Mailing List flyrotary@lancaironline.net Message #31880
From: cbeazley <cbeazley@innovista.net>
Subject: Re: "Designed" test was [Rationalization]
Date: Mon, 22 May 2006 15:42:52 -0400
To: <flyrotary@lancaironline.net>
The test does reveal some data, however "designed".  Here are a few holes in the testing/writeup:

For the time to climb test:
Why specify throttle setting, rpm AND speed for a climb test.  Different engine - different performance.  Pick speed only or better yet let the pilots pick their speeds and give them a few tries to optimize and get their best time (or manage temps).

For the X-country, what was the speed for each aircraft for the 160miles?  The fuel use for the recip cruise portions of the x-country flight looks to be well into the economy cruise power settings...

What was the noise data?

A better comparison would include some cruise/climb, straight and level flight at different speeds, say 130, 150, 170, top speed.  No contraints other than speed.

As has been noted, a comparison between a p-port and side port would be useful for us at various speeds.

fans of Mythbusters?

Cheers
Cary



Ed, you may want to reread the article. They weighed all the planes, added ballast to the light ones to equal things out, then all flew same speed, altitude on long cross country. The reported fuel use differences were real.
Only points they didn't consider was the fact that both rotaries were burning 87 octane instead of 100LL. I don't know the difference in energy per gallon, but there sure is a difference in $. So if they compared cost for the trip, rotary would win.
It would have been nice if the author had compared the operating expense difference, but in all fairness, pilots tend to think in terms of GPH.

-al wick
Artificial intelligence in cockpit, Cozy IV powered by stock Subaru 2.5
N9032U 200+ hours on engine/airframe from Portland, Oregon
Prop construct, Subaru install, Risk assessment, Glass panel design info:
http://www.maddyhome.com/canardpages/pages/alwick/index.html

On Mon, 22 May 2006 09:16:20 -0400 "Ed Anderson" <eanderson@carolina.rr.com <mailto:eanderson@carolina.rr.com>> writes:
Even the Aviation Sport article supports that conclusion, even if they did dwell on the fuel burn (and Noise {:>),being higher.  Well of course, the  fuel consumption was higher - it was producing more power and beating the lycoming power RV-8.
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