X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 03 Dec 2008 21:15:23 -0500 Message-ID: X-Original-Return-Path: Received: from imo-m19.mx.aol.com ([64.12.137.11] verified) by logan.com (CommuniGate Pro SMTP 5.2.10) with ESMTP id 3325996 for lml@lancaironline.net; Mon, 01 Dec 2008 18:43:45 -0500 Received: from Sky2high@aol.com by imo-m19.mx.aol.com (mail_out_v39.1.) id q.c54.3d5269c4 (29288) for ; Mon, 1 Dec 2008 18:43:39 -0500 (EST) Received: from SKILLIAC.cust.hotspot.t-mobile.com (m225336d0.tmodns.net [208.54.83.34]) by ciabeta-ma02.mx.aol.com (v121_r4.6) with ESMTP id MAILCIABETAMA022-7268493476aa97; Mon, 01 Dec 2008 18:43:38 -0500 X-Original-Date: Mon, 1 Dec 2008 17:47:50 -0600 From: Sky2high Subject: Re: [LML] Dynamic pressures X-Original-To: "Lancair Mailing List" In-Reply-To: X-Original-Message-ID: References: X-Mailer: Nexus Desktop Client 3.1.20.1 MIME-Version: 1.0 Content-Type: MULTIPART/alternative; BOUNDARY=fdc50454-e42c-4c5d-b95a-a232c9a8cf24 X-AOL-IP: 208.54.83.34 X-Spam-Flag:NO --fdc50454-e42c-4c5d-b95a-a232c9a8cf24 Content-Type: TEXT/plain; charset=us-ascii Ian, Righto.... After my wings were painted, they were set out in the sun behind the paint shop. That same day, as we were transporting the first wing back to the airport, upside down in a van, I was aghast when looking down the skin and seeing enormous bulges between the fuel tank ribs and highly relieved when I pulled the golf tee out of the vent opening with a reassuring ssssssh as the heated air escaped. I was pretty confident there was no leak in that tank and equally impressed with the strength since the wing was built prior to the cap strip technique. Grayhawk In a message dated 12/01/08 17:21:46 Central Standard Time, ian.crowe@sympatico.ca writes: FYI the following are the dynamic pressures at various airspeeds. I presume they are at standard atmospere. 100 knots 0.2351 psi 150 " 0.5290 " 200 " 0.9405 " These are derived from a formula q=0.5rho*v^2 where rho = 0.002377, v =ft/sec, q=#sq ft If you look carefully I think it is in the archives. If anyone wants the full table I could scan it and send it to the list. I tested my tanks for leaks with air at 1.5 psi 40" water and whilst the pressure did vary with the atmospheric, making me think I had a leak at one point, I saw no deformation of the skins at all. I would worry if mouth pressure could distort my skins although I am not sure I know what I would be worrying about. Ian B. Crowe LNC 2 C-FKRO --fdc50454-e42c-4c5d-b95a-a232c9a8cf24 Content-Type: TEXT/html; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE

Ian,

Righto....

After my wings were painted, they were set=20= out in the sun behind the paint shop. That same day, as we were transp= orting the first wing back to the airport, upside down in a van, =20= I was aghast when looking down the skin and seeing enormous bulges between t= he fuel tank ribs and highly relieved when I pulled the golf tee out of= the vent opening with a reassuring ssssssh as the heated air escaped.&= nbsp; I was pretty confident there was no leak in that tank and equally= impressed with the strength since the wing was built prior to the cap strip= technique.

Grayhawk

In a message dated 12/01/08 17:21:46 Central Standard Time, ian.crowe@s= ympatico.ca writes:

FYI the following are the dynamic pressures= at various airspeeds. I presume they are at standard atmospere.

100 knots   0.2351 psi
150   "    &n= bsp;   0.5290   "

200   "    &n= bsp;   0.9405   "

These are derived from a formula q=3D0.5rho= *v^2 where rho =3D 0.002377,

v =3Dft/sec, q=3D#sq ft If you=20= look carefully I think it is in the archives.

If anyone wants the full table I could scan= it and send it to the list.

I tested my tanks for leaks with air at 1.5= psi 40" water and whilst the pressure did vary with the atmospheric,=20= making me think I had a leak at one point, I saw no deformation of the skins= at all. I would worry if mouth pressure could distort my skins althou= gh I am not sure I know what I would be worrying about.

Ian B. Crowe
LNC 2 C-FKRO

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