The FAA "determined that `it would be costly for operators to develop inspection programs' for those operators that were not covered under the rule," Inspector General Zinser wrote. "As a result, a significant number of aging aircraft are not covered under any aging aircraft program."
Researchers at Wichita State University's National Institute for Aviation Research believe smaller operators should be included.
Air cargo pilots "are operating at a higher stress level on a more frequent basis," said Dale Cope, director of the Aging Aircraft Research Laboratory at Wichita State's aviation institute. "That usage puts a lot of wear and tear on the airplane and over time you are going to start developing cracks in areas that are not normally looked at on an annual visual inspection."
Cope said some industry leaders have begun enhanced inspections on older planes, though are not required to.
Yet weaknesses in the aging law remain. The deadly crash of the Chalk's Ocean Airways Flight 101 seaplane off South Beach last December is a case study.
Two months before the crash killed 20 people, the FAA had completed an inspection that found no structural issues. The National Transportation Safety Board later found fatigue cracking evident on both wings.
"Because the inspections are only visual in nature, the inspections will not identify subsurface cracks or hidden corrosion," an Inspector General report said of Chalk's, which was covered under only part of the aging rule and did not undergo the more detailed inspection.
"The Chalk's Ocean Airways accident highlighted the importance of ensuring the structural integrity of older aircraft," Zinser concluded. While the FAA, Congress and aviation industry have made strides in ensuring safety of older planes, he said, real vulnerabilities remain.
An FAA spokeswoman did not respond to Miami Herald requests for comment on the new Inspector General review.
The aviation agency maintains that air cargo operations are safe, noting that fatalities dropped in 2005 when compared to 2000. Zeroing in on those years, the FAA said accidents for small cargo operators "have declined dramatically over the last six years."
Yet records show that the FAA is using selective information to make the case.
Industry death tolls were very high in 2000 and 2001, dipped in 2002 and 2003, then rose again in 2004 to the same level as 2000 before dipping again in 2005, The Miami Herald found. In 2004, the cargo and other on-demand companies' fatal accident rate was 65 times greater than that of larger carriers, NTSB records show - and was the highest it had been since 1996.
Through this August, there have already been more U.S. cargo deaths than all of 2005.