View Single Post
Old Oct 27, 2012, 11:26 AM
Brutus1967 is offline
Find More Posts by Brutus1967
I convince things to work
The Netherlands
Joined Nov 2009
4,620 Posts
Usually when started from cold, I let the engine idle for approx 30 seconds, than spool up and take off typically it will take some 2 or 3 minutes for the engine to get constant, and power drops after 1.5 to 2 minutes.

If I set her down and idle for lets say, 30 seconds, the first minute after take off I have that "cold" power, after that is goes down again. But once it is heated through, it stays stable, and the helicopter is flyable with it, as long as you plan a little bit ahead and make use of speed/altitude conversion and v.v.

There is not much power left for a vertical climb: something like 8~10 ft/sec is about all the old lady can manage.... When cold, it will do maybe 12~13 ft/sec.
But the engine is in both cases labouring audibly.

If I look at the 110 deg C I observed, approx 15~20 sec after touchdown, it might well be that 130 deg C is a realistic value in flight.
According Vario, the guys that once thougt an OS FS 91 in a helicopter might be an acceptable plan, the engine temperature rises 1.5 degree for every % of additional oil over 10%. That would mean, that I could gain a few degrees by reducing oil content to let's say, 12% (compensating for the lower fuel consumption with spark ignition), but than we're talking maybe 5 degrees max, I do not know if that makes the difference.

Improving cooling.... I wish, I had some more ideas as to how, without modifying to liquid cooling....

Brgds, Bert

Brgds, Bert
Brutus1967 is offline Find More Posts by Brutus1967
Reply With Quote