I gave a talk on Wilderness Survival to a local chapter of aircraft home-builders of which I was a member. (Actually, I gave the talk twice, about a year apart.)

The first time, I put together a fairly large survival kit in a ziplock freezer bag. The major comment I received was that it was too big for most. (Homebuilt aircraft, especially, can be very small - some of them can barely carry the pilot and a set of golf clubs.) Not as much of a problem on a C172, but even there, the 172 won't take off with full fuel and four persons on board, so any weight saving is a bonus.

I've read that Bush pilots in Alaska/northern Canada typically consider their survival gear to be a fixed part of the aircraft. (The weight of the survival gear is included in the "empty weight" of the aircraft.) People down south may not see the need for it as much, so a minimal survival kit is less likely to be left behind.

This is probably going to sound like heresy, but for someone who doesn't live and breathe survival, a Bic lighter is probably a better choice than a BlastMatch. Reason is, it doesn't require any special training or practice.

For the desert, something to rig a shelter from the sun - a space blanket or two - would be invaluable.

The one thing that really got the attention of the pilots I spoke to was the SAS Gem Survival Guide. I pointed out that this would fit in a shirt pocket so there was no reason not to have it on you at all times. Several came up to me after the talk and asked for the ISBN number, or where they could buy it. So pilots are interested in this stuff (except for the guy who fell asleep, but he was killed in a plane crash a year later <img src="images/graemlins/frown.gif" alt="" /> - I don't know if the fact that he fell asleep during my lecture was indicative of his attitude toward safety but I've always wondered.)

Personally, I would always carry a GPS and hand-held aircraft transceiver, and have an ELT on board. The size of the survival kit should be tailored to what your friend is willing to carry. The best survival kit in the world is useless if it's still in the trunk of your car in the airport parking lot.