Mailing List flyrotary@lancaironline.net Message #33624
From: Ed Anderson <eanderson@carolina.rr.com>
Subject: Re: [FlyRotary] Flight test
Date: Fri, 15 Sep 2006 16:57:08 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Great to hear, Al.  Sounds like a bit more sorting-out to do, but at least you can get real data by flying and seeing the effects of any modifications.  I'm impressed with the take-off roll, heck you can fly off my 2200 ft strip.  Still a bit high on the oil temps (as you know), but given the OAT, I don't think your temps were out of whack - higher than you would like (isn't that always the case), but not extreme.  Coolant temps sound right on the money.  I found when I finally got my oil temps down, the coolant temps also dropped. 
 
Continue to post your results - needless to say all interested in a 20B flying.
 
Ed
 
 
 
 
----- Original Message -----
From: Al Gietzen
Sent: Friday, September 15, 2006 2:08 PM
Subject: [FlyRotary] Flight test

Finally got the proper alignment of the planets (basically test pilot schedule) for further flight of Velocity 755V – 20B.  Plane was in the air for ˝ hour this time, basically at level cruise orbiting the airport.  OAT was about 90F and flight was at DA of about 7000’.

 

Since the first flight when oil temps were high, I added a temporary ram scoop under the ‘wing root’ oil cooler inlet.  Oil temp reached near 230 during climb but later stabilized at 200 - 205F.  Coolant stabilized at 180-185F.

 

I have video recording of EM2 display, and this time the pilot remembered to push the page button, so I have lots of data.  For ‘% power’ readout of 65-70%, engine rpm was 4450, prop 2050 rpm, IAS (according to pilot) was about 145 kts.  TAS readout on EM2 was 165-170 kts, but my calcs indicate this is about 5 kts too high.  Fuel burn was indicating 16-18 gph running rich of peak.

 

The in-cowl radiator is handling most of the cooling load; with the wing root rad being very ineffective.  This is consistent with the first flight results on the oil temps with the matching wing root oil cooler.  The scoop added for the OC improved the air flow, but it is still marginal, with oil delta T of about 20F and air delta T of about 100F.  It is likely the main issue is with the exit fairings.  At least now it flies stably, so I can do some other changes and see the effects – hopefully get a differential pressure measurement set up.

 

Takeoff roll of about 1500’ at 1900# weight is quite good considering fixed pitch prop.  It accelerates from rolling start to 60-65 kts nose lift in 6-7 seconds.  This with an 85” pitch prop.  Something special about Catto props.

 

The thing looks and sounds great, and I have to be happy that it went up, stayed up for ˝ hr, and made a perfect landing.  Main issues right now are on-going problem with EC2 data corruption; apparently unique to my installation, and possibly ‘noise’ related; and the need for right aileron input in order to go straight, suggesting a need for wing incidence adjustment.

 

Al

 

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