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KING-56 CRASH Follow-Up |
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Click here to view the original King-56 crash cover story and the navigator to all 18 documents associated with it. |
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News Navigator |
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According to the July 16 Air Force memo, engine problems caused by high-frequency radios are so dangerous on C-130s that aluminum shields, called stovepipes, were placed around their antenna cables to reduce the incidence of "spurious" electrical signals. Inspection of the aircraft in Colorado revealed that the radio's antenna cable had broken and burned at holes in its protective shield. That means the "stovepipe can't perform its intended function," the Air Force |
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Photo: Brent Hirak |
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Recurrent Problems By Bob Young, byoung@wweek.com Months after the investigation into the King-56 crash was completed, Air Force C-130s continue to experience the same kind of engine problems suspected of causing the crash that killed 10 Air Force reservists from Oregon in November 1996. An Air Force memo obtained by Willamette Week details the problems behind a recent C-130 engine failure--or rollback--in Colorado. The memo is significant because it describes the first rollback to occur since the King-56 probe, makes it clear that C-130s are still plagued by chronic electrical failures, and says the problems can't be entirely fixed. "This is a far more complete report than anything we've seen," says Bill Galbreath, an attorney for several of the King-56 widows who was shown the memo by WW. "And it shows the Air Force still doesn't know all the causes of the rollbacks." The memo does, however, make it clear that the problems in Colorado were probably linked to a device known as a synchrophaser, a computerlike instrument that controls C-130s' four engines. Many people suspect that a faulty synchrophaser caused the King-56 crash. Air Force investigators, however, have continued to rule out that theory ("Why Did These 10 Men Die?" WW, June 18, 1997). Details of the latest incident documented by the July 16 Air Force memo, which was sent by a safety officer to Air Force bases around the country and obtained by WW last week, are as follows: Shortly after taking off from Peterson Air Force Base in Colorado in early May, a C-130 experienced signs of engine failure similar to those that endangered the King-56 crew: torque, turbine inlet temperature and RPM all dropped suddenly and precipitously on three of the four engines. Recognizing the problem--perhaps because of two safety bulletins issued in the wake of the King-56 disaster--the crew quickly disconnected the plane's four propellers from their electrical controls and saw full power return to the engines. When the plane landed safely, the maintenance crew removed the synchrophaser. The plane's four engines then returned to normal performance. What caused the apparent malfunction in the synchrophaser? According to the memo obtained by WW, it's most likely one of two things: First, it could be a voltage spike caused by the plane's high-frequency radio. "HF radio problems over the years have been identified as a source of rollbacks due to electromagnetic induction (EMI) into the synchrophaser," the memo confirms. That's exactly what Maj. Walt Mulder, an Air Force pilot based in Portland, pointed out to Air Force officials probing the King-56 crash; but chief investigator Col. Larry Landtroop dismissed Mulder's testimony as irrelevant. Galbreath, the widows' attorney, says, "Obviously, this memo raises a lot of questions about [Landtroop's] report." The other possibility--uncovered by further troubleshooting on the Colorado plane--is that circuit-breaker contacts and connecting wires in the vicinity of the synchrophaser were faulty. "Our electrical experts asserted that it was possible that electrical arcing between the loose [circuit breaker] contacts...could have also caused a power rollback," the memo states. The memo goes on to note that C-130s have "had these rollbacks for many years and modifications have been performed to help alleviate this serious condition." But although the modifications have probably reduced the number of rollbacks, the memo says they have not been able to "eliminate them entirely." The Colorado incident is the 59th multiple engine failure on an Air Force C-130 to be documented since 1986 and the 20th linked to synchrophaser problems. The July 16 memo says it's impossible to eliminate the risk of continued engine failures in C-130s because the "very design of a system that has one [synchrophaser] controlling or interfering with the operation of all 4 engines opens the door for problems such as have been experienced." The memo ends with two recommendations: that antenna shields for all C-130 radios should be examined; and that all C-130 units should inspect the circuit breakers surrounding the synchrophaser. The Air Force couldn't answer questions about the memo before WW's press deadline. The Portland Air Base referred all questions to Robins Air Force Base in Georgia. Maj. Joan Strong at Robins AFB said the Air Force would have answers later this week. Galbreath concludes that the memo supports his belief that the synchrophaser is responsible for the mysterious failure of King-56's four engines. "Again it all goes to the synchrophaser," he says. "It's a device that's not needed to fly the airplane and can interfere with all four engines beyond the control of the pilot." |
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