texts: What is the main difference between an ETOPS certified and non-ETOPS certified plane?

texts:
ETOPS stands for Extended-range Twin-engine Operational Performance Standards, a rule which permits twin engine aircraft to fly routes which, at some point, are more than 60 minutes flying time away from the nearest airport suitable for emergency landing.

However, it does not mean that a non-ETOPS plane physically cannot fly an ETOPS route, as American Airlines proved when they accidentally used a non-ETOPS certified plane to operate ETOPS-required LAX-HNL route. Everything went well except the cancelled return flight.

So, what is the difference between an ETOPS certified plane and a non-ETOPS certified plane when they are the same model?


texts: How does flying at ECON computed speeds optimise fuel burn.?

texts: I read in the FCTM GREEN OPERATING PROCUDURES that it’s recommended to fly at ECON computed speeds throughout the flight profile to optimise speed in accordance with the CI.


texts: What is the one-engine-inoperative maximum range flight configuration?

texts:
I was talking with a friend about what things would happen if you experienced engine problems in cruise. We were wondering the following:

What things would need to be changed to arrive in the optimal configuration for range?

Here I found that the speed is reduced to approximately 80% of the normal cruise value, but I can image that more things change, perhaps the altitude?


texts: What is the relative safety record of the Sukhoi Superjet 100?

texts:
After the last crash, numerous articles state that the Superjet has a poor safety record. Two fatal crashes in 8 years is not a lot, but then again, only around 150 planes have been delivered. Does anybody have numbers of fatal crashes pr. million flights, or similar?

Accidents pr. million flights for other major airplane models: http://www.airsafe.com/events/models/rate_mod.htm


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

texts:
I have this study question on the FIA written:

Which statement is true concerning the aerodynamic conditions which occur during a spin entry?

Correct Answer: After a full stall, the wing that drops continues in a stalled condition while the rising wing regains and continues to produce some lift, causing the rotation.

Incorrect Option: After a partial stall, the wing that drops remains in a stalled condition while the rising wing regains and continues to produce lift, causing the rotation.

Because the only difference between the two answer options is 'full' and 'partial' I was wondering what are the differences between a full stall and a partial stall?


texts: What is the difference between CAN and ARINC?

texts:
I want to know the difference between CAN and ARINC, I'm confused about their usage.

For example, the communication between the cockpit and the controllers is done using ARINC protocols. And the data transmitted by probes to the controllers goes over CAN. Why use a different protocol in each case? When is each protocol used?


texts: Why do uncontained engine failures still occur?

texts:
One of the absolute requirements of an aircraft turbine engine (usually some sort of turbofan or turboprop) installation is that, in the event of a destructive failure of the engine, the engine cowling must be able to contain any and all fragments released in the process.  In layman’s terms: engine blow up, engine parts stay in cowling.  The cowling’s ability to contain an engine disintegration must be demonstrated in testing.  All of this has been the case, without exception, for decades.

And, yet, uncontained engine failures continue to occur.  As recently as October 2016, a 767’s engine exploded during takeoff.  (Yes, I know about the one with the 737 earlier this year, but that one’s still under investigation, and, as such, off-topic until the NTSB releases their final report.)

Why is this?  It can’t be for lack of testing capability, as the engine manufacturers can and do – indeed, are required by law to – blow up engines in their test stands to verify their inability to escape their cowlings, and causing an engine failure for such a purpose is ridiculously easy: wrap some detcord around a fan or turbine blade (to test against the engine throwing a blade), tie it to a fan or turbine disk (to test against one of the rotors seeing fit to come apart in flight), or wrap it around the engine shaft (to test against a shaft separation and consequent turbine overspeed and disintegration, LOT 007-style), run the engine up to full blast, and push the button.  So why do engine cowlings still sometimes fail to contain rapid unplanned engine disassemblies?


texts: What is a normal EGT range of a jet engine?

texts: Out of curiosity at what temperatures are the exhaust gasses are expelled from jet engines? A normal reciprocating engine from what I recall should be in the 700 - 1100 degrees Celsius range. Does this apply to turbofans/turboprops/turbojet engines also since the fuel properties should be similar? Or are the temperatures much lower as the engine is being used mostly at high altitudes?


texts: What makes the loss of a flap track fairing strongly increase fuel consumption on Airbus planes?

texts:
Inspired from this question about the loss of a flap track fairing.

In the answer by Thunderstrike, a part of the configuration deviation list of an Airbus A320 is linked. In it, it says:

  One fairing may be partly or completely missing.

  Performance

  Fuel consumption is increased by 3.14%

That really is a lot!

I found a post on Airliners.net citing the CDL of a B757:

  Straight out of the MEL/CDL manual for the 757, The item falls under CDL 27-51-1 which states there are 6 installed [Flap Track Fairings, Remark] on the aircraft and up to one per side may be missing. No fuel burn penalty but there are a few small weight penalties, no speed penalty. Our A-300's with the same CDL item does have a 1% fuel burn penalty and only one can be missing out of the 10 installed. I see this item come up 3 or 4 times a year, no biggie.

What causes this very high increase in fuel consumption on Airbus planes?
What are the differences between the fairings of a Boeing and an Airbus (because Boeing has no increased fuel consumption, Airbus has)?


texts: What causes the phase to change in a VOR?

texts: I get the light house analogy, and how the VOR essentially works, although I'm wondering what actually causes this phase shift? As it hits magnetic north the variable and reference signal are in phase, as it continues it begins to go out of phase. What's causing it to go out of phase? Is it using constant frequency modulation, where both are being constantly modulated, and at a certain point they both hit the same frequency for a second?


texts: Why does GBAS broadcast Final Approach Segment data when SBAS does not?

texts:
Ground Based Augmentation Systems broadcast message four, the Final Approach Segment, along with corrections for GNS signals in messages one and two. Since the FAS is essentially a semi-static approach plate, it seems like it could be distributed by subscription along with all the other info in a flight database instead of wasting VHF link bandwidth as it does. In fact, the Satellite Based Augmentation System uses the flight database subscription method.

For SBAS, the FAS data block is stored in the aircraft’s navigation database, while for GBAS the FAS data block is broadcast as a VHF data message.

What was the purpose for the GBAS design choice? It is impossible for the SBAS system to do this, but once the less constrained method was established, it seems like both systems should use it.


texts: Why increase the number of cylinders in an engine instead of increasing their volume?

texts:
I've been reading about WW2 planes lately. Some of them have 12 or even more pistons in their engines.

But if your goal is to increase power, why would you add more pistons instead of simply increasing the size of the cylinders?

Example: The P-51 Mustang had a V12 engine with a total displacement of 27 liters. So that's 2.25 L per cylinder. Instead, why not have a V4 engine with the same total displacement, which would have been 6.75 L per cylinder?

Correct me if I'm wrong, but...

Such "collectivizing" of the cylinders would be more efficient for a number of reasons. The friction of piston rings scraping the cylinder would be less, meaning less oil and more power. The crankshaft and related things could be shorter. I believe it would be lighter for another reason too: the surface area goes up less than the volume (squared versus cubed). Probably the engine as a whole would be simpler.

I believe this concept can be applied to radial engines as well as inline engines. I made an assumption that 4-stroke engine needs a minimum of 4 cylinders. Today that is not true but during WW2 with the technology of the time, I'm not sure. There were radial engines with 3 cylinders. I'm unaware of any 4-stroke engines with 2 or less cylinders in that era.

Anyway, why not just make the cylinders bigger?


texts:
What is typically the limiting factor for how large a crosswind component a given plane can be safely landed in?

My impression is that larger planes are less sensitive to crosswind than smaller ones -- for example, many commercial airports seem to be doing quite well with a single or multiple parallel runways for transport-category aircraft, whereas airports catering to light aircraft will be proportionally more likely to have (and routinely use) a system of intersecting runways.

I can imagine one reason for this, namely that a plane with a higher landing speed will need less of a crab angle for a given crosswind component. But is this actually the determining factor?

If yes, then is is safe/legal/practical to land a light aircraft in more crosswind than it can usually handle, by landing faster, assuming there's a nice long runway available to decelerate on? (In other words, can an airport make up for having no crosswind runway by having a longer primary runway instead?).


texts: Why was the Yak-9U covered with Bakelite?

texts: According to Wikipedia the entire Yak-9U was covered with Bakelite (not sure if it was just that variant, the page isn't clear). What was the reason for this and was Bakelite used as a coating on any other aircraft?


texts:
Some airplanes have a button for the "yaw damper."

What is the yaw damper?
When is it used?
Is it ever required for certification or operation?
How does it work?


texts: Why does ATC ask a crew who has declared an emergency if their aircraft will be overweight when landing?

texts:
I have heard ATC ask an emergency aircraft if they will be overweight when landing.
Why do they ask?
I am not asking about the consequences of an overweight landing or what procedures are required following one, but rather why ATC would ask for this in advance of the landing.

E.G.

Does ATC take it into account when offering a runway?
Does passing it on to emergency services somehow allow them to be better prepared than if they were informed after the fact?


texts: Can I count solo complex time as complex training time for a commercial certificate?

texts: Does a combination of both dual and solo hours in a complex aircraft (PA28R-180) which total 10 or more flight hours meet the commercial pilot training requirements of FAR 61.129(a)(3)(ii) or must all the hours be dual instruction?


texts: Which air transport aircraft have a lavatory included inside the cockpit?

texts:
Another answer on SE Aviation (Why pilots would leave the cockpit in a short flight?
) had this bit of information in it:

  The cockpit of some airliners lacks a lavatory.

Isn't is more the other way around: i.e. A Lavatory inside a cockpit is a rarity?

Which airliner cockpits have an entire Lavatory inside them?

I always thought the Flight Crew came out to use the forward-most Business / First class lavatory.


texts: Can I do a CAT III ILS approach if minimums are above CAT I?

texts: I was going to an airport with weather at minimum for CAT I approach. Not wanting to know whether or not I could make it I thought about asking ATC if I could do a CAT III approach even though the weather was still above minimum for CAT I. Eventually the weather got better but my question is: Could I have requested from ATC and be granted a clearance for a CAT III approach (abiding by the CAT III weather mins) even thought the current weather was above CAT I minimums?


texts: Can a drone hitting a plane be mistaken for a birdstrike?

texts:
Could a bird-sized consumer drone be digested by a jet engine, and not be recognized as a drone, mistaking it as a bird strike?

I'm thinking of the situation during the flight - like an engine making a short unusual noise, but works OK; not sure that can even happen eating a small bird?

As was pointed out, the debris of the object will look different in obvious ways when checking the engine after flight

I would assume a major factor is how the engine handles the drone, in terms of defects or running anomalies.

The battery comes to mind, hitting a turbine blade might be a problem - depending on the battery size.

There are certainly drones with very small batteries, that I assume will do no obvious harm, and certainly ones with batteries big enough to do harm for sure.


texts: Do ramjets use variable geometry supersonic inlets?

texts: Ramjets are very often portrayed as super simple, I've read on few occasions that the only moving parts in a ramjet are the fuel pumps. However, turbojets operating at similiar speeds (mach 2 - mach 3) use very complicated supersonic intakes with variable vanes to maximize the number of shockwave reflections and their angle and to adjust for the refraction of the flow on these shockwaves. Why is that the ramjets do not require such advanced measures to maximize pressure recovery?


texts:
What equipment and preparations are necessary to shot a picture like this (an in-flight close-up, clearly shot over a large body of water, possibly from a short distance):

This question is somewhat similar to my question asked at Travel half a year ago. But, in that picture plane was captured during final approach, over a city, supposed from some building (actually turned out to be shot from a helicopter).

I assume that using a telescope or shotting from any building won't help much in shooting such picture as above. If not, then what? A drone? Again, a helicopter?


texts: It is said that they are exposed to 50% more of radiation than on the ground and they are prone to skin cancer, so, is there any way of reducing the amount of radiation for pilots?


texts:
Do you realize that we are living in a world where you can get on an airliner and disembark cleaner than when you got on?

Video: Shower in A380 First Class

This just blows my mind.

How much water does the Emirates A380 carry in order to provide onboard showers?


texts:
If you open www.flightradar24.com or their app, then this is what the scene commonly looks like:

As you can see, the South-Central China area is strangely empty and the aircraft look to take a circular route around it instead (like this Emirates A380 to Incheon):

So, my question is why don't aircraft fly over that area? Also, I occasionally see some China Air Force aircraft going to that area..


texts: Which aerodromes are in the scope of ICAO recommendations?

texts:
I'm looking for a clarification of how aerodrome characteristics are regulated in a country which has signed the ICAO Chicago Convention (more on Wikipedia). To guide the answer, I'm providing a list of ICAO statements, which may be ignored if non pertinent. The question follows this list.

ICAO statements

Under this convention, State members participating to international air travel agreed to follow ICAO recommendations and best practices:

  Article 12: Each contracting State undertakes to keep its
  own regulations in these
  respects uniform, to the greatest possible extent, with those
  established from time to time under this Convention. Over the high
  seas, the rules in force shall be those established under this
  Convention. Each contracting State undertakes to insure the
  prosecution of all persons violating the regulations applicable.

The States also agree to provide some infrastructure:

  Article 18: Each contracting State undertakes, so far as it may find
  practicable,
  to: a) Provide, in its territory, airports, radio services,
  meteorological services and other air navigation facilities to
  facilitate international air navigation, in accordance with the
  standards and practices recommended or established from time to time,
  pursuant to this Convention.

Nineteen annexes describe SARPs, standards and recommended practices. Annex 14 (volume 1) describes aerodromes. Applicability is defined in § 1.2:

  1.2.2 The specifications, unless otherwise indicated in a particular context, shall apply to all aerodromes open to public use in
  accordance with the requirements of Article 15 of the Convention.

Article 15:

  Every airport in a contracting State which is open to public use by
  its national aircraft shall likewise, subject to the provisions of
  Article 68, be open under uniform conditions to the aircraft of all
  the other contracting States.

Article 68:

  Each contracting State may, subject to the provisions of this
  Convention, designate the route to be followed within its territory by
  any international air service and the airports which any such service
  may use.

Each State member also publishes aeronautical information (AIP), described in Annex 15 to the convention:

  2.1.1 Each Contracting State shall: a) provide an aeronautical information service (AIS); or b) agree with one or more other
  Contracting State(s) for the provision of a joint service; or c)
  delegate the authority for the provision of the service to a
  non-governmental agency, provided the Standards and Recommended
  Practices of this Annex are adequately met.

Each State must list in the AIP the deviation from ICAO SARPs, in section GEN:

  4.1.1.1 c: a list of significant differences between the national regulations and practices of the State and the related ICAO Standards,
  Recommended Practices and Procedures, given in a form that would
  enable a user to differentiate readily between the requirements of the
  State and the related ICAO provisions;

From the statements listed, it's not clear if all aerodromes open to the public are in the scope of ICAO recommendations and SARPs. This may be only those open to international travel, there is some ambiguity.

Question

How do I know whether such aerodrome in a given country benefit from ICAO recommendations as included in the national regulations. For example, there is this recommendation (annex 14):

  3.9.6 Recommendation.— To facilitate the movement of aeroplanes,
  fillets should be provided at junctions and intersections of taxiways
  with runways, aprons and other taxiways. The design of the fillets
  should ensure that the minimum wheel clearances specified in 3.9.3 are
  maintained when aeroplanes are manoeuvring through the junctions or
  intersections.

How does that apply to aerodromes in Germany or in Canada for instance?


texts: Is $24.01 million for 15 used A320 reasonable?

texts:
A few hours ago the insolvent Austrian airline Niki was bought by the owner of British Airways, IAG for a whopping \$24.01 million (plus a further \$19.08 million to provide liquidity to the company). This was the highest offer available.

The acquired assets include 15 Airbus A320 and landing rights for some European airports.

So far this was basically a summary of the Reuters article.

Given that Niki kept their business up until December 14th, 2017 it can be assumed that the aircraft are well maintained and properly working.

So summing up and getting to the question, the price seems rather low for 15 airworthy A320 aircraft in my opinion.

Did IAG get those aircraft for unbelievably low cost, or is the amount in the ballpark for such a deal?

Edit: The article also states that the landing rights are the most valuable asset of the deal, thus further devaluating the aircraft.

Update: As many comments point out, the aircraft enclosed in the deal were not Niki's own, but leased. To date I have only found German-language sources that indicate this.

Update 2: This source (as hinted by @Eike Pierstorff) clearly states, that the aircraft themselves are not included in the deal. They are in possession of Lufthansa, which in turn is bound by this document (section 5 paragraph (40)) to lease or sell the aircraft to any possible acquirer of Niki (IAG in this case) at market terms.


texts: What is the difference between single and dual annular combustor?

texts: CFM56 uses single annular and GEnX uses dual annular combustion chamber. somebody please explain with pics.


texts: How long does it take Boeing to develop an aircraft?

texts: How long does it typically take Boeing to make a new plane model (e.g the 787), from the moment they decide to make a plane (the moment they decide to create a new 7X7) to the moment the first plane (in this case the first 787) flies commercially?


texts: Why is stabilizer trim often controlled by electric motor while other surfaces are mostly hydraulically controlled?

texts: What is the rationale behind the use of electrical motors instead of Hydraulic actuation for the stabilizer which I have seen in most aircraft like Boeing 787.


texts: Is it bad form to call "ready to depart" when you know you won't be cleared yet?

texts:
My local aerodrome is towered and has parallel hard and grass runways. Simultaneous parallel departures or landings are not normally allowed. On one occasion we had been instructed to "line up and wait" on the grass runway. While I was performing the pre-take-off checks, an arriving aircraft was cleared for touch-and-go on the main runway. I observed it on short final as I completed my checks, and called "ready to depart", even though I knew that we would not be granted take-off clearance until it was well into its climb-out.

My instructor later told me that asking for clearance when you know you can't have it yet is bad form, and that he would have told me not to, if he had seen the traffic (which had been in his blind spot). I can see how it could seem like impatience or poor situational awareness, but it seemed to me like it helps the controller by letting them know they can get me off the runway as soon as they're able. Additionally, I've been taught that in other situations it's good to get a call in as soon as I can and there is clear air (such as downwind and final calls).

I'd like to get some clarification on this. Is it bad form? Why: for one of the reasons I suggested, or because of some other reason? What other situations does this generalise to?


texts: Constant turn radius with Δ airspeed and bank

texts:
Can someone explain how speed impacts rate of turn and and degree of bank required?

I'm trying to understand this practice problem but can't get the concept: Say you have 2 vehicles travelling at different speeds and carrying out a turn at the same radius. The example states that the faster vehicle will have to bank at a shallower angle and will have a lower rate of turn.

In my mind, the faster vehicle would have to maintain a steeper bank angle to compensate for the higher relative speed, otherwise their radius would increase. If you're moving faster, and banking at a lower angle, wouldn't that mean you're travelling at greater forward distance and less lateral distance thus increasing you're radius?


texts: Does a request for passengers to open vents indicate pressurization issues or equipment failure?

texts:
This occurrence was a year ago, but it kept bugging me until this day. I am a frequent flyer and this happened only this one time. While the plane (a Swiss A320) was still by the gate and the boarding just completed, the attendants asked the passengers to open the overhead vents because (not sure about the exact term) they have cooling difficulties. At that point it sounded reasonable, but it was around 09:00 in the morning and it wasn't a particularly warm day, it was 20°C at most outside (history says that the maximum temperature that day was 25°C). Roll-back and lift off were briefly after the boarding was complete.

Does a request like that indicate a failure or pressurization issue? I believe we were safe, just curious.


texts: How can a "due regard" state flight that has been intercepted indicate to their interceptor that they need to deviate around a hazard?

texts:
Military (state) aircraft sometimes conduct observation and intelligence-gathering flights near (but not within) the territorial airspaces of other countries, flying without the express permission of said other country, but in international airspace with "due regard to safety of flight".  Since those other countries are often not on the best terms with the country performing said flight, they will send an interceptor up to meet and "shadow" the aircraft performing said due regard flight until it has cleared the area of concern.  This is all well and good provided nobody does something unexpected or silly-at-best, hazardously-dumb-at-worst.

However, military aircraft are still susceptible to hazards such as severe/extreme turbulence, severe in-flight icing (such as that caused by lofted supercooled large droplets), and thunderstorms, that would force a flight to deviate around said airborne hazard.  While some hazards (thunderstorms) might be visible to both interceptor and interceptee on radar, others (icing, severe/extreme CAT) aren't -- leaving other pilots and their PIREPs as the primary source of information about what's actually going on up there.

So, that brings me to my question.  If the interceptee gets a PIREP saying the hole in the thunderstorm line they planned to thread their way through is closing up, or a bunch of unforecasted icing is up ahead on their route, how can they unambiguously communicate "I need to deviate around this hazard up ahead by X miles left/right" to the interceptor so they don't wind up making the interceptor think they're being noncompliant? Or is this not a concern provided the interceptee's maneuvers stay within a normal maneuvering envelope (i.e. half standard rate to standard rate turns, gradual climbs or descents)?


texts:
There are two windows marked with a black triangle, which indicate that they provide the best view for the wing, when the crew needs visual.

Since A320s are probably the most popular birds out there nowadays, in which row are these best-view windows?

It would be nice to take that seat when I check-in in my next flight.


texts:
This question is only regarding aircraft that seat more than about 100 people.

Are cargo holds pressurised these days, what is the situation?

Are only some pressurized, most, of every single one? Does it depend on the carrier, operating region or are there other variations that matter?

Related questions:

Are cargo holds heated?
Do they have lights? (Aren't some lit for animals?)
I've noticed random mentions of "some" of the sections being pressurised. Is this correct? It would seem to me that, if indeed, only some are pressurised then, of course, you absolutely could not rely on your luggage being in a pressurised area.
and what about Fedex-type cargo-only aircraft?

To be clear, I ask this question re "today" because I noticed when googling on this, there is a lot of information, but only old information (say, 10 yrs old plus). That is a recipe for confusion and urban myth, so the total facts from you experts would be great.

(Possibly, it would be difficult to secure accurate online references for this - my quick searching anyway only revealed patchy, out-of-date looking stuffs. Note for example, the Wikipedia article on Cabin Pressurization has only one poor, no-referenced sentence on the whole matter!)

Note for example... Spray bottles (pressurized) in the checked luggage?


texts: Why might an airliner fly a large U-turn before landing?

texts:
I was on a flight1 from San Antonio, TX to Toronto and, when arriving in Toronto, the plane went quite a way past the airport, made a big U-turn, and then landed. We were coming from the west.

I thought it might have been a need to adjust for the runway, but as I said, we went quite a way past the airport, meaning after the turn we had to fly "a little bit to get back to the airport". All that even before starting the process of descending for landing (if it was just a matter of adjusting the direction for the runway, what would be the need to keep the high altitude and go so far to make the U-turn?).

Does anyone know the reason? It seems that some flights coming from the west do that move.

Air Canada 7722, October 8, 2017 (history will not persist)

(flightradar24.com) Image shows the flight's route with a final left U-turn prior to landing.


texts: Does the Cessna POH state the fuel consumption in Imperial or US Gallons?

texts:
I'm planning a trip in a Cessna 182T and was calculating fuel requirements and started wondering. I have always assumed that fuel consumption is in US Gallons (or 3.785 litres) but I can't find a section in the Pilot's Operating Handbook (POH) that really confirms this. The fuel tank capacity is expressed in USG so I reckon it's close to assume that this implies that GPH is US gallons per hour.

There is a Imp. Gallon to Liter and Imp Gallon to US Gallon conversion table in the POH, when do we need Imp. Gallons?

Any comments, did I miss something?


texts: Measurement discrepancy on vfrmap dot com sectional -- is the grid wrong?

texts:
At Nome Alaska-- KOME-- the E2 airspace (dashed magenta line) is listed as extending 13.2 (nautical) miles east of the airport-- according to this source page E-9 -- https://www.faa.gov/documentLibrary/media/Order/JO_7400.11C.pdf  --

"Within a 4.1-mile radius of the Nome Airport and within 3.4 miles each side of the Nome
Airport 106° bearing extending from the 4.1-mile radius to 13.2 miles east of the airport..."  'AMENDMENTS 07/07/05 70 FR 22590 (Revised) Corr: 70 FR 33349""

But when I measure on the online sectional chart http://vfrmap.com/?type=vfrc&lat=64.513&lon=-165.444&zoom=10, using the tic marks on the lines of longitude (the lines running north and south) as a scale equal to nautical miles,  the far edge seems to measure more like 15.5 nautical miles from the middle of the airport symbol (as shown by the little blue square) -- now why would that be?  That's about 20% further -- about 2.3 miles different -- not insignificant.

What is going on here?

Is the scale wrong, or is the dashed magenta line shown in the wrong place, or is the airport shown in the wrong place?

I assume "east" in the above usage means "generally east, measuring along the 106-degree radial".

It's not a one-time thing, I'm getting a similar discrepancy with some other similar measurements of other similar regions of Class-E-to-surface airspace, always biased in the same direction.


texts: How to adjust time of useful consciousness for pilots acclimatised to high altitudes?

texts:
The time of useful consciousness (TUC) is the length of time an average pilot, breathing ambient-pressure air without supplemental oxygen, is capable of functioning usefully at a given altitude.  For instance, at FL180 (approximately 18 kilofeet AMSL), the TUC is 20-30 minutes for a steady ascent to this pressure altitude, or 10-15 minutes following a rapid or explosive decompression; at FL280 (~28 kft AMSL), TUC is 3-5 minutes for a gradual ascent (and half as long for a rapid/explosive decompression), and, at FL400 (~40 kft), TUC is only 15 to 20 seconds, even for a steady ascent (and a mere 7 to 10 seconds following a sudden decompression).1

However, healthy humans are capable of a very considerable degree of acclimatisation to high pressure altitudes (and resultant low partial pressures of oxygen); humans have demonstrated the ability to acclimatise to, and live and function indefinitely at, altitudes up to 19.5 kft, and long-term acclimatisation is thought to be possible up to at least 24-26 kft (although complete acclimatisation takes an increasingly long time - up to weeks to months in the upper reaches of this range - at very high altitudes).2  As extreme examples, a pilot living in La Rinconada (elevation 16.7 kft AMSL) could have an indefinite TUC as high up as FL180 (where, as mentioned above, the average pilot would be able to function without supplemental oxygen for at most half an hour), and someone just back from climbing Mount Everest sans oxygène supplémentaire could potentially be able to maintain an indefinite TUC up to at least FL220 or so (where an average pilot would have a TUC not exceeding ten minutes or so).

A high-altitude-acclimatised pilot would obviously have considerably longer TUCs for a given altitude than a sea-level pilot (even at altitudes where even a highly-acclimatised pilot cannot function indefinitely); how does a pilot acclimatised to high altitudes adjust the times in the standard TUC table to account for this?

1: Despite the 50% reduction in TUC following a rapid or explosive decompression, these, paradoxically, tend to be less dangerous (except in the rare cases where the decompression is sufficiently violent, or occurs from a sufficiently inconvenient part of the aircraft, to cause severe damage to aircraft structure and/or critical systems, or to physically suck one or more of the occupants from the aircraft), due to their violently obvious nature, than gradual decompressions (where the aircraft occupants can easily become incapacitated by hypoxia before they even realise that they have a pressurisation problem).

2: Beyond 24-26 kft AMSL (in what is aptly known as the Death Zone), long-term acclimatisation is mostly thought to be beyond the human body's capabilities; however, some degree of incomplete acclimatisation (allowing one to survive and usefully function at these altitudes without supplemental oxygen for considerably - sometimes very considerably - longer than an unacclimatised person would be capable of, although not indefinitely) is possible (which is how it's possible for a sufficiently-acclimatised person to climb Mount Everest without using any supplemental oxygen at all), and some scientists (from Bolivia, appropriately enough) dispute that there is an upper limit at all (or, at least, one below 29 kft AMSL).


texts: What is the difference between LP fuel valve and LP fuel shut off valve?

texts:
In the Airbus A320 FCOM in some places "LP fuel valve" is mentioned (in Fire and Fuel System chapters) whereas in the engine chapter "LP fuel Shut off valve" is mentioned.
Is there any difference between the two?


texts: Is it acceptable to use VNAV data in lieu of localizer recommended altitudes?

texts:
My airline's vertical navigation data isn't certified for use and is considered 'advisory' only.  But, 90% of the time it provides highly accurate data.

Some instructors at my company contend that 'localizer recommended altitudes' are required to be used as the primary / only reference for a CANPA style continuous descent to our DDA (derived decision altitude) on localizer approaches.

I contend that any method chosen for a descent to DDA is purely technique and as long as our advisory VNAV data is backed up with other data & looks accurate, there's nothing wrong with using it.

Are localizer recommended altitudes regulatory in any way?  Is it legal to use an 'advisory' Vnav data to fine-tune your descent from the FAF to DDA? Any links, references, or regulations you can point me to on the subject would also be greatly appreciated.


texts: Could a commercial plane seat configuration look like a troop carrier?

texts:
I wonder whether Michael O'Leary has already seen that. I am pretty sure he would be eager to implement the idea. However, is that feasible - both from a legal, and as a security policy - for commercial planes transporting civilians? Maybe military personnel can be trusted to evacuate the plane faster than average civilians in case of emergency.

Source: dailymail.co.uk


texts: At what point can Approach mode be engaged in an A320?

texts: In my experience using Flightgear and other computer simulators, when flying an ILS approach on an A320, the approach mode can only be engaged at a certain point or later. What is this point, and why is it used?


texts: Why don't airliners carry radar jamming technology or missile counter measures?

texts:
Why is it that commercial passenger aircraft that fly through dangerous areas don't carry some sort of electronic counter measure to defend themselves from missiles?  Between terrorism and the various war zones dotting the globe, it seems like it would be prudent for airliners to have them.  At least for aircraft that are flying in places that are possibly dangerous.

I've been thinking that it's probably a lot of expense and weight for something that isn't terribly likely to happen, but I wondered if there might be more to the answer or if, at very least, someone could add some details to my assumption.  A good cost/benefit analysis would be appreciated if anyone is familiar with the cost of operating such a system.


texts: How to identify different pipes / hoses on aircraft engines?

texts: When looking at an aircraft engine (without any cowlings) is there an easy way of identifying what pipes are for fuel, air, oil, hydraulics etc..? Maybe certain fluid pipes are different size diameters or do you just have to know the engine system and components they are providing to be able to tell?


texts: How and why does the ATR-72 sometimes use reverse thrust to push back from its parking position?

texts:
Travelling with Czech Airlines via Prague in an ATR-72 I have already experienced multiple times that instead of pushback service the planes simply used their reverse thrust to leave their parking position, even doing a 90° degree turn while rolling backwards.

Personal experience as well as a Google search show that this is rather uncommon. What makes the ATR-72 special to be able to perform such kind of manoeuvre?


texts: Where can I learn more about pilots' dreams during G-LOC?

texts:
I came across an extremely interesting note from a wiki article on G-LOC (g-force loss of consciousness, or blackout):

  Brief but vivid dreams have been reported to follow G-LOC.

Sadly no citation. Where can I read more about this? I did a quick Google search on "pilots dream g-force blackout" but only got 2 relevant hits that didn't tell me much. Some reddit posts described a dream trapped in a maze and a trip to Hawaii, that's about it. They sometimes described it as an out-of-body experience instead of a dream.

Does anyone know where to go to read more? Is this really a common phenomenon?


texts: I have a test bench that can test the thrust of a propeller with my electric motor, is there a way that I can calculate the propeller efficiency (ηp)?


texts: May I fly from the right seat due to a temporary disability?

texts:
I am a student pilot with, and I have had carpal tunnel for years now. It has progressed to a point where my left hand is frequently weak and/or achy.  I do have use of the hand, and it is quite uncomfortable in the landing flare since I have to control the yoke left-handed when flying in the left seat to leave my right hand free for the lighter-duty tasks of operating the throttle and other equipment.

I am very close to my check-ride and I am scheduled to have surgery on my left hand next month.  I don't want to suspend my training and get rusty.  Also, after the surgery, I suspect that my left hand may not be 100% for some time, and I don't want to miss out on these great flying months.

I have seen articles about pilots with disabilities far greater than a case of carpal tunnel, so I'm wondering if there is a way I can avoid putting my training on hold.

Is it permissible to fly from the right seat so that my weak hand only needs to operate the throttle, flaps, etc. while letting my stronger hand handle the yoke?

Is this simply a request to my instructor/examiner or does this trigger an avalanche of FAA medical paperwork to make it legal?

I realize I would have to adjust to a slightly different sight picture in the right seat but I think that is a relatively minor transition in the grand scheme of things.


texts: What should a pilot do when facing a sudden tail, cross, or head wind?

texts:
Consider a pilot is flying a conventional fixed wing airplane with a ground speed of 60km/h with no wind. Then suddenly the wind starts blowing at 20km/h in either of the following directions:

from back to front (tail wind).
from front to back (head wind).
from left to right (cross wind).

What should the pilot do to maintain speed and altitude in each of the possible situations above?


texts: On many webpages it is said that a departure procedure will keep aircraft away from terrain and obstacles and avoid collisions. Which type of obstacles? Buildings? Towers? What is the purpose of a departure procedure? This is a follow up of this question.


texts: What is the rationale behind "One engine - Two propellers" configuration?

texts:
I stumbled upon a very unusual Russian amateur built ultralight:

One engine, two propellers configuration

My first impression is that it adds another useless layer of complexity and moreover it may involve some safety issue: I particularly think of the entry into a spin in case of one propeller failure.

What is the rationale behind it? The pros and cons?


texts: Do jet aircraft have a better glide ratio than propeller aircraft in general? If so, why?

texts:
Being fond of aviation, I play with software simulators a lot.
I have noticed that while jets seem to be able to glide for a long distance even at zero throttle, propeller aircraft need to be throttled right up to the runway.
Is this accurate in real planes? If so, why?


texts: Can a paying passenger ride in one of the cabin jumpseats?

texts:
Is there any regulation that prohibits passengers from using a cabin jumpseat (normally used by cabin crew) if there is no passenger seat available? Like the two shown below.

In other words, can any of the cabin jumpseats be sold? (Given that cabin members are fewer than the available jumpseats of course.)

(Source)


texts: Is it possible to fly a Cessna 172 vertically?

texts:
My question has two dimensions:

Disclaimer: Hypothetical question, I am a humble private pilot!

How fast you need to be and how fast you need to turn up so that you do not burn out all your kinetic energy in the lower arc of the climb and at the top you have enough authority to bank and dive back, not simply come to total stop and crash down like a rock.
Is Cessna capable of handling the kind of G's and maneuverability? Can it turn up into as sharp a rotation as required!


texts:
In general, what is the action taken by airlines when presented with a SIGMET in the projected route. Will they go around it, cancel the flight prior to takeoff, or simply fly thought it anyway?

As an example, there is a large SIGMET over the Sierra Nevada mountains right now due to high winds causing wind shear and moderate to severe turbulence. Knowing that severe turbulence can be a serious issue, would airlines, in general, cancel the flight, go around the area or simply fly anyway?

WSUS06 KKCI 250040
WS6N
SFON WS 250040
SIGMET NOVEMBER 2 VALID UNTIL 250440
CA NV
FROM 80N FMG TO 30ESE OAL TO 60NE EHF TO 50ESE RBL TO 80N FMG
OCNL SEV TURB BTN FL280 AND FL410. DUE TO WNDSHR ASSOCD WITH JTST
AND MTN WV ACT. RPTD BY ACFT. REPLACES NOVEMBER 1. CONDS CONTG
BYD 0440Z.

Source: aviationweather.gov


texts: Are there any IFR training plugins / addons for Microsoft Flight Simulator or X-Plane?

texts:
I am an IFR student, looking for software/plugins/add-ons/extensions to either Microsoft Flight Simulator or X-Plane to enhance the IFR training experience.

Specifically, I was wondering if there was an app that would evaluate my instrument approach in the simulator against the 'nominal' or idealized instrument approach based on the approach plate.

For example, it would evaluate the flight profile to see if I had stayed above the MDA; if I had followed the step-downs appropriately; if I had stayed within the required procedure turn completion distance, etc.

Is there any such software like this, or is specifically tailored towards IFR training?


texts: Can a runway have a displaced threshold and a closed section in the same area?

texts:
There is tricky question we weren't able to find a clear answer to.

Following roughness tests we decided to close part of the runway to all aircraft movements (1400 ft out of a total 3000 ft runway). The taxiway is located at the center of the runway (photo 1).

Actually the airport is certified under Canadian regulation (CARS 302) and this is what is indicated in this case :

Closed marking is placed at each end of the portion thereof, declared closed.
Runway threshold is temporarily displaced from the runway end, arrows are provided on the portion of the runway before the threshold.

It's not clear what the best practice is if we have the two situations at the same time; a displaced threshold, and a closed section in the same area.

For the moment, we decided to maintain the two type of marking at the same time; closed marking are installed on the side of the runway (photo 3).

This is a temporary measure. Phase 1 of corrective works was done. Roughness test still not acceptable, we have to come up with a phase 2 corrective works before this winter.

Has anyone seen this before and what do you do in this case? I'm also interested to see what do you do under FAA regulation.

Thanks

This photo show the marking this winter without the arrows. To be able to paint the arrows for displaced threshold marking we installed the closed marking on the side of the runway (see below).

Picture with displaced threshold and closed marking


texts: How do I figure out the right pronunciation for transitions?

texts:
For example, the CNERY transition,* how exactly is this pronounced? On the VATSIM community, it seems there's a huge debate on what this is called. Some people say CONNERY, and some people say SCENERY. I personally say SCENERY since it makes more sense, but what is the most proper one? And is there a place where we can find pronunciation of such things?

Like another one is SCTRR transition which some people say SCOOTER, some people say SCATTER.

* CNERY transition is part of KLAX's DOTSS TWO DEPARTURE.


texts: Do horizontal stabilisers provide any lift?

texts: Do jumbo and smaller airliners' horizontal stabilizers provide any lift? Apart from maintaining the aircraft's angle of attack, can they perform the dual function that includes adding some lift as well? Are there any aircraft designs that use horizontal stabilizers for lift as well, apart from delta wing aircraft?


texts: Can a Boeing 747 or A380 climb with only one engine?

texts:
Assume that a Boeing 747 or Airbus A380 takes off at max takeoff weight. Minutes after takeoff, 3 engines fail, leaving only 1 engine operating.
Can the aircraft still achieve a positive rate of climb?


texts: What are the best traffic pattern airspeeds in a Cessna 172N?

texts:
I have problems with my landings, and I would like to know what is the best speed
in the traffic pattern, especially on base and final? I am landing with 20 degrees flaps (in different weather conditions), and to be honest as a student pilot I am confused by the Cessna 172N POH, can anyone help?


texts: Why do the ailerons of this flying wing work oppositely compared to those of an airplane?

texts: I made this simple wing glider and put some ailerons on it. I thought that the ailerons in this glider would work the same way it works on airplanes, wherein the roll will be in the direction of the aileron that is pulled up. However, the opposite happens. For example, when I pull the left aileron up and the right aileron down, instead of rolling to the left, it rolls to the right. What is the reason behind this? And what is the difference between the control of this flying wing to a conventional airplane?


texts: Is Assumed Temperature used in conjunction with a Derate in the B737 NG?

texts: When using an Assumed Temperature for Takeoff, is it common operational practice to also use a Derate?


texts: How are aircraft protected from lightning strikes by conductive skin?

texts:
I've read this question and this one, but they don't really answer my question.

How or why are aircraft protected (from lightning) by a conducting skin, such as aluminum? Conductors allow current to flow through you! Wouldn't it be better to have an insulating shell?

I realize its not possible to have an ideal bubble completely protecting you, because the engines need to breathe air. Presumably these metal engines would then take the brunt of the lightning strike.

So let me try an example with a glider. Let's say we have a glider completely surrounded by an insulating skin. Just for the sake of ideal example, let's say this skin is the best material insulator known: diamond. (Okay, it's not solid diamond. It's just a diamond coating. Yes, they can build that via chemical vapour deposition. I know it's not economical, it's just for the sake of an ideal example.)

What would happen if this craft gets struck by lightning? Please don't say "it explodes" without some kind of citation or explanation or I will be suspicious of hollywood falsehood.


texts: How is the mass flow between 2 streamlines derived?

texts:
I am reading "Fundamental of Aerodynamics " by J.D.Anderson Fifth edition, At pages 177 and 178 (section 2.14 Stream funciton), the book said: given 2D steady flow, from:
$$\frac{dy}{dx}=\frac{v}{u}$$
with u and v are known function of x and y, then we obtain f(x,y) = c by intergration.

If we have steamline 1 is f(x,y) = c1 and streamline 2 is f(x,y) = c2, then why is the mass flow between two streamlines equal (c2 - c1)? The book said that but there is no derivation of that.

As far as I can do:


texts: What is Neil Armstrong teaching in this image?

texts: It seems to me that in this image Neil Armstrong is teaching something related with aerodynamics forces (lift, drag...), but I don't know exactly what is that "Triangle" that He drew (It doesn't seem to be an aircraft).


texts: Are lhe old King KX170B Nav/Com radios monaural?

texts: If so, does this mean I need to use an adaptor to play the output on stereo headphones?  My Stereo-Mono switch does not produce a two-ear audio.  Would this be solved with a converter? Would be nice to receive other pilots and ATC in both ears.


texts:
The FAA regulates logging time in FAR 61.51. There are plenty of questions about logging PIC time, as well as SIC time. Another type remains: what can be logged as total time? It's only mentioned once:

  Total flight time or lesson time.

It is clear that any time logged as dual, PIC, or SIC can be logged as total time. Is total time merely the sum of those, minus any overlap, or is there a situation where total time can be logged but none of the others?

In particular, two situations arise:

I'm at the controls of an aircraft I'm not rated for (i.e. an ASEL pilot in the right seat of a multi-engine aircraft, where the other pilot is appropriately rated and not a CFI). I can't log PIC, SIC, or dual - but can I log total time?
In a plane I'm rated for, I pass the controls to a non-certificated passenger. I'm not a CFI. I cannot log PIC, SIC, or dual while my passenger is the sole manipulator of the controls, but I am acting as the PIC for this portion of the flight. Can I log this as total time?


texts: Are there any aircraft where minimum-V1 is limited by Vmcg?

texts:
V1, unlike all the other Vspeeds, is not rigidly determined by the laws of physics, the aircraft’s specific abilities, and the conditions of the particular takeoff being attempted,1 but is, rather, chosen by the pilots from a range of possible V1s.

The lower limit of this range is generally set by the speed past which the takeoff can safely be continued while maintaining adequate obstacle clearance, even in the event of an engine failure (henceforth known as the first-safe-go speed).
The upper limit of this range is set by the speed past which the aircraft can no longer be guaranteed to stop on the runway in the event of a maximum-effort no-reverse-thrust rejected takeoff (henceforth known as the last-safe-RTO speed).

However, if an aircraft is sufficiently light and has sufficiently-powerful engines (especially if said engines are mounted far from the aircraft’s centerline), one could potentially conceive of a situation where the lower limit of the V1 envelope is not, in fact, determined by the first-safe-go speed, but, rather, by...

...the speed below which the aircraft has insufficient rudder authority to maintain directional control at takeoff thrust in the event of an asymmetric engine failure (known as the minimum controllable speed - ground, or Vmcg).

Such a light, sporty aircraft could easily have a theoretical first-safe-go speed that is lower than Vmcg, as low total weight and high thrust-per-engine both decrease the first-safe-go speed,2 and, simultaneously, increase Vmcg.3  This would force the lower limit of the possible-V1s range to be set, not at the theoretical first-safe-go speed, but, rather, some distance above that, at Vmcg (as an asymmetric engine failure at or above the theoretical first-safe-go speed, but below Vmcg, would result in an immediate loss of directional control, necessitating a rejected takeoff).  For added complexity, some aircraft have engines at varying distances from the aircraft’s centerline (for instance, a trijet with one engine slung under each wing and one mounted in the tailcone, or a quadjet with one outboard and one inboard engine slung under each wing), resulting in different Vmcgs for different engine-out scenarios, such that, at a given speed, an aircraft might be able to safely continue a takeoff if a centerline or close-to-centerline engine fails, but would suffer a loss of directional control, and have to reject, should a far-from-centerline engine fail.

Are there actually any aircraft for which the minimum-allowable-V1 is limited by Vmcg, rather than the first-safe-go speed?

1: ...except in the special case of the aircraft being at exactly its maximum allowable weight for the takeoff being attempted, in which case there is only one possible value of V1.

2: ...as a lighter aircraft needs less speed (and, thus, less thrust) to become airborne, and an aircraft with powerful engines has more thrust to work with in the event of an engine failure.

3: ...as an aircraft with powerful engines needs more rudder authority (and, thus, more speed) to maintain directional control with an asymmetric engine failed and the other(s) at takeoff thrust (a problem which grows steadily worse the further the asymmetric engine(s) get from the aircraft’s centerline, due to the larger and larger yawing moment arm generated as they move away from the centerline), and a lighter aircraft has less weight on its landing gear (and, thus, less traction force acting to resist the yawing moment from an asymmetric engine failure).


texts: Can foreigner fly model aircraft (quadcopter) in US without being part of an organization (like AMA)?

texts:
The title says pretty much all. I'm visiting Guam very soon and I just found out the FAA is enforcing some rules that are mostly common sense. However, one rule states "the aircraft is operated in accordance with a community-based set of safety guidelines and within the programming of a nationwide community-based organization;"

I have read the rules of AMA, but if i'm not registered with them, does this mean I can't fly my quadcopter in US territory? (non-commercial flight)

Thanks!
Lu


texts: Can I use my non-WAAS GPS receiver with ADS-B in the United States?

texts: I have a older style Garmin 530.  Can I use this GPS as the position source for an ADS-B installation?


texts: Why is on-time performance important for commercial flights?

texts: From the perspective of an airline, is it just to avoid penalty and also to portray reliable service to the customers?  Or is it just a matter of logistics and scheduling?


texts: Is the main landing gear of a large airplane designed for sideways (crabbed) touchdowns?

texts:
Is it just my imagination, or is it a fact that many large airliners actually touch down "crabbed" on difficult crosswind landings?

Here's what I mean in this video, or as shown in this picture:

Is the main landing gear specifically designed to allow this? Is it recommended or discouraged by the manufacturer?


texts: Why are airport firetrucks painted yellow green?

texts:
In my city, most of, if not all of the fire-trucks that serve city emergencies are red, just like this one:

But every time that I see an airport emergency that requires the fire-fighters, I see this kind of truck:

Is there a reason why the airport trucks are yellow-green and not red?


texts: How is varying modulation depth achieved by localizer ground transmitters?

texts:
An approaching aircraft's navigation receiver uses the difference in depth of modulation between the 90Hz and 150Hz signals which are amplitude modulated onto an RF carrier (on a channel between 108Mhz and 118MHz).

My understanding is that the ground transmitter is formed by several pairs of transmitters forming two interleaved phased arrays to achieved directional beam forming.

My questions is how is the difference in modulation depth achieved by the transmitter system based upon aircraft's position relative to the landing strip's entreline? The beam strength decreases as you move away from it's own centreline, so is it actually that the entire modulated signal strength decreases which when de-modulated is effectively a difference in amplitude modulation depth?


texts: What's the reason for pilots wearing uniforms?

texts:
Just came across an interesting answer to a question on uniforms for PPL Human Performance and Limitations:

Pilots wear uniforms:
a) so they can be easily recognised
b) so that they can be perceived to be important
c) so that they can feel important

Apparently the correct answer is b (I said a). Is this so that their authority is respected, is this a valid reason?


texts: Are there any LSA aircraft that can be flown IFR in IMC?

texts:
Are there any LSA aircraft that are IFR certified? A LSA would be the perfect private commuter plane for an instrument rated private pilot.

If not, what are the most cost effective airplanes that are IFR certified? Is there anything cheaper than a C172?

Just to be clear: I am asking about aircraft that are IFR certified, meaning that they can be flown IFR in IMC conditions. I am also aware that there is a huge difference between different countries with regard to aircraft certification so my question is mainly about the U.S.


texts: Why the pitot tube is heated but the static port isn't?

texts: In some light aircraft, like a Cessna 172, the pitot tube is heated but the exterior static port isn't. The usual reason I've heard is that static ports are much less susceptible to icing, but why is that the case?


texts:
In the Chart Supplement (A/FD) for CRQ/KCRQ, you will find RVR-T for runway 24.

I was wondering what 'T' stands for?


texts: What written tests are required to become a ground instructor?

texts:
What are the written tests required to become a ground instructor? Do I have to take the FOI, BGI and IGI? Or just the FOI and IGI tests?

I got confused if I should take the whole three tests - FOI, BGI, IGI - or if just the two IGI and FOI tests are enough?


texts: How are weather-related limits on arrival capacity determined?

texts: Most airports in Europe have the following traffic controls imposed during adverse weather conditions. I wonder whether these capacity limits are determined by airport operator's experience, or if there are any special algorithms?


texts: Why was there an increase in the number of airline accidents in 90s?

texts: According to this Aviation Safety Network article and dataset there was a significant drop in the number of airline accidents in the early 80s comparing to the years before - from ~50 per year down to ~30 per year. However, in the late 80s and the 90s this number increased back to ~50 and stayed at this level until early 2000s. Is there any explanation for the sharp increase of the accidents in the late 80s and the 90s? I see the number of flights increased linearly throughout the years, so this isn't the factor that explains the accident statistics.


texts:
I am a bit confused on how to come up with the flap hinge moment, like, what force is involved and where is the center that the force is wrt.
And why is the moment as shown in the above diagram seems to be in a different direction from that shown in the diagram below

( video is at

            )


texts: Is public data available for routes that enter/exit a certain airspace?

texts:
I'm interested in air traffic density and flux (i.e., traffic that enters and exits) for the ZLA airspace. A good first pass would be flights that begin or end in ZLA (and that data is pretty easy to get from somewhere like OpenFlights, but that doesn't include routes like PHX-SEA, where a flight would pass through ZLA on its way from ZAB to ZSE. Is there any public information available about what routes pass through ZLA?

(Actually, I'm much more interested in the air traffic density and flux specifically for the Los Angeles metropolitan area, but I figure starting at the area control center level might be a good place to start.)


texts: What is the meaning of AFT in airworthiness directives?


texts: Does it help to climb in case of a partial engine failure?

texts:
When the engines of a airplane show irregularities that do not reduce performance but indicate a possible failure of the engines, is it useful to climb to a higher level, to increase the glide length that is available in  case the engines stop completely?

The problem known in the cockpit is only that the engines do not run like they should. Say they make clearly unusual noises and slight vibration, but loose no performance. There is no indication whether the engines will fail, an in case the do fail, at which point in time that  will happen.
It's an emergency, without actual change in the planes performance.

As example, I think of a small single propeller plane, and a situation where longer glide path could be useful. But I think the question applies to any plane that can glide without power.


texts: How does new media streaming technology equate to fuel cost increase?

texts:
In regards to this article on BBC, which discusses the use of streaming technology to allow passengers to watch films/TV shows etc. on their portable devices, the following statement caught my eye:

  It would increase the drag of our aircraft by 2%, which equates to 20
  million euros [$23.6m; £15.5m] in extra fuel.

Is this cost increase purely to do with an increase in weight and additional drag owing to the new equipment required or is there any other factors at play here?


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

texts: Looking at a satellite map to the East of Heathrow Airport, there is a small passenger jet parked in a walled off area. Looking at the aerodrome chart the entire area is listed as Bealine Base, which I assume is used for BA operations. What it the purpose of this walled off area?


texts: Is there a standard for the trip paperwork packages that are used by the airlines?

texts: I have noticed that different airlines (like LIDO, Delta, AA, etc.) have different formats for their trip paperwork packages, containing pre-flight information that they give to their pilots.  These packages contain things like their flight plan, NOTAM's, weather, weight & balance, etc. There is some overlap of course, but I was wondering if FAA/EASA has some standard or guideline for generating the package?


texts: For IFR flights that require two alternates, is there a regulation that requires enough fuel to reach the furthest one?

texts:
For flights that have two alternate destinations, I'm looking for a reference - either EASA or ICAO - that states that you need enough fuel to reach whichever alternate would require the most fuel to get to.

I think this is common sense, but I need a reference if anyone has it?


texts:
What would happen if I exceeded mach 1 over a regulated area? Are there any penalties in place for this violation?

Would ATC actually know I’m flying supersonic or would they have to go out of their way to check my groundspeed and work out my approximate air speed?


texts: How can the required wing area for climb be calculated, given aspect ratio?

texts: I'm currently working on problem 3.20 from the picture above. In order to find the rate of climb, I'm using the formula Rate of Climb= (Power available - power required)/weight. Doing this, I need to find the power required, which the formula I'm using is Pr=sqrt((2*W^3*Cd^2)/(densitywing areaCl^2)). Now I have everything but the wing area needed for this climb. Given the aspect ratio of 12 and a Cd of .01, how do I calculate this. Also, please let me know if there is a simpler way of going about this problem. Thanks


texts:
The Financial Times' China targets rare earth export curbs to hobble US defence industry states:

Fighter jets such as the F-35, a Lockheed Martin aircraft, rely heavily on rare earths for critical components such as electrical power systems and magnets. A Congressional Research Service report said that each F-35 required 417kg of rare-earth materials.

Rare Earth elements are commonplace rather than rare in high tech devices and systems these days, but usually in small quantities. The exception are rare-earth permanent magnets used in electric motors and generators.
But 417 kg sounds like a lot; it's 3.1% of a reported 13,290 kg dry weight of an F-35A.
Could this be true? Or are they counting for just for example the whole motor rather than the rare earth within it?


texts: Does it make sense to use a canard in combination with a conventional aft elevator control surface?

texts: I am designing a UAV and have settled on a canard design.  However, I’m curious whether it would be helpful to have a typical horizontal stabilizer behind the wing as well as a canard wing in front of the main wing to increase lift towards the front of the plane and for better stablity.  Is this a bad idea? I’m looking to carry cargo ranging from 0-1000g, and initially fly for around 30 minutes. It is also using a special VTOL system I’ve designed.


texts: What would happen if blades are not pitched correctly on a propeller blades?

texts: What would happen on a 6 blade propeller if each blade opposite another was pitched in completely the opposite direction.


texts: Is a propeller with two long blades more efficient than one with three shorter blades?

texts: Is a longer, two-bladed propeller more efficient than a three-bladed propeller with a smaller diameter?


texts: How is the B737NG Autopilot controlling pitch?

texts: In particular, does the Autopilot in a B737NG control the pitch only via trim adjustment, or first via the elevators and then trim?


texts: What physical hardware does all the avionics on the B737NG run on? Some processor from the 1980s? Or some new and improved chip?

texts: So, I am a tech guy and likes to fly (in sims) so, I was wondering what physical hardware powers all the 737NG's avionics and related systems (PFD, MFD, EICAS, GPWS etc). Is there an answer to this?


texts: How do interceptors communicate with the airplane crew when the radio is dead?

texts:
A week ago an airplane lost the radio connection to the tower due to technical difficulties in German airspace (article in german). Thats why interceptors started to escort the plane and to check if everything was fine or an act of terrorism is happening. But how can they determine if there was a hijacking in progress of everythin is fine if the radio is dead?
Q: How are the interceptors communicating with the airplane?


texts: Can a commercial airline continue its flight if its landing gear fails to retract after take-off?

texts:
So after take-off, due to any reason, the landing gear does not re-tract, is there any standard procedure to be followed? Or can the airline continue with its flight?

Also, I would like to know any FAA regulation on the same (if any), which deals as to the procedure to be followed in such situations.


texts: Where can I find GA VFR maps for Australia?

texts:
Are there any sites similar to SkyVector (US-based) for GA aviation maps in Australia?

I understand that Air Services Australia has miscellaneous single-purposes maps available, but they seem to be mostly airport diagrams and approach procedures. I'm looking for GA VFR maps.

If the only thing available is SkyVector's world maps (of Australia), how accurate are they?


texts:
From Wikipedia:

  Aircraft on Ground or AOG is a term in aviation maintenance indicating
  that a problem is serious enough to prevent an aircraft from flying.
  Generally there is a rush to acquire the parts to put the aircraft
  (A/C) back into service, and prevent further delays or cancellations
  of the planned itinerary.

I know AOG is a really serious issue for an airline. What I want to learn is the liability and how far it extends. For example; if AOG happens:

how long can this airplane stay in that airport?
what is the airports role in this situation? Do they help them out or just charge the amount they stay on the ground?


texts:
I was stopped by NYPD for attempting to hang glide in an uncongested area by Midland Beach, Staten Island. They called their Legal Bureau and came back with "Illegal Navigation" and if I was to continue I would be arrested and my hang glider would be seized. I called the NYPD Aviation Unit to ask about the legality of my attempted flight and told me to call back again later since this was an unusual request. When I called them back they generically stated that it's not legal under FAA regulations within the NYC area, but did not refer to any specific law and suggested I go to Long Island or Jersey.

What is meant by a "congested area of a city/town/settlement" in FAR 103?

If it's not illegal, then it's legal. So if I can prove that it's not, then I should be legally good to go.


texts: The root cause for Boeing 787 Dreamliner battery problems

texts:
Wikipedia's B787 article states that:

  The causes of the battery failures are still unknown. There is still concern that because the root cause of the fires were not identified, the solutions put in place by Boeing will not be able to cover the full range of possible failure modes.

But 787 was still cleared for flight after it fixed the "Fire Propagation" problem by correctly packaging its batteries in a fire resistant material.

My question is :

What is the actual cause of such Battery problems? (If it's known?)
If Boeing is not able to resolve the root cause of the fires (according to Wikipedia), then is it safe for the Dreamliner to be allowed to fly?
Because what they have done to resolve the problem does not appear to be a permanent solution, but more of a temporary fix.


texts: Is it possible to have V1 greater then Vr?

texts: According to wikipedia, decision speed ($V_1$) is computed taking into account the runway length (and other parameters). If an aircraft uses a long runway (one listed here), there may be enough runway available to stop an aircraft rejecting takeoff at high speed. Thus $V_1$ can be higher than usual, perhaps greater than $V_r$ or $V_2$. Is the situation where $V_1$ is greater than $V_r$ possible?


texts: Can a flight instructor without instrument rating legally provide instrument training?

texts:
In the US the FAA requires student pilots to receive at least 3hrs of instrument flight training.

Can a flight instructor that does not hold an instrument rating legally provide a private pilot student the 3hrs of instrument training?


texts: Do Constant maximum lift to drag ratio variable pitch propeller exist?

texts:
Are there variable pitch propellers, where pitch is set so that the blades constantly are at their maximum lift to drag ratio AoA, whatever the incoming relative wind speed & direction?

Such a variable pitch propeller would be powered by some electric engine, able to equally produce torque for clockwise and anti-clockwise operation.

Such a variable pitch propeller would be free on its pitch axis, able to rotate 360°, each blade being mounted on two ball bearings, inside propeller's hub. This way maximum aerodynamic efficiency could be reached whatever the needs:

take off at low relative pitch,
cruise at some higher pitch,
ability to produce efficient reverse thrust after landing.
Each of these at maximum lift to drag ratio AoA.

Each blade is balanced about this pitch axis, so that it is statically stable, and aerodynamically always trying to pitch up by its own aerodynamic configuration, towards its best lift/drag ratio angle of attack.

Each blade becomes an individual glider/flying wing, trying to pitch up.

For the sake of understanding, imagine a propeller with trailing edge tabs set at an angle allowing only thrust generation, regardless of the direction of rotation of the propeller.

This tab is not a viable way to build such a blade, it may instead look like some conventional blade, having some negative incidence blade tip combined with swept back tip, or some standard geometry, with a reflex airfoil, or both, or something else.

The idea here could be to have an automated variable pitch prop with the least amount of moving parts, where pitch is set by aerodynamic forces at its optimal angle. Instead of going for constant rpm, this one goes towards constant maximum lift.

For instance, cutting power off would induce some reverse windmilling, adding power in windmilling direction will generate reverse thrust.

During forward flight, pitch would adjust on resultant airplane's velocity + blade's rotational velocity.

Question is : Are there propellers of this kind? If not what are the drawbacks I don't see?


texts: Is it possible to overheat or damage the engine on an F-16?

texts:
The MiG-25 can supposedly damage its engines by commanding too much thrust and gaining too much speed. Somewhere around mach 3 damage to the engines is likely, I believe.

What about the F-16?

What happens if the pilot, at altitude, attempts to simply go as fast as it will go?

I believe the F-16 has FADEC (Full Authority Digital Electronic Control). The MiG-25 does not. I imagine this would limit the amount of fuel flow by some limit.

However, even if this is true, is it still possible for the pilot to exceed the ordinary limits imposed by the computer?

As a bonus question, it would be interesting to also mention if this does or does not apply to other fighters, in particular the F-14, F-15 and F/A-18.


texts: Is induced drag caused because of the tilt of the wing backwards?

texts:
In this question:
Why is induced drag less on a high span wing?

In the answer it was stated that wing tip vortices do not cause induced drag. If this is the case then what causes the induced drag.

Thinks about this for 10 minutes

What if the Induced drag occurs because of the tilt backwards of the wing. Do the vortices just make the induced drag worse but, not cause it.

So basically I am asking if the backwards tilt of the wing causes induced drag and how do the wingtip vortices affect the induced drag

This may sound like a duplicate of:

Is induced drag not caused by tip vortices?

but, It is not because I am asking if the induced drag is causes by the tilt of the wing. I am not asking if induced drag is caused by wing-tip vortices or not.


texts: How can I correct the heading for this navigation problem?

texts:
I'm a pilot trainee in Hungary and just encountered a navigation question problem which is from the PPL Training Questions book. Would be glad if someone can briefly explain how to do this typical question which I come across a lot.

    An aeroplane has a heading of 090°. The distance which has to be flown
    is 90 NM. After 45 NM the aeroplane is 4.5 NM north of the planned
    flight path. What is the corrected heading to reach the arrival
    aerodrome directly?

  a) 6° to the right,

  b) 9° to the right,

  c) 18° to the right

  d) 12° to the right


texts: Could some kind of impact absorbing gels be introduced into the aircraft fuselage, to minimize impact damage on passengers & cargo?

texts:
There are a lot of impact absorbing gels, one example here.

Could some kind of more advanced gel be introduced into aircraft cabins, which expand rapidly on impact (like air bags) and fill the entire cabin, thus protecting the occupants from injury or death?


texts: Can pilots hear a car horn while on the ground?

texts:
In this question I asked about the pilot's ability to give a signal to others nearby while on the ground. My question here is, if someone else wants to get the pilot's attention on the ground, could the pilot hear someone honking a car horn from the cockpit?

Edit: thanks for all comments. I want to ask about a situation involved large aircraft, engine running, car is near the aircraft. Such as in large airport operation. My question comes from series Ultimate Airport: Dubai when a trainee is driven to different areas of airport as part of his certification. I wonder if he can call attention of pilot in cockpit by honking the horn. I am aware that more standard mode of communication such as radio, flare or ground marshall is preferable.


texts: What is the minimum separation between two landing A380s?

texts:
I have always assumed that landing separation depends on wake turbulence limits depending on weight class.

However I see that no minimum separation needed for the A380 as trailing aircraft (and in a few other cases):
http://www.ais.gov.hk/HK_AIP/aic/AIC22-12.pdf

In practice, what distance or time separations used in these cases, where wake turbulence isn't the limiting factor?


texts: What are the limitations in adoptions of GTF (Geared Turbofan) technology?

texts:
The only recent engine using GTF technology is the PW1000G, however some old designs like ALF502 or TFE731 use this technology. I understand the basic concept of the benefit obtained by the engine introducing this technology (basically giving another parameter to optimize RPMs at low pressure turbine and fan) and that benefit is compensated by the increase in weight.

What is blocking this technology to be further included in modern turbofans? Is it only a business case for P&W architecture?

What made it possible in PW1000G that blocked PW8000?


texts: On a larger airplane, how do they manage balance?

texts:
I have flown a bunch of times on a Bombardier Dash-8 Q400 on a couple of different airlines, and several times I have flown a shuttle flight that is basically empty.

I have been instructed to change seats on these flights, reportadly to balance the plane better.

It appears as though the request comes from the cockpit relayed back to the cabin staff.

The plane appears to be static in place, so how do they determine that they need to balance the plane?  Does the landing gear report this sort of info?

A Dash-8 is a reasonably 'large' airplane that it seems sort of surprising that the balance is so delicate that the weight of a few people can make the difference.


texts: What safety requirements are there when designing an electronic device to go inside the cabin of an airliner?

texts:
I am considering designing and building an automatic air-sampling unit that can be placed in the cabin of an airliner and left unattended for an extended period of time.  The device will use an electronic air sensor and (small) processor so that it can detect and sample fume events without crew intervention, will be battery powered using a small battery of a known-reliable type (i.e. not Lithium-Ion :), will not have any functions that intentionally emit RF, and will be packaged in an enclosure (either plastic with internal shielding or metal).

What EMC and electrical-safety requirements/specifications must this device meet in order to avoid posing a hazard to the aircraft it is placed on, and how do I ensure that this box is not mistakenly considered a security threat to the aircraft?


texts: How should I interpret the difference in flight direction (azimuth) for great circle and rhumb line?

texts:
I am trying to understand the image above. If you fly in the Northern Hemisphere going west. The image said it's 150 degree if you fly Great Circle while 270 degree flying rhumb line.

If you think about this on a map, how is it possible to be 150 degree? Shouldn't the degree be between north(360) and west(270) as you fly west? I'm so confused.


texts: Why UA954 was diverted to Houston IAH on 25th Feb?

texts:
Fligth UA954 on 25th February was diverted to IAH when in flight from SFO to TLV.

Passengers were updated and told that the plane had a technical issue that was preventing it from crossing the ocean.

According to flightaware the plane was close to the border between Wyoming and Montana. It continued flying and landed in IAH.

What was the reason for the flight not being able to continue flight over the ocean, but still allowing it to continue flying safely for around 4 hours?


texts: What is the stress tolerance of landing gear of commercial aircraft?

texts:
Context: The landing skills of commercial airline pilots vary widely -- ranging from the ability to routinely make feather-touch landings and taxi and almost imperceptible deceleration on the one hand, to habitually landing with a medium-heavy thud and decelerating abruptly, even under normal flying conditions. One guesses that the landing forces on various parts of the landing gear (and also other parts) would momentarily vary by a factor of three or four, or even greater, on some key parts.

Questions:

1) Please elaborate on the stress tolerances built into various parts of the landing gear of common commercial aircraft, such as the Airbus A320 and Boeing 737?

2) What kind of stress testing is done on crucial parts of the landing gear, such as tyres, wheels, axles and hydraulic parts?

3) What are the backups and fail-safe measures designed into such landing gear?


texts: I have read conflicting reports that this Russian helicopter is out of production, yet others say otherwise. Could anyone confirm?


texts: What is the life limit due to metal fatigue in large bombers?

texts:
This article explains how the B-52's will be kept flying for 100 years.

Replacing the engines, electronics, etc. is one thing, but when would metal fatigue become a problem? These planes are huge and, I expect, rather heavy (at least when loaded up) and although they fly fewer cycles than passenger airliners, a hundred years is a long time.

Obviously I expect the military to be aware of this, but I'd love to hear what you folks think.


texts: Are zero visibility landings a possibility for the future of commercial aviation?

texts:
Airports usually close or slow down activities in fog conditions, e.g. this seems to be a significant problem in winter at Delhi airport.

Large commercial aircraft would be able to land with no visibility (more accurately with no Decision Altitude/Height). However, if using the ground ILS, the runway must offer a Category IIIc landing system. While Cat IIIa and Cat IIIb are common at large airports, there are no Cat IIIc runways in the world of commercial aviation.

The reason is landed aircraft wouldn't be able to safely leave the runway and taxi to the gate because taxiways are not equipped with features appropriate to no-visibility conditions.

On the other hand driverless cars now are experimented on public roads without specific equipment, including in fog, and driverless vehicles push back aircraft prior to taxiing:

Driverless pushback at Heathrow (source Youtube and manufacturer site, can be autonomous with ground markings)

In the long term airports with autonomous tugs on the whole taxi phase may be interesting as they allow savings by providing power supply while taxing, which in turn can decrease fuel needs and mechanical wear.

Is there a possibility such zero visibility landings could happen in the near future, because desirable for airlines and airports?


texts: Does the aibus a380 has center tank compare with a320,in this picture above,it shows that it has 11 tanks including the wings and the elevator while many aircraftshas together with the center tank (i mean that :eg the a320 ,the fuel are in the wings and cantre tank which is in the centre of the aircraft


texts: What would it take to pressurize a cabin with surface pressure?

texts:
At cruise level around 10000 meters the cabin pressure is lower than surface pressure. The only reason for this, is to reduce stress on the structure of the plane, or fuselage, right?

My question is this:

Given the current state of technology, if manufacturers were to produce passenger aircraft, massive or robust enough to allow cruise flight with cabin pressure equal to surface pressure, then how much would the gross weight of the aircraft increase? How much would the range of the aircraft decrease or how much less cargo could it carry?

I suppose that the current planes could also fly at surface pressure, but the level of safety would decrease, due to increased forces on the structure. So, the question really is: Suppose we want to fly at ground pressure with the same levels of safety, how much would the gross weight increase, how much less cargo could a plane carry?

Many thanks.


texts: Is it incorrect to say that "passenger jets like to cruise at higher altitudes because there's less drag"?

texts:
I hear it stated quite often that aircraft like to fly high because there's less drag at higher altitudes.
$$ \text{Range} = \frac{V}{g} \frac{1}{\text{SFC}} \frac{L}{D} \ln \left( \frac{W_\text{initial}}{W_\text{final}} \right) \; . $$
Aside from SFC, it seems that none of the components of the range equation are altitude dependent. Lift/Drag should remain constant assuming the lift and drag coefficients remain constant. Therefore, is it incorrect to say that there is a benefit to range flying at a higher altitude due to decreased drag?
Another question is, does the lift/drag ratio of an aircraft increase somehow at  higher altitudes?


texts: How many flight hours do the first retiring A380s have?

texts:
I read news here that an A380 previously owned by Singapore Airlines has been decommissioned and scrapped. Another A380 from Air France was also retired. Others are nearing retirement as well. But it is not clear for me whether the retirement is due to the aircraft reaching the end of their design life or due to some other reason. If it is due to the design life, why are they still able to sell the scrapped parts (as done by the TARMAC)? Most comments I read are negative, which is sad.

Then my question, how many flight hours do these aircraft have? Is the retirement purely due to its design life being used up? Or for other reasons?


texts: How can I tell if a G430 or G1000 has WAAS or not?

texts:
Both the GNS430 and G1000 are/were available with and without WAAS, and I believe it's even possible to upgrade a GNS430 to add WAAS support. When I get into an unfamiliar rental aircraft, is there a quick and easy way to see if WAAS is available, by checking the avionics themselves? Is anything physically different about the units, is there some properties/status page I can check, or is there something different on the display?

Obviously asking the operator and checking the aircraft handbooks would be the right thing to do, but sometimes that doesn't work out, e.g. the FBO's instructors are all out flying and the admin people just don't know.


texts: Are any online resources available for ATC recordings?

texts:
liveatc.net is available, but the voice quality on there, I am given to understand, does not represent the quality of voice available to someone actually sitting in an ATC tower. So I am looking for a source which offers more representative recordings.

EDIT: I intend to use these recordings to evaluate which speech to text engine (Non comprehensive list) works best in the context of aviation, so recordings which best mirror what happens in reality are important to reduce pre-processing.


texts: When cleared for an approach and not on vectors, is a depicted course reversal always required?

texts:
At least where I fly, most instrument approaches now use a Hold In Lieu of Procedure Turn (HILO). The "full procedure" now consists of a turn in the hold before proceeding inbound.

In the example above (click to embiggen), if a pilot is northeast of EYWOK and receives the following clearance from Seattle Approach:

  Cessna 123AB, proceed direct EYWOK, maintain 3000 until established, cleared for the ILS Yankee approach at Paine Field.

Are they required to fly the course reversal, or can they proceed inbound on the final approach course immediately upon reaching EYWOK and fly direct to ITIPE?  If not, what instruction must be received in order to skip the HILO procedure?


texts: Is there any current and/or upcoming technology that alerts Air Traffic Controllers in case of loss of aircraft separation?

texts: Currently doing an assignment and it to analyse an accident where older atc systems could have been at fault. In 1995 there was an incident where two aircraft came closer than the then current separation standard due to an air traffic controllers miscalculation. With new tech such as ADS-B, are there ways the controller can be alerted of possible loss of separations with the aircraft they are handling?


texts:
What type Altimeter is an SA-91? It has three pointers 100, 1000, 10000.
Don't know if it is Kollsman. I can't find any info as far as repairing unit.


texts: How do I set up G1000 GFC700 autopilot for takeoff?

texts:
I want to be able to engage autopilot right away at a safe altitude, while taking advantage of flight level control at Vy for the climb.
Heading is set for the runway. I’d switch to NAV mode when I was ready to make the turn out.
Altitude is set for cruise altitude.
Does this look like I’m all set to just hit “AP” at a safe altitude, or am I missing anything? Thanks!


texts: In WW2, were self-sealing fuel tanks really cost-beneficial?

texts:
I just read this question and answer, which seems to confirm my fears that an incendiary bullet will still destroy you if it hits your fuel. In other words, a self-sealing fuel tank will not protect against incendiary bullets. The wing will be punctured, and the fuel will either explode, or catch fire and remain on fire. (Correct me if I'm wrong.)

So the question is, why have them at all? It seems so easy to defeat the system by just using incendiary bullets, which must be a whole lot cheaper than the rubbery fuel tank.

I know there is accident protection and flak fragmentation protection. However, if you're taking flak, it seems to me you've got many problem-areas under the aircraft to worry about. I remember reading about a lot of bomber pilots in WW2, who took hits in the legs from flak, and some of them started sitting on their flak jackets all the time.

I realize this is a complex question, because cost-benefit analysis is a complex thing. But maybe someone can explain the rationale held at the time. Self-sealing fuel tanks added cost and weight, yet seem easily defeatable with incendiary bullets. Maybe I am missing something?


texts: I know that many fighter jets such as the F16 and F22 use a JFS to get compressed air into the engine. However, I was also reading that an APU does this. Im very confused on what does what. Thank you.


texts: What are the negative associations with Continuous Descent Approach?

texts:
According to this Wikipedia article:

  Due to the negative association with the term CDA,[citation needed]
  new procedures introduced at LAX and other US airports are instead
  called optimized profile descent (OPD).

What are the negative associations with the term CDA?


texts: What is the cost savings of using electronic motors to taxi?

texts:
Aircraft manufacturers are now planning to use High Torque electric motors on the nose wheel of the aircraft, which is powered from the APU, to taxi the aircraft from the gate to the runway without using its main engines. This is intended to reduce the fuel consumption by the plane while being taxied using the main engines, but also adds additional 150 kgs approximately to the weight of the aircraft.

How much fuel savings are we talking about here? Lets say we are considering an A320?


texts: Do Air Passenger Number statistics on a route refer to both directions of flight?

texts:
Looking at the air passenger data for specific routes, I was wondering if this data referred to just one direction of the route, or both directions?
For example (see link below), Philadelphia's most served route is to Orlando, flying 548,320 passengers last year. Is that number referring only to PHL-MCO, or is that cumulative of PHL-MCO and MCO-PHL?
Thanks!
https://en.wikipedia.org/wiki/Philadelphia_International_Airport#Top_destinations
https://www.transtats.bts.gov/airports.asp?pn=1&Airport=PHL&carrier=FACTS


texts: How should I operate within the dashed magenta lines next to Class D airspace?

texts:
I am unsure of how to operate within this area (red dashed line) without connection to ATC.  It appears to come off of class D airspace.

Can anyone provide an explanation of what this area is and how to operate within it?


texts: How often is the exterior of airliners cleaned?

texts:
Do airlines such as American Airlines or Emirates clean their planes regularly?

If so, how regularly? After every flight or at scheduled maintenance points?

How long does this activity take? Do they apply any wax or polishing to the plane?

I am interested in the general upkeep of the exterior of the plane and what major commercial airlines do to upkeep their planes.


texts: What are the correct names for the two faces of an airfoil?

texts:
When representing a wing airfoil, often the low pressure is on the top side and the lift is positive:

In this case upper and lower sides are enough to understand the role of the surfaces, But this is meaningless for a rudder or for a compressor blade.
Are there names to identify the faces in relation with the direction of the lift. (In French specific names, extrados and intrados, are used in relation with camber.)


texts: Do I have to follow airways to meet the IFR cross country 250 NM flight requirement in 61.65?

texts:
I understand that there is cross-country flight of "a distance of at least 250 nm along airways or ATC-directed routing" requirement for the IFR rating, but I'm not sure if understand what the second part of that sentence means.

Do I have to follow Victor airways? Will obtaining flight following from ATC be sufficient?


texts: Could propeller wash provide sufficient lift to take off - even in theory?

texts:
I know this seems a crazy thing to ask but it is not the same as lifting oneself by the bootstraps. If you try to lift yourself that way, there are two equal and opposite forces, yet there are experiments with muscle powered planes that work.
So, provided the plane was stabilised somehow, and the wings were designed for the purpose, could propellor wash theoretically lift the plane? If not why not?

Note
I understand that a normal plane would start to move forward. Please assume that the plane is restrained from the rear by a cable and that the experiment takes place in the absence of wind.


texts: How is a misdeclared weight of a mail bag handled?

texts:
What is the proper process when a postal administration tenders a mail bag with under declared weight?

Is the bag returned to the postal administration or is the bag weight altered to match the actual weight or is there no weight verification of mail bags?


texts: Is there a required check before selling an airliner?

texts:
In France, when selling a car, the last check (more or less a C-check) must has been done within the 6 months before the owner change.

Is there an equivalent requirement for airliners? I'm more interested in ICAO's rules.

I'm thinking of budget airlines that tend to sell their aircrafts while still young (less than 10 years) and thus having been subjected to at most one D-check.


texts: Reducing camber for DrelaGW19 for L/D ratio

texts:
Okay , Thankyou for letting me know
But these airfoils (DrelaGW19 and GW27) have extreme camber on upper surface. Now why is that so? (The first reason could be good lift at high Reynolds number(~ 1.5 millions)). Now with same airfoil, a L/D ratio exists.
But if camber is reduced (may result into lower Cl) then maybe increased L/D can be obtained.
So is it good to reduce camber or modify airfoil profile for an improved L/D?


texts: Do airports have their own incident/accident investigation departments? or they are restricted to the NCAA/Safety department only?


texts: Can I use Stihl fs250 engine for ultralight aircraft?

texts:
RPM 9000
Hp 2.2
Engine weight 6kg
Plane weight 40kg
Body weight. 70
Propellers(2blades) length 30 inches
Wings length 120 inches


texts: Why do planes accelerate when they touch down on a aircraft carrier

texts:
I was watching a plane documentary, and when the part about aircraft carriers came on, I noticed that as soon as the plane hits the aircraft carrier runways, the plane speeds up. Why is this happening?

The question has not been answered in What is the procedure for landing on an aircraft carrier. This question explains the procedure to throttle up to full military power just after touchdown, however does not address the reason for doing so.


texts:
Are the Airport Operational Databases at major airports in the US available to the public? I am pretty sure it is not live but maybe released a month or so after.

AODB

An AODB system is usually the core IT system to support the airport ground operations, it integrates with various systems from the heterogeneous IT landscape found at the airport, compiling data from airlines flights schedules, flight plan management, communication between airlines and airports to building management systems, live ground movements and many more systems.
It serves as platform for CDM (Collaborative Decision Making) for the various parties forming the airport community, from airport operators, airlines, groundhandling agents to ATC.

It handles seasonal and operational flights by providing both real-time and historical data, supports resource management for facilities and equipment, as well for staff, it is an information portal.