lml@lancaironline.net Mailing List Archive

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