I've been lurking the flyrotary list
on occasion for the last year. I plan to hang a Renesis w/Tracy's RD-1C on my
under construction RV-7A.
My
questions:
1)
Has anyone flown
an RV with a super or turbo charged rotary/RD-1C combination? If yes,
I'd like to know how much flight data is available - specifically upper
airspeed under what flight and aircraft conditions (fairings on? prop
diameter/pitch/model/type? RV model? ...).
2)
For anyone
flying a normally aspirated rotary with the RD-1C on a Van’s RV. If you’ve
tested the upper airspeed of your aircraft in cruise flight would you be willing
to share your data with me?
Background:
The reason for this inquiry is
that I naively planned to supercharge the Renesis installation because
I thought the airframe could SAFELY cruise up to 200 KTS IAS (RV-7 Vne) in
smooth air. At my typical NM altitude (12,500 MSL), that would be 248
KTS TAS (285 MPH)!
However, my bubble was busted by the
Van's RVAtor article on flutter (6th issue 2004). Van’s engineers
instructed their readership on flutter – that Vne is really a TAS limit, not an
IAS limit. A US Air Force pilot and RV commuter corroborated the Van’s article
by telling his disturbing TAS flutter story (first 2005 RVAtor issue). If you
haven’t read this, I recommend it for all pilots, no matter what they
fly.
I’ve decided to follow Van’s advice
and restrict my upper airspeed to limit to 200 KTS TAS in smooth air. I don’t
want to be a test pilot. Therefore, I’m reconsidering my plan to supercharge the
Renesis/RD-1C installation. The weight penalty may not be worth climb
performance increase if 200 KTS TAS cruise can be easily achieved
with a normally aspirated installation. If I can collect empirical data
from RV Rotary flyers, it would sure help my decision.
Thanks,
John Burns
rv-7a@comcast.net
http://mywebpages.comcast.net/jgburns/Engine/Engine.html for
my engine webpage.