texts: Why doesn't GA aircraft use the JASC/ATA document standard?

texts:
By international law large aircraft are required to categorize aircraft information using a standard called the ATA document numbering system (Air Transport Association).

The ATA document chapters allow a pilot or mechanic to find the same information for any airplane under the same chapter/sub-chapter number. Thus a chapter number for a Boeing 747, B737, or Airbus 380 will be the same. Examples of this include Oxygen (Chapter 35), Electrical Power (Chapter 24) and Doors (Chapter 52).

A few examples of ATA chapter numbers...

ATA No. ATA Chapter name
ATA 00  GENERAL
ATA 01  MAINTENANCE POLICY
ATA 02  OPERATIONS
ATA 03  SUPPORT
ATA 04  AIRLINE USE Aircraft Handling
ATA 05  TIME LIMITS/MAINTENANCE CHECKS
ATA 06  DIMENSIONS AND AREAS
ATA 07  LIFTING AND SHORING
ATA 08  LEVELING AND WEIGHING
ATA 09  TOWING AND TAXIING
ATA 10  PARKING, MOORING, STORAGE AND RETURN TO SERVICE
ATA 11  PLACARDS AND MARKINGS
ATA 12  SERVICING
ATA 14  HARDWARE AND GENERAL TOOLS
ATA 18  VIBRATION AND NOISE ANALYSIS (HELICOPTER ONLY)

About 20years ago the FAA strongly urged GA aircraft to follow the standard with the anticipation that it would soon become law - it never did.

Why has the International community not mandated GA aircraft use the JASC/ATA document standard.


texts: What changes do narrow-body airliners undergo to serve (relatively) long routes?

texts:
I will try to pose a well-structured question here on the longest routes ever or currently served by small, narrow-body airliners - specifically, the Boeing 737 and the Airbus A319 and A320.

Set aside special versions in the likes of the Boeing 737-700BBJ, what makes a small, narrow-body airliner serve routes that are longer than those on which it is usually deployed?

Which is to say, what is added or changed, on the design side of things, to the structure or operability of planes that are not specifically designed for long distances, to make them capable of flying longer distances? I guess the answer is ETOPS, but I am not sure of what this implies from the operational standpoint.

For my moderate understanding it is quite impressive that narrow-body birds can fly from, say, Tokyo Narita to Mumbai - a distance of approximately 6,800 km or 4,220 mi (All Nippon Airways Boeing 737-700ER, flight NH829). Another example is Sunwing Airlines flight WG481 from Vancouver to Punta Cana (a Boeing 737-800 which flew for 5,930 km or 3,690 mi).

A list of such unusual performances can be seen here.


texts: Where to find information on the Daimler-Benz 606/610?

texts: There seems to be relatively little information regarding either of these engines on the web. Anyone have an idea where I can find more info?


texts:
I have 2500hrs and have flown over 30 types of aircraft. I am also a A&P. I have never seen a POH, manufacture or FAA suggestion for wear limits of a tire. The flight school I got my pilots license (1980), would wear the tires of Cessna training aircraft bald on the outside of the tire and flip them on the rims, then run then bald on the opposite side. On airliners and transport aircraft I have seen chunks of rubber missing, cord and belts exposed, etc more so on freight than passenger aircraft. Surely there must be some standard or legal requirement.

( I have seen FAA, mfg, and other info prohibiting flight if tire pressure exceeds +-5%)


texts: Can I charge for editing footage from a video that was taken during a flight as a private pilot in US?

texts:
I am a private pilot, and I went with one of my friends to a skydiving trip in a rented Cessna 172 that we split the cost on pro-rata.
I also used my video making equipment to record the duration of the flight.
He wants entire video now; I know that I may legally ask him to pay the $100 that is his pro-rata share, but can I charge him for my time spent editing and making that video as well?


texts: What happens to cabin pressurisation when the engines fail?

texts:
I was reading about the cabin pressurisation mechanism from Wikipedia and another article here. According to both of them, the aircraft's engine plays a vital role in the  pressurisation process.

My question is:

I have come across many air crash investigation articles mentioning that all the engines of an aircraft had failed, but the pilots were able to glide the aircraft and safely land it with no casualties. How is it possible for everyone onboard the aircraft to survive without cabin pressurisation (with all engines out) ?

UPDATE: What if a safe landing area is a bit too far? After losing altitude, the aircraft can't obviously gain altitude. Won't the plane crash due to low altitude (the descent is fast) gliding?So, isn't it better to maintain (sufficient) altitude to reach an emergency destination? I hope the altitude can be maintained provided cabin pressurisation is intact. But, how is this achieved in commercial aircrafts?


texts: How to correct dynamic stability of UAV fuselages?

texts:
I was trying to design a fuselage model of UAV with considering lift coefficient (CL), after this I analyzed stability of both wing on fuselage. First I did the individual analysis for wing and fuselage in which the result of main wing analysis is quite good but after adding fuselage the dynamic stability of the UAV was not perfect.
If any information might be lacking I would love to add details and I am onto sure if my question is reliable for this forum ,if so it would be great if you could suggest a specified forums where I can discuss with this issue.
Thanks in advance.


texts: Are there multiple reasons for the decrease in pressure over a wing?

texts:
I'm aware that the decrease in pressure over the wing is due to the curvature of the airfoil which causes a pressure loss due to the spreading of the air as it is redirected.

But is it also due to the increase in velocity from the squeezing of the streamlines at the leading edge, like in a converging duct there is no redirection of flow but there is still a decrease in pressure where there is an increase in velocity?
Is this down to a reduction in the number of collisions per unit time?


texts: How is an airplane towed/recovered after an emergency off-field landing?

texts:
I understand that there may be many different scenarios and situations, and that a similar question has some answers to this, but I was wondering if there are answers with existing examples. Some different scenarios are as follows:

General Aviation Airplane:

Landing on the beach
Landing on a road/interstate highway
Parachute Deployed Landing (Cirrus SR22) in a dense forest
Ditching in water

Large Jet Airplane:

Landing on the beach
Landing on an empty road/strip (such as the Gimli Glider)
Ditching in water (such as the Hudson landing)

I understand that the first priority is saving the souls on board. However, after that, the second-most important priority would be to recover the airplane as it is definitely a very valuable asset to the owner/company.

For all the above scenarios, what is a proven/tried method of recovering and towing while ensuring that the aircraft (or parts of it) can be put to use again?


texts: Can fighter jets be reloaded with ammunition mid-flight?

texts: I know that we can re-fuel fighter jets mid-flight, but do we have also a mechanism to reload them with ammunition during mid-flight so they don't need to go back to base to reload?


texts: Can you flag down / contact an airplane with a handheld radio in case of emergency?

texts:
A friend and I are going rim to rim to rim in the Grand Canyon this Wednesday.  It's a 46mi, 20+hr "hike" with some very physically challenging sections.  We are packing the minimal amount needed - meaning not too much extra in case of an emergency - it's especially risky given the below zero (fahrenheit) temperatures this time of year.  Normally for something like this, I would bring my Spot - to call for help if I needed to, but it's not working.

If I brought my VXA-220, would it be legal to use it to call for help?  From what I understand, most airliners are tuned into 121.5.  Could I tell them to send a helicopter for rescue?

Obviously, in a life or death situation it's not going to matter if I'm braking the law.  But it would be nice to know how such a situation would be handled.


texts: What will the pilot do if all the airspeed indicators fail?

texts: Are there any alternate instruments to indicate the airspeed in case of pitot tube failures?


texts: What modifications/upgrades were done to US MD-80 fleet?

texts:
I have often heard stories about how most of the MD-80 fleet that are being retired in the US were modified and upgraded.

What were the modifications or upgrades done?


texts: Why do you think Pakistani LACM and SLCM have different ranges?

texts:
https://en.wikipedia.org/wiki/Babur_(cruise_missile)

The following is the picture of Pakistan's LACM Babur-II. Its billed range is 750 km.

The following is the picture of Pakistan's SLCM Babur-III. Its billed range is 450 km.

Why could the range of Babur-III possibly be smaller than that of Babur-II?


texts: When are winds given with respect to true vs. magnetic north?

texts: Wind information can be reported by various sources (ATIS, METAR, TAF, spoken on the radio, etc). I was taught that officially some of these sources are relative to magnetic north and others to true north (although practically this isn't always followed). Which sources are supposed to use which reference system?


texts: Runway Number Landing and Departure Left Traffic Question

texts:
If I am "departing runway 36", what does that mean? I understand that runway 36 is at the north end of the runway (360 magnetic); So my question is does the aircraft start at the north end 36 and take off on the south end 18? Or am I starting at the 180 position and taking off at the 360 position/runway 36?

And when landing is it the same or opposite? "Final for runway 36", does that mean the plane is touching down on the 360 north end of the runway heading to stop on the 180/runway 18 side?


texts: What are the statistical probabilities of commercial aircraft accidents?

texts: Is there any study showing how probabilities of various kinds of aviation (e.g. crash-landings, fatal crashes, mid-air collisions) accidents have increased or reduced over time?


texts: How are "Owner-Produced Parts" handled under FAA regulations?

texts:
FAR 21.9 provides the ability to install parts that were "Produced by an owner or operator for maintaining or altering that owner or operator's product". This seems like a pretty broad scope of authority for aircraft owners.

Under what circumstances are owner-produced parts typically used, and what requirements are imposed on the part (and the owner producing it)?


texts: Is there a common template or mnemonic for a take-off briefing?

texts:
I know that a take-off briefing is a good idea so that your actions are a bit "spring-loaded" should a unexpected event occur.  Is there a common template on mnemonic out there (something like CRAFT for instrument clearances)?

For example, I was talking to a flight instructor who broke down the altitudes based on the elevation of the airport and what he would do in the event of an engine failure at or below those altitudes (example, airport elevation is 427 ft MSL, then 900 ft MSL, land straight ahead, 1400 MSL, turn back to runway...) The notable thing in this case is that he pre-computed the altitudes so he wouldn't have to think about them if something happened and had a straight-ahead, and turn back to airport plan and altitude.


texts: Is A380's center of gravity really too far back?

texts:
I have searched and even studied plans from Airbus itself, but I was not able to confirm the following and would like to ask if the information I have is correct.

TLDR version so you don't have to read all the text: Does A380 really have the center of gravity positioned BEHIND the aerodynamic force center?

(What I know so far): For any passenger aircraft, without (almost any) exception, the center of gravity is always closer to the nose of the aircraft than the aerodynamic forces resultant. This is to provide an auto-stabilising force for the aircraft in case it stalls for whatever reason. Since the airplane is "nose heavy", it would eventually establish itself "towards the air flow" and after some height drop, should at least partially regain normal flight mode. Also it prevents the aircraft from going into a flat loop. While this setup is safe, it also means that the tail wing needs to correct for the center of gravity and "pull down" (omitting the duck planes now), which means it does not help to create lift, instead reducing the total lift. This increases fuel consumption.

(What I need to confirm): During my UL theory training, one of the instructors told us that A380 (and all the new passenger planes driven mostly by computers alike) will have the center of gravity behind the aerodynamic center, which enables to use the huge tail wing to actually create lift instead of decreasing it and thus lowering the fuel consumption dramatically. While this is great from economical and ecological point of view, it would only work while the computers look after the plane. It would become so unstable that there is no way a human could fly it "by hand".

I understand that if the computers go down on a "fly-by-wire" airplane completely, the joystick/rudder becomes just a piece of plastic anyways, but a computer that constantly looks after the stability of the plane seems much more "error ready" than a simple wire between a cockpit and a servo.

Modern jet fighters have CoG behind the aerodynamic center and it is said that you only stall them once. There is no way to recover a stall like you would do with your good old Cessna. It strikes me that something like that would get approved for a civilian aircraft.

Thank you for your inputs. I was not able to find any resource concerning A380's CoG.


texts: How can the lift force be changed without changing velocity?

texts:
I am facing a problem for calculating the 4 forces affecting the aircraft balance.
Suppose the following inputs:
Aircraft velocity is 222 m/s.
Aircraft mass is 23500 kg.
Aircraft weight is 227360 kg.m/s2
At zero angle of attack the lift coefficient is 0.2
By Calculating the lift force from one wing 172899 N.
for the two wings lift force *2 = 345799.125 N

The problem is:
Now I want the aircraft to go to balance state to move with constant velocity.
So all the four forces should equals to zero thus the lift force should equlas the weight force.
How Can I decrease the lift force?

Assuming:
I still need the aircraft to move with constant velocity 222 m/s.
The lift is affected by angle of attack which is zero.
The air density is constant.

how can I the aircraft balanced with velocity 222 m/s?
Can I decrease the lift force without affecting the velocity?


texts: Could an airliner get better fuel efficiency at higher altitude?

texts:
By higher I mean like 60k feet instead of 30k.
Seems like the rate limiting step is engine performance at 60k feet.
Are people working engines that can operate at higher altitudes? How close are we to good performance at high altitude (60k feet).

For example: Proteus high altitude aicraft


texts: Is the ILS only used for landing when weather conditions are poor?

texts:
Either I'm missing something, or this article clearly suggests, that pilots are using ILS for landing only in bad weather conditions. Which could lead to an assumption, that in perfectly clear weather they're landing always or nearly always in visual.

Even though I'm completely new to aviation, I was always sure that ILS is used on every landing procedure, no matter if weather conditions are good enough to do it visually. ILS landing seems to be faster, more precise, more safe, and thus -- in my naive opinion -- should be used whenever it is available (i.e. whenever ILS is commissioned and operational).

What am I missing?


texts: What are the drug testing procedures for EU airlines?

texts: How do EU airlines test aircrew for drug use, specifically marijuana? Do they use hair tests, and how far back in time can they detect marijuana use?


texts: Did the Douglas SBD Dauntless have a second set of controls?

texts: In the book Never Call me a Hero, the author mentions that there were controls in the rear seat of the Douglas SBD Dauntless. However, I don't recall ever hearing this before, though I know the TBD had controls in the second seat. Did the SBD have controls in the rear seat?


texts:
How can I calculate the distance on the ground during the climb?

Assuming the climb power is 700ft/min, the climb speed is 65 kts, the wind 260/10kts on runway 26.
Start: 700ft
Top of climb: 3500ft

How far is the distance flown on the ground (in e.g. ft) and the GS?

What I understood:
The difference in altitude is 2800ft and therefore 2800ft / 700ft min = 4 minutes. I can say that I fly 4 minutes long 65 knots:
65kts -> 6582 ft * 4 = 26 328 ft but I don't use the wind in this calculation.
Can someone please help me?

Thanks!


texts: What kind of g-forces do birds experience and how does it compare to humans?

texts:
So bit of an odd one, but I was just looking at a sea-gull flying and wondering what kind of G-forces it could see in day to day flight?

There are probably very fast birds of prey that when pulling out of dives must experience fairly high G Force, but can they (in general) handle more or less than a human flying an aircraft?


texts: What are cowl flaps and what are they used for? It seems I have only heard of them in connection with old planes, are they peculiar to radial engines?


texts:
Here are two airfoils (lets focus on Re 100,000):

SD7043-il which is simple to build and has a glide ratio of about 60
e376-il a birdlike and much harder to build if using paper or similar due to the hollow inside but claims to have a glide ratio of about 105

I have never seen such birdlike airfoils on an aircraft (RC or other). Is it because of construction difficulties?


texts: How can I calculate a pitch/power table?

texts:
I want to make a pitch and power table for C172s based on calculation, just like I attached above.

I picked up this table on internet, but I'm not sure where it comes from.

Do you have any ideas how to get these values?


texts: How does an aircraft distribute fuel equally between powering the turbines on the engine and injecting it into the afterburner?

texts: How does an aircraft distribute its fuel equally between powering the engine turbines and injecting it into the afterburner?


texts: Just read this abstract by a Regeneron STS finalist.  Is the idea of a virtual winglet a viable concept? Seems interesting.


texts: Are speed limits used for departure turns imposed also on the rest of the procedure?

texts:
ICAO's PANS-OPS manual 8168 ("Aircraft Operations") defines turing departures as described below:

  2.4 Turning Departures. When a departure route requires a turn of more than 15°, it is called a turning departure.

It also defines maximum speeds used for turning departures.

  2.4.4 Turn Speeds. The maximum speeds used for departure turns shall be those of the final missed approach increased by
  10 per cent to account for increased aeroplane mass in departure (see Table II-2-2-1), unless otherwise annotated on the
  procedure.

What I am having trouble understanding is if these speed limits are valid only while the aircraft is performing the turn, and are cancelled during the subsequent straight track of the procedure (only for them to be valid again when another turn takes place).

I am asking because I remember reading somewhere that a speed limit imposed on a fix remains active for the rest of the procedure, unless it is cancelled by another speed restriction.

Thanks for anything that could point me in the right direction.


texts: What is typical ATC procedure when a non-pilot calls from a commercial flight for help?

texts:
"This is ShinyWings 123, I'm not a pilot, the pilot and copilot are unconscious. Help."
Probably a day air traffic controllers dream of with dread, when a member of cabin crew, or even worse, a passenger, calls for help with an incapacitated pilot(s) and a plane full of souls still unaware of the situation.
I'd imagine given the incredible amount of training and experience put into air traffic controllers, this is a situation they prepare for, and have a standard operating procedure prewritten and pre-taught specifically for. What is that procedure?
To keep the question from being overly broad, I'll restrict this to (1) ICAO standard procedures, if one exists for this situation and (2) procedures within the United States and European Union.


texts: Can private pilots drop skydivers if the pilot pays a pro-rata share?

texts:
This question was inspired by this other question. If a private pilot was to pay the pro-rata share of a flight for some skydiving friends, could they take those friends up and let them jump out?
If so, what counts as "pro rata share"? Is it expenses for the whole flight from takeoff to landing, or does the pilot assume 100% of the cost after the point where the skydivers leave the plane?


texts: Did the airfoil choice on the P51D affect its maneuverability?

texts: Did the wing design on the P51D, which used a laminar airfoil, affect its maneuverability? If so, how? To what extent?


texts: What is the best method to time your round out or flare in Cessna 172?

texts: I am a student pilot and I usually round out too high and I am not sure why. Can somebody  guide me how to make decision whether I am too high or not.


texts: Is it useful for twin propeller airplanes to have twin vertical stabilizers, in line with the propellers?

texts:
In some twin propeller airplanes, there are two vertical stabilizers which are on the same line as the propellers.

Is this shape helpful in terms of efficiency?

Like this one (twin boom tail):


texts:
I have the design lift coefficient of the plane during the cruise condition. Now, I want to calculate the lift coefficient required by the airfoil which makes up the wing, taking into account the Aspect Ratio, Sweep, etc. Is there a formula for that? I have seen formulas that give the slope of the lift curve for a wing using the slope of the lift curve of an airfoil.

I need the design lift coefficient of the airfoil for choosing an appropriate airfoil.


texts: I'm 67 and would like a recommended easy airplane program to play. I cannot afford to really learn to fly so I would like something that is not to complicated to use.  Thanks.


texts:
How many flight training hours can a student realistically do in a week?

I have 11 PIC flight hours (and solo'd at 7hrs) but I havent flown (PIC time) since 2008. I want to finally get my license but am unsure if I can realistically do it before I leave the country in one month.

In one week, I can actually devote my entire day to flight training so I'm wondering how many PIC flight hours a student can realistically do in one day and thus a week. Is 2-3hrs flight time (2-3 actual sorties) for 7 days realistic?

Also, I know this is highly dependent on my CFI but let's assume I can find one to match my speed...


texts: How to calculate the Pitching moment coefficient of wing?

texts: I want to check the trim condition for aircraft. For this I need the pitching moment coefficient of wing. How to calculate?


texts: What is the relationship between your tail number and air traffic control?

texts: Obviously a tail number is used to distinguish yourself from other aircraft, but after the first call, a callsign does the same thing. It is also used for investigation purposes I would imagine, by listening to radio recordings, but are controllers typically even able to read tail numbers from the tower or do they just see a plane around where you say you are calling from and assume that it's you?


texts:
Why are there fewer air carrier operations on weekends? Looking at PHX data, we have the following annual trend that clearly shows a weekly drop of about 8% on weekends:

and when I average the data a strong weekly pattern is evident:

Is this simply telling us that most traffic is business related? Or is it, in part, that major cargo haulers don't work as much on weekends? As the charts show, we're talking about a 1200 vs 1000 daily operations difference.


texts: What determines the positioning of PAPI lights from the runway threshold?

texts:
Why are PAPI lights installed 300m from the threshold?
What are the conditions that define the position of the PAPI lights from threshold?


texts: In an airliner, does the Captain or the First Officer fly the airplane?

texts: If there is such a thing as a 'normal' flight (in a commercial airliner), who flies the plane? Is it usually the Captain, the First Officer, or whomever needs the hours?


texts: How can an airplane roll, yaw and pitch up and down without control surfaces?

texts: This is a Sprat 103 ultralight, it has no ailerons, and no ruddervator (on its v-tail). How then does it fly controllably?


texts: What is this aircraft and the Air Force it belongs to?

texts:
Hi,
Could someone identify the fighter jet type and the Air Force it operates in? Thanks


texts: Why does the FAA ban preboarding passengers from sitting in emergency-exit rows?

texts:
Of the several restrictions every U.S. airline passenger knows about regarding who can and can’t sit in an aircraft’s emergency-exit rows (no one under 15, or physically disabled, or travelling with small children, yadda yadda yadda), one of the strangest is a blanket prohibition against preboarders sitting in exit rows.

Now, this does make sense for some specific subsets of preboarders; for instance, one common category of passengers allowed to preboard comprises those with physical disabilities severe enough for them to require extra time, and a near-empty aircraft, in order to board (if someone is disabled enough to severely impair their ability to board the aircraft, one would probably not want to have to rely on them to potentially have to open and maneouvre a heavy emergency exit hatch), while another common preboarding group, families travelling with small children, is already excluded by the prohibition from exit-row seating of small children and those travelling with same.

However, the severely-physically-disabled and the possessed-of-small-children are far from the only types of preboarders; a third group of passengers routinely afforded preboarding rights by most airlines are active-duty military personnel, who are among the best possible choices for exit-row duty, due to their generally-excellent physical condition and discipline.  So why does the FAA ban preboarders as a whole from sitting in emergency-exit rows, rather than only those preboarders whose reasons for preboarding would actually impair their ability to perform emergency-exit tasks in an emergency?


texts:
Commercial aircraft are identified on the radio with an airline call sign and their flight number.

The answer on this related question mentions:

  the telephony designator of the aircraft operating agency

How is this designator assigned? Are there requirements for getting one?


texts: When is an aircraft handed over from Center to Approach?

texts:
I'm trying to understand how an IFR flight an ACC (center) controller communicates the hand over to the pilot to contact local airport frequencies.

I tried listening LiveAtc but my English is not so good and I still have a couple of questions. I must emulate a center hand over to local destination frequencies, is this order correct for pickup the right frequency?

Approach (if present)
Departure (if present)
Tower

Is departure eligible if an approach frequency is not available?
If approach is available, which ATC gives landing clearances, tower or approach?

Also at which distance from airport ACC should do the hand off to the approach frequency?


texts: What is the FAA's official outlet for informing the public of permanent, systemic changes?

texts:
When the FAA changes a regulation or rule, such as the recent change in April that student pilot certificates will be a plastic pilot certificate without an expiration date... (This page)

  Student pilot and medical certificate are no longer the same document, therefore, refer to 14 CFR 61.23 for complete information on duration of a medical certificate.

  After April 1, 2016, Student pilot certificates do not expire; the certificate will be surrendered and superseded upon successful completion of the higher certification. Student pilot certificates issued prior to April 1, 2016, will expire according to their expiration date, either 24 or 60 months from the date of issuance.

... what is the standard, official, go-to document to keep abreast of the existence of these new changes?  How often is is released or how are we notified of its release if it is irregular?

This question is not about NOTAMS which cover temporary changes, or changes that will later be added to a document with regularly occurring updates at known intervals such as those for approach charts.

This question is also not asking about the contents of advisory circulars; however, I would view an update to an advisory circular or release of a new one as being a pertinent, permanent change considering many of them have been around since the 1970s and contain official FAA information on various topics.

So, to be totally clear, I am asking how we are notified when there are changes and where they are located not necessarily what the specific, full-text contents of the changes are.

The changes could be to such things as:

Handbooks and manuals
Federal Aviation Regulations
Advisory Circulars
Practical Test Standards
The Airman Information Manual
FAA knowledge exam contents


texts: How calculated the drag coefficient lift coefficient with pressure coefficient?

texts:
I have got the Cp Plot on a wing, now  I am trying to calculate Cl and Cd. And the angle of attack is 0 degrees, the wing has been split into N Panels, and the normal vector ni for every Panel is already known, The airfoil(AQUILA) is like the picture:

If the friction can be ignored.
For Cl, I integrate Cp with x from 0 to 1;
For Cd, I integrate Cp with y from 0 to breadth of the airfoil.
I have tried several ways:

(CD, CL) = sum(Cp(i) * L(i)* n(i))/(reference length)

-Here L(i) is the length of the i 'th panel, Cp(i) ist the pressure of center point of the i 'th panel and n(i) is the normal vector for the i 'th panel.

like the below equation in the screenshots:

With these two methods, I can get the same Answer, Cl = 0.09, Cd = 0.006
But actually Cl should be 0.2~0.4.
Could someone give me some advice and explain, I haven't studied aerodynamics before, but there are a few parts about that in my paper


texts: Do fighter jets have deicing in their wings?

texts: If there is such thing as deicing for fighters? If so, is bleed air or electric heating preferred? I could not imagine that a $50MLN fighter jet would not be able to get the ice off its wings.


texts: What happens to the cabin pressure if all the packs (ACMs) stop working?

texts:
I have gone through the cabin pressurization article in Wikipedia. It says there will be some number of Air Cycle Machines (ACMs, or packs) to supply pressurized air into the cabin.

What happens if all the ACM machines stop working? Does the flight have enough oxygen on board supply all passengers until they can safely land the flight somewhere?


texts: Where can I find (online) manuals for refueling A320/B737 for a given destination?

texts:
Surely, airline crews must have manuals/apps by which they calculate the (minimum) amount of refueling before departure to a given destination. I have been looking online for such sources, with zero hits.

Specifically, I'm intersted in such free manuals/apps for the Airbus A318...A321 and Boeing B737 families.


texts: How does the fan in the jet engine suck in air while the engine is stationary?

texts:
This question is related to the fans and compressors in jet engines.

(Please Note: I know how a propeller driven airplane works. The propeller has the shape of the airfoil and when this propeller moves through air, a pressure difference is created between the front and the back of the propeller. This causes the airplane to move forward)

Most of the fans that I have encountered till now merely recirculate the air in an enclosed area (for example: the ceiling fan recirculates the air already present in the room)

I am comfortable with the idea that fans recirculate air when they rotate. But my intuition is failing me when I think of fans (exhaust fans) that suck air out of an enclosed area.

The exhaust fan sucks out air from an enclosed area (ex: room). The fan in a jet engine sucks in air from outside into a enclosed area.

I would appreciate it if someone could explain how these fans manage to suck-in/suck-out air. Does it have anything to do with the shape/orientation of the blades of the fan?


texts: Why did my LGA-ORD flight make an S-shaped turn round the time it was passing a storm?

texts:
On a recent United UA1709 flight into Chicago (hit by a heavy storm at the time), I felt a noticeable descent, combined with two wide banks around 1 hour before landing. Looking at the flight path, I see an S shape that deviates from the original flight path.

Looking at the altitude readings here, the plane registered a descent of around 3000 fpm around the time of the turns from a cruising height of 30000 ft to 21000 ft. This descent took the plane under cloud cover and into the storm, so I am certainly confused as what motivated this flight path. Given that the flight was an hour away from landing, I find it hard to believe that this was a holding pattern of some sort.

Some more things that I noticed during this flight (not sure if relevant) was that a few minutes after this, I noticed lights indicating a plane flying directly above (hard to estimate distance given bad visibility). Furthermore, in-flight WiFi briefly cut out for a few minutes.

Can anyone explain what happened here?


texts: Do air-driven gyroscopic instruments suffer from icing or any blockage of filter?

texts:
Do gyro instruments suffer from icing in an air-driven gyro system? Do they have any particular way to protect them against blockages of filter or any type of other blockage? (Alternate source?)

I am more concerned on light aircraft C152, C172, PA28, etc.


texts: Can I obtain a license over several years?

texts:
How long does training for student, sport, recreational, or private licenses "count" toward your license, before it's considered outdated/expired?  Can you start the process, intending to spread out the expense over something like 5 years, or in that situation, do you need to "save up" and do it all within a year or two?

Bonus question - My luck that I'm just starting to look into this, and there's a private pilot ground school course starting tomorrow nearby.  Is it premature for me to take this class, not having taken any other steps?  Would it be over my head, or would I need to take it again if I don't get the private license within a certain amount of time taking the class?


texts: Is it possible to isolate COM1 and COM2 on a Garmin G1000?

texts:
Is it possible to isolate COM1 to one pilot and COM2 to the other pilot?

When I'm getting the ATIS it's hard to listen to both COM channels sometimes depending on the amount of traffic.

I used to be able to do this on an older aircraft I flew, and loved the feature in a crew environment.


texts: How can investigators trust flight instrumentation from aviation accidents?

texts:
I encountered the original question here; I tried to improve the prose by editing it:

  Secondly, about all air disasters involving high-speed impact with terrain, how can investigators trust results from testing instrumentation that hit the ground? In Copa Air Flight 201 they tested the captain's gyro and found it faulty. It probably was, but isn't there the possibility that the gyro was damaged as a result of the impact? I'd really like to hear from an investigator on how it is they determine that test results are so reliable that they can come to a definitive conclusion as to why the accident occurred.

  [User 'bonmec101' writes,  week of 2015 Feb 3]

    +[user] Marvin Kitfox "If you test an instrument from a crashed plane, and it works, you can be pretty dang sure it worked before the crash."

  you haven't seen "Hidden Danger" then [which examines USAir Flight 427). One of my most favorite episodes.

User 'diegus012' answers here, on 2015 Feb 21.


texts: What are the differences between Cat I, Cat II, and Cat III as concerns aircraft requirements?

texts: I understand that Cat I, II, and III ILS approaches have progressively smaller weather minimums. However, I am asking about the aircraft themselves. What are the differences between Cat levels as concerns aircraft equipment requirements and approvals?


texts: When I traveled on a commercial aircraft, I had a meal which came in a small box, I was wondering if the meal is precooked and then re-heated or if it is cooked on the plane?


texts: Do jet engine exhausts usually glow orange?

texts:
In these two lovely images:
Source: Wikimedia Commons
Source: wvi.com
The exhaust end of the engines are glowing bright orange from being so hot. Do they get that hot during normal flight operations, or are they hot because the engines are statically mounted for testing and have (relatively) minimal air flow to cool it?
If it's normally this hot, what is the exhaust made of, and how is it insulated to keep it from melting the nacelle around it?


texts: How efficient would an airliner be if it did not have to carry its own fuel?

texts: Hypothetically, if all the fuel was supplied externally or pulled from the atmosphere to where the plane had never to carry any fuel on board, how much more efficient would an airliner be? The plane would not fluctuate in weight.


texts: What main landing gear actuator does the Boeing 777-300ER have?

texts: I can't remember the name of this system was, but all I do know is that is a big actuator that only exists on the Boeing 777-300ER variant. It will pressurize the actuator according to the thrust input the cockpit. It will automatically tilt-up to get a better AOA.


texts: Could a triplane fly using a dihedral wing in the middle?

texts: I wonder if a triplane glider whose front view is shown in the figure can be built and flown successfully.  As you can see, the middle wing has a dihedral angle, but the top and bottom wings do not.  The vertical lines represent structural members.  The idea behind this strange design is that a box-shape with diagonal members is structurally very strong, hence my interest.  I realize that the structural members at each end will contribute to the drag, even if they have a streamlined shape.  I also realize that every corner of this shape will not produce much lift, but will produce much interference drag.  Yet, I wonder if this weird triplane will fly properly at low speeds.  Any thoughts?


texts: How many tendencies are affected by Gyroscopic precession for single propeller airplane?

texts:
I have heard about LEFT turning tendency affected by gyroscopic precession of propeller (which is turning clockwise or counter clockwise if seen from front side). But I just watched a video on Youtube explains the tendencies affected by the gyroscopic precession, that the airplane is pitch up (nose up or tail down), which means, there are two tendencies.

Then my question is, is that explanation true? Is the second tendency true?


texts: What is this aircraft, when was it produced and used and what was its role?

texts: What aircraft is this, when was it produced, used operationally, and what was its role?


texts:
There are companies such as this that offer one day full simulator experiences where you take several attempts at landing a 747 or something similar. Some people report success after a couple of attempts.

In this question, asked recently here on ASE, it was generally agreed upon that no-one could land such an aircraft without many hundreds of hours of training.

So how do these day-courses/experiences work? Do they somehow 'dumb down' the simulator, automating most or all of the process'?

Side-note: I am asking, because I am interested in learning the basics of flying, but could only afford simulator training, the actual school in my real country offers block bookings for a reasonable price.


texts: What is this old pusher propeller aircraft?

texts:
I am researching the history of pusher aircraft and came across this photo. Any information or guesses as to its history? Country, designer, mfg, pilot, etc? It looks to me like perhaps a 1920's powered glider (looks like a wheel not a skid at the front but can't tell for sure) but that's a guess.

Update: I found another picture without comments of the same aircraft dated 1912 - so this is one of the very first attempts at flight. Which means it likely is not a glider but an experimentation with configuration. It does have a wheel at the front - not a skid.


texts: Saw this plane in Falkland war documentary. What type is that?

texts: That nose reminds me of ground attackers, but IDK why


texts: Why is a special certification needed to land at Paro Airport?

texts:
Why is Paro Airport (currently the only international airport of Bhutan) considered one of the most dangerous airports to land in the world?

Is it because of the mountains? In my opinion, Princess Juliana International Airport is also as challenging as Paro.

Why do the pilots need a special certification to land there?
How do they achieve this certificate?


texts: If the engine of a helicopter fails, is it possible to land safely?

texts: Imagine the rotor of a helicopter is not spinning anymore, can you control the aircraft to land safely?


texts: What would happen if a Cessna flew into a power line?

texts:
When I was going through my private pilot training, I asked my instructor what would happen if a Cessna flew into a power line. His response was that the power line would go through the single engine plane like a cheese slicer, no challenge.

How accurate is this statement? I - luckily - haven't come across any evidence to support one way or another.


texts:
In Is there a minimum separation between a landing aircraft and another crossing its runway? it was explained that once an aircraft has clearance to land, that runway is reserved for the exclusive use of that aircraft.

At busy airports you can usually see a long line of four or more airliners descending a glideslope towards a runway.

Image by nustyR AirTeamImages (found via LondonReconnections)

Looking at FlightRadar24, the time between aircraft appears to be of the order of about 85 seconds according to my stopwatch.

It seems as if, by the time the previous aircraft has turned off the runway, the following aircraft has a very short time to obtain clearance or decide to go around.

At what point is each aircraft given clearance to land by ATC?


texts: Is it possible to back up a single magneto ignition system using an electronic system on the same spark plugs rather than having to change to two plg heads?


texts: Why and how do flaps increase the curvature of the wing?

texts: Why or how do flaps increase the curvature of the wing? Do they alter the curvature of the upper surface of the wing?


texts: What is the youngest age allowed to fly any sort of plane in the USA?

texts: I have wondered this for quite some time, but what is the youngest age to fly any sort of plane in the USA? Does it also vary on what type of plane you're flying? (Commercial, Private, Training.)


texts: Is the Reynold's number a function of the fluid flow stream or the obstruction?

texts:
I am slightly confused with this notion of the Reynolds Number. Specifically, I am looking at airfoil performance at very low Reynolds number.

I am reading a lot of papers saying things like because it is a small model aircraft, the Reynolds number will be small (so then it is to do with the shape of the obstruction in the fluid flow?). But then I see something like large turbine performance at low speeds involve low Reynolds numbers (from here I would think it is to do with the 'quality' of the fluid flow itself, whether it is laminar or turbulent, uniform etc).

If it has something to do with the fluid flow, then why do I see Reynolds numbers attributed to specific airfoils etc? Say that an airfoil has $Re=100000$, what does this mean then? If the fluid is flowing at a very low speed with high viscosity, then how can we make use of this number at all?

Do correct me if I'm wrong, I am only beginning to learn these things!


texts: How is vibration isolation achieved in helicopters?

texts: In many helicopters, they say they have reduced the vibrations significantly, but how is this isolation being achieved?


texts: How do I use the FAA's WINGS program as a flight review?

texts: I know pilots can substitute WINGS phases for the Flight Review otherwise required every two years. How do I do this? Do I have to attend a class to meet all the equivalency requirements?


texts: Does an instrument exist to measure the different types of drag?

texts:
Does a 'drag meter' exist that separately shows total, induced and parasite drag?
If it doesn't, and in theory, would it be possible to build one?


texts:
As I'm studying, I found that GPS has to have 5 satellites or 4 satellites with "blind encoders" to use RAIM.

What is a blind encoder and what is its purpose?


texts: How do I renew my ability to fly after 40 years?

texts: I am 83 years old and it has been over forty years since I piloted an aircraft and would like to go back to flying again. I hold a single engine rating and had flown several hundred hours, but my log book is long gone. Much of my time was ferrying new Cessnas from Kansas to Houston for a dealer. Other than a physical and a checkride what would I realistically need to resume flying again without endangering myself or others?


texts: Why are the affected engine's bleed and pack switched off when there is an engine bleed under MEL?

texts:
My question mainly pertains to A320neo's equipped with PW engines. The MEL procedure states that the crew has to switch off the affected side's engine bleed, and its associated pack pushbutton to off.

One of the reasons given by my company is that with the engine operating at idle it may cause a reduction in the air supply and then lead to the automatic closure of the remaining bleed system due to a low pressure related failure.

However, this doesn't convince me, and I also tried raising it but I haven't gotten a response. The reason why it doesn't convince me is that one engine bleed can supply both packs, and the idle N1 automatically increases once the crossbleed is placed to open.


texts: Will Aerodiesel engines replace Avgas engines?

texts:
I've been following aviation for the last 20 years and have seen particularly since the last 10 a lot of talk of aero-diesel engines for light aircraft. The idea being they're cheaper to run using Avtur rather than expensive Avgas.

I'm surprised that in 10 years since I first really saw this mentioned not much has changed. There are a few new aircraft available and retrofits, but by and large engines are still traditional in new aircraft.

Is it likely that aero-diesels will replace traditional aircraft engines any time soon?


texts: How can I rebuild my missing logbook after 20 years of not flying?

texts:
I took flying lessons when I was a senior in H.S. in Illinois.  I got through solo and all of my x-countries (even the long one).  I was about a month away from finishing when we moved to Colorado and I started engineering school.  I intended to continue flying but school became the priority.  I lugged my log book and text books around for years (I can remember seeing my log book only 4 years ago).  I am about to finish what I started and go back and start the process again.  Now of course I cannot find my log book (I have turned my house upside down) :(

I want to state (because I know someone will make the point) that I am not looking for a short cut and I fully intend to make sure I get great training (its been 20 years) and plan on working my way through the requirements for a second time. I will defer to my instructor on what I need to learn and practice. I remember I had about 80 hours and I would like to get credit for them (if only to show the new school that I'm not starting from ground zero) as well as I plan on getting my instrument as soon as I can and the hours would help.

The flight school is no longer in business.  I remember the first name of my instructor (and have the first solo picture).  I thought I could contact him if I could find his last name and search some sort of data base?  I have searched the business records of the state and found a business record that for the old flight school that lists the owner.  I thought I would start there and see if I get lucky. If I can find the instructor's name I think there is a good chance he'll remember me and could provide documentation that would allow me to start a new log book with credit for my existing hours.

I found a local news paper article from the time period that mentions another flight instructor that worked there (AmCorp out of Lansing, Illinois in 1995) at the same time.  Is there a way to look them up in some sort of pilot data base to contact them and see if they remember my instructor's last name?

I remember filing my flight plans (I assume there is no record of that with the FAA because it's so long ago)?

Hopefully you get the idea of my quesition and hope you guys can give me any ideas on resources that I don't know of that may help me out.


texts: Could the cargo hold of an aircraft be re-designed to carry passengers?

texts:
This image had me intrigued:

It looks like two semi-circles, the upper part for passengers and the lower part for cargo.
I was wondering, for short haul flights, could the lower part be converted like the upper part, so the plane could carry more passengers, like a basement stuff, no windows and lower fares. We could do away with cabin luggage and stuff to take care of maximum takeoff weight, and anyways my thought was towards short haul flights.


texts: How does a gyro compass indicate true heading?

texts:
From what I've researched, a gyro compass is usually calibrated with with reference to a magnetic compass. Once you've engaged the gimbal locks, and start to rotate the compass to a magnetic heading; will it automatically compensate for true heading or will you not even reference a magnetic compass when calibrating?

Or are there cards used to indicate what's your position from true north, based on your magnetic indication?


texts: Why do aircraft use hydraulics instead of pneumatics?

texts:
I was reading about how the F-35 is having trouble with the "fueldraulic" system. This made me wonder:

Why don't aircraft use pneumatic systems instead of hydraulic/fueldraulic systems?

There are several advantages of pneumatic (compressed air) over hydraulic (pressurised liquid) or fueldraulic (pressurised fuel) systems:

No need to carry hydraulic liquid. That saves weight and maintenance cost.
Half as much piping, as there is no need to return hydraulic liquid to the pump - compressed air can be released after use. That saves more weight.
Leaks are less dangerous. There is no danger of running out of hydraulic liquid or of leaking fueldraulic liquid catching fire.

There are disadvantages too: less pressure -- which means less power per unit of gas/liquid -- and less precision, as gas is compressible. But I feel like these problems should be solvable in a modern computer-controlled aircraft. So what's the problem?


texts: Why would an ILS have a glide path angle less than the preferred 3°?

texts:
According to EASA the preferred Glide Path Angle is 3°:
EASA Easy Access Rules - Page 22 - 4.1.2.1.
There are some airports (e.g. Larnaca 2.75°) which are using a lower Glide Path Angle than 3°. Using a steeper angle (e.g. London City 5.5°) makes sense due to obstacle clearance. But what's the reason for using a flatter angle than recommended?


texts: Why the need for the MCAS on the Boeing 737 Max 8?

texts: Was there a problem with stalling on 737 jets before the 737 Max, if not then why is MCAS needed on the 737 Max 8.If it was a problem why did Boeing wait so long.


texts:
This website describes twin-tail aircraft. It has a photo of a strange-looking aircraft with a twin tail, and turboprop engines, resembling a C-130 Hercules.

There was no registration or tail number on the aircraft. I looked around at other images trying to find the name, but it did not feature the same aircraft. The aircraft looks fictitious.


texts: What fomula use for calculating pressure altitude?

texts:
I'm having some trouble making my calculations of pressure altitude match those in apps and text books.

I'm using the formula from Wikipedia:

  (29.92 - altimeter setting) * 1000 + airport elevation

In the app I'm using, the altimeter setting is currently reported as 29.70 with an airport elevation of 22. Using the above formula I would assume:

  (29.92 - 29.70) * 1000 + 22 = 242

Yet the app is telling me it is 229

Even more confusing, when looking at the Airman Knowledge Testing Supplement for Sport Pilot, Recreational Pilot, Remote Pilot, and Private Pilot (FAA-CT-8080-2H), figure 8, page 2-8, the pressure altitude for altimeter 29.7 is listed as 205. I assume this is using an airport elevation of 0, but then I would expect the answer to be:

  (29.92 - 29.7) * 1000 + 0 = 220

So my questions are:

Which answer is correct? Wikipedia, the app or appendix 2?
Why are there 3 different answers?


texts: Why do the engines seem to power down and then back up after take-off?

texts:
What is the phenomenon on a commercial airliner (say, a 737-800) where shortly after takeoff and before we reach 10,000 feet the engines feel like they slow down dramatically or even power off momentarily, then spin back up?

This happens fairly frequently when I'm flying and, although I'm used to it, it still takes me by surprise every time!


texts: Could the CVR and FDR record to the cloud?

texts:
Another enthusiast question. I watch a lot of the National Geographic Channel's "Air Crash Investigation", for better or worse, and it seems accident investigators make tremendous use of the Cockpit Voice Recorder "CVR" and Flight Data Recorder "FDR" to determine the chain of events leading up to- or the root cause of an accident.

One of the more recent episodes of ACI (Season 12 Ep. 13) was about Air France 447, the worst disaster in French aviation history. That investigation spent two years and $50 million just locating the CVR and FDR which were ultimately found resting 4 kilometers beneath the mid-Atlantic. Even after the recovery, there were concerns one of the drives had failed.

That ACI episode also mentioned that the Airbus A330-203 in that accident came equipped with a system which periodically transmitted maintenance data to a remote Airbus location in Paris to alert ground crews of possible maintenance issues with inbound aircraft.

Given that Airbus already uses similar technology for maintenance data (and I think I recall hearing Boeing does too), I was wondering if either Airbus, Boeing, or the FAA, plan to facilitate or mandate that the CVR and FDR record to the cloud or a remote location either in lieu of or in addition to the physical devices installed in commercial aircraft. I would think this would be an accident investigator's dream come true, with almost instant access to vital investigative information, while drastically reducing instances of going without these crucial tools when the physical devices are unrecoverable.

So, does anyone in the know have any idea if there are plans for CVR and FDR data to be transmitted and recorded to the cloud or a remote location?


texts:
I could not understand what is the difference between ADS-R with anonymous address (CF=6, IMF=1) and TIS-B CF=5, which on ICAO Doc 9871 is described,

for Version 1 as:

  Fine TIS-B Message AA field contains a non-ICAO 24-bit address

and for Version 2 as:

  TIS-B messages that relay ADS-B Messages using anonymous 24-bit
  addresses

Any specific example when CF=5 is used?

Thanks!


texts: Can you identify this aircraft at Chilliwack(YCW)?

texts: This aircraft is sitting at YCW, with no visible registration numbers.  Can you identify it?


texts: Can someone identify this warplane silhouette?

texts:
I saw this picture today in a news article about the current conflict in Iraq/Syria.

The caption claims it is a US warplane, but I don't recognise the silhouette. Can someone identify this plane?


texts: Why would seaplanes use a curved takeoff run?

texts:
I came across this interesting factoid in another SE Aviation answer (How flat does a runway need to be?):

  seaplanes often use a curved takeoff run.

I'm trying to imagine why but cannot come up with a good reason.

Does anyone know why?


texts:
Why are contra-rotating jet engines so rare? Such a jet engine would have contra-rotating turbines, or contra-rotating compressors, or both.

In fact I cannot think of even one aircraft that has this. If some prop-engines have contra-rotators, I don't see why some jets don't have it either.

It seems to me the contra-rotating parts would be more efficient in extracting power or compressing air. There are already contra-rotating turboprobs (Tu-95), and turboprops are very similar to jet engines, so I think it is not a question of technical knowledge. Another benefit would be reduced or eliminated gyroscopic forces hampering yaw or pitch torque, which I will ask another question about.

BTW, I am considering axial-flow jet engines only. I totally forgot there used to be centrifugally compressed jet engines, which have all but disappeared.

EDIT: The question is about jets (either turbofans or turbojets), but I mentioned the Tu-95 and its turboprop engines because turboprop spools are very similar to jet engines. However, I thought those Tu-95 engines had contra-rotating everything, but it turned out only the propellers were contra-rotating, not the turbines. Nevertheless, if there was a turboprop with contra-rotating spools, I would very much like to hear about it here because I think it would have great bearing on the question of contra-rotating jet engines and their efficiency.


texts: Under FAR Part 121, is it mandatory to execute a missed approach when unable to land within the touchdown zone?

texts: If the crew of an aircraft operating under FAR Part 121 and conducting an instrument approach determines, as they begin their descent from the MDA/DA/DH, that they will be unable to touchdown within the touchdown zone of the runway is a missed approach mandatory?


texts: How to calculate the fuel flow using the thrust specific fuel consumption?

texts:
Using the following parameters:

Static Thrust : $T_0 = 12 KN$
Thrust specific fuel consumption: $C_T=0.7 N/NH$

I know that the fuel flow is linked to thrust with the following formula:

$F=C_TT$.

And I need to calculate the fuel flow in Kg/s.

I started by converting $C_T$ in Kg/Ns:

$0.7 N/NH = 0.7 \frac{1}{9.80665} \frac{1}{3600} = 1.9828* 10^{-5} \frac{Kg}{Ns}$

Then I multiplied this value with the thrust:

$F = 12000* 1.9828* 10^{-5} = 0.2379 \frac{Kg}{s}$

However this does not seem to be the correct answer. What am I doing wrong?


texts: How is wind measured at this small U.S. airport?

texts:
While launching gliders at Front Royal, VA (KFRR) over the weekend, a fellow pilot and I got curious about the airport's weather equipment.  We know that KFRR has local equipment to measure wind speed and direction. There is a screen in the FBO that shows a graphical readout of the wind situation.  However, it was not obvious looking at the equipment itself how this is done.

Here are two pictures I took:

Nothing on either of these two pieces of equipment was actively spinning or being visibly affected by the wind.  At the time we has a 10-12 knot headwind almost directly down the runway.  This equipment is ~40 feet to the left of the runway threshold.

Question: Is one of the pieces of equipment I've photographed responsible for measuring wind speed? If so, how?


texts: What happens if you take off with a direct tailwind?


texts: Are you required to report leaving an altitude if you have been given a crossing restriction?

texts:
If ATC gives me a clearance to cross a fix at a specific altitude or a descent at pilot's discretion and I read back the clearance, is my readback considered the report specified in the AIM, or do I have to inform them when I actually start down?

  AIM 5-3-3. Additional Reports

  a. The following reports should be made to ATC or FSS facilities
  without a specific ATC request:

  1. At all times.

  (a) When vacating any previously assigned altitude or flight level for
  a newly assigned altitude or flight level.

  ...

An Example - Say that a pilot is flying at flight level 340 100 NM from Wilmington VOR and gets the following clearance:

  ATC: N1234, cross Wilmington VOR at flight level 240
  Pilot: Cross Wilmington VOR at flight level 240, N1234

or

  ATC: N1234, descend at pilot's discretion to flight level 240
  Pilot: Descend at pilot's discretion to flight level 240

It's a little early to start down since we want to stay high for fuel efficiency, so the pilot decides to wait until 30 NM from the VOR to start down.  When they reach that point, are they required to inform ATC before starting the descent or are they considered to have reported the descent earlier?

I hear pilots that do it both ways and each camp is pretty emphatic about it....


texts: When starting a turbine helicopter, why should one slowly increase RPM (throttle)?

texts:
After the ignition switch is turned ON, my Captain always increases the RPM (throttle) very slowly.
I don't know why, because our helicopter has an ECU.
One day, my Captain asked me "Do you know why we increase RPM slowly?"
so I answered "umm, to prevent a hot start?"
Then my captain said "Nope. It is related to ENG OIL PRESSURE."

Is there any other reason about this slow operation (related to ENG oil pressure)?

Maybe compressor stall or surge?


texts: When should pilots observe a "Sterile Cockpit"?

texts:
A "Sterile Cockpit" means avoiding all conversations and actions not related to flight during important flight times.  (eg. No extraneous conversations, no non-important electronics, no eating, etc)

Commercial pilots are told to observe Sterile Cockpit below 10,000 feet.

But what about Private Pilots who may rarely ever go above 10,000?  When do you begin observing sterile cockpit?  When do you consider it safe to talk with passengers, take a snack, or fiddle with the new GPS?


texts: Do I need explicit clearance to taxi on an inactive runway?

texts: I received taxi instructions from ground at a class D airport in the USA as follows (I was at ramp): Taxi to runway 04, Right on Bravo, left on 10, right on Alpha (no explicit clearance or hold short instructions for 10 were given). 10 was an inactive runway that intersected 04 with the Alpha taxiway turning off prior to the intersection with 04. I held short when I got to the 10 threshold and asked for clearance to taxi on the runway. The controller followed with Taxi left on 10, right on Alpha, but again no explicit clearance to enter the inactive runway at which point I taxied as instructed. My question is did I need to ask for clearance to taxi on the runway given the original instructions above?


texts:
In general, cloud height is measured from ground or AMSL (above mean sea level)?

If they measure from AMSL, how are low level clouds' height measured in higher terrain?


texts: How to handle vacuum and turn coordinator failure in IMC?

texts:
I just earned my FAA instrument rating and a considerable amount of time was spent training partial panel. This meant flying with no vacuum gyro instruments - attitude indicator and directional gyro. After my check ride the examiner said "you fly better without those instruments" which I considered a nice compliment to both myself and my instructor.

In reflecting upon this, I started thinking, what if I had an additional failure of something - how would I handle it? I launched X-Plane and set up an LNAV+V GPS approach on a windy, bumpy low IMC day and gave it a shot. Unsurprisingly, this was HARD.

I used the instruments as follows:

Altimeter / VSI and on the final approach the VNAV glide slope for altitude control. Not too bad.
GPS track and a bit of magnetic compass checking, along with the CDI needle. This is a very poor way to navigate. The magnetic compass obviously has lagging/leading errors and the GPS track is what I'd call a rate instrument - it lags a little.

The main problems I faced were that you can't time turns with no turn coordinator and the bumpy/windy air made constant corrections required. There appears to be no way to identify wings level. You can tell when you're no longer turning but you might be starting a turn the other way.

My strategy as I worked through this was to slow the plane (C172) down with 10 degrees of flaps throughout the procedure to make heading changes have the least effect. In the end, I tried to keep the track as close to the DTK and the CDI as centered as possible - effectively chasing two needles. This resulted in a sinusoidal course when I looked back at it on the X-Plane instructor console.

(By the way, I did land the plane safely but I'm not sure I'd be able to do this in the real world - the workload I experienced in my comfy chair was EXTREME.)

I know the scenario is unlikely but it's certainly possible. There appears to be no guidance that I can find on the Internet about it.

My question: is there a better way to do this? If so, what's the procedure?


texts: Can a plane land safely if it loses power during approach?

texts:
British Airways Flight 38 experienced a loss of power during approach to Heathrow and ended up crashing 270m short of the runway.
The aircraft was on glideslope when it lost power. The name "glideslope" suggests it should be able to glide to a safe landing. So why didn't it?

Suppose a commercial aircraft (e.g. 7X7, A3X0) lost all engines (say, due to birdstrike) shortly before landing. How likely would a safe landing on the planned runway be?

It would make sense for the approach angle to be such that a safe landing is very likely. So if not, why not?

EDIT: To clarify (due to @rbp's comment): I want to know how far is the typical approach angle from being able to glide in? And why is the approach angle not chosen so that gliding is possible?


texts: What is the type of a SID that is neither RNAV nor RNP?

texts:
I am studying FAA's Order 8260.46F and I have noticed that, as far as the different types of SIDs are concerned, it states:

  [3-5] (1) “RNAV 1” will be the default designation for RNAV DPs. Annotate procedures with a standard note: “RNAV 1” on Form 8260-15B [see appendix E].
  (2) “RNP 1” (in-lieu-of RNAV 1) will be used when a DP that contains an RF leg or when surveillance (Radar) monitoring is not desired for when DME/DME/IRU will be used. Annotate the procedure with a standard note: “RNP 1” on Form 8260-15B [see appendix E].
  (3) All RNAV DPs will contain a note that describes the equipment sensor limitations.

However, I have trouble figuring out what type of SID is the La Guardia Five Departure ( route description and take-off minimums ) of La Guardia airport. It is does not have the indication "RNAV" and, as far as I can tell, it is not an RNP departure procedure either.

Could someone point me in the right direction?


texts: Why are cockpit alarms still so distracting and unable to be silenced?

texts:
I'm watching video RV 10 N783V My 1st Emergency
At 8:45 a stall alarm goes off and is a horrible piercing whistle. Why? Surely the pilot has enough distractions without also being deafened while trying to talk to ATC.
Isn't there a better way of indicating a continuing alert, and why can't pilots switch the the thing off when they need to?

EDIT: The video shows that it is a false-positive warning. The pilot eventually manages to switch it off by resetting all his electronics.


texts: What exactly is a variable incidence tailplane?

texts: I've been reading about it regarding trim changes and such, but I don't exactly know what a VIT is? Can someone explain that to me?


texts:
EASA states that Certification Specifications (e.g. CS-25) is non-binding on their website. See the regulations structure PDF.

Each Part to each implementing regulation has its own Acceptable Means of Compliance and Guidance Material (AMC/GM). These AMC and GM are amended along with the amendments of the regulations. These AMC/GM are so-called ‘soft law’ (non-binding rules), and put down in form of EASA Decisions. A comprehensive explanation on AMC in form of questions and answers can be found on the FAQ section of the EASA website.
Furthermore, Certification Specifications are also related to the implementing regulations, respectively their parts. Like AMC/GM they are put down as Decisions and are non-binding.

The FAA's 14 CFR 25 is certainly what I would interpret as binding or required. As a manufacturer you are required to show compliance to applicable parts of 14 CFR 25.
What does EASA mean then? Or what are they trying to communicate about Certification Specifications such as CS25? Or what is different about their organization that makes CS-25 “non-binding”?


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

texts:
Assuming one  does not have a driver's license, is it possible for one to obtain a pilot's license to fly a helicopter? Cost is not the question here. I want to know if one can never obtain a driver's license (for ground, motor vehicles) and still be able to obtain a pilot's license to fly helicopters, planes, etc.

This is applicable for the U.S. only.


texts: What is the difference between Assumed Temperature and Derate takeoff thrust?

texts:
Airlines like to avoid a full thrust takeoff as it increases the wear on the engine. There are two methods to achieve this: Assumed Temperature and Derate.

In the Assumed Temperature method, the takeoff performance is calculated by commanding the engine to mimic the thrust produced if the outside temperature is higher. Derated takeoff thrust basically tells the engine to pretend it is a weaker engine.

Both methods result in a takeoff thrust setting that is lower than 100% power. What are the differences between these methods, and how do the flight crew choose between the two?


texts: Can wind shear conditions be identified visually?

texts: Without relying on winds aloft or LLWS data, can pilots identify wind shear conditions visually, by watching clouds or otherwise?


texts: Is there a time limit for a line-up and wait?

texts:
So this was from a barrage of History Channel documentaries celebrating the century of flight, some 13 years ago. In one of the shows, I recall it being said that an airliner has a time limit for a line-up and wait, else an asphalt runway would start melting behind the jet engines.

Update:

Maybe, it was the case in the early jet age. For those good at finding historic regulations, etc.


texts: What Height Atc radar reads from pilot selection

texts: Just want to know whether ATC radar always reads aircraft height with respect to standard altitude setting or will read the change in height if we select QNH instead of standard 1013 hPa (QNE)?


texts: Aside from the Stratolaunch, how many other aircraft have split bodies?

texts:
So there's a lot of excitement about the new (and massive) Stratolaunch

Split bodies are uncommon (although launching spacecraft from them commercially is a new thing). The only other airframe that I've seen like this would be Virgin's White Knight 2 (also a spacecraft launcher). Do any other aircraft use a split body like this?


texts: Is this Part 23 Final Rule document the final regulation and what are the main improvements?

texts:
Is the FAA's new Part 23 Final Rule the final new Part 23 document? Or will another document be released? The formatting is totally different and kind of a discussion can be found in all the paragraphs.

Also, what are the main improvements in this new version of Part 23?


texts: What are the specifications of the General Electric J85 engine compressor?

texts:
On the internet I can't seem to find all the specifications I need.

Mostly I'm looking for the tip and hub radius and the angular velocity of the blades.

Thanks.


texts: Has a life raft ever been successfully deployed on a modern commercial flight?

texts:
Has a life rift ever been successfully deployed in the event of an air accident involving a commercial aircraft?

For the purposes of this question a "life raft" is an inflatable device designed specifically and only to be used as a life raft and normally stored inside the aircraft, not some multi-purpose or makeshift device.

Criteria for inclusion:

A commercial jet flight after 1945
Carrying paying passengers
Minimum aircraft capacity 50 people, although fewer may have been on-board at the time
Raft stored inside the aircraft prior to deployment
Raft designed for this purpose, i.e. not just something a passenger was randomly carrying
The raft actually worked as intended, i.e. people were able to float on the water in it and not drown

In short I'm asking about the rafts often seen stored away on commercial flights. The raft may have been used on rivers or the ocean.

(Image source) A Boeing 737 ceiling compartment where such raft can be stored.


texts: Why do aircraft manufacturers produce families of aircraft?

texts:
Let's take the case of the Airbus A320 family of aircraft. Airbus manufactures A318, A319, A320 and A321 planes, which all belong to the same family.

What is the need to manufacture multiple aircraft from the same family having different ranges and capacity, when one could just invest in making just two or three different planes from three different families providing a wide range of range (distance) and capacity?


texts: Could the Wright brothers fly across the US today?

texts:
If the Wright brothers were still alive (and in very good health for their age), could they fly one of their aircraft across the United States today?

Specifically, I'm looking at the Wright Model B, a commercially-produced biplane with a maximum speed of 45 mph, a range of 110 miles, and no radio on board.  It was originally produced in 1910, while the first flight across the US (with plenty of stops) was in 1911.

Could a pilot with a Wright Model B use modern airports?  Could they navigate?  Could they keep to their designated airspace?  Could they do all they needed to do to fly in an FAA-approved manner?


texts: How is separation managed when there are only two parallel runways in a very busy airport?

texts: In the world's busiest airports, how is separation managed between departures and arrivals when there are only two parallel runways like in London Heathrow. What is the minimum safe separation?


texts: Are pilots expected to keep an ear out for conflicting authorizations?

texts:
I just watched the Mayday episode Cleared for Disaster, a dramatization of USAir Flight 1493. The episode covered how the controller lost situational awareness and gave a landing clearance to 1493 while SkyWest 5569 was still on the runway, as well as how the runway lights obscured 5569's lights. They did not, however, talk much about 5569. This was at least partly because 5569 was not carrying a CVR.

The tower would have given 1493 the clearance to land on runway 24L on the same frequency that 5569 should have been on. In other words, 5569 would have been sitting on 24L and hearing tower give landing clearance for 24L, which would be a big red flag. Are they expected to be listening and thinking about landing clearances given to other aircraft? If they noticed, would they be expected to speak up, or to shut up and trust the controller?


texts: What is the heat signature of a piston engine, relative to a jet engine?

texts:
I'm reading about the AIM-9 Sidewinder Missile again. I noticed this interesting photo:

Notice, that's a piston-engined aircraft, and a small one at that. So I'm asking myself, how did the missile lock onto it? The AIM-9 is a very early heat-seeking missile (~1956). I thought early heat-seekers could only lock onto a jet engine, which I believe has a much larger heat signature than a piston engine.

Now I know today that IR missiles can lock onto almost any heat signature, even the heat of the adiabatically compressed air at the wings' leading edge. But in 1956, I'm surprised that an IR missile could lock onto a piston engine's heat.

So I want to start with this question: What is the heat signature of a piston engine, in terms relative to a jet engine? 2x less? 3x less? Or somehow equivalent?


texts: What reasons exist for not designing airplanes with breakaway wings for crash safety?

texts: As most crashes are on takeoff and landing, and fire is the real killer, most often. Why not have breakaway wings? That's where the gas is. Let's assume a plane has to make a hard landing..upon touchdown/contact jettison the wings. They serve no purpose at that point and they definitely kill people. Breakaway parts/modules are employed in many arenas, so why not wings?


texts: Would a vertical stabilizer that extends both above and below the centerline be benefit or hindrance?

texts: Ignoring for a moment potential schematic difficulties in creating an aircraft that can land and take-off without threatening a downward vertical stabilizer, would a vertical stabilizer that extends both above and below the aircraft's centerline improve or hinder in-flight stability?


texts: Is the transition altitude around Denali still 18 kft AMSL, and, if so, how is this handled?

texts:
In North America, the transition altitude - the altitude below which everyone reports their altitude in feet above mean sea level (AMSL) and sets their altimeter to whatever the weather dictates that the local altimeter setting be, and above which everyone reports their altitude as a flight level (FL)1 and sets their altimeter to 29.93 inches of mercury (inHg) - is 18 kilofeet AMSL, this altitude having been chosen so as to put the transition altitude well above the elevation of every airport on the continent.

However, although the highest airports in North America are well below 18 kft, the highest land in the continent is not; Denali, the highest mountain in North America, reaches up all the way to 20.31 kft AMSL.  It’s also not particularly inaccessible, and happens to sit in one of the most aviation-centric - indeed, in great measure, aviation-dependent - regions of North America, fairly close to said region’s major city and said city’s major airport.

Given that one’s ability to maintain terrain clearance (read “avoid flying into the side of the mountain”) depends on one’s height above the ground, which depends on one’s actual altitude, on the ground’s actual altitude, and on the difference between the two,2 how is the situation of a mountain poking its nose above transition altitude handled?  Is there a higher-transition-altitude bubble surrounding Denali?  Are pilots required to set one baroaltimeter to 29.93 inHg (for flight-level purposes) and a second baroaltimeter to the local altimeter setting (for terrain-clearance purposes)?  Do they simply have to watch their radar altimeters like hawks anytime they’re flying near Denali’s peak?  Something else?

1: One flight level is roughly equal to one hectofoot; it does not equal exactly one hectofoot unless the sea-level barometric pressure happens to be 29.93 inHg and the atmospheric profile happens to match the International Standard Atmosphere (ISA).

2: And given that, while terrain clearance is always a high priority, it’s even more so where even the gentlest crash would be unsurvivable for anyone but a well-acclimated mountaineer, due to Denali being inconsiderate enough to locate its peak in what is, for non-acclimated persons, the Death Zone.


texts:
I was told a long time ago that having the weather radar turned on when at low altitudes helps to scare birds out of your way because the can sense/feel the radar.  Casey also mentioned this in another answer of his.

Is there any evidence that weather radar actually scares off birds, or is this another "urban aviation legend"?


texts:
How are aviation charts made? What kind of techniques are used?

From what I understand a GA aircraft equipped with:

A camera: takes images of the ground
Radar: calculates altitude and detects obstacles


texts: Has a small airplane ever been air launched from a heavy-lift helicopter?

texts:
I would like to know if a small airplane, like a Cessna, has ever been air launched from a heavy-lift helicopter, perhaps as a stunt or as an aviation experiment?

I think it would have been a simple matter of lifting a small airplane with a special detachable hitch on the top of the airplane and then for the helicopter to have taken it up to a height of say 10,000 ft. I imagine the airplane would have then started its engine, detached from the lift cable, gone into an immediate dive, and then would have come out the dive after a thousand feet or so.

I have searched the Internet for a stunt/experiment like this one, but have not found any.


texts: Based on any historical records, who has been the oldest pilot ever? "Pilot", I mean, somebody who managed to take off, return to the airport and land without  help. That much is probably not possible without training; would still be interesting to know if this pilot had a valid or maybe expired license.


texts: Has the typical cabin pressure in airliners changed in recent decades?

texts:
Two or three decades ago, I would experience quite uncomfortable blocking of the eustachian tubes, which would noisily unblock and become blocked once more as the plane descended.

I haven't experienced that in recent years, in which I have been flying on considerably newer aircraft.

Is this likely to be a change in the cabin environment or my own physiology - that is, have cabin pressures generally increased so that changes during descent are less dramatic, or have I just become older and less susceptible to blocked ears?

Recent airliners such as the 787 and the A350 have much-touted higher cabin pressure levels; has there also been a general increase in standard cabin pressures over the years?


texts: How can I tell the difference between Spitfires and Hurricanes in photos?

texts:
The Spitfire was one of WW2's iconic aircraft, its fame coming from its spectacular performance in the Battle of Britain. But in that battle, Hawker Hurricanes outnumbered Spitfires 2:1.

Often articles about Spitfires use images of Hurricanes. How can I tell the difference between a Spitfire and Hurricane visually?


texts: How are arriving aircraft assigned to runways?

texts:
A similar question to this one was asked before, however my question is not about who assigns runways to arriving aircraft, but what the reasons behind those decisions are.

As an example, let's look at Frankfurt EDDF with four runways (map here). 18 is only used for departures. Of the three parallel runways 25L/07R, 25C/07C and 25R/07L, one is usually also used for departures, leaving two of them for arrivals (from my experience, usually 07L/25R because it's for landings only, and then 07R/25L).

Besides runway length (as discussed in the above referred question) and width, what factors into the decision of which of the two arrival runways an arriving aircraft is assigned? (and other than that it is regulated that certain types may not land on 25R/07L such as A380, B747).

Can airlines / pilots request a runway? In particular, landing on 25R in Frankfurt should be pretty unpopular due to the long taxi time to the terminals.


texts: Why do reciprocating aircraft engines have more than one spark plug?

texts: Most reciprocating aircraft engines have two spark plugs per cylinder. What are the reasons for this?


texts: How can I calculate a gradient using a Jeppesen Student Flight Computer?

texts:
On a Jeppesen Student Flight Computer (CSG), how does one calculate the gradient in percentage if the ground distance and height above ground level are given?

I can't find anything in the accompanying manual. Apparently this is possible on the E6B and CRP-5.


texts: How can the breath of a pilot be recorded?

texts:
On a plane, as a passanger, I can't hear my own breath. I can't hear my own breath even in a silent room.

On a plane, there is a continous background noise.

And the microphone recording the noises in the cockpit, are probably not directly at the lungs of both pilots.

I am really wondering, how can the breath of a pilot simply be recorded on the cockpit, if it wasn't designed specifically for that (or it isn't a very high quality recorder placed directly to the body of the pilots)?


texts: How do aircraft window size compare to each other? What are some possible improvements on them?

texts:
I'd like to see a comparison about the window sizes of various commercial aircraft, maybe to give evidence of eventual progress in it over the generations.
For example, I surely know that the B-787 has the biggest ones but it seems strange to me that A350XWB has smaller ones in comparison, considering that it, too, is made with composite materials. Why this difference?
In addition, Boeing increase their window sizes between different iterations of the same model (for example, the first 747s had smaller windows than the later generations, and 777X has larger windows than the original 777), but Airbus seems to not have this approach (neo versions are equal to ceo ones).
Finally, I heard about Boeing Skyview, a very big single windows in Business variants but... is already delivered as solution? Any similar solution from Airbus?
P.s: I found only a link with similar topic but is more general and not specific to a comparison chart between models and/or difference B787 and A350 construction design related to window size


texts: In a 747 is it normal for the Vr (takeoff speed) to vary greatly depending on fuel load and ambient temperature?

texts:
I was reading one of the documents linked on this question, particularly I was reading case study number 8 of this particular document.

In the conclusion the author notes that the aircraft flight characteristic calculations had been messed up to the point that all V-speeds were calculated for a 747 100 tons lighter than their actual Take Off Weight (TOW).  Thus, they tried to rotate too early, couldn't get enough lift and the tail of the 747 struck the ground.

When reading that brief description, I had assumed that perhaps they were off by 5 to 8 knots, or something along those lines.  So, I was surprised to see the author later note that Vr was actually off by close to 30 knots!

I'm really curious suddenly, how much can a 747's rotation speed change?  I was told that rotation speed was generally somewhere around 130 knots for that class of plane, but if there is a 30 knot variance. Can it really be anywhere from 115 to 145 depending on the weight of the plane?


texts: Is this a Janet Airlines 737 at Area 51?

texts: I was looking at the satellite image of area 51 on google earth and i noticed an airplane that was taxiing alone on area 51 at 37°14′0″N 115°48′30″W or (R-4808N) could this be a Janet airlines Boeing 737 from Las Vegas that carries the government workers to and from the base??


texts: Does Lift/Drag generally improve at higher Reynolds numbers?

texts:
I have been looking at the lift/drag polars for various airfoil profiles.  The L/D ratio seems to improve at higher Reynolds numbers. Obviously different wings are optimized for different speeds, and there are many other factor to consider, but in general terms do wings get more efficient at higher speeds?

I believe a 747 is more efficient than a model airplane because of the higher Reynolds number it operates at. Is this correct?


texts: Are there ever temporary flight corridors?

texts:
A recent question on FAA handling of evacuations prompted me to wonder if there are ever temporary (emergency based) flight corridors set up by any of the governing authorities?

For example, is there ever the airspace equivalent of one way highways set up for a temporary period?


texts: Does the AOA and G-Force increase if a fighter uses the afterburner during a max G level turn?

texts:
My understanding is that if you apply power (increase the thrust) for a jet in level flight, it will momentarily pitch up, and then gain some speed.

So, if a fighter pilot lights their afterburner at a certain time when in a max-G level turn, does this further increase the achievable angle of attack and Gs, due to the increased thrust from afterburners helping to pitch the aircraft up, or does it just allow the max G-force to be sustained for longer?


texts: What is the reference chord for AoA measurement or calculation in a twisted wing?

texts: Let us assume we have a rectangular, unswept wing with no dihedral and a given wing twist and we want to measure in flight or calculate its $c_L$ vs $\alpha$ (angle of attack) diagram. Of course each airfoil along the span will have a different local angle of attack at every flight attitude. Which y-coordinate along the span must (or should?) be used as a reference?


texts: At KOAK, how can I get a passenger from the GA terminal to the commercial terminal?

texts: I want to land at the GA side of Oakland International (KOAK) in order to drop my passenger off for a commercial flight from the main terminal. I was told by a local guy that they do not allow a taxi on B over to the main terminal so I would need to park on the GA side and grab a shuttle/crew car/Uber over to the main terminal. I've contacted two FBO's and they tell me of about $50 in fees just to stop in. Has anyone done this and what is the best way?


texts: Why is the range of transponder digits 0 to 7 rather than 0 to 9?

texts: As a controller on IVAO I sometimes assign codes like 0168 and find out later that the code isn’t valid. For me, the range 0-9 seems more logical. Why do we have to use octal numbers and not decimal?


texts:
I found an equation to calculate angle of attack based on the velocity vector in the body frame of the aircraft.

$\arctan(v_x/v_z) = \alpha$

1) Is this correct?

When I input in a $v_z$ approaching zero, the value approaches $\infty$ which means that angle of attack moving only in the x direction is 90 degrees since $\arctan(x)_{x\rightarrow \infty}= \pi/2$

2) Is there supposed to be an assumption that you never calculate Aoa of zero with this?

3) Am I misinterpreting what the velocities and angles represent?

Overall I am just a bit confused, because I kind of expected something that wouldn't mess up at level flight.


texts: Where can I find maintenance manuals for the A380?

texts:
My friend recently acquired an external green light from an A380. They are the only details i have from him. I tried hunting the internet for maintenance manuals, technical details, schematics, basically anything i can think of. Apart from a couple scam websites selling Haynes manuals, i came up with nothing.
Does anyone know the power requirements for the lights or, ideally, a document that lists aircraft details and specifications. I imagined that maintenance details will be available, but nothing came up.


texts: Why does the ACS forbid activation of the stall warning during slow flight?

texts:
In section VII. Slow Flight and Stalls, page 54 of the Private Airplane ACS, the Skills section contains in part

  $$\begin{array}{l|l}
\bf{Skills} & \text{The applicant demonstrates the ability to:} \\ \hline
\textit{PA.VII.A.S2} &
\begin{align}
\text{2. } & \text{Establish and maintain an airspeed, approximately} \\
& \text{5-10 knots above the 1G stall speed, at which the airplane} \\
& \text{is capable of maintaining controlled flight without activating} \\
& \text{a stall warning.}
\end{align}
\end{array}$$

During my primary training and when I took the practical test under the old Practical Test Standards, slow flight was conducted at minimum controllable airspeed with the stall horn blaring.

What are the motivation and supporting data behind this change to slow flight strictly above $V_{MC}$?


texts: Did large winglets contribute to the spin behavior of the SB 13 tailless glider?

texts:
The SB-13 swept wing tailless beauty was developed in the early 1990s as a small recreational glider with relatively large upright winglets.  The design proved very spin prone.

It occurred to me these vertical "winglets", set upright, would generate a yawing "lift" component in side slip.  Since these are set behind the CG, the plane would spin INTO the slip (as the change in relative wind increased their AOA).

This phenomena seems to have similarities to excessive spiral instability in a conventional wing/tail design.  Would reducing the size or shape of the winglets help cure this tendency?
Or lengthening the nose a bit?


texts: Why don't single-engine jets suffer severe gyroscopic effects?

texts:
I was reading up on World War I fighter aircraft, and saw that rotary piston engines, which powered many of those planes, produced extreme gyroscopic effects due to the large, heavy chunk of metal spinning at several hundred RPM; as a result, single-engine aircraft using these engines had extreme difficulty turning to one side but could make exceptionally sharp and quick turns to the other side.

Why don't modern single-engine fighter jets experience even worse gyroscopic precession than their World War I counterparts, seeing how the compressor/shaft/turbine assembly in a turbojet engine is far heavier than a WWI rotary engine and spins far faster?


texts: If the pilot cabin loses pressure, can the pressure difference lock the cockpit door?

texts:
I think, if there is only a 0.1 bar pressure difference with a single square meter door, around the weight of a ton would be needed to open it - if it is sealed hermetically and opens outward.

Is it possible?


texts: Why does only class C airspace have an "outer area"?

texts:
There is an area called "outer area" near class C airspace. As described by this AIM:

  Though not requiring regulatory action, Class C airspace areas have a procedural Outer Area. Normally this area is 20 NM from the primary Class C airspace airport. Its vertical limit extends from the lower limits of radio/radar coverage up to the ceiling of the approach control's delegated airspace, excluding the Class C airspace itself, and other airspace as appropriate. (This outer area is not charted.)

As it is not charted and there is no FAA regulations about outer area, I would think it could also be set near class B or D airspaces. Why don't any other airspaces but only class C airspace has the outer area?


texts: Aircraft emergency oxygen: how hard do I pull on the mask?

texts:
AKA 'why is the safety briefing/training inadequate'.  I tried Googling my title and got lots of sites explaining the emergency oxygen systems, procedures etc. that I already mostly knew.  The briefing: 'Pull sharply on the tube to start the flow of oxygen' is not exactly fully informative or reassuring.  The things look so fragile that it must be fairly easy to rip the tube away from the oxygen generator/supply bus pipe/whatever.

How am I supposed to know how hard to pull?  Is there some sort of click/detent that can be felt as I pull on the tube that indicates 'OK, you've turned the oxygen on'?

Could not a simple mechanical flag indicate oxygen on, eg 'Pull on the tube until the indicator flag turns green', or the like?


texts:
Does anyone happen to have a reference or such that explains the naming convention used by Prof. Wortmann for his airfoils?

Usually it follows that for symmetrical ones, the first 2 digits are to indicate the planned transition location at zero alfa and the last 3 for for the thickness.

ex:
fx76-120 -> fx (prefix for FX.Wortmann) 76 (transition) 120 (12%)

would like to double confirm this with a reference if available and also the meaning of the middle letters used in some foils.

Ex: FX76-MP-150 (MP for man-powered in this case but there are many more)
2 is known thanks to Peter Kampf. Any idea on remaining?


texts: I'm looking some information about the so called Jozza Bombsight used for example on board of the Savoia-Marchetti SM-79 during WWII. Thank you


texts: Does a system exist that can bulk process satellite data to find a plane lost over ocean?

texts:
The case of the lost Malaysian Airlines plane is tragic for all those involved.

In the case of such a plane lost over the ocean, hypothetically (and described very simplistically), it would seem that the fastest way to search for wreckage would be:

to define an area to be searched
wait for the latest satellite images for that area at high-resolution to be available (given appropriate positioning and programming of the satellites)
then search the captured imagery for deviations from ocean blue

Presumably this could be done reasonably quickly by a computer, and that satellite imagery is taken after a suspected crash, and exceptions (e.g. spots of white amongst the blue) are able to be verified by a human.

Does such a system exist? Are imaging satellites able to be configured to take such imagery on demand over a large area? And do such batch-image processing systems exist for this purpose?


texts: Is it possible to determine the approximate climb rate of an aircraft knowing its top speed, engine power and weight?

texts:
Is it possible to determine the initial climb rate of a craft with a few key pieces of data such as top speed, engine power and weight?

For example the XB-42 was an experimental bomber design from the WW2 era.

Its top speed was 660 km/h at 7,145 meters.

Its empty weight was 9,475 kg and maximum weight was 16,194 Kg.

Its twin engines produced a total of 2,498 kW at takeoff and 2,834 kW using war emergency power.

Is that enough information to determine the approximate climb rate?  Thanks so much for any help!


texts: Are the captain's and first officer's brake pedals always mechanically linked?

texts:
I heard that for Boeing and Airbus aircraft, the pilot's and copilot's brake pedals are mechanically linked, is that true?

Why did they make that design decision? What's the advantage? Do all kinds of passenger aircraft have the same design?


texts: Does/did Russia or the Soviet Union ever fly rocket planes?

texts: Did Russia or the Soviet Union ever have their own experimental or military rocket planes (other than the Buran), or did their military merely use jets and other non-rocket aircraft? America flew those many experimental X-planes, did the Soviet Union have any similar planes? Afaik all MiGs are jets.