Fresh tech hiccup for V-22 (Osprey) tiltrotor fleet

[FarCenter]

The famous V-22 Osprey tiltrotor, which flies like a plane but tilts its props upwards to land and take off like a helicopter, appears to have hit yet another technical snag.

The troubled military combo-copter, which suffered through a decades-long and accident-prone development to finally go operational in Iraq last year, has now been subjected to a fleet-wide safety grounding. This followed the discovery of loose bolts rattling about in an engine nacelle on an Osprey after landing at the US air base at al-Asad.

The bolts, according to reports, had fallen out of the "swashplate" in the propellor hub. The swash plate on a helicopter or tiltrotor is used to convey control inputs from the pilot into the spinning rotor disc. Should it break loose, a complete loss of control would result.

After the initial discovery, other Ospreys in Iraq were found to have loosened swashplate bolts and the entire fleet was grounded as a precaution. Initially it was thought that the loose fastenings might have been the result of maintenance failures, but Flight International now reports that at least one further V-22 in America is suffering from the same issue, and that all the affected aircraft are "high-time" ones - that is, ones which have been flown a lot.

<snip> http://www.theregister.co.uk/2009/03/27/swashplate_bolt_snag_hits_osprey/