Forest Service says fatigue caused wing to fall off airtanker
April 23, 2003
WASHINGTON — An airtanker fighting a Colorado forest fire last year erupted in flames and crashed because of a crack that started at a half-inch rivet on its left wing and spread, according to a Forest Service investigation.
It was almost identical to the failure that caused the crash of another tanker fighting a fire near Walker, Calif., a month earlier, killing three, said Dan Hawkins, president of Hawkins & Powers Aviation Inc., which owned both planes.
The Forest Service report obtained Tuesday identified the cause of the Consolidated Volte PB4Y-2 crash as fatigue and failure of the left wing’s forward spar, a unit that helps hold the wing to the fuselage. The crash killed pilot Rich Schwartz and co-pilot Milton Stollak.
After the crashes, the remaining PB4Ys and the Lockheed C-130As were grounded. The Forest Service has not renewed the contracts for either model of plane, believing they pose an unacceptable risk.
Both planes were old — the PB4Y was 57 years old and the C-130A was 45 years old — and had been flown long hours in brutal conditions during last year’s severe fire season.
“It has been bone-rattling, teeth-tearing-out rough,” a pilot who had been flying alongside the PB4Y-2 when it went down told investigators. “Just beating us up every day, all day long. We’ve been flying, flying, flying, flying, flying.”
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On the evening of July 18, 2002, however, skies were calm. The plane was making a gentle turn when the pilot, whose name was withheld by the Forest Service, saw the wing rise and separate.
“To have an airplane that we’ve always considered to be absolutely bulletproof, the 4Y, just shed a wing, everybody’s going, ‘My word, what is this all about?”‘ the pilot said. “It’s telling me that this retardant dropping is hard, hard, hard on airplanes.”
The Forest Service report was obtained under the Freedom of Information Act. Reports by the National Transportation Safety Board and Federal Aviation Administration have not yet been released. Last September, the NTSB said fatigue cracks caused the wings to shear off both planes.
On the Net:
Forest Service: http://www.fs.fed.us
Hawkins & Powers: http://www.hawkinsandpowers.com