51
votes
Are seaplanes allowed to taxi in residential areas?
A sea plane was just going around it. It was very loud and got like 10 feet from the shore. It's just going in circles and won't take off and leave.
As has been pointed out in other answers and ...
- 39.2k
46
votes
Can I stop crop dusters repeatedly flying over my home?
In a rural area pilots can fly pretty low, and are permitted to fly even lower while carrying out a lawful activity such as crop-dusting. Even if the pilot flew at 500 feet above your house, which is ...
- 8,532
43
votes
Accepted
Are seaplanes allowed to taxi in residential areas?
If you have concerns over the safety of what is going on, here is what you should do:
Record a video with your phone. Try to get the N number (it should be painted in large letters on the side of the ...
- 36k
43
votes
Accepted
What is the loud noise of a helicopter when the rotors are not yet moving?
The sound you're hearing is the APU (Auxiliary Power Unit) running.
Turbine (jet) engines turn at a much higher RPM than reciprocating engines. This means that an electric starter motor would have to ...
- 12.8k
43
votes
Will you be able to hear a supersonic aircraft flying away from you?
Yes, actually you can only hear a supersonic aircraft after it has passed over you and is now flying away from you since it is moving faster than the sound moving towards you. The sound waves will ...
- 54.3k
41
votes
Can I stop crop dusters repeatedly flying over my home?
I did some Pawnee flying years ago, and have fielded a bunch of complaints about ag applicators from people. Here's my experience:
The FSDO will probably not care. Ag application is a different ...
- 17.7k
38
votes
What could explain the fact that during 1976-80, I used to hear commercial jets make sonic booms while flying overhead?
Note that 747's and other jumbo jets operating out of Bradley could not have produced sonic booms because they do not fly above the speed of sound (they only do 500 to 550 MPH at high altitude cruise) ...
- 20.7k
37
votes
Accepted
Why don't airliners use noise cancelling?
First, some airliners do use it - the Bombardier Q400 uses a NVS (Noise and Vibration Suppression) system to reduce cabin noise. Basically, it uses devices called Active Tuned Vibration Absorbers (...
- 100k
37
votes
Accepted
Why would a turboprop rev down just before going full throttle during takeoff?
Because the pilot is taxiing the airplane with the props in the beta range (turboprops turn into landsharks if you don’t do this and you end up really riding the brakes to keep the speed down), then ...
- 72.8k
32
votes
Are there any reported cases of noise from helicopters causing damage to property?
The article states that it's not even clear the damage was caused by the helicopters, that there is no other known incidence of such damage being caused by helicopters, and that a scientific study has ...
- 15.9k
32
votes
Why would a turboprop rev down just before going full throttle during takeoff?
It's because he was taxiing in DISC (discing, or flat pitch making the prop like a big disc), which is in the ground beta range, then coming out of it.
Beta range is a mode where propeller blade ...
- 126k
29
votes
Is an afterburner louder than the same jet engine without it?
This PDF indicates an increase by ~10 dB for an F-8K in afterburner versus the same aircraft in 100% dry thrust.
This PDF indicates smaller increases:
+5 dB for an F-15
+4 dB for F-22 and F-35
- 10.2k
27
votes
Why are winches not used for towing commercial planes up?
If you ever get the chance, do try a winch start in a glider. It is, to say the least, an interesting experience. I do not believe it would be accepted by the general public.
So, that is one more ...
- 1,546
27
votes
Why don't modern jet engines use forced exhaust mixing?
Why don't modern jet engines use forced exhaust mixing?
Because there isn't as much gain to be achieved from the jet exhaust any more, and because forced mixing impacts performance.
Gains. From The ...
- 61.3k
26
votes
What causes descending aircraft to make a noise like a giant blown bottle?
Short Answer:
The sound is caused by airflow across holes on the underside of the wings of certain aircraft.
Long Answer:
I too have noted the sound phenomenon that you describe. This video has a ...
- 16.5k
26
votes
Why are winches not used for towing commercial planes up?
I won't prove it's not possible, but I'd would be surprised it is. I'll develop the reasons why and provide the physical framework you can use to compute a solution to have, with some effort, a final ...
- 70.9k
25
votes
Accepted
Why is a Lockheed MC-130J Commando II creating such a loud droning sound?
There are two factors reducing the volume of a sound when travelling through the air:
The pressure wave expands as the surface of a sphere, which will reduce pressure as a function of distance $r$:
$...
- 54.3k
24
votes
Is an afterburner louder than the same jet engine without it?
It has been around 20 years since I've been on a carrier deck, but I recall that it wasn't as dramatic of an increase as you might think. It may have gotten a little bit louder, but what I remember ...
- 24.9k
23
votes
Accepted
Why do flying wires hum louder in a sideslip?
Here is one reason.
It once was common for suspension wires to be flattened rather than circular in cross-section, to reduce drag. those wires were then aligned with the airflow past the wing and ...
- 20.7k
22
votes
Won't sonic booms prevent Space X's BFR intercity transport plan from being acceptable?
The only way to get anything that far that quickly is to send it into space, and that's exactly what Musk is suggesting. The BFR will launch a passenger carrying spacecraft out of the atmosphere and ...
- 52.9k
22
votes
Accepted
Does any of the hearing protection worn by aviation professionals use active noise reduction?
If you're talking about crew/pilot headsets then ANR is a very popular option - especially in General Aviation. The Bose A20 is probably the most popular headset, but both Lightspeed and David Clark ...
- 9,278
21
votes
What is the loud noise of a helicopter when the rotors are not yet moving?
You may be expecting the rotor to spin up in lock-sync with the engine.
That's not quite what happens on a turbine helicopter.
Turbine helicopter engines (turboshaft engines) have a turbojet ...
19
votes
Accepted
Do quadcopter propellers break the sound barrier?
Almost certainly not. Given the comments specifying a $0.5$ inch radius (blade length,) that means the circumference of the path of the blade tips would then be
$$2 \pi \cdot 0.5 \, \text{inches} \...
- 19.4k
19
votes
When a typical commercial airliner flies overhead, what is the actual noise we are hearing?
It depends on the type of operation:
Approach (close to airport):
Much aerodynamic broadband noise from the air-frame
Modern turbofan engines are less noisy than the air frame during approach. But ...
- 430
19
votes
What is this sound on a B737-800 Takeoff?
It's the main gear wheels vibrating as they spin down. As the RPM of the wheel assembly drops, the wheel will pass through resonant frequencies and if there are small amounts of imbalance, the wheel ...
- 126k
17
votes
Why are light aircraft engines so noisy?
Engines could be made quieter by the simple solution of adding a muffler (or silencer as it's called in some places). They are available for many models and can be installed, at an astronomical cost. ...
- 52.9k
16
votes
Why don't airliners use noise cancelling?
“It's a well established technique for dealing with low frequency noise”
– exactly. Noise cancellation works precisely if, and only if, the area you try to shield from the noise is significantly ...
- 783
16
votes
Accepted
Can supersonic booms intensify as you fly longer?
They don't really pile up like that. The 'pile up' description of how shock waves form is pretty flawed.
The shock wave forms at an angle off of the body. Generally speaking, it forms a cone off of ...
- 7,244
Only top scored, non community-wiki answers of a minimum length are eligible