Comments on: Stored energy

By: Bruno G.

Bruno G. — Mon, 09 Aug 2010 01:07:51 +0000

I love your helicopter articles. It always helps to revisite/recurent train the basics.
Thanks

By: Tim McAdams

Tim McAdams — Fri, 06 Aug 2010 15:16:54 +0000

Stephen,

Good point. As Ehud pointed out those two sources of stored energy are not helpful in autorotation, however, when writing this I wanted to be complete with regard to all sources of stored energy and forgot to exclude the fuel. Thanks for catching it.

Tim

By: Ehud Gavron

Ehud Gavron — Fri, 06 Aug 2010 14:49:40 +0000

For the purposes of autorotation, the helicopter’s energy in the fuel cell and/or battery doesn’t help, as they cannot be used to either spin up the main rotor, keep it spun up, or give it extra juice for the flare.
MR momentum, inertia (forward airspeed), and gravity (altitude) are the three primary sources of that energy. Frank Robinson’s low-inertia aircraft (R-22, R-44) get the primary source from airspeed, secondary from gravity, and lastly from the already-spinning rotor.

By: Brendan Fitzpatrick

Brendan Fitzpatrick — Fri, 06 Aug 2010 14:40:48 +0000

Great job explaining!

By: Stephen Early

Stephen Early — Fri, 06 Aug 2010 13:39:08 +0000

I love these articles but have to say that a helicopter sitting on the ground contains stored energy in the fuel as well as the battery.