How difficult is it for a helicopter to fly a loop?
OK, I know that helicopters can fly a loop and that the movie scene where Blue Thunder does one were faked. But how difficult is it really? Could a real-life Gazelle or MD 500 do it?
shareI dont know about the MD 500 only ones i have seen do it on film is the apache and the lynx, a lot depends on the pilot though the helicopters may be capable because the have stiffer rotars but its not like any pilot can just jump in and loop a one of those without it becoming a dart and heading groundwards very quickly. Search Youtube for Lynx Loops. No helicopter can actually stay inverted and fly only RC's
shareAs I understand it, any helicopter can in theory do a loop, but they are not real loops, not perfect circles like an airplane. Once a chopper gets on its back it will begin to accellerate towards the ground quite rapidly and that spoils the arc.
They can also be rolled but will usually always lose altitude during the roll.
The rotor disc just doesn't work effectively upside down with the weight of the aircraft above it, as it does the right way around.
Some helicopters can do it quite easily and others need more effort, it's mostly down to a difference in the design of the rotor head.
Also, doing these kinds of things places enourmous strains on the rotor system and the driveline components, resulting in reduced life and economical impacts, so they aren't done that often.
Mike.
Very informative. Great post Mike.
shareSorry Mike, but planes, as much as choppers, can't perform perfect circular loops. They fly an eliptic course, much like the shape of an egg, due to the different flight performance at different heights.
I agree on the rest. Every chopper can actually loop, but doin' it on some machines s much easier than on others.
I beg to differ...
I fly in aerobatic competitions and we are judged on exactly that.
To get a round loop you alter the pull through the four quarters, on top, I put in about three of four seconds of forward push, or negative G, on the airplane to "float" it over the top. It is quite possible to get a perfectly round loop, it just isn't easy.
Helicopters with a rigid rotorhead can perform aerobatics. Teetering rotorheads, like what is on a Huey or Robinson, can not perform aerobatics.
The three most famous are the MBB BO-105, Westland Lynx and the Gazelle, what BT was, albeit highly modified.