119
votes
Accepted
Can this helicopter/wrecking ball combo remain airborne?
EDIT
Huge apologies to one and all, in my first version of this answer I mistyped 184 as 84, and then proceeded to do all my calculations based on that. This is the corrected version.
Also, huge ...
- 936
80
votes
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Do helicopters use more fuel when hovering?
Yes it is correct that helicopters use more fuel when hovering: the engine needs to apply more power to overcome drag. Here is a graph of the engine power required for different airspeeds, from J. ...
- 62.9k
76
votes
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Should the helicopter be washed after any sea mission?
The helicopter shown is an Anti-Submarine Warfare Helicopter. ASW helicopters generally have the ability to detect submarines either Passively or Actively. Passively, sonar-buoys are dropped into the ...
- 1,166
69
votes
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Why do helicopters have windows near the pedals?
These fall into a category known as vertical reference windows. They can be used for many purposes, but essentially, they allow us to gain a better spatial picture of the orientation of our aircraft, ...
- 4,877
62
votes
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What helicopter has the most rotor blades?
Special mention for Raúl Pateras Pescara de Castelluccio (good article) who was fond of lots and lots of rotor blades, settling on sixteen for most of his designs, although his Model 3 had twenty.
...
- 14.6k
60
votes
Can you identify this helicopter seen near Boscombe Down?
Apache Longbow headed a slightly different direction.
Specific model is AH-64E, indicated by the presence of datalink antennas (OP's photo) on the stub wings.
- 21k
57
votes
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Can helicopters create contrails?
If the temperature and conditions are right, yes.
Any aircraft which has a heat engine that burns hydrocarbon fuel, which is pretty much any reciprocating or gas turbine engine used in aviation, will ...
- 75k
56
votes
Why can't helicopters or Zeppelins drop fire-fighting material on burning buildings?
First, they have been used, like in case of the Federation tower fire in Moscow on 2012. The image below shows a Kamov Ka-32A11BC being used to fight fire in that case.
Helicopter fighting Federation ...
- 101k
56
votes
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Is a helicopter ride unsafe for young children?
A few notes of update.
Evidence from other operators that there is no hard age limit
There is no upper or lower age limit for pleasure flight however we recommend that children under 12 are ...
- 35.7k
55
votes
Can all helicopters hover, and how long does it take to "stop"?
As noted in another answer, all helicopters can hover, but a so-called "high hover" (out of ground effect or especially at operational altitude) is a more difficult maneuver, requiring more power than ...
- 17.3k
53
votes
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Do the Mt. Everest rescue helicopters have modified engines to operate at high altitudes?
No, the helicopters are standard production versions. The Eurocopter AS350 is a common model used for these operations.
In 2005, Didier Delsalle landed a Eurocopter AS350 B3 on the summit of Mt. ...
- 73.8k
51
votes
Can this helicopter/wrecking ball combo remain airborne?
The helicopter would be a UH60 Blackhawk. Max payload on a hook is 9000lb. At your mild steel density this is half a cubic meter, so the picture as you describe is impossible.
- 21k
51
votes
Why are there no helicopters with the rotor mounted on the bottom?
If the rotor would be underneath the helicopter, then:
The helicopter body would still generate vertical drag from being exposed to the vertical airflow, but now above the rotor,
The rotor would work ...
- 84.5k
50
votes
Can a helicopter carry a large airplane?
If you look more closely, this "airplane" is only the husk of a Tupolev Tu-134, a rather small airliner, and the helicopter is a Mil-26, the heaviest helicopter ever to go into production. Not only ...
- 237k
50
votes
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Why is the UH-60 tail rotor canted?
John K and Koyovis's answers are both correct. However, as a former pilot of the UH-60 and a mechanical engineer here is a simpler version.
A helicopter must be balanced. If the front is much ...
- 516
48
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Can this helicopter/wrecking ball combo remain airborne?
Of course the photo is absolutely real. I know a guy who knows a guy who says he met the guy in front!
3) Assume the wrecking ball is solid mild steel with a density of 7.85 g/cm3.
That's where ...
- 30.1k
46
votes
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What happens when all electrical systems in a helicopter fail?
The reason for the failure is important actually. If all the electrical systems on an EC135 helicopter fail in your classic EMP scenario then the helicopter has to make an emergency landing as the jet ...
- 54.4k
46
votes
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How do helicopters avoid detection from enemies by using IR suppressors?
An IR sensor detects objects that are at a higher (or lower but that's not how missiles work) temperature than the surrounding environment, most of the helicopter won't be that much hotter or cooler ...
- 54.4k
44
votes
Why do helicopters have skids?
Image source
Larger helicopters have landing wheels, and as we can see on the picture above, they are placed as far outward as practically possible in order to provide stability in the landing. Touch ...
- 62.9k
43
votes
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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
42
votes
Do helicopters use more fuel when hovering?
Yes, it is correct, if the helicopter doesn’t fly too fast. A helicopter will produce the necessary lift most efficiently at a moderate forward speed.
In a hover all the airflow which is available ...
- 237k
41
votes
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Why don't we have helicopter airlines?
They do in fact exist, though they often use smaller helicopters. A Google search on the term "heli taxi" yields thousands of results, and while a lot are probably irrelevant, the first few pages give ...
- 16.3k
41
votes
What helicopter has the most rotor blades?
The most blades I've seen are 8 on the Mi-26.
Source
But the highest theoretical lifting efficiency is achieved with the fewest blades and experiments have been done with single blade rotors (with a ...
- 136k
41
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Is it allowed to let the engine of an aircraft idle without a pilot in the plane. (For both helicopters and aeroplanes)
You won't see it done in the fixed wing world unless the aircraft is tied down or otherwise securely restrained (like when you tie off the tail to something when hand starting your no-starter ...
- 136k
40
votes
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Helicopters: why hasn't NOTAR been more popular?
Though NOTAR looks simple from outside, its actually a bit complicated. Let me use the following figure to elaborate on this point.
By Voytek S - Own workThis vector image was created with Inkscape., ...
- 101k
40
votes
Are there any helicopters with ejection seats?
Many years ago I read about the Kamov-50 helicopter family* being the first helicopters equipped with ejection seats. And Wikipedia verifies my memory:
It is the world's first operational helicopter ...
- 7,020
39
votes
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Were there any instances of aerial combat between helicopters?
Yes, there has:
In the Iran-Iraq War, Wikipedia:
The war also saw the only confirmed air-to-air helicopter battles in the history of warfare, with Iraqi Mi-25s flying against Iranian AH-1J SeaCobras ...
- 36.2k
38
votes
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Why do helicopters not roll over when flying forwards?
Juan de la Cierva's first autogiro did roll over, twice, and he then applied the principle of blade flapping, a stroke of genius. Flapping is created by allowing the blade to move up and down. ...
- 62.9k
38
votes
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Could Swashplate be replaced with small electric motors?
Yes that is possible and has been attempted by the german company Airbus Helicopter Technik GmbH (formerly called ZF Luftfahrttechnik GmbH) in cooperation with Sikorsky. They have published two papers ...
- 5,044
Only top scored, non community-wiki answers of a minimum length are eligible