Clear up an argument. My mate says a helicopter can "loop the loop" I say this is mechanically impossible

Question

Who is rite and has any idiot ever tried it an lived?
It is physically NOT possible for a helicopter to fly upside down and "loop the loop" - Am i right?

Answer 1

The British Lynx Helicopter can. The rotors are designed to invert as it goes oven 90 degrees in order to allow for air flow to always push towards the ground. This was developed about 7 years ago, I don't know if any more have been designed to do it since mind.

Answer 2

A "loop the loop", even though I have never seen one done by helicopter, could be possible with enough speed and altitude, by one such as an Apache, or similar helicopter. I have seen videos of Apaches and others doing barrel rolls, rolling the aircraft left or right 360 degrees. RC helicopters can hover upside down because the rotor blades pitch both directions. "Real" helicopters can not, their pitch is from flat pitch and up, no down. If they did, the blades would easily cone enough to hit the aircraft. Which some will flex enough during EXTREME conditions to do this from flat pitch. Sustained forward flight is not possible inverted. Aerobatic maneuvers like this, if possible on the type of aircraft, could easily overstress the airframe and overtorque the engines. No helicopters have "boosters" to help do this stuff, and "jet" helicopters as someone called them, are simply ones with a turboshaft engine, which is 90% of all helicopters, the engines dont produce thrust, just horsepower, and lots of it to turn the rotor. All the time I spent in the military, I don't think I ever knew of a pilot that would attempt something like this with passengers on board. They would not be a pilot much longer. Never even heard of a UH-60 mechanic say one could do it, but it may be possible. More or less this stuff is limited to modern military ATTACK helicopters, most civillian and cargo birds either wouldnt have the power or airframe strength to do it. I think you are both right and wrong, just depends on the aircraft. And yes they live through it because the pilots that are allowed to do it are usually factory trained test pilots.

Answer 3

The blades of a helicopter are really rotary wings. Like any other wing, the pitch can be varied from maximum lift to none at all. When an aerobatic airplane is upside down the wings are also trying to push it to the ground but the pilot counter-acts that through the pitch of the wings, same with a helicopter. It is rare but some high performance helicopters can definitely do loops. You need plenty of altitude but it can be done.

Answer 4

I am afraid your mate is quite right helicopters can loop the loop. I have seen it done on several occasions once at an airshow the other at sea when a British navy Lynx looped his helo they sure do like to show off. The rotors of a helo are like the props on a plane the pitch can be changed so that the thrust is reversed same with the rotor change the pitch and instead of thrusting down it's now thrusting up.

Answer 5

It can be done, there have been several demonstrations of this at air shows over the years, the difficult part is getting enough speed up to carry the helicopter through the apex of the loop, so only military copters can do it, and they are only completely upside down for a fraction of a second, so you are partially right helicopters can't fly upside down since the thrust from their blades would drive them towards the ground.

Answer 6

Quite a number of the newer machines can do loops. There is a video somewhere on the internet of a Bell 407 doing an aileron roll, and the Blackhawk will loop, as will a Hughes 500.

The critical factor is a rigid or similar rotor head.



I've heard an Astar will loop, but I've never quite done a true loop in one. Come close though.

Answer 7

There are 3 basic types of Helicopter rotor head.

1/ Semi rigid, used for twin blade helos such as the ubiqutous Bell Jet Ranger.

2/ Fully articulated, used on big helos such as Sea Kings and Coast Guard SAR helos.

3/ Rigid Rotor. This is where the rotor blade roots do not have hinges but rely on the metal of the root to flex and take the strains of powered flight. These ones can loop the loop and include Westland Lynx and Apache Longbow.

Your friend is right, if you have money on this, put your hand in your pocket.

Answer 8

can helicopters fly upside down?



"...this is an experiment that few helicopter pilots ever want to try out....

for most, it is the fastest route to the ground, and not in a good way, although it is possible....



wings are designed so that air passing over the top surface, when the plane is flying normally, pulls them up...

that means they should be sucked down to the ground faster than you can say 'drop like a stone' when they go upside down. ..



what really happens when pilots are doing aerobatics

is that they effectively change the shape of the wings

using the flaps at the back

and angle at which the wings meet the air,

which gives them back some lift....



...helicopter pilots can also change the angle of attack...but, one of the biggest problems for helicopters when it comes to flying upside down is that the rotors have hinges...

this makes them easier to control when they are the right way up...turn them upside down, and the rotors smack into the tail.... which is not good...



...helicopters with rigid blades have been designed, and could fly upside down but have, so far, been too troublesome to make reliable...



...but you will see model helicopters fly upside down as they can now make use of strong carbon-fibre rotors..."

http://www.flipside.org.uk/say/lowdown/





best answer to your question

from other asker...

https://answersrip.com/question/index?qid=20060918035746AAID3HG

Answer 9

Certain helicopters can pull it off. http://www.youtube.com/watch?v=VZlqfYLFR-4

http://www.youtube.com/watch?v=LGSq2OwL4ks

and here is a RC chopper pulling it off

http://www.youtube.com/watch?v=V4eYXYTEG-I

http://www.youtube.com/watch?v=GFOZZLRTaYc&mode=related&search=

So yes it is mechanically possible to fly a helicopter upside down, The RC chopper works exactly the same as the fullsize, But I would imagine a full size helicopter is unable to due to this because of the stresses involved or the pilots dont feel like dying.



If the engine fails on a helicopter, the blades will autorotate, (think of a maple tree seed as it falls to the ground) meaning the air moving up through them will move the blades slowing the aircrafts descent, this would mean that the blades have to be able to have negative pitch.



And its not just new helicopters than can loop, look at the first video, thats way back.

Answer 10

Your mate is right many makes of helicopter can loop the loop

Answer 11

The newest helicopters can loop the loop. The British Army Display team do it.

Answer 12

he is right certain types of helicopter can loop the loop, those that are fitted with a rigid rotorhead like the lynx can indeed back flip.

the Americans built the Comanche which could do virtually anything a fixed wing plane could do.



AIRCRAFT ENGINEER

Answer 13

Your mate wins.... The Apache and the black hawk can loop the loop, however they can not fly distance upside down. It takes great momentum to build the speed up to loop the loop.

Answer 14

Some military attack choppers can. Just about ANY fixed wing aircraft CAN loop the loop.... its just unless it is approved to do so, chances are you will break the plane. IF not DURING the loop then certainly after as the airframe will be stressed.



but sorry mate... cap in hand on this one, better pay or mate the slab of beer you bet

Answer 15

Certain very fast helicopters can do it. They do it at a high altitude to allow for the effect of it pulling itself down. Not quite a true circular loop, but very close.

Answer 16

Normal helicopters cannot. As soon as they reach the apex they'd plummet and have no way to stabelize themselves. Some of the military's newest chopers can. They actually have a thruster to give them greater speed and control. This gives the ability to push on over the apex and finish the loop.

Answer 17

Do not just take anybody's word for it. See the MBB Bo 105 in aerobatic mode.

http://www.metacafe.com/watch/257162/helicopter_aerobatics_3/

http://my.break.com/Media/View.aspx?ContentID=135033

http://www.griffin-helicopters.co.uk/videos/

Watch the video from the airshow.



The first to do this was the Hughes 500. Enstrom 280 FX Shark is also aerobatic.

Fury helicopters does it an Aerospatiale Gazelle.

http://www.furyhelicopters.com/content/

Answer 18

I'm led to believe that only those helicopters with rigid rotors can perform this manoeuvre. Most Helios have the flexible kind and therefore would be unable to carry this out. I believe the Westland Lynx can do so whilst the Gazelle cannot.

Answer 19

Yes there are certain helicopters that have reverseable rotor blades on them, although most of these aircraft are military only you proabably will never see one, but it is possible...and in respose to an earlier answer are airplanes can be flipped up side down with the proper procedures!

Answer 20

Your mate wins. Although very few can do this there are a few that can. From personal experience, a UH-60 Blackhawk can do a loop. Not sure if it's certificated for it, but it CAN do one!



(That was the only time I lost my lunch on board an aircraft.)

Answer 21

there are military type attack helicopters that can loop the loop but you average helicopter wont as you say due to the engineering of it

Answer 22

Some can loop the loop but what they cannot do is fly upside down.

RoyS

Answer 23

correct, it is impossible for a helicopter to fly upside down so they cannot loop the loop mechanically.

however they can loop the loop just from sheer momentum with the pilot literally throwing them round..taking control when they return to level.

Answer 24

Yes it can loop the loop-maybe for a second..then you die. Maybe for a second it can fly upside down....NO it should NOT be tried. I just asked my son--who is training in Helicoptors.

Thank god he has not done this. (he has a private license now)

Answer 25

I believe that there is a helicopter that can do a 360 like that. Sorry, but the name escapes me, though I do believe it is American military. It is both most difficult and I would say quite dangerous.

Answer 26

most helicopter are unable to fly upside down BUT one is able to its a military helicopter and can sometimes be seen at RAF airshows where I have seen it, sadly I cant remember what it is called and the one person I know who is likly to know is not here to be asked

Answer 27

I'm no expert, but I'm pretty sure you are correct. A helicopter cannot fly upside down. I think the way helicopters work is because of the angles of the blades, so if you went upside down it would push the copter towards the earth.

Answer 28

Sorry but you are wrong, the Westland Lynx is able to barrel roll and loop.



It also holds the world record for fastest helicopter.

Answer 29

I have seen Radio controled Helos' do loops. I suppose full size could if it could take the G forces

Answer 30

Some helicopters can do it. I didnt think they could either til i saw one at an airshow.

Answer 31

apache helicopter - yes. not sure about other types of helicopters. it's not an idiot, it's a genius.

Answer 32

Friend right, you Wrong. However *NOT* any old Chopper can pull off this miracle of Physics. Can't remember which ones do, but i aussure you it is indeed possible

Answer 33

The comanche can because it is so fast and maneuverable. I saw a royal air force pilot do it on TV. You have to be a really skilled pilot to do it.

Answer 34

A standard rotor helicopter cannot BUT a jet copter can!

Answer 35

Sorry and all that,but the Westland Lynx will backflip with no problem.

Answer 36

You lose

I have seen it done and talked with the pilot later

Answer 37

Pay up. See Cyber Comm’s answer, it’s the most accurate.

Answer 38

yeah they can, the military's apache has done loops

Answer 39

You lost



The newer military ones can and do

Answer 40

Your mate is right.

Answer 41

certain ones can. seen them do it in person

Answer 42

I have yet to see it happen. You would think if it had been achieved there would be video of it somewhere.

Answer 43

I believe you are. Even with planes, I think only stunt planes can do that.