CC... I suppose he is thinking of the crash(es) from hydraulic system failure due to line leaks in the nacelles... but those were due to chafing and vibration, and had nothing to do with the rotating joint.
A quick re-routing and proper securing of the lines against movement and that was fixed.
In that particular case, it also didn't help that a number of operational procedures weren't followed (including the decision to fly non-stop from Eglin to Quantico). In fact, the aircraft itself gave two warnings enroute, one of which dictated an immediate landing, which wasn't done (remember, it can land like a heloicopter). The leaks continued and when the nacelles passed through 44 degeres as they were tilted, proprotor gearbox fluid ran into the intake, ignited, and the gearbox started coming apart; the right engine surged and failed. The crosshaft functioned as advertised and the left engine began powering both proprotors. However, the intense heat and fire led to a failure in the shaft which then led to a hydrualic leak preventing control of the nacelles.
One of the probable causes was considered to be maintennace errors at Eglin resulting in incorrectly installed seals. So, while the tilting of the nacelles allowed fluid to run into the intake at that point, given what was going on, it's quite possible that something similar would have happened anyway had the aircraft remained in the air longer. In other words, it wasn't the fact that the nacelles tilted that caused the accident.
As you said, rerouting of lines, plus a titanium shield prevent a recurrence, but an incorrectly installed seal is still an incorrectly installed seal. Doing it right remains vital. Another Osprey was lost on its first flight because part of the flight control system was wired backwards, and so the aircraft would do the opposite of the commanded input!
Last edited by Commando Cody; 22nd Apr 2013 at 19:03.
Reason: spelling