Cause May Have Been Found, Already

One of the small fleet of V-22 Ospreys came back to Earth more quickly than planned, earlier this week, at the Marine base at Quantico (VA). It's undamaged, as far as we know; but mechanics and technicians are swarming over the troubled bird, trying to figure out exactly what went wrong with, reports say, 'the hydraulics.'

'Hydraulics,' of course, describes a huge load of systems in this plagued system. Since the Osprey's inception roughly 20 years ago, 'hydraulics,' and control systems therefor, have come up as trouble spots more than once.

The machine is inherently complicated; this is exacerbated by the Osprey's need to have as many as three separate hydraulic control systems. If it ever gets sorted out, and all the lines aren't in the same places, the triple system should be plenty safe.

The machine's main-drive tilt-rotor system, designed to take off and land vertically, then pivot into position as as wing, is hydraulically-operated; what would pass for 'normal' flight controls, ditto; and power systems also move a lot of oil -- a 'hydraulic' problem could be nearly anything that isn't a 'computer' problem.

V-22 program spokesmen have told reporters that Monday's problem was not related to hydraulic lines' chafing and defective non-flexible titanium pipes, both of which have been fingered before, as points of potential or actual failure.

No one was hurt in Monday's SNAFU; that news is gratefully received. Two Ospreys killed 23 Marines in 2000, in two separate accidents.

Bell's Official Statement:

On August 4, V-22 A/C #21 made an unscheduled landing during a routine flight over the test range at the Marine Corps Base at Quantico, Va. A backup system was automatically activated and the aircraft completed a routine landing at the airfield at Quantico. The V-22 performed as
designed with regard to pilot warning indications and the backup system action. 

A preliminary check revealed that a clamp holding a hydraulic line filter was not installed as required with the resultant vibrations causing the connection to loosen with loss of fluid to the number two hydraulics system.

The faulty part was replaced and the clamp re-installed and the aircraft then completed a normal flight back to its home base at NAS Patuxent River, Md. This is not a design issue and the missing clamp appears to be a maintenance or manufacturing issue that is under review.

FMI: www.defenselink.mil