All Questions

1
vote
0answers
47 views

What lights to use for a high-altitude weather balloon?

I am designing a high-altitude weather balloon for a college project. The balloon may fly at night, which means that, per FAA regulations, I need a light that is visible for 5 miles. Does anyone ...
4
votes
0answers
108 views

If all control surfaces were disabled, could a passenger plane be controlled by distribution of the passengers?

Let's assume that a large military plane has its control surfaces disabled in combat. The engine(s) can still be controlled. There is a substantial number of ground forces being transported. In ...
0
votes
1answer
49 views

Is overall pressure ratio same as compressor pressure ratio for a gas turbine engine?

For a typical gas turbine engine, turbofan in particular, is the compressor pressure ratio same as the overall pressure ratio? For modelling purposes can we use the same value of overall pressure ...
8
votes
0answers
167 views

Who decided that the Boeing 737 MAX planes that were airborne when the grounding was issued cannot enter and land in EU air space?

On March 12th, 2019, EASA grounded the Boeing 737 MAX series by publishing their Emergency Airworthiness Directive 2019-0051-E (AD): Effective Date: 12 March 2019, 19:00 UTC  [...] ...
2
votes
0answers
52 views

What's the theoretical background of the critical angle of attack?

The critical angle of attack seems to be at all (most?) airfoils around 15-20°. Why is that? Why is it in this range and not lower or higher? Is it just the result of optimizing airfoils? Or is it ...
-1
votes
1answer
191 views

What are the “certain” flying scenarios in which the Boeing MCAS is supposed to assist pilots? [closed]

Boeing bulletin issued last November said "MCAS provides automatic nose-down inputs to assist pilots in certain manual, flaps-up flying scenarios, especially at slow airspeeds and high AOA." ...
2
votes
1answer
54 views

Why do some airports have class E airspace to the surface only at certain times?

Below is the depiction of the Truth or Consequences airport on the VFR sectional. Notice that it states that Class E to the surface is only effective for certain hours. The Chart Supplement lists ...
0
votes
2answers
106 views

What is being depicted w.r.t. AoA in this video?

I was looking at this video of the AF447 crash simulation and at about 4:45 the angle of attack diagram shows a few things I don't understand (frame above). I get the orientation of the airplane, ...
0
votes
0answers
72 views

Which was the last Boeing crash that didn't send its black boxes back to the US?

I couldn't find an answer online, so I am asking the community. The real question is how frequent it is for a Boeing crash not to send the black boxes back to the USA, and a reply to title's question ...
33
votes
3answers
12k views

How difficult is it to simply disable/disengage the MCAS on Boeing 737 Max 8 & 9 Aircraft?

With regard to the Ethiopian crash of the 737 Max 8 aircraft, where according to preliminary reports, it appears to be related to the MCAS which is a safety system that pushes the nose down to correct ...
2
votes
0answers
62 views

How are rotorcraft and/or VTOL aircraft handled once they get to an airport? [duplicate]

I am asking this from an ATC perspective ... my experience as a pilot is that they would make helicopters fly the same approach but once they got the airport environment in site where do they go? Taxi ...
2
votes
1answer
59 views

What is difference between TAA and MSA?

I know the 'TAA' usually used in RNAV chart, but sometimes it can be used in ILS chart as well. (When defining an IF, GPS is solely methods) but While I'm studying, I can't find exact difference ...
0
votes
1answer
522 views

Why is it the ATC recording of Ethiopian Airlines Flight 302 is not yet available online?

I understand sites like liveatc.net constantly stream the conversation between the ATC and pilots. Why is it that there's no such recording for Ethiopian Airlines Flight 302 yet?
0
votes
1answer
185 views

Why can’t takeoff rejection be automated?

According to this comment on my previous question about automatic instrument takeoffs (or, rather, the lack thereof), the reason takeoffs are always flown manually is to allow the pilot to quickly ...
1
vote
1answer
123 views

Why does the A320 use the rudder for lateral control in mechanical law?

When the Airbus A320’s flight control system is operating in mechanical law (the simplest and lowest-tech of the A320’s flight control laws, where deflections of the pilots’ joysticks are transmitted ...
1
vote
1answer
97 views

Why don’t airliners use stabilizer movement to assist with large pitch control inputs?

Most large airliners not only have elevators for pitch control, but also moveable horizontal stabilizers. The elevators are used for primary pitch control, with the stabilizers being used to trim the ...
11
votes
1answer
3k views

Why are there 40 737 Max planes in flight when they have been grounded as not airworthy?

Many countries have already grounded 737 Max planes and as of Mar 13, 2019 the FAA have stated: The FAA is ordering the temporary grounding of Boeing 737 MAX aircraft (PDF) operated by U.S. ...
0
votes
1answer
84 views

Are the holes inside the engine nacelle used for uniform intake of air? [duplicate]

I read the post here: What is the function of the holes in splitter plates? My question is, what are those hole looking things inside the engine nacelle? It seems reasonable to me that as air enters ...
2
votes
1answer
99 views

How to literally take the wing off a single engine Beechcraft-style airplane?

First off I do not want to do any kind of maintenance. I was driving past an auto junk yard and saw they have half of a low wing, maybe a Beechcraft, airplane and I would like to try and buy the wing ...
9
votes
1answer
215 views

What were the advantages of the L-1011 AoA sensor design?

The Lockheed L-1011 had an unusual type of AoA sensor. Instead of the usual vanes it used a tube with two rows of holes in it about 90° apart. A diaphragm sensed the pressure differential between the ...
14
votes
5answers
6k views

Why do passenger jet manufacturers design their planes with stall prevention systems?

I understand why passenger jets use software that overrides pilot inputs that might cause the jet to exceed the flight envelope. But why do passenger jet manufacturers design their planes with stall ...
2
votes
1answer
265 views

Is there less vertical space for an engine under the wing of a 737 Max than for an A320neo?

The source of this question is the understanding that the LEAP-1B couldn't fit under the wing of a 737 without changing its longitudinal position. But this wasn't the case with the design of the LEAP-...
1
vote
2answers
111 views
8
votes
2answers
308 views

How much of a plane is replaced over the lifetime of an aircraft?

A photo of an OC-135 with (presumably) P&W TF33-P-5 engines made me wonder how many of the components had been replaced, and what was left of the original airframe, engines, and other parts. There ...
24
votes
3answers
6k views

Why would a flight no longer considered airworthy be redirected like this?

I ran across this tweet covering the saga of Smartwings 1201, a 737 MAX 8 that was apparently redirected from Prague to Ankara after the MAX was grounded by the EU. (flightaware.com) It seems like ...
0
votes
0answers
39 views

In which countries in the world its easier to buy and/or receive airworthiness certificate for weight shift control aircraft (trike)? [closed]

In which countries in the world its easier (less bureaucracy+less money) to buy and receive airworthiness certificate for weight shift control aircraft (trike)? Situation: My small country (local CAA)...
1
vote
1answer
122 views

What is the relation between altitude and vertical speed?

I recently saw 2 graphs on a flight path on BBC, shown below. For those interested, it's the path of the recently crashed Boeing 737 max flight ET302, but that's irrelevant to my question. My ...
0
votes
1answer
529 views

Has the number of angle of attack sensors been reduced in Boeing 737 Max, in comparison to the older models?

Boeing 737 is flying since 1967. I would like to know first how many ' angle of attack sensors' does it have, and has they number been reduced for Boeing 737 Max, in comparison to the older models ...
13
votes
2answers
723 views

Why is not every airplane equipped with 3 angle-of-attack sensors?

For critical systems, redundancy is built into the system. It is common knowledge among designers/architects to have three different inputs so in case one is faulty, input from the remaining two can ...
0
votes
1answer
65 views

What does mean 'GS' in RNAV (GPS) Chart?

Hello. I have a question about 'GS' in my RNAV(GPS) Approach Chart. Usually, (Including PAPI, VASI whatever...) Normal Glide Descent Angle means 3.00 degree. but some 'GS' says 3.07, 3.04, 3.09 ...
0
votes
1answer
92 views

About Flat Spins [closed]

Everybody seems to remember Maverick's flat spin in Top Gun, but If you watched "The Right Stuff", it was a flat spin that caused Chuck Yeager to Eject from an F-104. He didn't fly through jet wash, ...
4
votes
1answer
425 views

Why is Germany not able to read data from the Boeing 737 MAX black boxes?

It is my understanding that Germany stated it does not have the capacity to read the new software, declining Ethiopia's request: "The French announcement resolved uncertainty over the fate of the ...
-1
votes
1answer
262 views

Why is Boeing being blamed for the recent 737 Max crashes? [closed]

Boeing has received more than 5,000 orders for the aircraft, it has delivered 350 so far and only 2 of them have crashed. That's not a very high crash rate. The FAA, until just a day ago, was very ...
-1
votes
0answers
154 views

Why don't airliners on overwater routes carry SOFAR bombs?

Naval aircraft carry SOFAR bombs - devices which, in the event of a crash, sink to the SOFAR (deep sound) channel (a layer of water - usually 500 to 1000 metres below the surface except at very high ...
1
vote
1answer
57 views

What are the three sources that are relayed to the brakes and steering control unit of an A320?

There is the sentence: Electrical signals from the three sources are relayed to the brakes and steering control unit (BSCU) and are computed into the nose steering angle. The question: What are ...
0
votes
2answers
112 views

What is a 73W aircraft [duplicate]

With all the issues surrounding the Ethiopia crash can you tell me what a 73W is? Is it a 737 Max 8. We're trying to figure out if our flights with Westjet on Friday might be effected. Thanks ...
1
vote
2answers
146 views

What is the longest period of time an aircraft type has been grounded due to safety concerns?

Obviously inspired by the current 737 Max situation, what is the longest period of time that any individual type of airliner has been grounded for safety concerns (excluding those that never returned ...
7
votes
4answers
365 views

Are pilot YouTubers breaking any rules?

Recently, I've been watching a few YouTubers (mostly FOs) who make great videos like this: Then I realized... They must spend a lot of time setting up cameras, ...
-1
votes
0answers
40 views

Are pilots with impaired vestibular function less prone to crashes in IMC than those with fully-functional vestibules?

As you all will know already, the vestibular sensors of the inner ear are the human body’s primary attitude and acceleration indicators on the ground; however, as humans did not evolve as an aerial ...
0
votes
0answers
39 views

Can high G aircraft handle extreme turbulent weather?

Can aircraft that can handle high G forces, such as military or aerobatic aircraft, enter extreme weather like thunderstorms or lenticular clouds without structural damage?
0
votes
1answer
125 views

What happens when an aircraft type is grounded while in flight? [duplicate]

Over the past few days, many countries have decided to ground the 737 MAX. Among these, several have also decided to deny passage to the affected models through that country's airspace. How does this ...
2
votes
1answer
61 views

Pitot tube model

EDIT: Background on my application I am making a few measurement models for an extended Kalman filter (EKF). The EKF is meshing an INS and a GPS currently, but the GPS update rate does not update ...
1
vote
1answer
90 views

What is the recommended pressure for refueling an Airbus A380?

What is the recommended pressure on the hose that refuels an Airbus A380 when fueling this aircraft? How many litres per minute does it pump into the tanks. Can it safely be increased to reduce ...
4
votes
1answer
1k views

Are the Boeing MCAS and Airbus Alpha Protection systems the same?

I have a little question concerning MCAS from Boeing and Alpha Protection from Airbus. I think these two systems are the same, if I'm wrong please tell me. If the two 737 MAX crashed because of the ...
5
votes
1answer
157 views

Are all the Airbus A380's 16 exits designed for everyday use?

Are all the Airbus A380's 16 exits designed or everyday use for embarking and disembarking the aircraft, or are some specifically designed for use as emergency exits, such that opening any of those ...
0
votes
0answers
48 views

Is it economically profitable for airports use jetties that use all the airbus A380's 16 exits at the same time [duplicate]

Does it make economic sense or is it economically profitable for airports to build jetties or jetty facilities that use all the airbus A380's 16 exits at the same time. This would be very convinient ...
2
votes
1answer
85 views

How to correctly interpret the taxi procedures in ICAO Doc 4444?

I have a question to ICAO Doc4444, Chapter 12.3.4.7, Taxi procedures for departure, c). My question is how to interpret the following, knowing that words in parentheses are mandatory, and words in ...
0
votes
1answer
45 views

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

For flights that have two alternate destinations, I'm looking for a reference - either EASA or ICAO - that states that you need enough fuel to reach whichever alternate would require the most fuel to ...
4
votes
2answers
950 views

What is the blue range indicating on this manifold pressure gauge?

This is baffling me. Does anybody with experience with this type of indicator have any idea what the blue range of this gauge means? It's mounted in a mock-up panel. I know nothing about where it ...
2
votes
1answer
78 views

How is a composite fuselage repaired when structurally damaged?

In case of FOD, a fuselage puncture for example, what is the repair process? Considering time, complexity and cost, how is compared if it was an aluminium fuselage?

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