X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail.fdic.gov ([167.176.6.5] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTPS id 3568572 for flyrotary@lancaironline.net; Thu, 02 Apr 2009 18:14:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=167.176.6.5; envelope-from=brogers@fdic.gov X-MimeOLE: Produced By Microsoft Exchange V6.5 Content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C9B3E0.4E546610" Subject: RE: [FlyRotary] Was; Video of First Flight - Mustang II Now: HOW DO THER DO THAT Date: Thu, 2 Apr 2009 17:13:51 -0500 Message-ID: <1F44A251F397E444B05E240B8688AB790267A7BC@DALEXC100P.PROD.FDIC.GOV> In-Reply-To: X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: [FlyRotary] Was; Video of First Flight - Mustang II Now: HOW DO THER DO THAT Thread-Index: AcmyVHgsCeNMZHZIR0Syig8fGs9dHgBiYb/w References: From: "Rogers, Bob J." To: "Rotary motors in aircraft" Return-Path: BRogers@FDIC.gov X-OriginalArrivalTime: 02 Apr 2009 22:13:53.0379 (UTC) FILETIME=[4EDAFB30:01C9B3E0] This is a multi-part message in MIME format. ------_=_NextPart_001_01C9B3E0.4E546610 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable The designer and original manufacturer of the Mustang II kit, Bob Bushby, is the one who published the procedure, which is to protect the leading edge with masking tape to avoid scratches and tap on the outer leading edge with a rubber (or other soft) mallet repeatedly until a measurable rounding (or flattening) occurs. This is done carefully and slowly, a little bit at a time. The wing on the Mustang II is thin and has a fairly sharp leading edge, which makes the onset of a stall relatively sudden, compared to a Piper or RV wing. A little rounding of the outer leading edge will delay the separation of airflow, leading to a lower stall speed. Of course, a more rounded leading edge has more drag and causes a slight decrease in top end speed. One must seek a careful compromise. I am willing to sacrifice a couple of knots of speed for a plane that breaks straight ahead on stall. If I had built the wings perfectly, I am sure that I would not have this problem. There is probably a slight difference in the twist (washout) or dihedral between the wings. The fix is pretty easy, all things considered. The wing drop was much less severe on the second flight after an initial round of flattening. I worked on the right outer leading edge some more this weekend and expect to see it nearly perfect on the next flight. This is why they call these airplanes EXPERIMENTAL. =20 ________________________________ From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bob Perkinson Sent: Tuesday, March 31, 2009 5:59 PM To: Rotary motors in aircraft Subject: [FlyRotary] Was; Video of First Flight - Mustang II Now: HOW DO THER DO THAT =20 Bob Not knowing how the Mustang wing is built I am curious as to how you are changing the leading edge airfoil? Could you give a little more detail, or post a link to an explanation of this procedure.=20 Curious Minds Want to Know Bob Perkinson =09 =09 =09 Bill, =20 I came a little faster on my second landing (second flight) and greased it on. I am using the fix published by the Mustang II designer, Bob Bushby, in an early newsletter, which is to make the leading edge of the outer 1/3 of the wing that drops - more round, i.e. not as sharp. This allows the air to flow over the leading edge more easily at higher angles of attack without separating from the wing and lets the wing keep flying longer. After my initial re-work effort, the right wing drop at stall was much less severe on the second flight and the plane more stable leading up to the stall. The right wing still drops first, so I plan to continue rounding the outer leading edge of my right wing per Bob Bushby's method until both wings stall at the same time. =20 The radiator and oil cooler are located between the engine and the firewall, much like the Powersport installation http://powersportaviation.com/rv-6a_n225ps.htm Here is a link to my engine installation before the baffling was installed that forced all air to pass through the radiator and oil cooler before exiting the engine compartment. http://www.eaa1246.org/big_photo.asp?id=3DTurbo%2Ejpg =20 Bob =20 ------_=_NextPart_001_01C9B3E0.4E546610 Content-Type: text/html; charset="us-ascii" Content-Transfer-Encoding: quoted-printable

The designer and original = manufacturer of the Mustang II kit, Bob Bushby, is the one who published the procedure, = which is to protect the leading edge with masking tape to avoid scratches and = tap on the outer leading edge with a rubber (or other soft) mallet repeatedly = until a measurable rounding (or flattening) occurs.  This is done carefully and = slowly, a little bit at a time.  The = wing on the Mustang II is thin and has a fairly sharp leading edge, which makes = the onset of a stall relatively sudden, compared to a Piper or RV wing.  A little rounding of the outer = leading edge will delay the separation of airflow, leading to a lower stall = speed.   Of course, a more rounded = leading edge has more drag and causes a slight decrease in top end speed.  One must seek a careful = compromise.  I am willing to sacrifice a = couple of knots of speed for a plane that breaks straight ahead on stall.  If I had built the wings = perfectly, I am sure that I would not have this problem.  There is probably a slight difference in the twist (washout) or = dihedral between the wings.  The fix = is pretty easy, all things considered.  The wing drop was much less severe on the second flight after an = initial round of flattening.  I = worked on the right outer leading edge some more this weekend and expect to see it = nearly perfect on the next flight.  = This is why they call these airplanes EXPERIMENTAL.

 

From: = Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Bob Perkinson
Sent: Tuesday, March 31, = 2009 5:59 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Was; = Video of First Flight - Mustang II Now: HOW DO THER DO = THAT

 

Bob
Not knowing how the Mustang wing is built I am curious as to how you are changing the leading edge airfoil?  Could you give a little more = detail, or post a link to an explanation of this procedure.
Curious Minds Want to Know

Bob Perkinson



Bill,

 

I came a little faster on my second landing (second flight) and greased it on.  I am using the fix = published by the Mustang II designer, Bob Bushby, in an early newsletter, = which is to make the leading edge of the outer 1/3 of the wing = that drops - more round, i.e. not as sharp.  This allows the air to flow over the leading edge more easily at higher = angles of attack without separating from the wing and lets the wing keep flying longer.  After my initial re-work effort, the right wing drop at = stall was much less severe on the second flight and the plane more stable leading = up to the stall.  The right wing still drops first, so I plan to continue rounding the outer leading edge of my right wing per Bob Bushby’s = method until both wings stall at the same = time.

 

The radiator and oil cooler are = located between the engine and the firewall, much like the Powersport = installation http://powersport= aviation.com/rv-6a_n225ps.htm

Here is a link to my engine = installation before the baffling was installed that forced all air to pass through = the radiator and oil cooler before exiting the engine compartment.  =  http://www= .eaa1246.org/big_photo.asp?id=3DTurbo%2Ejpg

 

Bob<= /o:p>

 

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