Can a free-falling aircraft with no horizontal (or minimal horizontal velocity) start up and fly to safety?

Rather obviously, both of these situations are far from likely to occur. As a result, the following is just idle (but hopefully informed!) speculation — I don't recommend experiments!

I'm going to be a little bit cheeky in answering this question -- you've asked if it's possible for “a fixed wing aircraft to [...] get the engines up to speed and fly off.” I'll answer “Yes, but it depends on the aircraft.” For the fixed wing aircraft I usually fly, a K-21 glider, getting the engines up to speed is a doddle — it’s powered by gravity (and essentially stays aloft by the sun). What matters here is the stall speed of the aircraft in question, and how quickly the pilot could recover from the ‘upset’ of being kicked off the top of a tall building, and land somewhere sensible (which can only realistically happen once the aircraft is not stalled). If the relative airflow over the K21’s wings is about 35 knots (40 mph, 65 kph) or greater, they generate enough lift to keep it airborne (and going about 30 m forward for every meter down).

If we assume that you’re a free-falling body, Newton (in the form of $v=u+at$) says that it’ll take about 1.8 seconds to reach that speed, and you’ll fall ($v^2=u^2+2as$) about 16 meters during that time.

Of course, you’ll be pointing nose down at the ground, accelerating, and needing to do something about it — which will take time, and, more importantly distance. But, in the grand scheme of sky-scrapers, mountains and cliffs, 16.2 m isn’t that high. Incidentally, for this reason, bungee launching is a traditional method of getting gliders airborne in parts of the world with big hills — a team of runners using glorified elastic bands shoot brave pilots into the blue yonder, as illustrated by the picture below (at the Long Mynd).

So, given that a hill is enough height for a sailplane to take off, possibly for a few hours on a good day, I’m reasonably sure that something like the John Hancock Centre would provide more than enough time for a pilot to recover from an odd attitude, loop forward to a nose-down dive, recover smoothly from it, and fly away (from the big building behind him).

The gif you linked to featured what looked a lot like a small private jet. I defer to the others on this site with a lot more turbofan experience than I, but I’ll just say this: given an hour that I spent in a 777 simulator, twenty minutes were spent going from “cold and dark” to pushback, I suspect you’d have a much harder time doing it. Of course, rapid engine starts are possible in some aircraft. It depends a lot on the exact circumstances you're asking (and passenger jets tend not to be designed for inverted flight, for example).

By all accounts, this situation isn’t probably going to be very recoverable. If the blades are stationary when the aircraft starts falling, they’ll be fully stalled, resulting in a low-rotor RPM stall, which, depending on the brand of helicopter may not “be recoverable” (e.g., even with a working engine, Robinson helicopters are generally not recoverable from a very low rotor RPM stall). Autorotation is the driven motion of the rotor by the air falling through it, but, as pointed out, fully-stalled blades at any angle will not generate much torque (or lift), and therefore be unable to arrest the rate of descent of the falling aircraft. I presume that the only exception would be a fuselage that could provide lift through another means, such as the V-22 Osprey.


How can I certify an ultralight design as complying with part 103?

No certificate needed and "satisfactory evidence" is only needed "upon request". From the FARs:

  103.1   Applicability.

  This part prescribes rules governing the operation of ultralight vehicles in the United States. For the purposes of this part, an ultralight vehicle is a vehicle that:

  (a) Is used or intended to be used for manned operation in the air by a single occupant; >(b) Is used or intended to be used for recreation or sport purposes only; (c) Does not have any U.S. or foreign airworthiness certificate; and (d) If unpowered, weighs less than 155 pounds;

  or (e) If powered: (1) Weighs less than 254 pounds empty weight, excluding floats and safety devices which are intended for deployment in a potentially catastrophic situation; (2) Has a fuel capacity not exceeding 5 U.S. gallons; (3) Is not capable of more than 55 knots calibrated airspeed at full power in level flight; and (4) Has a power-off stall speed which does not exceed 24 knots calibrated airspeed.

  § 103.3   Inspection requirements.

  (a) Any person operating an ultralight vehicle under this part shall, upon request, allow the Administrator, or his designee, to inspect the vehicle to determine the applicability of this part.
  (b) The pilot or operator of an ultralight vehicle must, upon request of the Administrator, furnish satisfactory evidence that the vehicle is subject only to the provisions of this part.

  103.7   Certification and registration.

  (a) Notwithstanding any other section pertaining to certification of aircraft or their parts or equipment, ultralight vehicles and their component parts and equipment are not required to meet the airworthiness certification standards specified for aircraft or to have certificates of airworthiness.


If a CDI needle is deflected to the right, why is the aircraft off track to the left?

The CDI indicates your desired course. The white circle in the center of the instrument represents your position. If the desired course is to the right of your position, you need to move to your right to rejoin your course.


What is the effect of earth's speed on flight?

The stationary plane and the atmosphere were already moving at the speed of Earth's rotation. Because of this, the Earth's rotational speed really has very little effect on aircraft speed. To answer the second part of your question, almost all passenger jets fly slower than the Earth's rotation. The Earth rotates at 1675 km/hr at the equator; average cruise speed is 878-926 km/hr.


How are the costs managed in a codeshare?

As the wikipedia article clearly states, there are several types of Codeshare Agreements :

  Block space codeshare: A commercial (marketing) airline purchases a
  fixed number of seats from the administrating (operating/prime)
  carrier. A fixed price is typically paid, and the seats are kept away
  from the Administrating carrier's own inventory. The marketing airline
  decides on their own which booking classes the seats are sold in (the
  block of seats are optimised just like another aircraft cabin).

  Free flow codeshare: The airlines' inventory and reservation systems
  communicate in real-time by messaging, commonly IATA AIRIMP/PADIS
  messaging (TTY and EDIFACT). A booking class mapping is defined
  between the airlines. No seats are locked to any of the airlines, and
  any airline can sell any number of seats.

  Capped free flow: Basically the same as above, but a capping (max
  number of seats) are defined for each of the marketing airlines
  participating in the codeshare with the Administrating
  (operating/prime) carrier.

In these cases, profitability of the Airline Marketing the other airline's tickets is possible in any of the following ways:

There might be an agreement with the Carrier Airlines where the Marketing Airline gets to sell the tickets at the same rate as being sold by the Carrier Airline,but the Carrier Airline sells the tickets to the Marketing Airline at lower prices. This helps the Marketing Airline to generate revenue and improve its indicated (apparent) frequency on the given route. The Carrier Airline is benefited in a way where its tickets are sold on more than one portals, so better visibility (Marketing) and hence the name.
Now a days alliances like OneWorld are being formed, where multiple carriers come together and form codeshare bases to mutually benefit each other.
The Marketing Airline might even sell the tickets at a cheaper price than the original Carrier Airline, just to establish its base in the route before starting its operations, so that when it starts its operations, people already know about it. hence, without deploying planes for the route, it can already have an established consumer base.


How much is an airliner's drag coefficient?

Is Cd measured at zero lift AoA or when the plane is flying in a straight line?

Both.
$C_D$ is a function, not a number.
The "numbers" are the partial derivatives: $C_{D_\alpha}$ measures how $C_D$ changes w.r.t. the angle of attack $\alpha$, for example.


What are the pros and cons of buying a kit aircraft vs. a factory-built one?

The objective is very important.  You don't build an airplane because you want one faster or cheaper.  Neither is the case.  The kit won't be cheaper, and it'll take 1 to 2 thousand manhours, minimum, of your time (take the building time claim of any kit and double or triple it to get reality).
You build one for the experience of building one.  A lot of people who build aircraft go on to build another for that reason (the guy that built the homebuilt I own built two more after mine).
If money's an issue, the most cost effective and efficient way to keep flying after your training is to find one or two partners and buy the nicest creampuff Cessna 150 or similar aircraft you can find (really nice 150s go for around 30k).  With the fixed costs split 2 or 3 ways the expenses don't become painful (if you have to start making financial sacrifices, it takes away the fun - been there done that) and it'll be easy to sell when you want to get something bigger.
If you're mechanically handy and want to maintain an a/c yourself, buy a used homebuilt or LSA.   Only look at a kit because you want to experience the building of the kit.


What is the official term for a gas / petrol station for planes?

At airport with a standalone self-serve facility, it's a Self Serve Fuel(ing) Station.  If it's a business selling fuel in addition to other services, that is a Fixed Base Operator, or FBO.


Why do we see "page intentionally left blank" so often in aviation related documents?

I've worked as a technical writer on flight and maintenance manuals in a previous life.  It's done with technical publications where there is a kind of quasi-legal status you might say, insofar as the information published is required for operation or maintenance, is invalid for use if not up to date, and where pages are revised, numbered and dated with a List of Effective Pages (LOEP) that goes at the front, that confirms the issue date of each page.

It provides a ready confirmation that a blank page is not a misprint (even as a PDF or other electronic format), saving the reader from having to check against the LOEP to make sure there isn't a missing page every time a blank page appears at the end of a section.


From what I can tell, it's a Burt Rutan design. I then searched and it appears to be a Rutan Defiant.


How much are aircraft nose paintings restricted by regulations?

It used to be that nose art was pretty outlandish and sexually charged, and it remained largely unrestricted as this B-24 from WWII demonstrates.

With the current gender integrated units and women serving in combat squadrons, this kind of stuff is non longer acceptable.  Currently there's a rule, in at least the USAF, that nose art must be 'non-gender specific' i.e. you can't paint naked women on your airplane.


Can a Bombardier CRJ derate the takeoff thrust?

Indeed the CRJ can use reduced takeoff thrust setting.

  Flex power is selected by entering an assumed temperature on the PERF MENU page of the FMS CDU. If the FMS is not available, the assumed temperature can be entered on the EICAS menu page using the EICAS control panel.

It's set up using the CDU or the EICAS control panel. That control panel is on the pedestal aft of the thrust levers, between the radio panels. Do note:

  The FLX indications on the EICAS menu page are only displayed if the FMS has failed or is not available.

As for the activation:

  When programmed, the FLX power setting is activated by the FADEC when the thrust levers are in the TOGA detents.

Source: CRJ700 FCOM

Note on terminology:

Derate and assumed temp/flex are not interchangeable. In derate the takeoff calculations are done based on the derated value remaining the highest even when an engine fails. It can be used to lower the Vmcg/a and in turn the V1 in certain situations (related post).


Why does the A320 have an anti skid system and how does it work?

It's very similar to Anti-Lock-Brakes on cars.

The main reason aircraft have it is that a locked tyre will heat up, wear excessively and can burst (aircraft tyres are typically run at much higher pressure than cars or even HGVs).
If you lock a wheel under braking, it no longer provides any steering. Aircraft might not be swerving around obstacles, but staying on the runway is more important than minimising stopping distance.
A locked wheel generates slightly less than maximum stopping force. An automated system can hold the brakes at the point where it's not quite skidding, and brake harder than a human trying not to skid.

They work by monitoring the speed of each wheel, and releasing the brake on any wheel that slows down significantly more than the rest.

I believe that airliners are tested to check that locked wheel won't wear to the point where it bursts, but you can only do that once!


Why do Airbus sidesticks add their inputs?

I believe that there is some logic in the design, actually, even if I don't really fancy it. If you think of the traditional yoke as a control element where a certain force (or moment, rather...) results in a certain change of flight path, then if both pilots apply the same force (rather than targeting the same deflection), the resulting aircraft reaction is more pronounced than if only one pilot applies that force, although probably not with linear relation. The sidestick controlled flight control system does the same.

What is missing much more, to my mind, is feedback to one pilot about what the other one is doing with the stick. I believe that having them interconnected or back driven would probably not have been such a bad idea.


What is the purpose of using 8.33 kHz instead of 25 kHz frequency spacing?

The purpose is to accomondate more dedicated frequencies within the airband VHF range (117.975 to 137 MHz).

Increasing number of stations made this necessary, if the smaller division was not implemented, it was estimated that only 70% of future requirements for frequencies in Europe can be met.

833radio.com has further information and an nice table describing the channel spacing:

For simplicity, the actual 8.33 channels are displayed as rounded to .005 values.
For example to use the frequency 118.0083MHz, you dial 118.010


What's this red cabin light indicator inside a Boeing 737?

I found this pertaining to the new interior design of some Boeing737(s), I can only guess the coloring is from one of the mood lighting (Blue or red) has a defect in the connections.https://www.airlines-inform.com/flight-reports/amarchukov-1754.html


Can thrust reversers be set to automatically activate on touchdown?

Can it be done? Yes. Is it done? No. The consequences of unintended operations are serious.
To the best of my knowledge, no aircraft has the option set automatic thrust reverser. Using the levers are the only way to operate them. In fact, most of the design efforts have gone the other way- to ensure that thrust reversers are not deployed inadvertently.

In most aircraft, the Reverse Thrust Levers can be raised only when the Forward Thrust Levers are in the idle position. The thrust reversers have separate levers in front of the engine controls, which are prevented mechanically from operating otherwise.

Source: bloginblack.de

There are sensors installed in the engines which auto-stow the thrust reversers in flight.
The design philosophy of thrust reversers is that it is better to not deploy them when needed rather than deploy them when not needed i.e. they are designed to fail.

The main reason for such a design philosophy is safety. Any uncommanded deployment of thrust reversers in any phase of flight can have serious consequences.

Takeoff- If the trust reversers are deployed in one engine before $V_{1}$, the aircraft will veer off the runway. If it is deployed after $V_{1}$ and before $V_{2}$,the aircraft cannot achieve $V_{r}$ required to initiate rotation.
Flight- Deployment of thrust reversers during flight can lead to controllability issues.
Landing- Deployment of thrust reversers during landing practically eliminates the option of rejected landing.

Because of these reasons and reliability issues with thrust reversers, there is no option for automatic deployment of thrust reversers.


Could fly-by-wire protect against a takeoff tail strike?

On Airbus aircraft, the guidance law provides attitude protection on take-off which should prevent a tail strike. However, this is not fool-proof and it remains up to the PF to maintain the correct nose-up angle.


Is it possible to get a purely VFR job with colour blindness?

There is another test, called the Farnsworth Lantern test, which you can take.  Not many aviation medical examiners have the lantern, so you might have to ask around, but if they have it and you can pass with that, you meet the medical criteria.

The waiver that Terry discusses is the SODA (or statement of demonstrated ability).  I had to get one for nearsightedness when I got my Class I, which consisted of a trip to the local flight standards office, a checkride with the FAA inspector who agreed I could fly just fine with my fully corrected 20/15 but uncorrected >20/200 vision.  There are plenty of airline pilots floating around with waivers of this type.


What is the format of data stored by a Flight Data Recorder?

To simplify explanations:

FDR: flight data recorder (flight parameters),
DFDR: digital FDR,
CVR cockpit voice recorder (audio recording).

In commercial aircraft, aside the mandatory FDR/CVR used by investigation agencies (the scope of the question), there are recorders used for maintenance and operational purposes by the operator. The progress made around these additional recorders influences the regulation around the mandatory recorders.

Short answer to the questions:

Sensor data are collected by a central acquisition unit which, for commercial aircraft, is compliant to standards, e.g. a digital acquisition unit will be compliant to ARINC 717 and use the frame format from the standard.
Data are then distributed to other units under this format, this directly influences the format used by recorders. Today most FDR store data as bits in a digital memory or a on long term media (e.g. optical disc). The FDR required by regulation uses a crash-resistant digital memory.
Since a few years, recorded data format can be described using ARINC 647A specifications in an XML file, known as FRED file. This file simplifies FDR data exchange and interoperability, a current requirement for aircraft parameters monitoring and analysis using products from different manufacturers/editors.
A FRED file can also be stored along with data, and as a matter of fact, mandatory FDR regulation now requires the FRED file to be embedded in FDR.
Readout hardware/software is provided by the recorder manufacturer.

As mandatory and non-mandatory recorders from a given manufacturer are susceptible of using a common format, readout devices are usually combined with monitoring and data analysis software.

Details: Regulation

Quite surprisingly, there is no mandatory format for storing flight data. International regulations don't require or recommend a specific scheme. They only require data to be provided to the aeronautical authorities in a timely manner if an investigation has to be carried out after an incident/accident.

ICAO Chicago Convention, annex 6 states:

  6.3.5.2 In approving the means to make flight recorder data available in a timely manner,
  the State of the Operator shall take into account the following:

  a) the capabilities of the operator;
  b) overall capability of the aeroplane and its systems as certified by the
  State of Design;
  c) the reliability of the means to recover the appropriate CVR channels and
  appropriate FDR data;
  d) specific mitigation measures.

ICAO member States implement this international requirement, by requiring a documentation describing how data were calibrated and converted for recording and how to read them back. The related documents are known as Data Frame Layout and Conversion Data. E.g. for the US this is found in FAR 125.226:

  Documentation sufficient to convert recorded data into the engineering
  units and discrete values specified in the applicable appendix must be
  maintained by the certificate holder.

and more details for DFDR in AC 20-141:

  The data stream must be correlated to EU or to discrete states for an
  accident investigator to use the data.  This appendix provides the
  specific information that operators must provide to the NTSB
  investigators decoding and converting the raw data stream recorded by
  the DFDR.  This data format information can be contained within an
  electronic file or in hardcopy document format.

The description of the data frame layout and conversion method encompasses:

The origin of the recorded parameter, and any computation done
The method used for parameter calibration
The method used to encode the value of the parameter
The unit used.
The method to be used to convert recorded values into readable values.

In addition there are requirements about the certification of the mandatory recorders themselves, for most countries, the acceptable means of compliance directly or indirectly (e.g. via TSO-124 wrapper) refer to EurOCAE Document 112A (ED-112A) Minimum Operational Performance Specification for Crash Protected Airborne Recorder Systems.

Since 2016, ED-112A forbids the use of analog recorders, including magnetic tapes, for mandatory recorders. Non volatile solid state memory (EEPROM, typically Flash memory) is used instead.

More: What data file format is used by FDRs?

Recording format is influenced by the FDAU

Overall, data are recorded in any efficient format, not a user readable format. Data are compacted as much as possible to save memory and volume requirements of the crash survivable memory unit (CSMU), because of the cost of making this unit highly reliable and protected from the effects of an accident.

On large aircraft, parameters are collected by a flight data acquisition unit: Analog FDAU are compliant to ARINC 573 and digital DFDAU to ARINC 717). Digitalized data can be distributed to other avionics units using a local area network, e.g. the common ARINC 429 LAN. Units receiving data include cockpit displays, ACARS, and mandatory and non-mandatory recorders.

  Is the raw data fetched from the FDR available only in binary format?

If we refer to large commercial aircraft, the answer is yes. Using ARINC 429 LAN already means data have been digitalized and streamed over the bus according to a well documented format. The FDAU choice greatly influences in practical how data will be recorded. It is easier to design a DFDR aligned on DFDAU ARINC 717 stream. ARINC 747 is an alternative with data compression for solid state memory.

ARINC 717 DFDR

The logical choice of the DFDR manufacturer is to use ARINC 717 both for a mandatory FDR and the various maintenance recorders. In this standard, the recorded data stream consists of a frame with four subframes.

Source

Each subframes is recorded at the rate of one per second, and contains a certain number of bits grouped into 12-bit words. The actual number of words depends on the need, hence on the aircraft. The cycle repeats after 4 seconds.

DFDR data example: Magnetic heading

Delays are to be taken into consideration, sensor output from the IRU takes some time to get to the recorder, this must be described by the manufacturer as part of the information needed for the recorded parameter readout:

Source CAP 731

Data transits on ARINC 429 bus identified by label 320, a BNR data:

Ibid

While no recording format is mandatory, the data sampling rate is critical: Transient values may be invisible if sampling is too slow. Therefore regulation mandates sampling rates.

A given parameter may appear only in some subframes, due to its sampling rate, and specific frames (superframes), recorded once per 64 seconds, are used for parameters which vary very slowly (e.g. gross mass). Examples of sampling rates:

Source

Data is recorded at some location in the overall framing of the FDR, this location is a choice of the DFDR manufacturer. For non-mandatory recorders (e.g. Quick Access Recorder, QAR) recorded parameters are chosen by the operator, as well as their location in the frames. For our example:

Ibid

Last but not least, the documentation describes how the recorded value must be processed to get the original parameter value and unit:

Heading Degree = 0.1758 x FDR Count (11 bit) - 180

Compliance to regulation

In spite of regulation, there are cases where data layout is unknown, e.g. BEA, the French investigation agency noted for a case:

  The operator was not able to provide the BEA with any data
  frame layout documents. A list of recorded parameters and
  their allocation in the data frame was obtained, but the
  conversion equations and the calibration reports were missing.
  The FDR data could not be analyzed.

(Flight Data Recorder Read-Out, §2.3.2.1)

In the same document you may read other cases where the FDR data readout has been difficult or impossible.

The mandatory data frame layout and conversion method documents can be embedded into the FDR, to facilitate the readout and produce a file which can be understood by any compliant software. There is a standard for the documentation: The Flight Recorder Electronic Documentation (FRED) which is described in ARINC 647A.

There have been cases where the missing documentation prevented data interpretation (see below), but since 2016 and ED-112A, the FRED file must be carried in the recorder itself with the data, to ensure the data decoding.

FDR readout

  What are the software tools that are used to convert it to readable format?

FDR manufacturers provide the tools required to read out data, based on their own recording techniques. Readout is done using simple hardware/software.

Readout is facilitated by reusing the embedded FRED file or using an external file (a FRED file is an XML file describing in detail the way the recording was done, and the format used):

Source: ARINC 647A

It should be noted manufacturers usually also sell non mandatory recorders (QAR and the many variants of QAR) and they provide not only readout tools, but also analysis/monitoring tools. Example:

ROSE analysis unit, source

Other readout solutions:

KGB Aviation
ATM

You can see the FDR itself is used for the readout. In case the FDR unit is broken (which is frequent after accidents), the protected memory unit is extracted and read with another working FDR.

Extraction of the memory module protected in temperature resistant foam:

(Source: ATSB accident report)

Readout facilities and readout certification

FDR/CVR readout cannot be trusted unless it's done with appropriate knowledge, skills and documentation. This is the reason readouts used by official agencies, which can be used at courts to try determining responsibilities after an accident, are required to be done by certified personnel in approved facilities.


Do some right-handed pilots fail to use the left stick of an Airbus?

In a study titled 'Role of handedness in flying performance', the author notes:

  [Leon had reported] that movements in one limb were not affected by actions in the other limb. It may be for similar reasons that in multi-crew cockpits of transport and passenger aircraft, pilots have not reported any difficulty in operating controls at either the left or right seat even though the layout of the controls is a "mirror image".

From an observation that may or may not have been studied, operating controls is not like handwriting—handwriting requires major shifts in body position to use the other hand. The human brain is really good at ordering one hand to mirror or follow the path of the other hand. If you think of the yoke as a steering wheel, then when switching from right to left seat, the left hand follows the circular path of the now free hand.

It takes getting used to, but unlike handwriting, it's very quick. I've done this experiment years ago. If you have a flight simulator, setup the plane on approach and switch the joystick from your preferred side to the other. In my case, just like the study above, I did not find any difficulty.

https://commons.wikimedia.org/wiki/File:Patria_pilot_training_OH-GSC_Malmi_3.JPG

Above is the cockpit of a Cirrus aircraft, it's often remarked that the stick resembles half a yoke, and would be operated much like any yoke. The same is said about the Airbus stick.

But Airbus also has an armrest, which is very beneficial as the precision increases when the arm is rested, see here: Why don't we fly helicopters with yokes?


Are there any new orders for the B747 passenger version?

I will assume that you have conflated "orders for 747s" with "airlines operating 747s", and you are actually asking if any airline has a passenger 747 on order with Boeing.

Per Boeing's Order & Deliveries page, there are no unfulfilled 747-8 (the passenger variant) orders.

You can generate the report by going to http://www.boeing.com/commercial/#/orders-deliveries, selecting "Report by Model", and then selecting "747-8" for "Current Model Series".


The idea works but only with active automated re-configuration of the
  shape of the step(s) during flight. Further testing has shown that
  this airfoil is effective in low Reynolds number flow.

source: Wikipedia

The Reynolds number is indicative of the speed of the airflow over the wing. The higher the speed, the higher the Reynolds number and vice versa. This is why they would be more suited for model aircraft rather than large aircraft which would experience higher Reynolds numbers.


Lift and Drag Coefficients using load cell data

I guess your design is a conventional one.

One approach could be integrating two load cells in between the tail and wing sections.

You can measure drag force and moment. And the moment may help you estimate the tail lift (with some serious assumptions though).

If space is a concern, you can try building a scaled model (2:1?) to test a larger model. The resulting forces and moments must be corrected for Reynolds effects.


Who to contact when inbound to adjoining class deltas?

You should contact the tower of the Delta you intend on transitioning through/entering first. Tell them you want to transition through their airspace. If they clear you to enter their airspace you can request a frequency change while still inside the first delta and contact the second. This is the same procedure as say departing a Delta that abuts a Bravo then taking a Bravo transition. You could also ask for a handoff to the second delta from the controller at the first.

For example I fly out of KPNE often a Delta abutting a Bravo, if I want to fly south through the bravo before take off I can call the tower with something along the lines of,

  "Archer 123PB holding short at 33 ready for departure to the south to KWWD.
  Can I get a bravo handoff as well?"

An example in your case might be

  Camarillo tower, Piper 123PB 5 miles to the east looking to transition through your airspace to KOXR

The tower may respond with

  Piper 123PB approved as requested maintain 1500 ft. hold course and overfly the field

Then as you are a bit more east (most likely past the field in this case)

  Camarillo tower requesting frequency change

Tower

  Frequency change approved

You can then call OXR with

  Oxnard tower Piper 123PB 3 miles to the east inbound for a landing at OXR with information {current AITS}

This is going to happen fast and you will need your frequencies in hand for this. You can ask the first tower for a handoff which they may orchestrate but you should be prepared for both options. If you have some kind of a pre-programmable radio this is a great example of where queueing up your frequencies will help.

Your other option (in this specific case) weather permitting you could overfly KCMA above 2000 ft. since the delta ends at 2000 Ft. and simply request entrance to the second delta. In this case you never actually enter the first delta and no clearance is required.

In some cases, there are prior agreements that may not match the charts for adjacent airspaces.


how to know about designed airways above my house

Airways is a term that is used for the sort of "highways in the sky" that a lot of commercial air traffic use.

However, as you are reasonably close to an airport what you're most likely referring to is SIDS (Standard instrument departures) or STARS (Standard terminal arrivals). Both of these can be found quite easily by searching for the airport name/identifier along with those 2 terms

One such example is here: https://v1aviation.co.uk/wp-content/uploads/2016/10/LIMC.pdf

It is a long document with a lot of information, however around page 19 you start to see some example departure routes from one of the northerly runways, which do indeed turn east and west depending on the route the aircraft is taking. You might recognise some of the local topography and be able to estimate where your house is based on local knowledge.

Edited to add: The screenshot you have added looks similar to the easterly departure from 35L.

However, as pointed out in comments, the actual departure of that flight was from 35R, so the SID followed is likely to be the one later on in the linked PDF (pp 23-onwards).


Do airliner spoilers really "spoil" lift?

You modified the lift distribution diagram by adding spoilers without showing how that modifies the lift of the wing. The trailing edge of a wing controls how much lift is produced, whether you call it flow turning, circulation, or whatever.

Your diagram implies that lift is produced regardless trailing edge position. If this were true ailerons would have no effect since they only occupy the trailing quarter of the typical wing. Look at the camber line of the wing in your diagram with and without spoilers and you'll see. Flow does not turn with spoilers deployed, so you lose lift and gain a lot of drag.

source

  Extending the wing flaps increases the camber or curvature of the wing, raising the maximum lift coefficient or the upper limit to the lift a wing can generate.

A spoiler of the variety shown in the first diagram works like a split flap upside down, reducing camber and maximum lift coefficient.

inverted

source


How much does a D-check cost compared to a new aircraft?

Keep in mind that during a D check, the parts on the plane are already owned. There will of course be a certain amount of parts replaced, but it will be much less than the manufacturer's cost to buy/manufacture all of the parts. There will be thousands of hours of labor, which will be most of the cost of a D check. The cost of maintenance space and taking the plane out of revenue service may also be considered.

According to this financial reference:

  For a 15-year old Boeing 737-300, a D check would likely cost \$1.25-\$1.5 million, representing about 8-10% of the cost of the aircraft.

This book is now 15 years old along with the newest 737-300's, so in today's dollars this would be \$1.73-\$2.08 million, not accounting for changes in the cost of maintenance. Larger aircraft will have larger costs. This seems to put the cost in the same range as other sources.


Is a magnetic assisted takeoff feasible?

Catapults are used to launch airplanes on aircraft carriers, most are currently steam powered but the US Navy are developing an electronic catapult system called EMALS to replace steam ones in the future. Other countries are developing the same technology. The US Navy system has been shipboard tested, apparently there are still some problems but they will likely get worked out, so the technology is viable - it is possible.
Shipboard catapults are used to accelerate airplanes quickly in the very short distance you have on an aircraft carrier deck, not to save energy or fuel. It doesn't make practical or economic sense to use the technology to accelerate airplanes in a normal airfield for the following reasons:

It's very expensive technology to buy and maintain. It would cost enormous amounts of energy to deploy this technology
It will limit airplane operations to those airfields which have the technology. I can fly a Cessna 172 into and out of remote strips, but if I require a catapult of some kind my options become very limited
It doesn't actually help much. It's not the take-off roll which is energy intensive, it's the climb to altitude, and a catapult wouldn't help with that. When you think about it the take-off roll is a minute, climbing to altitude is 20 minutes in a commercial jet, you'd be reducing the energy needed by at most 5%, which isn't worth the investment


How does handover between Air Traffic Controllers work?

The answer to your question heavily depends on jurisdiction which you don't specify. I will answer for Europe-Greece where I have some knowledge. The procedures might differ between the ANSPs and are subject to change.

how can the controller know that there is not another aircraft approaching out of scope range that is on a collision course with the aircraft leaving or approaching or traversing the boundary of his scope range?

There are several factors affecting that and I would say it's part of the job:
Training and personel
In Greece I know that controllers are specifically requested to setup their CWP in such a way that they can see at least 10 nautical miles from the border of the controlled area and definitely they should see the whole sector at all times. Also if some area is quite busy they have a secondary radar screen (imagine it like a PIP) that can focus in that area. That way they can have a good look of crowded areas without losing the full picture.
Also there is not one controller per sector, there are two. The RO (radar operator) and the planner. It's the planner's job (among others) to coordinate with the neighboring sectors for the trajectory of all incoming flights, and if there will be significant deviations they will notify RO.
Actual handover procedure
When a flight approaches the boundary (geographical or vertical both can happen and are valid) the RO initiates in their CWP the handout sequence. At the same time they switch the plane to the next sector's frequency. The other controller is not supposed to assume control of the flight until the plane calls them (yes there can be errors in frequency switching, that's why planes have the standby frequency on the comms panel). When the plane calls the next sector, the controller assumes control, finishes the handout sequence and the plane is officially theirs and doesn't belong to the previous controller anymore.
If the next controller doesn't accept the handout, the flight returns back to the previous sector controller. The details of that process changed after Helios 552 accident happened;(1) that's why I've said that the procedures might change at the ANSP's discretion.
There are exceptions and nothing is carved in stone:
A flight might have requests that the current controller cannot grant safely: Altitude, higher or lower. Direct to some point outside of the sector. Speed change like for example 250 knots speed restriction waiver for approach sectors. Then the controller currently controlling the flight might handout the flight earlier to the next sector with or without coordination with the next controller depending on the situation.
FIR Design
Also note that the FIR design (sectors, airways and points) is not done randomly but in such manner that there are no conflict points on the boundary of a sector but closer to it's core. So that the surprises on sector seams are minimized. See the appendix for a detailed example.
Finally, for sectors where the handover of climbing or descending flights is routine (TMAs for example), there are predefined altitudes for handover. For example a flight should be at FL210 when crossing the sector boundary. Again, nothing is carved in stone and there might be small deviations. If there are big deviations, the sectors coordinate as I've mentioned before.
Coordination between FIRs
All the above happen between control sectors in the same FIR. When handing over control to other FIRs that is a whole other story. Flights are coordinated via a communications channel, either manually (via telephone) or automatically (via protocols like OLDI). The boundary sector controller of the next FIR expects the flight on a specific point at a specific time. If the flight doesn't show up they start looking for it... They call at the expected frequency, they call at the emergency, they call the previous FIR (and not necessarily with that order).

how each centre knows who has control over the aircraft and if situations could occur where nobody is...?

There is no such thing as nobody is in control when we talk about en-route ATC. The flight is in the control of the sector (and FIR consequently) that "contains" the flight in the 3D space. The fact that you "see" the flight doesn't mean that you control it. It means that you know its presence which is a good thing.

I have to assume there is more than one human at busier control centers all working together. How is that managed? Who controls what?

Please see above the comment about RO and planner. There are also other very good answers on that specific question like this one where  you can see somewhere in the end, a

Typical sector radar team

consisting of two people, and from what I see, the left one is the RO equivalent and the right one is the planner equivalent.
Appendix I: Sector design importance explained
Here is an example from Milos sector (aka AC5) of Greece. To declutter the map, I've hidden the coastline, and displayed only the aerodromes. The sector is the black area and the rest of the FIR is in gray. Note that this is not the case in reality, I've just changed the color setup to highlight the area of interest.

To get a better idea of the area, here is what is displayed. Milos island is on the center.
Without getting into the details of the sector as this will be off topic, you can see that the conflict point I was talking about is where the red arrow is. That is MIL VOR-DME located in Milos island. There you have 10 airways(2) converging, being "fed" by Athens airport (LGAV) in the North and Heraklion airport (LGIR) in the South (green arrows). As I've mentioned, the conflict point is almost on the sector's center. It's right in the controller's eyes, away of the "ambiguity" of the sector border.
One might argue that there are 2 more points where airways converge, one in the North (KEA VOR-DME, name not shown) and one Northwest (DDM VOR-DME , name not shown) that are very close to the next sector border. Though this is true, the points are not as big conflict points as MIL VOR-DME because

KEA and DDM are major navaids for Athens TMA and it's expected to have that many airways converging towards them and
most of the flights that will cross these points over 250 (Athens TMA vertical limit) will usually be en-route, ergo no unexpected changes in heading and altitude

Also notice that Athens TMA (light coral line) overlaps will AC5. That means southbound departures from LGAV will be handed over to AC5 when they are way in the sector, away from the boundary.

Notes
(1) Many people ask how the Helios 552 accident can be related to the process. It's not related directly. Before Helios accident, the process was as follows: Propose the aircraft to next sector. Next sector accepts the proposal. Previous sector sees that and switches the frequency. That was reversed: the receiving sector is not accepting the handover unless the aircraft calls first. That way it's easier (and faster) to spot flights that for any reason did not call. As you can see, it's not directly related, but it was a change to keep the procedure on the safe side.
(2) For the record these are A10, A14, B26, B34, J56, R32, L617, M601, N134, P32
Acronyms
ANSP Air Navigation Services Provider
RO Radar Operator
CWP Controller Working Position
OLDI On-Line Data Interchange
TMA Terminal Maneuvering Area


Do some light sport aircraft have clipped wings to lower their cruise speed?

You must have heard wrong. Clipping wings is done to reach higher maximum speed.

You mention light sport aircraft, so I assume they have propellers driven by piston engines. This means their power output is constant over speed and the thrust is inverse with speed. To calculate their optimum cruise speed, you can use the venerable Breguet equation which shows that the aircraft has to fly at its optimum L/D for maximum range. At this speed, induced drag equals zero-lift drag, and span helps to cut down the former. Clipping the wing will shift the optimum cruise speed up, not down.

With clipped wings the aircraft has less surface area, which will reduce zero-lift drag. This is the drag component which determines maximum speed. Induced drag at a given speed will go up, but it is insignificant at maximum speed, so the aircraft will be able to fly slightly faster.


What is the measurement system used in the aviation industry?

Outside US, SI is generally used for everything except altitude, distance and speed.

Altitude: 1000 ft happens to be reasonable vertical separation, which is somewhat easier to calculate with than the corresponding metric figure 300 m.
Distance: There are two quantities that were never converted to decimal. Time and angle. Since we didn't switch to gradians, it makes sense to keep nautical mile, which corresponds to 1 minute along meridian or equator, as it makes calculating distances from navigational maps somewhat easier. If the maps were marked in gradian coordinates, 1 gradian would be 100 km and kilometres would be used.
Speed: Obviously based on the unit of distance in use.

In Russia, Commonwealth of Independent States (most former Soviet countries) and China (and I am not sure whether some other Asian countries), metric system is used for everything. I believe in Russia they recently switched to flight levels based on feet, but they do use metres below transition altitude.

Before second world war, aircraft built in continental Europe usually had instruments in metric units as well. However before the war aviation was more advanced in the USA, instrument procedures were developed in USA and after the war there was surplus of US-built planes, so most of the world just adopted the US procedures including the units they used as everybody using the same units was more important than any personal preferences. Without these reasons we'd be probably using metric in Europe for everything too.


How to calculate the forces and moments required to aerodynamically actuate slats?

Very interesting challenge and very interesting design approach.

I've read this had been done few times with TE flaps but not with LE slats. If i were you I would take the following approach to figure a way out.

In Javafoil you can model open slat multi element air-foil. The results are not very accurate at your Reynolds number if there is a huge separation bubble though. xfoil does not support this feature at the moment but if you are thinking of using TE Flap your best bet is to use xfoil). Calculate several slat gaps by geometrically altering the input file for a list of angles of attack.
You can easily export the local CPx data to a text file in Javafoil. Then use these data to find out how much of aerodynamic force the slat generates by integrating the local surface slope and CPx values for each slat-gap, alpha pair.
Then this data-set could be interpolated to find out what would be the slat-gap distance for given angle of attack for a given spring constant and substantially to find L/D for each angle of attack.

Hope this helps.
ABCD

PS: One example of automatic TE flap deflection is discussed here. I think LE slat would be much more effective because $Cp_\alpha$ near the LE is much higher than that of the TE


Will the landing gear work mechanically in case of total power loss?

Not a real example, but this comes from the FAA, including some nice drawings around page 13-20:

The emergency extension system lowers the landing gear if  the main
power system fails. There are numerous ways in  which this is done
depending on the size and complexity of  the aircraft. Some aircraft
have an emergency release handle  in the flight deck that is connected
through a mechanical  linkage to the gear uplocks. When the handle is
operated, it  releases the uplocks and allows the gear to free-fall to
the  extended position under the force created by gravity acting  upon
the gear. Other aircraft use a non-mechanical back-up,  such as
pneumatic power, to unlatch the gear.
The popular small aircraft retraction system ..... uses a free-fall valve for emergency  gear extension. Activated from the flight deck,
when the  free-fall valve is opened, hydraulic fluid is allowed to
flow  from the gear-up side of the actuators to the gear-down side  of
the actuators, independent of the power pack. Pressure  holding the
gear up is relieved, and the gear extends due to  its weight. Air
moving past the gear aids in the extension  and helps push the gear
into the down-and-locked position.
Large and high performance aircraft
are equipped with  redundant hydraulic systems. This makes emergency
extension less common since a different source of hydraulic  power can
be selected if the gear does not function normally.
In some small aircraft, the design configuration makes  emergency
extension of the gear by gravity and air loads  alone impossible or
impractical. Force of some kind must  therefore be applied. Manual
extension systems, wherein  the pilot mechanically cranks the gear
into position, are  common. Consult the aircraft maintenance manual
for all  emergency landing gear extension system descriptions of
operation, performance standards, and emergency extension  tests as
required.


The only mention of it I could find in relation to a CPL is from a New Zealander CPL syllabus (govt.nz; PDF).
Including NZ in the search leads to this definition:

The westerly index is the Trenberth Z1 index (Trenberth 1976), which is the departure of the monthly mean pressure difference between Auckland and Christchurch (near 44°S) from its mean over the 1961–90 period.
— journals.ametsoc.org

From that definition, a pilot needs to be aware of the pressure difference between Auckland and Christchurch.

Others here may be able to expand on its usage (feel free to reuse, anyone).
From an Earth Science perspective, I asked on the sister site: What does a change in the mean pressure across 750 km indicate/signify?


Do the indications match up and make sense compared with indications of a nearby airfield and other weather sources?

Legally the FARs require that pilots obtain "all available information" (FAR 91.103). $ could mean a number of things and since Metars are still available, you should be able to trust them, but I recommend to check more then one source regardless.


How does jet engine water injection work?

On many early jet airliners water was sprayed it into the engine air intake or compressor where evaporation cooled the air and allowed cooler, denser air to be ingested by the engine. The result was increased thrust, especially needed for operation from hot and high airfields, or a cooler temperature in the hot section of the engine at the same thrust. From SAE Paper Number 2004-01-3108:

  Water injection was first used over 45 years ago on commercial
  transport aircraft to increase thrust. Boeing 707-120 aircraft with
  Pratt & Whitney JT3C-6 engines and later, the Boeing 747-100 & 200
  aircraft with Pratt & Whitney JT9D-3AW and -7AW engines, all used
  water injection for thrust augmentation.

This report discusses various techniques for water injection:

ahead of the low pressure compressor. This is the common method for thrust increase in hot and high conditions.
ahead of the high pressure turbine. This is used in cold weather, when injection ahead of the low pressure compressor would run the risk of ice accretion.
together with fuel into the combustor. This technique is commonly used with stationary gas turbines in order to reduce nitrogen oxide emissions.

And NASA-TM-2010-213179 is more specific on the system:

  Four water-injected Pratt & Whitney JT3C–6 engines were used on early
  Boeing 707–120 Stratoliner aircraft to augment takeoff thrust on days
  above 20 °F. This system used a belly tank to store demineralized
  water and an electrically driven boost pump to deliver water to the
  four engines. At that point, an engine-driven mechanical pump
  increased the pressure to about 400 psi for injection before the
  low-pressure compressor (LPC) on days as cold as or colder than 40 °F
  and for injection into the high-pressure compressor (HPC) only on days
  between 40 and 20 °F.

What would happen if kerosene instead of water was filled into the water tanks was tried out by a BAC-111 on September 6, 1971:

  The aircraft collided with a bridge, shearing off both wings, after a
  double engine failure occurred during takeoff. The water-injection
  system to cool the engines during takeoff was inadvertently filled
  with kerosene instead of water.

More recent work on water injection focused on the reduction of nitrogen oxides which form in lean combustion and high temperature. By lowering the temperature level of the combustion process, the nitrogen oxide pollution can be greatly reduced.


Why do wingtip vortices affect the upwash ahead of the aerofoil?

This is a fascinating topic, and it really boils down to the mechanics of lift. Physically, upwash and downwash are generated as the air accelerates/decelerates and curves around the LE of the wing. At the wingtips, higher pressure air curves upward and generate the vortices we are familiar with. In fact, there are vortices generated at the trailing edge of the wing, too, just not as noticeably. Obviously, this picture is unsatisfying since it doesn't give us any insight to lift.

According to the potential flow theory (irrotational, incompressible and inviscid), lift is generated whenever there is a net circulation of air. A particularly successful model, the Lifting Line Theory, models the span of the wing as a collection of U-shaped horseshoe vortices: there's a bound vortex at the span location, and two trailing vortex arms extending to the far field.

So there you have it. A tiny downwash is generated by an individual vortex as it turns the flow downwards at that location, and a tiny upwash is generated as it turns the flow upwards. If you proceed to do the math and sum over all the influences at any point on the span, the net effect is a downwash (which changes the effective AOA and gives rise to induced drag as you mentioned).

If you do the same for a location ahead of the LE, you will get a net upwash, and inverse for TE. This seems intuitive: if you zoom out and treat the whole wing as one single circulation, the circulation should be clock-wise (assume air comes from the left), with air moving upward to the left and moving downward to the right.

There are more complex models, like vortex lattice, vortex panels, etc. But this theory is fairly intuitive and introduces the induced drag. By the way, induced drag is a finite span phenomenon. If you have an infinite span, you fully recover the 2D lift coefficient and the induced drag disappears, even though the vortices remain.


What are the advantages and disadvantages of have the wing positioned further aft on an airplane?

The overall centre of lift must be coincident (in the horizontal plane) with the centre of gravity, otherwise the plane would tip over forward or backward.

Since most planes have a large wing that contributes most of the lift and a small horizontal stabilizer that only contributes a little bit, the main wing needs to be close to the centre of gravity. So the wing is mounted further aft if the centre of gravity is further aft.

Now the cargo will always have its centre of gravity near the centre of the fuselage. So if the empty aircraft has aft centre of gravity, loading it will cause larger change of the CG position and for this it needs larger horizontal stabilizer so it can provide enough balancing force.


The document is about navigation.

By using an online OCR tool (I used this one which is not so good) on page 177 of the document, and then translating from Ukrainian using Google Translate:

... I can confirm @Federico 's suggestion: This figure doesn't introduce a new coordinate system, it just tells about rotating a good ol' geographic coordinate system to facilitate navigation / calculation.

A GCS is defined by its equator, rotating it means the equator is not anymore the Earth equator.

Such frame transformation is also used for INS (SINS) to minimize the accumulation of rounding errors. Just changing the frame orientation allows a better use of the same sensors.

This document says, with fig 7.7, that in some cases, depending on the type of mission or route of the aircraft, it is appropriate to rotate the usual GCS (latitude, longitude) to facilitate calculations and increase accuracy of the results.

An example is, when following a great circle (orthodromy), to align latitude and longitude so that the system equator is parallel to the great circle to follow.

You will easily improve both the OCR rendering and the translation by spending some time on it.

I made this answer a community wiki, so anyone can improve it.


Do I have to notify ATC if I go-around when I was cleared for a touch and go?

From the Instrument Procedures Handbook, page 4-41 (as part of the Missed Approach section), there is a quote about what to do when you need to go around when operating beyond the missed approach point:

  In the event a balked (rejected) landing occurs at a position other
  than the published missed approach point, the pilot should contact ATC
  as soon as possible to obtain an amended clearance.

I have seen several other references in FAA documents which say to "contact ATC as soon as practical" in similar situations, but nothing which specifically says to do it any time that a go around is initiated by the pilot (i.e. under VFR).

That being said, if you have received a specific clearance (for a touch and go), and decide that you prefer to do something else (low approach/go-around), you should always receive an amended clearance first.  If you know ahead of time, your best option is probably to request the "option", in which case you have a clearance to do either one.

On the other hand, if the reason for the go-around is due to a safety issue then execute the go-around immediately when needed, and follow the above guidance to contact ATC as soon as practical if they don't call you first.

I was taught by my flight instructor to always report it, and the tower certainly needs to know about it in order to provide proper separation with other aircraft operating in the area.  If nothing else, it is a "best practice" to ensure that the person in the tower doesn't get distracted and not notice that you didn't land.


In a pusher configuration with turboprop(s), how is the superhot exhaust avoided?

Because the blade is moving in and out of the exhaust stream at high velocity, and the exhaust stream is perhaps 20% of the total exposure, the heat transfer to the blades is negligible from the standpoint of heating up aluminum enough to affect its heat treat, or heating epoxy to its transition temperature.  Meanwhile there are the anti-icing benefits.

There is an issue with the exhaust impinging on the prop on the Avanti, and there is a Hartzel Service Bulletin http://hartzellprop.com/wp-content/uploads/SB181A-R06-W.pdf that covers it.   The carbon and heat from the exhaust attacks the aluminum of the blade and the problem is blade corrosion once the paint finish starts to erode.  The SB is to inspect, clean up, and repaint the blades from this damage.  (Carbon and aluminum are at opposite ends of the galvanic scale and don't like to live together; this caused much grief on the CRJ program when someone who evidently missed their corrosion module in university decided to put carbon floor panels on aluminum support beams without an adequate barrier, with unfortunate results and driving a switch to titanium beams).

Really though, with the Avanti the biggest problem is the prop directly behind the gear acting like a FOD catcher for stuff thrown up by the tires.  You wouldn't want to try to fly an Avanti off a gravel strip, that's for sure.


Can a non-IFR rated pilot accept an IFR clearance, provided the operation occurs in VMC only?

Operating as PIC under IFR always requires an instrument rating and currency, regardless of flight conditions.
14 CFR 61.3(e) requires the rating, and there's no exception for VFR conditions:

(e) Instrument rating. No person may act as pilot in command of a
civil aircraft under IFR or in weather conditions less than the
minimums prescribed for VFR flight unless that person holds:
(1) The appropriate aircraft category, class, type (if required), and
instrument rating on that person's pilot certificate for any airplane,
helicopter, or powered-lift being flown;

61.57(c) requires instrument currency, again regardless of flight conditions:

(c) Instrument experience. Except as provided in paragraph (e) of this
section, a person may act as pilot in command under IFR or weather
conditions less than the minimums prescribed for VFR only if:

See this question for more details on filing IFR flight plans without being instrument rated (not a good idea).
Michael Hall suggested in a comment that some pilots might think that to operate under IFR they only need to file a flight plan and get a clearance, because of the wording in 91.173:

No person may operate an aircraft in controlled airspace under IFR
unless that person has—
(a) Filed an IFR flight plan; and
(b) Received an appropriate ATC clearance.

However, 91.173 doesn't override or invalidate any other regulation. The general rule is that regulations add up and you have to follow all of them unless the wording makes it clear that something doesn't apply (e.g. 91.1(e) says that part 91 regulations don't apply to part 103 ultralights).


Are airliners' cruising altitudes we know indicated or true altitudes?

The altitudes are "indicated." That is the altitude shown on the aircraft's altimeter.

In the U.S. at and above 18,000 feet (known as Flight Level [FL] 180) all aircraft altimeters are set to 29.92 in. Therefore the "indicated" altitude on the aircraft's altimeter (at and above FL180) is also "Pressure Altitude." In other parts of the world "Flight Levels" (where all altimeters are set at 29.92) varies.

"True Altitude" (actual altitude above mean sea level) is not, in an operational sense, used other than a reference for weather reports, terrain, obstacle clearance, etc. It is important, but when aircraft are flying (below FL 180) their altimeters are set to a "local" altimeter setting which adjusts the "indicated" altitude to correspond closely to "true altitude." This eliminates "true altitude" as being an operational consideration.

It sounds complicated, but it really is not.  Just a bit difficult to explain.

The range of cruising altitudes varies considerably for air carrier aircraft.  It would be fair to say that the range is generally between FL290 (about 29,000 ft. msl) to FL 400 (about 40,000 ft. msl).  This varies due to ATC operational considerations, wind speed and direction aloft, and aircraft weight and performance capabilities.  There are times when some aircraft will fly a bit lower or, if the capability exists, fly higher, say FL430.


Is the NTSB hostile to pilots, as depicted in the movie 'Sully'?

I think it is quite unfair to paint the NTSB investigators as villains just for the dramatic effect when nothing of the sort happened in real life.

It is the job of the NTSB to investigate all possible reasons for the accident. It includes pilot error among other things. They were doing precisely that in the actual investigation. Among other things, the NTSB concluded that:

The captain’s decision to ditch on the Hudson River rather than attempting to land at an airport provided the highest probability that the accident would be survivable.

The simulations carried out by the NTSB were part of the investigation and were much more elaborate:

The pilots were fully briefed on the maneuver before they attempted to perform it in the simulator. The following three flight scenarios were flown:
(1) normal landings on runway 4 at LGA, starting from an altitude of 1,000 or 1,500 feet on approach;
(2) attempted landings at LGA or TEB after the bird strike, starting both from zero groundspeed on takeoff from runway 4 at LGA and from a preprogrammed point shortly before the bird strike and loss of engine thrust; and
(3) ditching on the Hudson River starting from 1,500 feet above the river at an airspeed of 200 kts.

Note that the NTSB clearly mentions that the pilots were briefed before the simulation. NTSB noted clearly in its report that immediate turning of the aircraft after the bird ingestion did not reflect what could've been done in real world:

The immediate turn made by the pilots during the simulations did not reflect or account for real-world considerations, such as the time delay required to recognize the bird strike and decide on a course of action.

The simulations (along with the case where there was a 35 second delay to account for pilot response) was done entirely by the NTSB with no input whatsoever from the flight crew. As The Guardian notes:

And then the investigators – not Sullenberger – asked a pilot to wait 35 seconds before attempting an airport return. That flight didn’t make it. Consequently, the NTSB was unequivocal in its declaration that the Hudson was the right call.

Actually, the movie was so inaccurate in the portrayal of the NTSB that the real people involved asked the names of the investigators in the movie to be changed:

... a draft script included the names of real-life NTSB officials, but Sullenberger - who is an adviser on the film - requested they be taken out.
He said, ‘These are people who are not prosecutors. They are doing a very important job, and if, for editorial purposes, we want to make it more of a prosecutorial process, it ain’t fair to them,”’ said Hanks.

There is no evidence to determine that the NTSB acted in the interest of insurance companies (or anyone else) in this investigation. The situations in which an insurance company is liable depends on the particular policy (as far as I know, liability is usually for negligence).
While the investigation may not be perfect, there was no kangaroo court anytime during the investigation. There was no attempt at public lynching, as The Guardian notes:

In fact, in his memoir, Sullenberger reflects that he was “buoyed by the fact that investigators determined that Jeff and I made appropriate choices at every step”

There was no cover-up by the NTSB and there was no Kangaroo court (you can easily look up the public hearings in this case) to pin everything on the flight crew on behalf of somebody else. Though not perfect, there is nothing to suggest that the investigation was not conducted professionally.
It is sad that the movie portrayed officials performing their duty as villains just because it was decided that the people would rather have the ancient good Vs evil show in the movie rather than the truth (while I'd have to agree that the movie would've looked more like documentary otherwise, that is no excuse).
The problem though, is that more people will be seeing the movie than reading the report or looking up the actual investigation that people will have a entirely uncalled for negative opinion of the NTSB, which may affect the future investigations. As Robert Benson who carried out investigation on the Flight 1549 noted in an article:

"I do not know why the writer and director chose to twist the role of the NTSB into such an inaccurate depiction. .... The movie may actually be detrimental to aviation safety. Pilots involved in accidents will now expect harsh, unfair treatment by investigators. They and others who see the movie will now believe that the NTSB enters into any investigation with preconceived notions, and that we are intent on destroying reputations. Simply untrue. The NTSB is the best friend an airline passenger never gets to meet."


What is the approximate thrust at sea level for a C-130J Hercules?

Okay guys, so I found some data from an old service publication from Lockheed. It says that the new C-130J propulsion system under standard conditions and flying 80 kts is rated "4,637 SHP, but produces 10,200 lbs".
So using the equation for thrust available for a propeller aircraft I get:
$T_a = \frac{\eta \cdot P_s }{V}$
with:
$T_a = $Thrust available
$\eta =$propeller efficiency
$P_s =$shaft power
$V=$air speed
$\eta = \frac{T_a \cdot V}{P_s}$
$\eta = \frac{10200 \textrm{lbf} \cdot 80 \textrm{kts}[ \textrm{aka. }135 \textrm{ ft/s}]}{4637 \textrm{shp} [\cdot 550 \textrm{ conversion}]}$
$\eta = 0.54$
This seems quite low but its what I got for anyone wondering. The service publication I got the info from is this:
https://www.sikorskyaerospace.com/content/dam/lockheed-martin/aero/documents/sustainment/csc/service-news/sn-mag-v21-v30/V25N03.pdf


How far away from the airport is the descent for approach and landing initiated?

As J. Hougaard said, 3 nautical miles per 1000 feet is the general rule. However, large aircraft that can vary greatly in weight may vary that figure. Also, best to factor in whether tailwinds or headwinds in the descent.

In 747-100/200 freighters in the 1990s, we used the 3 nautical miles per 1000 feet most of the time. However, if we were heavy, i.e. we would be landing right up against the max landing weight, we would use 3.5, and especially if we would be descending in a tailwind. If we were light, in other words no cargo, 2.5 was a good figure to use. And, of course, you didn't have to use exactly 3.5, 3.0 or 2.5. What I often did was figure the 3.0 distance and then just add or subtract 10 miles or so.

In one memorable instance, I used 2.0 and it worked, but just barely. I had heard that if you had an empty aircraft and used a maximum drag procedure it could be done. I only had a chance to try it once going into Hong Kong's old Kai Tak airport on a clear day with no traffic, straight in to rwy 31.


What is the peak of coffin corner called?

Yes.

The peak is the actual coffin corner. That's why it is called a corner.

In the coffin corner the aircraft cannot climb any higher, which is a definition for the absolute ceiling. Going any faster will reduce L/D and cause the aircraft to sink; that Mach effects are involved is of minor importance. Going slower will also decrease L/D because the aircraft is approaching stall.

What is special about the coffin corner is not the corner itself, but what happens when the aircraft gets too fast: Now stronger shocks will increase drag and decrease the maximum lift coefficient such that the aircraft is locked into a shallow dive from which it is initially not able to recover. Going too fast while flying at the "regular" absolute ceiling merely means that you will lose some altitude but not lose control.


It's the sensor of the IRST (InfraRed Search and Track) system.
An IRST allow an aircraft to search and track aerial or ground targets using passive infra-red radiation only thus reducing the probability of being discovered (for example using a Radar Warning Receiver).

The Su-27 can use it's IRST to track a target at very long distance and engage it using IR homing AAMs like the R-73 "Archer" or the R-27T / R-27ET "Alamo" without using its radar.

Nowadays, many current fighter aircrafts use some sort of IRST, for example the Eurofighter Typhoon.


What would happen if an aircraft were to touch down on EMAS?

will the plane's momentum carry it on to the main part of the runway unharmed?

An aircraft landing on the EMAS must not suffer control problems.

According to an EMASMAX document

  FAA Advisory Circular (AC) 150/5220-22A
  ...

  No adverse aircraft affects in the event of short landing
  ...

The referenced document doesn't state this but does say that EMAS should be set back from the runway end and

  must not cause control  problems  for  aircraft  undershoots  which  touch
  down    in    the    EMAS    bed.

According to RUNWAY SAFETY AREA PROJECT - IGOR I. SIKORSKY MEMORIAL AIRPORT,
there is only a three inch reveal at the transition of EMAS bed to runway. So a landing gear transitioning this part this part would likely not be catastrophic. I imagine crushed EMAS material still has some thickness.


Do the ICAO and IATA codes for an airport ever change?

Yes it does happen.

A city can build a new airport, in which case it will usually get a new ICAO code, but will get the original IATA (city) code. For example, Oslo changed from Fornebu to Gardemoen - Fornebu is ENFB, Gardemoen is ENGM; the OSL code was Fornebu but uis now Gardemoen.
A city can rename its airport for political reasons, so again the codes are liable to change.
Example 1 is New York - Idlewild KIDL was change to John F Kennedy KJFK
Example 2 is Johannesburg - Jan Smuts International was FAJS, then renamed to Oliver Tambo International FAOR.


How did the two F35 planes get from Fort Worth to Williamtown?

The two aircraft had been delivered to the RAAF at Luke in September and October and delivered to Williamtown via Hickam Air Force Base in Hawaii and RAAF Base Amberley, south-east of Brisbane.

From Defense News.


It looks like the "weather product age" for NEXRAD weather data, i.e. how old the current data you're seeing is (see Pilot's Guide, p.13). The number is contextual, based on the weather information type:

The age of the displayed weather product—or the effective time of
Winds Aloft predictions—is shown in the upper right corner of the
display. For example, if NEXRAD is displayed, “0:05” indicates that
the data are five minutes old. If Winds Aloft predictions are being
displayed, “10:00” indicates the effective time for the displayed
prediction is 10:00 AM.

In the first image, the data is 15 minutes old, in the second it's 6 minutes old.
The information and images on p.72 show that NXRG is "Region NEXRAD" and NXCO is "CONUS NEXRAD". P.70 also mentions NXRD, which seems to be just "NEXRAD" and it's used when no data is available.
As for the color, the manual says:

When the age of the displayed XM Weather product reaches one half of
its expiration time, the color of the displayed time changes from
green to amber

NEXRAD data is good for 30 minutes per the Guide, and that matches with the color change at 15 minutes in the first image.
Note: although the manual talks about SiriusXM providing NEXRAD data, ADS-B radar data is also from NEXRAD. Presumably the display uses the same abbreviations, regardless of which service provides the NEXRAD data.


What are typical airspeeds and lift coefficients for UAVs at different flight stages?

Observation UAVs are flown in a narrow range of lift coefficients. This can be seen from their wings: Like glider wings, they have a very high aspect ratio and a highly cambered airfoil. If you look at the optimum speeds for propeller and turbofan-powered aircraft, a high aspect ratio drives the optimum lift coefficient to high values which translates into a low calibrated air speed. Note that flying high does not necessarily mean that they operate at a low true air speed, however. Details depend on the altitude in which they are operated.

Let's look at the MQ-1 Predator for an example. Its aspect ratio is 19, and with all the protrusions I would guess the zero-lift drag coefficient to be no less than 0.025. This means the optimum lift coefficient for loiter is close to 2, which is probably above the maximum lift coefficient of the wing airfoil. For piston powered aircraft the best climb speed is identical to the optimum loiter speed, so the Predator should be flown close to its stall speed of 54 knots over the whole mission in order to get the most endurance out of this airframe. Note that the maximum g force the airframe can withstand is only 2, which means that top speed needs to be limited to 76.4 knots in order to avoid structural damage from flying into gusts.

Another giveaway is the low ground clearance of the tail surfaces: The predator lands at its regular flight attitude; there is no need to slow the aircraft down when it comes in for landing.

Short answer: The lift coefficient in all flight stages is high (0.8 to 1.4) while the true airspeed depends on the altitude. Turbofans tend to fly faster than piston-powered aircraft, but the difference is marginal.


Which 737 generations doesn't have Alpha Vane (Angle of Attack sensor)?

I have experience on the 737 -100,-200, Classic, Next Gen and the Max8 and even the 707 every one has an AOA sensor.  Different part numbers to be sure but they still have them.

Obviously it senses angle of attack and feeds numerous systems: stall warning and auto slat come to mind immediately.


Which air traffic controller is responsible for a taxiway between parallel runways?

Typically, neither. A separate controller, "___ Ground," controls taxiing traffic. On a big enough airport such as Denver (KDEN) or Atlanta (KATL), there may be more than one ground control, each on its own frequency. Their domains are split geographically: one controls east (DEN) or north (ATL) of the terminals, while the other controls west or south.
At some airports, though, a single Tower frequency owns both parallel runways, for example Austin TX (KAUS), and in San Francisco, one controller works all four runways (1L/R and 28L/R). No rookies working that position!


How are the IFE Server, Floor Disconnect Box (FDB), Seat Electronic Box (SEB) and Seat Display Unit (SDU) connected to each other?

Airbus IFE system

All data sources and servers are concentrated in the IFE Center which delivers them to the cabin LAN using Ethernet. The LAN itself is Ethernet.

Some data are received by the IFE Center from the Cabin Intercommunication Data System which is itself connected to AFDX (Ethernet, ARINC 664) ADCN network.

The cabin network then distributes data and power to overhead displays and seat IFE units.

Schematic:

Source, page 15

Architecture:

Source, page 15

IFE System for the A350

The IFEC rack is the source for all data sent to the passengers IFE units and the flight attendants panels. It contains files and media servers, is linked to external cameras (ETACS), landscape cameras and SATCOM.

IFE: In Flight Entertainment
IFEC: In Flight Entertainment Center. A system with redundant sources and redundant outputs.
ETACS: External and Taxiing Aid Camera System
SATCOM: Satellite Communications

The IFEC is also interfaced with the CIDS which supply it with data from systems like CDAU and ADIRS and other aircraft systems using AFDX, engine data from PCS, or discrete signals like cabin systems (oxygen) or public address.

CIDS: Cabin Intercommunication Data System, the main way for attendants to control the cabin systems other than IFE.
CDAU: Centralized Data Acquisition Unit
ADIRS: Air Data/Inertial Reference System
AFDX: Avionics Full Duplex Switched Ethernet (ARINC 664)
ADCN: Avionics Data Communication Network
PCS: Propulsion Control system

IFE power is supplied by some SPDB.

SPDB: Secondary Power Distribution Box

The IFEC and SPDB are controlled by ICPs, FAPs, CWSs and RCCs.

ICP: Integrated Control Panel (in cockpit)
FAP: Flight Attendant Panel
CWS: Cabin Work Station
RCC: Remote Control Center

The IFEC delivers data (audio, video, other data) as Ethernet frames to FDBs using a switch. There are actually two or more IFEC switches, each one feeds some FBDs.

FBDs also receive power from the SPDB. Ethernet frames and power are distributed by FDBs to overhead displays and IFE units.

FDB: Floor Disconnect Box. Used as a switch to create the network. FDB ensure network redundancy: Each FDB receives data from one IFEC switch, but as FDB share the same network, IFEC is still available when one of its switch is failed.

Each seat gets its IFE unit which is connected using a SEB. The IFE unit encompasses the SDU, the PCU and headset.

SEB: Seat Electronic Box. A network interface card, with power management.
SDU: Seat Display Unit (touch screen in front of the passenger)
PCU: Passenger Control Unit (interface)

The big picture:

Source

Security aspects

Your question was motivated by the security aspects of the cabin network vs. the other aircraft domains (e.g. avionics or cabin systems).

For Airbus, the cabin IFE network is only a layer 2 LAN with multiple Ethernet segments linked by Ethernet switches. There is no possibility to route malicious packets to other domains, since there is no routable (layer 3) protocol.

The interconnection between IFE and other systems is made through the CIDS, which is based on a redundant "director" which controls data destination. Without other elements, the assumption is security is primarily at CIDS level.

More information in this presentation (some pages are in German, most are in English).


Why is fuel quantity expressed in flight hours

It’s primarily due to wind.
Aircraft move through the air at a certain speed, which makes it tempting to give range in miles (or kilometers), but the air itself is moving as well, and often at a large enough fraction of the aircraft’s airspeed that it materially affects range across the ground.
For instance, say you have a Cessna 172 with four hours of fuel (plus reserves) and a cruise speed of 110kt. With a 30kt tailwind (140kt ground speed), your range is 560nm. But going the opposite direction with a 30kt headwind (80kt ground speed), your range is only 320nm—just over half as far!
To make it even more complicated, the winds will have different directions and speeds at different altitudes and locations, and all of that changes over time too, which is one of the reasons pilots (or dispatchers) have to carefully plan each flight’s route and fuel load, even for a “fixed” daily route between the same two airports.


Are there all terrain landing gears for planes?

The closest anyone has come to something that could be called a feasible all-terrain gear is the Air Cushion Landing System developed by Bell Aerospace and tested initially on a Lake Buccaneer, which lead to a test of a system Bell developed for the DeHavilland Canada DHC-5 Buffalo under a joint program between DH, the Canadian Govt, and the USAF.

The cushion was inflated by a pair of P&W PT-6 turboshaft powered inflation sytems (a kind of ducted fan setup), which are in the sponsons on each side of the fuselage.  The testing was completed in 1977.  I dimly remember that the biggest problem with the system was wearing out of the bottom surface of the cushion (it wasn't open like a hovercraft skirt, but more like an air mattress with an array of holes in the bottom, and the bottom surface would brush the ground and wear out really fast).  That and the obvious performance penalty issues (you're giving up a lot of payload to haul all that gear around) kind of killed it.
It could take off and land on any flat surface, and being a Buff, only needed a few hundred feet of space (the DHC-5 Buffalo could land and take off from a soccer field, and the normal version once did so in a civil defense demo in New York City, causing numerous calls by apartment dwellers to report the "crash" in a park).
I worked on this airplane as a mechanic when it returned from the test program to DH in 1979, removing the tip floats and the cushion system and patching the fuselage up before it was returned to its RCAF operating squadron.


Is Naproxen (medication) approved for flight?

There's no fully authoritative source for this information, other than consulting an AME directly. AOPA's medication database is considered pretty reliable (and it says Naproxen is allowed) but their generic disclaimer explains why you can't just look up a medication in a list:

  Although these medications are generally allowed by the FAA for flight
  duties, there are variables with each individual's situation that
  could render a particular medication inappropriate for flying because
  of case history or adverse side effects. Some medications are being
  used "off label". This means that a drug is prescribed for symptoms
  that do not fall within the FDA's approval guidelines for that drug.
  This is just one example of why the FAA might not approve a drug that
  is on the list.

In other words, as with all medical questions you have to consult a  professional to get the right answer for your personal situation.


How does turning a small plane by opening the doors work?

The second explanation is right. The blocking effect of the door below the wing will force more air above it, so suction and lift above get higher. Of course, the blocking effect will also increase pressure locally on the lower side of the wing.

If you do the same on a low wing aircraft, it will roll to the opposite direction. Now the door acts like a spoiler and reduces lift.

Generally, such a one-sided creation of a disturbance will upset the aircraft and will make it roll and yaw in an uncoordinated manner. And the "rudder" explanation is wrong - a rudder creates a sideforce at a distance to the center of gravity, while the door is pretty much where the pilots and the center of gravity are. The better explanation would say that the door acts like a spoiler, and those are used routinely for roll control:

in airliners
in unmanned vehicles


Does a rotating control surface change the wing area?

TL; DR: It depends on the specific assumptions of the aerodynamic model, but normally wing area is considered constant.

Wing area normally is defined as fixed, and the CL is given so that any control surface deflection results in a change in lift curve, i.e. CL, only. One could equally attribute the change in total lift following a control surface deflection to an associated change in surface area, and then the resultant new CL to go with the deflection would accordingly be of different magnitude, so as to yield the same total lift.

It is a convenient general convention as far as I know, to consider wing area (also very appropriately dubbed as reference area) as constant, because it essentially eliminates one variable from the model.


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

The Aviation Safety database lists 91 accidents due to turbulence as of writing. None are on Airbus aircraft. The most recent in flight breakup of a transport aircraft listed was in 1993.

All of the aircraft in your examples are fairly old designs, dating back to the 60's or earlier. Your statement that the A350 has the exact same design requirements as an F-27 is inaccurate. While the load factors required for certification may have remained constant, the actual loads aircraft must be designed to survive have changed over time. As an example, for transport aircraft, the FAA regulation on gust and turbulence loads is 14 CFR 25.341, which has been updated 3 times since it was originally introduced in 1965. For the F-27 incident in Alaska, one of the factors noted was cracks in the wings from a lack of maintenance. Maintenance has been improved since then, as has the durability of aircraft designs. As accidents happen and the industry learns from experience, designs improve to better anticipate the conditions that aircraft will actually experience.

Other than the DC-8 in your last link, all of the occurrences happened in the 60's. Apart from the design of the aircraft, a lot has changed operationally since then. Weather radars have improved dramatically, both on the ground and on the aircraft. Modern radars have a much better ability to detect turbulence, even clear air turbulence to a degree. They have also become much less prone to operator error. Weather satellites now provide information on weather even in remote areas. Forecasts have improved as well, providing pilots and dispatchers a better idea of areas that should be avoided.

Below is an example of the kind of information that modern radar systems can provide to pilots about weather conditions in their path.

Source


Are task cards still used in aircraft maintenance?

I just watched Engineering Giants - Jumbo Jet Strip-Down, following a British Airways 747 on its D-Check in 2012.

At least for BA, it would seem that paper task/job cards are still heavily used. Apparently there are over 12,000 individual jobs.

I've taken a short (7 secs) clip from the episode, showing walls full of task cards:


What is the difference between a partial stall and a full stall?

For GA aircraft with straight, rectangular wings, the stall usually starts at the root and progresses towards the tip. So, at some point, only a portion of the wing will be stalled. This is sometimes referred to as partial stall, though it is not a common term.

Image from boldmethod.com

This is usually achieved by having a washout or a wing cuff. In case of root-first stall, the wing tips are still producing lift, helping to prevent rolling motion (which may occur if the whole wings stalls at once), which in turn prevents the aircraft from entering a spin.


Stalls: which flight control surface is effective last?

It depends on the type of stall and the loading configuration of the aircraft. The short answer is that the rudder typically stalls last because the angle of attack of the wings is independent of the AOA of the vertical stabilizer. However it's usually among the least effective control surfaces in getting out of a straight dive (very useful for recovering from spins and spiral dives though).

Of the horizontal surfaces, it depends on which one has a higher AOA at the time the wings stall, which is dependent on how the plane entered the stall, and how the aircraft is configured. A sudden pitch-up in an airframe with an aft CG will cause the horizontal stabilizers and thus the elevators to depart first. In most other situations especially when the CG is forward of the CL, the wings will have the higher AOA as the nose pitches downward, so the elevators will remain useful as long as the tail isn't caught in the turbulent airflow off the wing. T-tails have this disadvantage; the higher tail location normally puts the tail in cleaner air, but in a stall the turbulent air off the wing shelters the tail making it less effective.


Your question is based on an incomplete picture of how aircraft work, I'm afraid.

As a passenger on any major airline, the only lead you are likely to encounter is in the shielding on the security x-ray machines.

Fact: leaded fuel is relatively uncommon

First, tetraethyl lead is only present in what we call avgas - it is most often sold these days as 100LL (100-octane low-lead) aviation gasoline. Avgas is only used in piston (reciprocating piston) engines. Very few commercial aircraft in this day and age are powered by piston engines; most airliners are turbine-powered (jet or turboprop engines) and are fueled by Jet A, a variation on kerosene.

Fact: exhaust shouldn't be in the cabin anyway

Second, even if you happen to be flying in a light aircraft with a piston engine (or old, think Douglas DC-3 in Alaska), you shouldn't actually encounter any lead. The cabin air intakes are positioned intentionally to avoid any exhaust entering the cabin.

If exhaust carrying lead particles was reaching the cabin, you've probably got bigger and more immediate problems with carbon monoxide poisoning anyway.


What is the procedure to climb and level off using a Bendix/King KAP140 autopilot?

Only the KAP140 two-axis autopilot with altitude preselect supports capturing a preselected altitude (which is the one installed in the Cessna 172 before the introduction of the Garmin GFC700)

Preselect the desired altitude using the altitude preselect knob, switch to VS mode, select the desired VS and the AP will switch to altitude hold mode when the preselected altitude is reached.

Taken from the manual.


Can I apply for ASEL and Glider class ratings at the same time?

You "apply" for a rating or certificate by showing up at the examiner with proof of your written test and taking a flight test -- so of course you can only do one at a time! But I think you want to know if you can train for both airplanes and gliders at the same time, under the authority of the same student pilot certificate. Yes you can do that.

However I do not recommend it. They are very similar of course, but there are enough differences that while you're learning to fly, you should just pick one and get your certificate. Then learn the other.

If you want to fly both airplanes and gliders, there is no particular order that is better than the other. I fly both airplanes and gliders; I happened to do airplanes first because there was no convenient glider field close to where I lived at the time. Now I fly both and I feel they complement each other and it's great!

But while you're learning, pick one and get it done; then do the other one.

(This may only be correct with the FAA in the US. And to be fully FAA-pedantic, Airplane and Glider are "categories"; "single-engine land" is a "class" that is available in the Airplane category. Thus ASEL is category-and-class, but Glider is just category.)


Is airfoil thickness proportional to drag coefficient?

There are several reasons for using thick$^*$ airfoils.

Slow planes need high lift coefficients in order to fly slow. The increased drag coefficient is the prize to pay for a higher $C_{L,max}$. Take a look at this diagram:

Source: H. Schlichting, E. Truckenbrodt, Aerodynamik des Flugzeuges. Colors added.

At low Reynolds-Numbers the maximum lift coefficient is achieved by the thickest airfoil (18%). At slightly larger Re-Numbers the 12% thickness airfoil gains the upper hand. However, the thinnest airfoil (9%) has on average about 20% less maximum lift capability than the thicker ones.

The following diagram shows polars of symmetric airfoils with different thicknesses.

Source: B. Rögner, Flugwissen. I couldn't find the original source Rögner took the diagram from, if anybody knows it feel free to comment.

The quality of image is bad, but you can recognize both the higher $C_{L,max}$ and drag coefficient of thick airfoils.

The drag coefficient depends on many factors and, as shown in the formula given in Peter's answer, is not proportional to the thickness. The drag coefficient's thickness dependency however, can be assumed to be proportional to the thickness: the $\delta^4$ term is one order of magnitude smaller than the term multiplied with $\delta$.

$$\frac{c_{D,\text{normal airfoil}}}{c_f}=2+4\cdot\delta+120\cdot\delta^4$$

$$\frac{c_{D,\text{laminar airfoil}}}{c_f}=2+2.4\cdot\delta+140\cdot\delta^4$$

In Hoerner's Fluid Dynamic Drag, Chapter 6.A.2, you can find more formulas to approximate the drag coefficient and take other parameters into account.

A good resource for understanding the influence of airfoil parameters on their aerodynamic properties is NACA TM 824.

Stall behavior of thicker airfoils is usually more forgiving.
Another reason for using thick airfoils is that it decreases the wing's weight, as thick structures can carry better the bending loads in a wing. If a wing tank is used, thicker airfoils allow for a higher tank volume.

$^*$: I interpret thick as >12%, e.g. 15% as found in the wings of many GA airplanes.


Was there any progress in ramjet-powered helicopters after 1960?

Tip jet rotors are still being developed, none of them are ramjet powered as far as I know. The Dragonfly DF1 is tip rocket powered, while the Pegasus uses air jets powered by a conventional engine.

Ramjet technology has not improved, so the cases for using them on rotor tips has not changed. They are still too heavy, thirsty and noisy.


Do airlines in Middle East use higher cost indexes?

Not all of the Middle East countries are oil rich. And recent developments highlight that there's a shift away from an oil-based economy. Most recently Saudi Arabia introduced taxes for the first time, with a 83-127% hike in petrol prices. And Dubai introducing VAT also for the first time.

An in-depth analysis of Emirates' financials as of Jan 2017 can be found here, in an article titled, 'Is Emirates in trouble?'.

  Jet fuel is still the highest operational cost item but has declined sharply since 2014/15.

They also had issues with yield and load factors. It's a business like any business, if you can't fill the seats, you're not making money.

Here are the latest fuel prices from IATA as of 2 Feb 2018:

A metric-ton is \$17.7 cheaper than the most expensive region. So for a long-haul that needs say 100 tonnes of fuel, that's a saving of \$1,770. But, don't forget that when a Gulf carrier flies to anywhere outside the region, they'll fill up their tanks there, likewise for say a European carrier filling up in the Middle East.

It may be more beneficial to a regional low-cost carrier though. But since short flights are not as affected, any little saving will help towards a profit. Also note a high cost index is not just about cheap fuel, but also expensive maintenance. It is used when the flight-hours need cutting down as the plane ages. A low cost-index could also be used to delay the arrival to let a storm subside (even with cheap fuel on board). It's complicated.

Taking Emirates for example, when they fly westbound with the cheaper fuel, they could use a higher cost index to offset the headwind, and on the return, a low cost index to offset the more expensive fuel they picked up, but since now they are in tailwind, the time penalty won't be big.

As for the exact cost indexes, that information is not public, and with the aforementioned developments and putting the fuel costs in perspective, I hope that helps.


It's most likely a Boeing B-29 Superfortress. It was a strategic bomber used by the US in the Pacific theater of World War II. The lower row of four windows and then another further aft matches pictures of the B-29. The "U.S. AIR FORCE" markings are a post-WWII style.

Source

It's also possible that it's a B-50 Superfortress. This was an upgraded version of the B-29 with new engines and other changes that are hard to see in the picture. Only 370 were built. Although it's not clear when the picture was taken, and only 5 examples of the B-50 still exist. The B-29, on the other hand, has way more.