Unanswered Questions
1,355 questions with no upvoted or accepted answers
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Can I fly an RNAV DP (GPS & RNAV 1 required) with no FD/AP?
I’m currently planning an instrument flight which includes a full stop at an airport with a RNAV (Obstacle) Departure Procedure.
The procedure plate requires RNAV 1 and GPS.
In ground school I ...
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3
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610
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Which was the first aeroplane to have fuel tanks within its wings?
Wings with substantial thickness start appearing after WW1, with Junkers pioneering all-aluminium aircraft such as the Junkers F 13 (1919). It as a far from universal trend, however; compare with the ...
- 14.6k
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Streamline Curvature Theorem applied to Airfoils?
I am new to studying aerodynamics and taking up aeromodelling and am currently learning how lift is obtained in-depth. When studying the two common explanations as to how lift is generated by an ...
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How effective was the computer-controlled gunnery on the B29?
The Boeing B29 Superfortress was equipped with multiple gun turrets which were linked to a central
computerised fire control system. This training film covers the gunner's control interface, which ...
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What is the highest operational ceiling for a nuclear scramjet?
A similar question is:
What is the highest operational ceiling for an air-breathing jet engine?
The answers point to scramjets. Cited reports focus on combustion kinetics.
The Wikipedia Scramjet page:
...
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Are empennage airfoils always symmetric in conventional airliners?
I'm specifically interested in these models: A319, B737-700, A220, E195-E2. You could call these conventional airliners, so I suppose the question is if these "conventional" planes have only ...
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Can UK CAA modular exams done before Brexit be used towards an EASA license?
I am stuck with some EASA basic modules (Form 148) and some UK CAA modular exams.
Now I want to apply to get an EASA B1.1 license but the problem is German aviation authority (Luftfahrtbundesamt) is ...
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Can I document a VOR check with a photo to comply with 91.171(d)?
I'm interested in understanding the limits of what it means to "sign" a record. While enroute for any meaningful length of time, I try to tune two VOR's and I take a photo of the G1000 NXi ...
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How Jozza Bombsight worked?
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
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Is this vintage altimeter from the Cuatro Vientos?
My father who was a pilot, passed away some years ago and I have a vintage altimeter that he told me someone gave him. They assured him that it belonged to the Cuatro Vientos airplane, but I'm not ...
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How did the Wright brothers measure the maximum airspeed of their 1904 plane?
The Wright brothers used during their 1904 trials (105 in total, according with their claims) a Richard anemometer mounted on Flyer II (there are numerous pictures on the net with such a device). The ...
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What is the speed of gas in the core of a jet engine?
Coming from a slightly related question, I want to know what is the speed of the gas in the core of a jet engine, after combustion but before the first turbine stage.
I'll just pick a random example: ...
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Why would changes in jet-engine power settings not result in changes in engine loudness?
My casual AAR reading has dredged up another counterintuitive detail of aircraft behaviour, this time regarding the relationship between engine power and engine loudness:
1.16.7.3 Sound Similar to ...
- 28.6k
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How does the maintenance cost of turboprops compare to turbofans?
I was initially under the impression that the added complexity of gearing in a turboprop would lead to more maintenance. Then I found out geared turbofans are becoming fairly common so there should be ...
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What were the rules about night flights from LHR in the 80s?
I was just reading a question over on movies.SE: How could Ryan land in New York in early morning?, and the accepted answer suggests that Jack Ryan's plane takes off from LHR at about 4am.
One of the ...
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I have a PPL in Australia and own a plane. I am wondering if I am legally allowed to hire my plane out to other pilots and make money?
I have found multiple answers that state I can lease to a school and things like that but I need to know if I can hire my plane out privately to other pilots (I.e mates) And actually make a profit ...
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An-225 antenna layout
Does anyone have a good reference or information about the antenna layout on the An-225?
Particularly interested whether the VOR antennas are up on the V-Stabs, or somewhere more creative.
Thanks in ...
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F-16: MAIN PWR ticking sound, what is it?
What is that sound that starts when MAIN PWR switch is turned on in the F-16? Its sorta like a fast ticking sound.
Why is it there, what makes it, when does it stop? And is it also there when only ...
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80
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How did lateral and longitudinal separation minima evolve?
What is the evolution in time of lateral and longitudinal separation minima?
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First Boeing 757-200 N757A 'Catfish' was modified with a Canard foreplane. How did it behave?
The aircraft had these changes made around 2006 to act as an F-22 Avionics test bed. One would expect that the fore plane changed many performances of machine, including take off and landing attitude ...
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Why don't private jets use higher bypass turbofans?
Common private jet engines such as the Williams FJ44 has a bypass ratio of just 2.8:1. Installation requirements aside. From an engineering perspective is there much to gain in efficiency by going to ...
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How to determine when a non precision approach does or doesn't have a Final Approach Fix (FAF)?
I am curious to know how to know for sure whether a non precision approach has/doesn't have a final approach fix by looking at its plate. From what I can see, a Break Cloud and/or NDB procedure might ...
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Can RNP AR APCH be defined as NPA or APV or PA?
How to define RNP AR APCH as a
Non-Precision Approach / Approach with Vertical Guidance / Precision
Approach?
or it varies when complying with different standards just like RNP APCH?
or it's ...
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3
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119
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How do jetliners age (major or notable checks and part replacements)?
As commercial airliners can be (and are) operated for many years (or even decades), I've started to ponder - how do they actually age? Or - in other words - what are major or notable maintenance-...
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What is the stall speed of the Antonov An-225?
Under certain circumstances - maximum gross weight, unaccelerated 1G flight, clean configuration (landing gear up and flaps)? Indicated airspeed (KIAS) of course.
- 1,005
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During airshows, how common is it to fly armed with (inert?) missiles?
I notices that these three Su-35s were armed with missiles during an airshow. At the 1-min mark, you can clearly see that jet #38 has 2 missiles under each wing as well as a bomb / (spare fuel tank?) ...
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147
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What are the differences between foward air controllers in US military?
US Military has forward air controllers that join the forces on the front line and help them communicate with aircraft on the battelfield.
I found several Wikipedia articles describing such position, ...
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Is it possible to display WAAS enabled GPS Flightlines on older mechanical flight directors such as S-tec?
We are in the research process of a panel upgrade in a M5 Maule.
The ac is used for transportation and aerial survey to support ground survey. We frequently fly tight, low alt grids. Lateral and ...
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What effect did the AWACS radar dome have on the stability of the 707?
The large disc shape of the AWACS radar dome, and its attachment pylons to the fuselage, above and behind the wings, seem to have the potential to actually improve the pitch and yaw stability of the ...
- 21.4k
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What are the differences between a compressor wash on wing vs on test bed
I work in an aircraft engine overhaul facility and I’m trying to understand the process of compressor washing engines on Wing compared to washing them in a test bed. What process steps are different ...
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Is there a specific reason Delta Airlines is allowed to have a call sign that's also code word in the NATO phonetic alphabet?
This is a followup to Is there any specific reason why Delta Air Lines doesn't have its own callsign? I was... "helpfully" informed that, um, actually, Delta Airlines does have its own callsign, it's "...
- 12.8k
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How much N1 difference between two engines are acceptable?
While I was flying with 10+ year Airbus 320, IAE engine with EPR, I saw a constant difference between N1 parameters around 2%. I checked the Engine Hours and Engine Cycles that they are almost the ...
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What were the typical rotation and landing speeds of the X-29?
Looking online through all the available literature, I could not find the typical rotation ($V_r$), landing or even stall speed of the experimental forward swept wing X-29 aircraft.
I'm curious to ...
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Why was the Tu-104 so prone to navball-disabling electrical power failures?
Of the (rather numerous) accidents involving the Tu-104, several were either caused or aggravated by major electrical failures, which disabled the aircraft's navballs, which caused the pilots to ...
- 28.6k
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What will happen to wing Vortices on supersonic aircraft?
Having looked at the new Aerion AS2 design I wondered whether anyone could tell me what happens to wingtip vortices at a cruise of Mach 1.4 with the strange wing shape of the AS2 design? I know that ...
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Can the assumed temperature be lower than the flat rated temperature?
I was playing with reduced takeoff thrust in a Boeing 737-800 simulator yesterday and was surprised that I could enter assumed temperatures below the flat rated temperature of the engines. The ...
- 58.3k
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What happened to EC-ATQ?
EC-ATQ was a Douglas DC-7C.
It was damaged beyond repair on 2.10.1970 in Madrid.
Does anyone have more information?
Was a piano dropped on top of it and nobody was willing to take the blame?
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How is training for an SIC type rating accomplished when an aircraft is two pilot certified only?
For an aircraft which is certified for two pilots and a simulator doesn’t exist, how does someone go about receiving the required training for an SIC type rating without having the type rating already,...
- 3,718
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How many executive jets does the US military have access to (as opposed to owning outright)?
Last night around 8pm at least 12-15 executive jets flew into PSM over my house one after the other. Apparently the Air Force brass were having some kind of powow, which isn't surprising given that ...
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How did the Caproni Ca.60 electrical communication system work?
On the wikipedia page for the Ca.60 it says:
The two nacelles also housed a cockpit for one flight engineer each, who controlled the power output of the engines in response to the orders given by ...
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Are speed limits used for departure turns imposed also on the rest of the procedure?
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 ...
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Why would it be logical to call clearance delivery prior to CTAF during an instrument approach?
I am quoting this directly from the FAA's Instrument Procedures Handbook publication.
"The communication strip provided near the top of FAA approach charts gives flight crews the frequencies that ...
- 9,072
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Why does the SSM decoding vary between different A429 label types
For A429 there are different label types, for example: BCD, BNR, Discrete...
These types have their corresponding SSM (Sign/Status Matrix) that is unique, for example an SSM of "00" represents a ...
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Are there any cases on record of an aircraft crashing into an occupied air traffic control tower?
Aircraft frequently1 crash, or come close to crashing, from almost every cause imaginable, on or near airports, these being places where aircraft of all sizes take off and land and sleep with many ...
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What failure modes did Airbus seek to eliminate or mitigate when they changed the design of the A310/A300-600's rudder travel limiter?
In the NTSB report on the crash of American Airlines Flight 587, it is mentioned (in the context of the changes between the A300-B2/B4's rudder system, on the one hand, and the A310/A300-600's rudder ...
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Is the combustion process in turbofans and turboshafts different?
According to a journal paper, for a Gnome turboshaft engine, fuel-air equivalence ratio decreases as power output increases. However, for a CFM56 turbofan engine, the opposite trend is true, and ...
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Could injectors be used as an alternative to turbopumps in jet engines?
Could injectors be used instead of turbopumps in aeroengines? Are there jet engimes that already use them?
https://en.m.wikipedia.org/wiki/Injector
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Using the APU for heating on the ground with engines shut down
I would like to refer one technical question to you that I couldn’t able to explain myself. It is from the FCOM Supplementary Procedures Chapter of a Boeing 737 Classic. This question concerns the use ...
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Is it legal to fly this approach in Bahrain if the VORTAC is out of service?
Can I fly the VOR/DME/ILS RWY 33R approach at Bahrain/Isa Airbase (OBBS) if the OBBS VORTAC is out of service?
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What is APS (Aircraft Prepared for Service) Weight? What does it include?
I am looking for a complete explanation of what APS weight includes and how is it different from Dry Operating Weight and Basic Weight.
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