The Canadian Transportation Safety Board is recommending the FAA and Transport Canada beef up certification standards for small aircraft in light of a study that shows many crash victims survive the impact only to be killed or horribly injured by fires that start after the crash. In a report issued, ironically, a day after Comair Flight 5191 crashed in Lexington (at least some of the 49 who died were believed to have been killed by fire), the TSB says occupants of small airplanes are potentially more at risk from what it calls post-impact fires (PIF) because of the close quarters of the cabin and the proximity of the occupants to the fuel. It wants regulators to impose fuel-system safety standards on light aircraft similar to those adopted for helicopters in 1994. The TSB report says fuel-system technology has come a long way and a lot can be learned not only from the helicopter industry but from the fire prevention systems employed on race cars and on newer vehicles available through the dealer. In the TSB's ideal world, new fuel system standards would apply not only to certified aircraft, but to homebuilts and ultralights. But it also recognizes that it won't be easy. "The implication of design improvements on new aircraft will be significant, and even more significant on existing designs," the report reads.