Posted on 06/19/2002 3:07:44 PM PDT by Shermy
WALKER, CA (AP) -- There's a new development in the fatal crash of a firefighting air tanker in the Sierra Nevada.
The Associated Press has learned that the 1956 C-130-A transport plane owned by the Wyoming-based Hawkins and Powers Aviation Incorporated had undergone earlier repairs to fix wing cracks.
The air cargo plane under contract with the Forest Service had just completed a pass over a 10-thousand-acre blaze yesterday when its wings snapped off and the fuselage plunged to the ground, bursting into a fireball in the town of Walker, California.
A government document obtained by A-P today shows that Hawkins and Powers notified the Federal Aviation Administration in April 1998 that an inspection discovered two one-inch cracks in the surface or "skin" of one of the wings of the plane made by Lockheed.
A company official said from Greybull, Wyoming tonight that the damage was repaired and no problems had been reported since in the 46-year-old plane. The air tanker passed its last major inspection in October.
Dianne Nuttall, an administrative assistant there, said, quoting now, "All I can tell you is there were some wing repairs done to the aircraft. I don't know the extent of that."
Nuttall says company mechanics did regular inspections but the last major 300-hour inspection was done in October 2001 and there were no problems.
Hawkins and Powers notified the F-A-A of the wing cracks in a "Service Difficulty Report" describing the small cracks near a rivet hole on the bottom of a wing.
The company's only accident listed in a National Transportation and Safety Board database is a 1999 hard landing of a helicopter during coyote research in Utah. The company owns six C-130s and 22 other aircraft.
An National Transportation Safety Board investigator said at the crash scene today that a television station's videotape of the tragedy may help provide some clues in determining the cause.
George Petterson says he's never seen "near-simultaneous wing failure" before, as appears to have been the case here.
The National Interagency Fire Center grounded the other six C-130-As the Forest Service has under contract to fight fires nationally among its fleet of 43 airplanes, pending a review of the cargo aircraft.
Nevada Congressman Jim Gibbons is a pilot who flew in the Vietnam and Persian Gulf wars and has about 1,000 hours' experience flying C-130s.
He says it was shocking to see the wings break off in mid-air. He says it will be important to investigate obvious potential causes, such as a stress fracture or metal fatigue.
The plane was fighting a blaze north of Yosemite National Park. Investigators were trying to determine if a practice campfire set by Marine trainees started the blaze Saturday. The fire has grown to about 15-thousand acres and fire officials fear it will burn as much as 50,000 acres before it is contained.
The victims were identified by the Mono County, Calif., sheriff's department as 42-year-old pilot Steven Wass of Gardnerville, Nevada... 36-year-old co-pilot Craig Labare of Loomis, California and 59-year-old crew member Michael Davis of Bakersfield, Calif.
AP News Alert (Three crewmen dead in crash of air tanker near Yosemite)
As previously posted by mhking.
Crashed Air Tanker Had Wings Repaired
But not very well.
Overload failure. If it was a stress crack one wing would have failed. Most likely there would not be the same stress crack on both wings so as to make them both the same strength.
On airplanes in the "Normal" catagory full deflection of the elevators will pull the wings off if the aircraft is above manuvering speed.
If the pilot tried to pull out of a dive too fast that is what will happen. Both wings overloaded to failure.
Seems simple enough -- Stress of loaded flight + weakened spars = failure and crash. Sad.
I don't see where skin cracks could have caused this (yeah, the skin bears some loads but most are borne in the spar). The AP guy is snapping at morsels he can't digest. The skin cracks, though, may have been speaking to us about the overall condition of Tanker 130.
One thing we don't know is whether the craft struck anything. Or might have beeen about to (control overload). However in the video it appeared nearly level. The right wing did separate first but they both started failing simultaneously (it appears).
Each part of a transport has an expected service life. For a standard C-130 outer wing that life is 12,500 hours. Source.
The center wing box has a service life which depends on severity of loads, but baseline (i.e. not accounting for high stress low level flight) 40,000 to 60,000 hours. The typical military 130 flies from 450 to 600 hours a year. The military C-130E fleet is nearing obsolescence (or rebuild) at almost 20,000 hours on average. Source.
Things aren't automatically replaced when the hours come up because these planes (in AF or commercial service, no difference) are subject to stringent inspections... when something fails (or gets close to failing) on an inspection it is replaced. But the USAF and other C-130 operators use this as a guide to planning upgrades and maintenance.
d.o.l.
Criminal Number 18F
Maneuvering speed goes up with weight of the aircraft (as you move closer to critical alpha).
We'll have to wait and see. Certainly by the start of the video the crew had no chance of survival.
d.o.l.
Criminal Number 18F
But not very well
Well, they've got a live witness, at least:
In Reply to: Cannon C130 Crash
posted by Mark R. Beadle
on June 18, 2002 at 03:11:08<
I flew in that airplane back from Mexico several years ago with a cracked wing. Cracking in the wings has been an ongoing problem for several years now. I helped replace two wings on that airplane, and assisted in the ultrasonic testing of the structure externally, and inside the tanks. I spent a lot of time in that airplane.
I'd agree that it doesn't sound likely that skin cracks are the cause, at least at first glance, but they could be indications of alclad corrosion or the result of skin wrinkling caused by other mechanical problems- I suspect it may be a symptom rather than the cause.
But I'd bet that the AP guy got his theories on the skin cracks either from here- the report on the crash of Tanker 82 in California in 1994- when the wings came off a previous C130A air tanker, or from military C130A crash report analysis.
We'll see if they write this one off as frayed electrical cable arcing/fuel tank leak, or swamp gas, or whatever the most recent protocol calls for.
You happen to know if the C130 in which the Army Golden Knights went down in back around 1959 or '60 was a C130 A or a B model? As I recall, that was one of the first C130s to have the wings come off, but that's been a long time back, and Tiny McKee is no longer around to recall the details. He died in Pan Am 103 over Lockerbie.
-archy-/-
Khe Sanh? There's a fair chance that the bird could have been one of those that flew the Belgian Paras into Stanleyville during *Operation Dragon Rouge* back in 1965....
Many of the aircraft used by firefighters are as old or older. It is common to see recip C-1's and even Constellations. It seems to be the nature of the business to not have the money to invest in newer A/C.
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