Can a helicopter fly...

scholar007

......upside down?

Davidth88

You know I am old enough to remember seeing a US CH53 doing a roll at either Greenham Common or Mildenhall AS

If you check you tube out , there are videos of this being done

Now of course this isn't sustained inverted flight .

xflyer

Model helicopters can so there's no reason to suppose full size can't. The Lynx as I recall can roll and loop. Also the Bo105. Both have rigid or semi rigid rotors, whatever that means. But it allows them to turn upside down but presumably with positive g. Too much negative g and it all ends in clatter of rotor blades and tail rotors.

But there is no practical benefit for a helicopter to fly upside down. Which is presumably why sustained inverted flight is never a design feature of any helicopters. Stressing for negative g would just add weight.

Xpro

Turbo Porter

The Indians can also do loops with their Hindustan ALH Dhruv.
http://jetphotos.net/viewphoto.php?id=5789795

SNAKEDOC

helicopters can't maintain inverted flight for any period of time other than to transit through the inverted position due in part to its rotor design and the fuel tanks. aircraft that preform inverted maneuvers have specificly designed fuel tanks so when flying upside down or in a negative g dive the engine will still have a fuel supply and therefore will not stall. a helicopter is an inherently unstable platform that by all accounts simply should not fly so flying upside down for more than a fraction of a second is unheard of in anything but a small toy radio controlled helicopter which can hover upside down due to the rigid design that cannot be mimicked by a full size chopper
answer full size choppers can't hover upside down but can transit through inverted

radio controled can hover upside down

Turbo Porter

The rigidity of the rotor design has also to be taken into account...anyone ever witness a Bell 212 doing a loop :eek: