Return-Path: Sender: (Marvin Kaye) To: lml Date: Tue, 12 Nov 2002 19:36:32 -0500 Message-ID: X-Original-Return-Path: Received: from imo-r05.mx.aol.com ([152.163.225.101] verified) by logan.com (CommuniGate Pro SMTP 4.0.1) with ESMTP id 1861528 for lml@lancaironline.net; Tue, 12 Nov 2002 17:21:31 -0500 Received: from Sky2high@aol.com by imo-r05.mx.aol.com (mail_out_v34.13.) id q.c9.2b898db1 (4320) for ; Tue, 12 Nov 2002 17:21:30 -0500 (EST) From: Sky2high@aol.com X-Original-Message-ID: X-Original-Date: Tue, 12 Nov 2002 17:21:29 EST Subject: Re: [LML] Re: why don't we talk more about how we fly our Lancairs? X-Original-To: lml@lancaironline.net MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="part1_c9.2b898db1.2b02d8e9_boundary" X-Mailer: AOL 8.0 for Windows US sub 75 --part1_c9.2b898db1.2b02d8e9_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 11/12/2002 12:24:24 PM Central Standard Time, harrelson@erols.com writes: > I worry a little bit about the twisting moment on the flaps since the > actuator pushes from the extreme inboard end of the flap. Anybody had any > problem here? Bill, You are correct to worry about the twisting moments. However, the outboard end of the flap is not much larger (in chord) than the ailerons (also activated at one end) and we are quite willing to whip those around at 185 KIAS, 42 kts higher than maneuvering speed. Also, I think that the wing was designed to operate "out of reflex", ergo I don't see that tremendous forces are being applied until you go beyond about 10 degrees. I also like to get the nose down early by extending some flaps so I can see pattern lagards (i.e. everyone else) or fauna on the runway. Frankly, I think the forces on the end of the flaps at full extension and 100 kts (max drag, little lift) are far greater than those at partial extension and higher speed. Maybe someone has strain guages we could experiment with or perhaps Lancair has some flap twisting force vs airspeed data? Caveat - I'm not an engineer and I didn't play one on TV. All the risks anyone takes are their own, chosen in light of God's gift to humankind, free will. Scott Krueger N92EX, the EX stands for experimental - not expert or expired. --part1_c9.2b898db1.2b02d8e9_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 11/12/2002 12:24:24 PM Central Standard Time, harrelson@erols.com writes:

I worry a little bit about the twisting moment on the flaps since the actuator pushes from the extreme inboard end of the flap. Anybody had any problem here?


Bill,

You are correct to worry about the twisting moments.  However, the outboard end of the flap is not much larger (in chord) than the ailerons (also activated at one end) and we are quite willing to whip those around at 185 KIAS, 42 kts higher than maneuvering speed.  Also, I think that the wing was designed to operate "out of reflex", ergo I don't see that tremendous forces are being applied until you go beyond about 10 degrees.  I also like to get the nose down early by extending some flaps so I can see pattern lagards (i.e. everyone else) or fauna on the runway.

Frankly, I think the forces on the end of the flaps at full extension and 100 kts (max drag, little lift) are far greater than those at partial extension and higher speed.  Maybe someone has strain guages we could experiment with or perhaps Lancair has some flap twisting force vs airspeed data?

Caveat - I'm not an engineer and I didn't play one on TV.  All the risks anyone takes are their own, chosen in light of God's gift to humankind, free will. 

Scott Krueger
N92EX, the EX stands for experimental - not expert or expired.

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