X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao05.cox.net ([68.230.241.34] verified) by logan.com (CommuniGate Pro SMTP 5.1c.4) with ESMTP id 1405921 for flyrotary@lancaironline.net; Sat, 16 Sep 2006 11:10:03 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.34; envelope-from=alventures@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao05.cox.net (InterMail vM.6.01.06.01 201-2131-130-101-20060113) with ESMTP id <20060916150921.CQGR12909.fed1rmmtao05.cox.net@fed1rmimpo02.cox.net> for ; Sat, 16 Sep 2006 11:09:21 -0400 Received: from BigAl ([72.192.132.90]) by fed1rmimpo02.cox.net with bizsmtp id P39N1V00G1xAn3c0000000 Sat, 16 Sep 2006 11:09:22 -0400 From: "Al Gietzen" To: "'Rotary motors in aircraft'" Subject: RE: [FlyRotary] Re: Flight test Date: Sat, 16 Sep 2006 08:09:32 -0700 Message-ID: <000001c6d9a2$1d426e20$6400a8c0@BigAl> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0001_01C6D967.70E39620" X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook, Build 10.0.6626 Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.2962 This is a multi-part message in MIME format. ------=_NextPart_000_0001_01C6D967.70E39620 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I don't recall what you prop arrangement is, but the RPM's that you have listed sound pretty low. Even with a variable pitch prop, I'd think = that you'd want 2250-2300 at the prop, in cruise. =20 =20 I have a 3-blade Catto fixed pitch; 66 x 85. I get 5000-5100 rpm static = on a warm day, and about the same rpm on climbout at 110 kts. Perhaps just = a bit too much pitch, but I don=92t think the engine parameters are = optimized yet. =20 Basically the reason for the low rpm numbers while flying level is = because the power was pulled back. MAP was only 19=94. What rpm do you get at = 19=94 MAP? =20 The percent power readout was about 65%, but how meaningful is that = since I see on the video of the engine monitor it showed 110% (290 hp) at 20=94 = MAP as the power was pulled back at the top of the climb. All it means is that = the mixture was too rich. Having to rely on a test pilot who is not that familiar with the engine operation, or the instrumentation; definitely = is a drawback. But also, until I can get stable operation of the EC2, it=92s = hard to draw any conclusions. =20 I just wonder if higher RPMs wouldn't improve cooling by increased flow. =20 I guess you mean on the fluid side. The data indicates fluid flow is = fine, the oil side temp drop across the oil cooler is only about 15 degrees, = while air temp increase is more than 100 degrees. Clearly needs more air = flow.=20 =20 Buly wrote: Again, let the engine rev higher, since right now your performance =20 numbers for the same weight are very close to my engine, and should =20 be 50% higher? =20 For now I can=92t let the engine rev higher for a given power with a = fixed pitch prop. I wish 50% higher; but since performance goes as the cube = root of power; mine should only be 15% higher (cube root of 1.5):-). =20 So when I get the wings shimmed, the EC2 stable, more air flow through = the wing root coolers; and, oh yeah =96 schedule the test pilot (or cancel = the insurance and fly myself) we=92ll fly again and have more data. And at = some point =96 if I=92m still young enough to fly . . .=20 =20 Al (I=92ll be more optimistic next week) =20 =20 Steve Brooks Cozy MKIV N75CZ Turbo 13B =20 =20 -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of Al Gietzen Sent: Friday, September 15, 2006 2:09 PM To: Rotary motors in aircraft Subject: [FlyRotary] Flight test Finally got the proper alignment of the planets (basically test pilot schedule) for further flight of Velocity 755V =96 20B. Plane was in the = air for =BD hour this time, basically at level cruise orbiting the airport. = OAT was about 90F and flight was at DA of about 7000=92. =20 Since the first flight when oil temps were high, I added a temporary ram scoop under the =91wing root=92 oil cooler inlet. Oil temp reached near = 230 during climb but later stabilized at 200 - 205F. Coolant stabilized at 180-185F. =20 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 =91% power=92 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. =20 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 =96 hopefully get a differential pressure measurement set up.=20 =20 Takeoff roll of about 1500=92 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=94 pitch prop. Something special about Catto = props. =20 The thing looks and sounds great, and I have to be happy that it went = up, stayed up for =BD 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 =91noise=92 related; and the need for right = aileron input in order to go straight, suggesting a need for wing incidence adjustment. =20 Al =20 ------=_NextPart_000_0001_01C6D967.70E39620 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

I don't recall = what you prop arrangement is, but the RPM's that you have listed sound pretty = low.  Even with a variable pitch prop, I'd think that you'd want 2250-2300 at = the prop, in cruise. 

 

I have a 3-blade Catto fixed = pitch; 66 x 85. =A0I get 5000-5100 rpm static on a warm day, and about the = same rpm on = climbout at 110 kts. =A0Perhaps just a bit too much pitch, but I don’t think = the engine parameters are optimized yet.

 

Basically the reason for the low = rpm numbers while flying level is because the power was pulled back.=A0 MAP = was only 19”. =A0What rpm do you get at 19” MAP?

 

=A0The percent power readout was = about 65%, but how meaningful is that since I see on the video of the engine = monitor it showed 110% (290 hp) at 20” MAP as the power was pulled back at = the top of the climb.=A0 All it means is that the mixture was too rich.=A0 = Having to rely on a test pilot who is not that familiar with the engine operation, = or the instrumentation; definitely is a drawback. But also, until I can get = stable operation of the EC2, it’s hard to draw any = conclusions.

 

I just wonder if higher RPMs = wouldn't improve cooling by increased flow.

 

I guess you mean on the fluid = side.=A0 The data indicates fluid flow is fine, the oil side temp drop across the oil = cooler is only about 15 degrees, while air temp increase is more than 100 = degrees. =A0Clearly needs more air flow.

 

Buly wrote:

Again, let the engine rev = higher, since right now your performance=A0

numbers for the = same weight=A0 are very close to my engine, and should=A0

be 50% = higher?

 

For now I can’t let the = engine rev higher for a given power with a fixed pitch prop. =A0I wish 50% higher; = but since performance goes as the cube root of power; mine should only be 15% = higher (cube root of 1.5)J.

 

So when I get the wings shimmed, = the EC2 stable, more air flow through the wing root coolers; and, oh yeah = – schedule the test pilot (or cancel the insurance and fly myself) we’ll fly = again and have more data. And at some point – if I’m still young = enough to fly . . .

 

Al (I’ll be more optimistic = next week)

 

 

Steve = Brooks

Cozy MKIV = N75CZ

Turbo = 13B

 

 

-----Original Message-----
From: Rotary motors in = aircraft [mailto:flyrotary@lancaironline.net]On Behalf Of Al Gietzen
Sent: Friday, September 15, 2006 2:09 PM
To: Rotary motors in = aircraft
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 =BD 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 =BD 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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