
  a safety pilot does not conduct the entire flight, a person acting as
  a safety pilot for a portion of the flight may not log any
  cross-country flight time for the flight.


Identification of this control panel for a four-engine plane

This is almost definitely the cockpit of a Short Stirling of unknown mark, a 4-engine British heavy bomber from World War II.

The RAF Museum's website has an (admittedly low-resolution) photo that matches quite closely, as does this history website. Here's my thought process:

the placards (not just the photo's labels) are in english, so it's likely either Commonwealth or American-built
the Stirling power quadrant is a match (2 levels of 4 levers each; it's a 4-engine bomber)
engine instruments directly above throttles
the engines have boost gauges; the Bristol Hercules engine of the Stirling was supercharged
odd-shaped cutout on the right side (just above the marked Air Speed Indicator in your photo)
my second link has a photo with a matching CAUTION JETTISON CONTAINERS BEFORE BOMBS placard on the right side
the Lorenz system was used in British (and German) aircraft during WW2, but I can't seem to find any US bombers that used it.
it has a retractable undercarriage; Short's Sunderland flying boat has a lot of the panel in common, but it was wider and didn't have the goofy notch on the right side, and it obviously had no landing gear.

In short, I'm pretty confident this is a Stirling.

Other aircraft I looked up and discarded as not a match:

Avro Lancaster
Avro Shackleton
Boeing B-17
Consolidated B-24
Handley-Page Halifax
Short Sunderland
Avro Vulcan (similar throttle quadrant, otherwise way off)


What is the reason behind the colors used for different flight categories?

VFR and IFR existed first. LIFR and MVFR were added later. I don't have a source on why magenta was specifically chosen, but red couldn't be used for LIFR because it was already used for IFR and in aviation we like to avoid obsolescence whenever possible.

I haven't been able to dig up exact timeframes for the implementation of IFR (since VFR was the default.) Although the terms VFR and IFR appear in the history of the FAA in the 50's, some references such as FAA's historical perspective cite the piedmont mid-air of 1967 as the source of the modern culture surrounding ATC including IFR rule enforcement.

For more reading on how flight rules came to exist in the US, I recommend an article on gizmodo.


What's the advantage of the F4U Corsair's gull wing design?

The wing shape in the F4U Corsair is called the inverted gull wing. The main reasons for use of this is the large propeller used in the aircraft.

The Corsair design was in response to the US Navy RFP (Request for Proposal) in 1938, which mandated the following things:

It should have maximum attainable speed
The stall speed should be 70 mph
Minimum range of 1000 miles
Bombs should be carried under the wing (this was supposed to be dropped on aircraft formations from above, which didn't work out)

In order to achieve this, the Vought engineers used the largest available engine, the Prat and Whitney R2800 Double Wasp radial engine (this was done as the Navy, in a change of heart, vowed to consider designs with liquid-cooled engines, in contradiction with a policy settled in 1927 that required air-cooled engines for shipboard aircraft). Also, the wing area of F4U was the largest naval aircraft of its time.

During design, the oil cooler and supercharger inlets were moved to wing leading edges. In order to extract power from the engine, a large (~4m dia) propeller was chosen. This large propeller caused problems with ground clearance, which necessitated an increase in the landing gear length.

The Vought team overcame this by choosing an inverted gull wing, which starts out with a strong anhedral, and then curved upwards to strong dihedral, with landing gear at the lowest point in the bend.

"F4U-Corsair OE-EAS OTT 2013 04 main landing gear" by Julian Herzog. Licensed under CC BY 4.0 via Commons.

The main advantages of this configuration are,

Shortened landing gear
Elimination of the need for wing fillets, and reducing drag as the wing and fuselage were perpendicular.
Simplified wing folding (the wings were folded at the lowest point), with the folded wings nearly at the height of the propellers. This enabled simple automatic mechanism for folding/unfolding, unlike the F6F Sto-wing which was manual, as the hydraulic mechanism added too much weight.

Source: www.airport-data.com

The main disadvantages were:

The design added weight compared to straight wing.
(To some people) It was ugly

This design has been used in a number of other aircraft too, mostly to reduce the length of the landing gear and carry large external stores, the most famous being the Junkers Ju-87 Stuka.

"Bundesarchiv Bild 101I-646-5184-26, Russland, Flugzeug Junkers Ju 87 edit 1". Licensed under CC BY-SA 3.0 de via Commons.

The inverted gull wings were also used in Fairey Gannet, an ASW aircraft of Royal Navy.

Source: www.maritimequest.com

This was also used in some twin engined aircraft like the Caproni Ca.331.

Source: flickr.com

Note that in some books, this design is called the gull wing instead of inverted gull wing.


How can I convert an FAA pilot's certificate to a Canadian one?

Transport Canada has all the information here for each FAA license type (and type ratings); the necessary forms and contacts are here. These are the basic requirements for a private pilot, for example:

  6.1 Conditions for Conversion - Private Pilot – Aeroplane.

  (1) Must hold an FAA Private airman certificate with airplane category and
  class rating(s).

  (1) Age: Must be at least 17 years of age.
  (2)
  Medical fitness: Must hold either a Category 1 or Category 3 TCCA
  medical.
  (3) Knowledge: Must pass the Conversion - Private Pilot
  Licence – Aeroplane, (FAAPA) written examination on air laws and
  communications. Must be able to read, write and communicate in English
  or French.
  (4) Experience: Must provide proof of a minimum of 45
  hours pilot flight time.
  (5) Skill: No additional practical flight
  test is required.


Why are all engines identical in typical commercial airplanes?

Engines don't fail, on average. And if they do, it's a very low probability that two engines will fail at the same time.

Modern jet engines are extremely reliable, with failure rates on the order of 0.01/1000hrs. And if you do have a failure, you have redundancy, as you have two (or more) engines. A plane can stay aloft and land with a single engine.

It would add a lot of complexity and maintenance costs, with no real benefits.

If the failure is external, such as water in the fuel, lack of fuel, or ash ingestion, two different engines are unlikely to help, because all jet engines works in a very similar fashion. The external problem would simply affect both, maybe at slightly different rates, but ultimately shutting them down anyway.

So it adds cost and complexity, without providing any real improvement. Jet liners simply does not crash because all engines stops due to internal problems.

The one case where it would help is if there's a design fault with the engine, e.g. manifesting in turbine breaking after x hours. But engines are extensively tested before being put into serial production, and this occurs very rarely on production aircraft. In addition, the likelihood of the same problem occurring on two engines in such a sport span of time as a flight, but not at all during testing, is a rather low likelihood.


Do all A320-family planes have leading edge high lift devices?

Unless something broke mid-flight -- which you would have probably been told about as a passenger because of the faster landing speed -- leading edge devices (slats) are used for takeoff, approach, and landing on the A320-family.

For takeoff the slats are put in position 18 or 22, and for landing in position 22 or 27, as the table below from an A320-family flight crew operating manual shows:

If you are sitting well ahead of the wing, you may not notice a change if you don't know what to look for. Here are the 4 positions:

(YouTube) Slats 0, 18, 22, and 27. Also note the arrow showing the 3 extended position markers.

One of the few jetliners built without slats is the DC-9 Series 10.

  The Series 10 was unique in the DC-9 family in not having leading edge slats. The Series 10 was designed to have short takeoff and landing distances without the use of leading edge high-lift devices. Therefore, the wing design of the Series 10 featured airfoils with extremely high maximum lift capability in order to obtain the low stalling speeds necessary for short field performance.

The rationale would have been weight and maintenance cost saving, which was helped by the short range of the plane. For faster cruise speeds and longer range, high-speed tailored wings with slats for low-speed are better than low-speed tailored wings.


Do airline pilots use speed stability to cope with unreliable airspeed indications? If not, why not?

I don't believe the procedure you've described is formally recommended. Instead there is the unreliable airspeed procedure. The exact parameters vary among aircraft types but the basic principle is that by setting a specific pitch and power combination, you're guaranteed a certain airspeed/performance.

These procedures have existed for many years but perhaps the biggest change to come from the AF447 crash is an increased emphasis on this in recurrent training.

See: What is the correct crew procedure for an unreliable airspeed alert?


how are UAV systems (aircraft+ground facilities) fitted with landing aid system?

Each project will have its own specifications. Military UAVs will have different use cases from civilian ones, and, as the comments mention, unmanned does not mean unpiloted.

Most of current UAVs are remotely piloted, meaning that there is a front facing camera relaying images to the ground, where a pilot will command flight adjustments to the vehicle to keep it aligned, no special equipment involved (except for the air-ground communication apparatus). The aircraft will be equipped with the usual inertial sensor unit(s) and GNSS receiver(s).

For situations where you might have an unpiloted aircraft (that are extremely rare today), it is still solvable by simple INS + GNSS, with the additional requirement that you will have to accurately measure the position of the runway in the GNSS reference system (published charts are not precise enough, as they are created for eye-bearing humans, that can correct the course by sight). This is the method we used and we landed 2 meters from the centerline (the two pilots where there for safety, being it the first attempt).
Other projects might include ground-based aid signals akin to an ILS system.


Does MMO (limiting Mach number) assume any maneuvering limits?

The problem is that in a deliberately entered spiral dive it is very difficult to keep things in check.  In an idle descent, pitch is your only speed control (well... really, in the end, pitch is your speed control all the time; any glider pilot understands that), and in a spiral dive trying to slow down by increasing pitch is trickier because a lot of the pitch input just steepens the spiral and you just pull more G instead of slowing down.  Which is the whole reason spiral dives are to be avoided in the first place, especially in the IFR world.

In a jet in an emergency descent you will generally dump flight spoilers with the engines at idle and push over to accelerate to MMO/VMO.  An attempt to maintain MMO/VMO in a spiral dive turn would probably end poorly.  If you are diving straight at VMO, spoilers out, and want to get down faster, depending on the airplane you might get a faster descent by slowing to gear extension speed and extending the gear, but I don't think most manufacturers recommend that and it's not something I was trained to do (on RJs).

Sideslip doesn't come into it as sidesliping swept wing aircraft deliberately is very dangerous (it doesn't take much skid/slip to make a swept wing airplane want to roll on its back), and nasty dutch roll situations can result.  In any jet, once you are off the ground, the yaw damper system takes care of adverse yaw and any random disturbances, and you never touch the rudder pedals unless an engine quits.  It's generally feet on the floor after the initial departure profile until final approach.

In any case, in an emergency descent you are way above maneuvering speed so pulling too hard will fold the wings before stalling AOA is reached and trying to get more descent rate by spiraling would be suicidal.


What happens to Cessna electric flaps that are moving when power is lost?

Stays where it is. The mechanism is a leadscrew and like most leadscrews it's "self-locking", which means that it's held in position by frictional forces whenever the motor isn't turning and it can't be back-driven even by substantial loads. The 20 degree (etc) "stops" are just reference positions for which aircraft performance and load limit data have been determined.


Does acceleration increase linearly on a takeoff roll?

Thrust depends on speed and the type of engine. To simplify things, we can say that thrust changes over speed in proportion to the expression $v^{n_v}$ where $n_v$ is a constant which depends on engine type. Piston aircraft have constant power output, and thrust is inverse with speed over the speed range of acceptable propeller efficiencies, hence $n_v$ becomes -1 for piston aircraft. Turboprops make some use of ram pressure, so they profit a little from flying faster, but not much. Their $n_v$ is -0.8 to -0.6. Turbofans are better in utilizing ram pressure, and their $n_v$ is -0.5 to -0.2. The higher the bypass ratio, the more negative their $n_v$ becomes. Jets (think J-79 or even the old Jumo-004) have constant thrust over speed, at least in subsonic flow. Their $n_v$ is approximately 0. Positive values of $n_v$ can be found with ramjets - they develop more thrust the faster they move through the air.

Drag depends also on speed, and in addition on lift. During the takeoff roll the dynamic pressure grows with the square of speed, and drag is almost proportional to the dynamic pressure. Since the flow's Reynolds number also increases with speed, the zero-lift drag coefficient (aka friction plus pressure drag coefficient) decreases with speed. Depending on the ground attitude of the aircraft it will create already some lift during the rolling phase, but lift substantially increases during rotation when it is raised to lift the aircraft off the ground. When the aircraft accelerates further after liftoff, the lift-dependent part of drag goes down with speed while the zero-lift part continues to increase with dynamic pressure.

For most aircraft, thrust is highest when the aircraft is at rest (constant pitch propellers can have a lousy efficiency at takeoff when they are optimized for fast flight, so here you might have higher thrust at some positive speed), and decreases the faster the aircraft moves through air. Since drag is also lowest with the aircraft at rest, the highest acceleration is possible right after brake release. As soon as the aircraft rotates, the new lift-dependent drag component will cause a marked decrease in acceleration, and when the aircraft climbs, some of the excess thrust needs to go into climbing, so acceleration decreases again.

Newton's first law gives a formula for acceleration a: $$a = \frac{T - D}{m}$$
where T is thrust, D is drag and m is the mass of the aircraft. The integration of acceleration over time gives speed.

There is no single formula for the velocity curve, and my recommendation is to split the take-off into three sections: Ground roll, rotation and initial climb. In all phases you need to calculate with speed-depependent drag and thrust, so it will be best to integrate the parameters stepwise in small time steps.

The comments encouraged me to give a more detailed list of drag components. These here have to be considered during the take-off roll:

Zero-lift drag of the airframe (due to friction and pressure)
Induced (lift-related) drag for the aircraft in horizontal attitude, including reduction due to ground effect
Drag increment due to flaps in take-off position
Landing gear drag
Wheel friction (0.025 * weight on a hard runway, but a lot more on soft ground)
Kinetic energy loss or gain due to runway slope

With rotation onset these drag components must be added:

Trim drag due to elevator deflection to lift the nose
Induced drag at the actual pitch angle

When the aircraft lifts off, these changes must be considered:

Reduced power for acceleration due to power requirement for climb
No more wheel friction
When the gear is retracted, drag increases as the doors open and is greatly reduced once all wheels are stowed.
Ground effect is reduced as the aircraft climbs away from the ground

Don't forget to include wind speed in your calculation!


Are there any airliners and or aircraft that use bleed air and excess heat from the engine to prevent icing

Quite a few actually, and this has been dealt with here before. Most systems use the bleed air from the engine, which is directed through pipes to wing leading edges, engine cowlings etc.

For example, the Boeing 767 anti-icing system, from this question:

Image from Aircraft Anti-Icing Systems by Leslie Mehl and Annie Parsons

This question has answers which explain about the anti-icing systems in large aircraft.

Boeing 727 anti-icing system, image from this answer