I've been a professional pilot for about a decade, now, and I seldom fly without my trusty Olympus OM-2n. It's been all over the world with me for more than 20 years. I also do nature photograhy, so between airplanes and 4WD's and backpacking into the most remote places, I can hardly complain about the camera's ruggedness and reliability. I primarily fly turbine and jet equipment now, so vibration isn't the problem it once was, but big and fast lenses are the order of the day. I seldom use a focal length shorter than 135mm for aerial work and f2.8 or bigger helps keep the shutter speed up. There are occasions for wider lenses, I just don't see them very often. On the ground, however, my 24mm is pretty much my favorite lens. Under the circumstances, depending on exactly what kind of aerial work your friend wants to do, he might be better served by going with the Nikon (or similar) and taking advantage of the cost savings by getting a bigger arsenal of lenses. As previously stated in tis thread - the operating environment of a piston aircraft is certainly no harsher than driving down a gravel road or hundreds or other situations that all kinds of cameras put up with every day. Tell your friend "good luck!" There's quite a learning curve involved with aerial photography; after all this time I think I'm still on the beginning part of it. :-)

Bruce