Return-Path: Received: from [65.54.168.112] (HELO hotmail.com) by logan.com (CommuniGate Pro SMTP 4.2b2) with ESMTP id 3199664 for flyrotary@lancaironline.net; Fri, 30 Apr 2004 18:23:09 -0400 Received: from mail pickup service by hotmail.com with Microsoft SMTPSVC; Fri, 30 Apr 2004 15:23:00 -0700 Received: from 4.174.3.218 by bay3-dav8.bay3.hotmail.com with DAV; Fri, 30 Apr 2004 22:23:00 +0000 X-Originating-IP: [4.174.3.218] X-Originating-Email: [lors01@msn.com] X-Sender: lors01@msn.com From: "Tracy Crook" To: "Rotary motors in aircraft" Subject: RD-1C test results Date: Fri, 30 Apr 2004 18:22:58 -0400 MIME-Version: 1.0 X-Mailer: MSN Explorer 7.02.0011.2700 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0003_01C42EE0.2A2BC4C0" Message-ID: X-OriginalArrivalTime: 30 Apr 2004 22:23:00.0283 (UTC) FILETIME=[B21B68B0:01C42F01] ------=_NextPart_001_0003_01C42EE0.2A2BC4C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Here are my (very brief) test notes and some background comments. 04-27-04 Flight Tests w/ old 13B & RD-1C drive. 1 min Timed climb from 1000 agl to 3650 agl at 130 mph , 2650 fpm OAT= =3D 76 F, high humidity ?%. Was a little disapointed as I thought it was in excess of 3000. It will = be higher at lower airspeeds and under standard day conditions. I used m= y old Vy speed with the B drive and short prop. Vy is now lower because = the engine is up in its power band even at lower speeds and prop efficien= cy is much better at lower speeds compared to old prop. Will do a test = at lower speeds next time. What I really like is the effortless feeling the plane has during climbs = at lower throttle settings. Don't have any past bench marks but here is = a number you can bounce off your own performance numbers. =20 Climb rate while holding fuel burn at a constant 10.0 GPH =3D 1600 fpm cl= imb @ 140 mph. Was able to sustain this number from SL to 10,000 feet w= hich is where I stoped the test. =20 Cruise @ 11,300, OAT 37 F, IAS 140, TAS 171 @ 6.0 gph 5600 rpm This is only slightly better performance than before. RPM was a little h= igher and MAP a little lower. This was supposed to be done at 12,500 but I had drifted a bit lower whil= e staring at instruments and re-dialing the EC2 map table in (needed chan= ging due to the different loading on engine with C drive). Good thing t= he sky is not crowded, I don't think I looked outside the cockpit for 20 = minutes. =20 Cruise @ 12,500, OAT 36 F, IAS 163, TAS 203 @ 8.6 gph 6460 rpm (WOT, mi= xture leaned for best economy) This is respectable performance for an RV but it is not significantly dif= ferent than with the old prop (except the rpm was lower with B drive) Very low speed (110 mph) sight-seeing fuel burn is also lower. Was arou= nd 4 gph and now about 3.5. Conclusions: The C drive gives significantly better takeoff & climb perf= ormance but only a slight advantage in economy cruise. I do like the fue= l savings that show up when looking at the fuel burned during cruise-clim= b phase of flight. On a long cross country, I would typically set a fuel= burn of 8.5 gph during climb to cruise altitude but now I can get the sa= me climb rate at 7.0 gph. The other thing I like is that the engine vibration signature is now chan= ged just enough that the airframe resonances are almost all gone. Beer-c= an airplanes are a bunch of aluminum skinned drums flying in close format= ion looking for any excuse to start drumming. Tracy ------=_NextPart_001_0003_01C42EE0.2A2BC4C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Here are my (very brief) = test notes and some background comments.

 

04-27-04   Flight Tests w/ old 13B &= ; RD-1C drive.

 

=

1 min = Timed climb from 1000 agl to 3650 agl&n= bsp;  at 130 mph , 2650 fpm=    OAT =3D 76 F, high humidity ?%.

 

Was a little= disapointed as I thought it was in excess of 3000.  It will be high= er at lower airspeeds and under standard day conditions.  I used my = old Vy speed with the B drive and short prop.  Vy is now lower becau= se the engine is up in its power band even at lower speeds and = prop efficiency is much better at lower speeds compared to old prop. = ;  Will do a test at lower speeds next time.

=  

<= o:p>What I really like is the effortless feeling the plane has during cli= mbs at lower throttle settings.  Don't have any past bench mark= s but here is a number you can bounce off your own performance numbers.&n= bsp;  

 

Climb rate while holding fuel burn = at a constant 10.0 GPH =3D 1600 fpm climb @ 140 mph.   Was= able to sustain this number from SL to 10,000 feet which is where I stop= ed the test.

 

Cruise @ 11,300, OAT 37 F, IAS 140, TAS 171 =  @ 6.0 gph  5600 rpm

 

This is only slightly better= performance than before.  RPM was a little higher and MAP a little = lower.

This was supposed to be done at 12,500 but I had drifted a bit lowe= r while staring at instruments and re-dialing the EC2 map table in (neede= d changing due to the different loading on engine with C drive). &nb= sp; Good thing the sky is not crowded, I don't think I looked outside the= cockpit for 20 minutes. 

=  

Cruise @ 12,500, OA= T 36 F, IAS 163, TAS 203  @= 8.6 gph 6460 rpm  (WOT, mi= xture leaned for best economy)

 

This is respectable performance for a= n RV but it is not significantly different than with the old prop (except= the rpm was lower with B drive)

V= ery low speed (110 mph) sight-seeing fuel burn is also lower.   = ;Was around 4 gph and now about 3.5.

 

Co= nclusions:  The C drive gives significantly better takeoff & cli= mb performance but only a slight advantage in economy cruise.  I do = like the fuel savings that show up when looking at the fuel burned during= cruise-climb phase of flight.  On a long cross country, I woul= d typically set a fuel burn of 8.5 gph during climb to cruise altitude bu= t now I can get the same climb rate at 7.0 gph.

 

=  

Tracy

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