> our title:

USAF Still Doesn’t Know Why Its Block 1 MQ-9s Fail

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USAF Still Doesn't Know Why Its Block 1 MQ-9s Fail (excerpt)

(Source: FlightGlobal; posted March 17, 2016)

By James Drew

WASHINGTON, DC --- The US Air Force says it has avoided 17 more MQ-9 Reapers crashes since last April thanks to a backup electrical system that has been installed as a safeguard against a still-undetermined problem with the starter-generator on the Block 1 version's Honeywell turboprop engine.

Speaking at a congressional hearing on army and air force unmanned aircraft programmes, US Air Combat Command chief Gen Herbert Carlisle says many General Atomics Aeronautical Systems MQ-9 Block 1 crashes have been directly linked to starter-generator failures, resulting in an Electrical Safety Improvement Programme (ESIP) that installs a direct-drive, brushless alternator that keeps the aircraft flying for another 10h.

“Since last April, we have recovered 17 MQ-9s using this direct drive, brushless alternator,” says Carlisle.

The air force has lost dozens of MQ-9s over the years, at a cost of between $20 million and $25 million per aircraft, according to Pentagon documents. Significantly more MQ-1s have been lost in combat and the type will be phased out by 2018.

A Washington Post report quoted by one US lawmaker identified 10 MQ-9 and 10 MQ-1 crashes in 2015, when operations were stepping up against terrorist networks in Afghanistan, Iraq, Syria and across Africa.

“It has generally been centralised on the starter-generator on the MQ-9 community,” says Carlisle. “The new MQ-9s, the Block 5 MQ-9s that we are producing now, have a different electrical system, so it does not have the same starter-generator and does not have the same problem.”

The general says the air force has been working with the manufacturer to identify the problem and uncovered some “quality control issues”. “We have still not found the root cause,” he says. (end of excerpt)

Click here for the full story, on the Flightglobal website.