Eight times since 2000, the NTSB was unable to determine the cause of a fatal cargo crash, leaving companies and families without closure. Other times, the safety board blamed the pilot, even without the so-called black boxes, which are required on passenger aircraft but not on small cargo planes. The devices typically cost about $20,000 apiece.

"They are far too quick just to blame the pilot and move on," said Mary F. Schiavo, former Inspector General of the U.S. Department of Transportation, now a private attorney. "I've noticed a real trend of blaming the pilots."

IGNORING THE OBVIOUS?

Cargo pilots die nearly once a month on average flying in an industry known for old planes, tight deadlines and overnight flying -- factors that help make it the deadliest form of commercial flight in the United States, a Miami Herald review found.

By nearly always pointing to the pilot, the government has ignored more systemic problems in an industry dogged by safety failings, the newspaper found.

The NTSB is an independent government agency that investigates fatal crashes, concluding a probable cause in each case and suggesting broader reforms to the FAA.

"In every investigation we look at all factors -- theaircraft's history, the pilot's history, the environment -- before determining a probable cause," Acting Chairman Mark V. Rosenker said in a statement to The Miami Herald.

The safety board declined to discuss individual cases, but it defended its overall pattern of citing pilots.

"Who is the last person who could have prevented the accident?" asked Tom Haueter, a pilot and Deputy Director of the NTSB's Office of Aviation Safety. "The vast majority of the time, it's pilot action or inaction that results in the accident."

Schiavo, the former top regulator and one-time aviation professor, draws a different conclusion. "They get blamed unfairly for a lot of things," she said.

The Salmon Air crash is one example.

While the safety board was investigating the crash and ultimately blaming the pilot, records show, it was completing a separate inquiry of the Cessna itself.

Icing on wings is a major potential hazard for cargo pilots flying small planes. In mere moments, icing can accumulate to the point that pilots lose control: If the ice adds too much weight, a plane may not be able to maintain altitude. Just as important, the flaps that control the plane can freeze up.

With these hazards, ice detection systems are vital.