Cessna C337 SID

[skymstr02]

Originally Posted by tropical

Yes you can delineate it. Separate by O-2, 336 and civilian 337. It's not a matter of "exclusion" but rather model. And it's a known fact the O-2's lived a harder life and also had wing hard points.

What I'm saying is that some civil registered 337's may have experienced the same stresses that an O-2 has. If you are not the original purchaser from Cessna on your aircraft, you do not know what kind of stresses have been accumulated on the airframe. i used to work on a 337G, N200ZF, that was a fish spotter. It had a 175 gal fuselage fuel tank to give it 22 hour endurance. It was not uncommon for that airplane to take off at 6100 lbs, and seven leg it from Houston to Cape Town South Africa. What kind of stresses have been placed on that wing structure?

Fatigue is cumulative on aluminum and it doesn't matter if Lt. Hamfist or commercial pilot Hamhand is at the controls.

O-2A wings are different from 337 wings, as there is additional structure on the rear spar to absorb the firing loads from the hard points. The wing spars and center carry thru spars are also physically larger than its civillian cousins. Even the wing attach bolts are two sizes larger than its 337 counterpart. An O-2 wing will not mate up to a civil fuselage.

There's no way that a prudent engineer could simply dismiss a portion of the population just because if was never in military service.