At approximately 1715L on June 28, while hovering over the flight deck conducting interaction testing with Osprey No. 10 turning on Spot 9, Osprey No. 22 experienced a componenet failure in the right nacelle. The pilots landed and secured the aircraft. The initial evidence pointed to a failure of the right hand nacelle blower, which cools drive system components. Following normal protocol, HX-21 classified the incident as a Class B mishap (damage cost between $200K and $1 million).

Initial engineering investigation revealed like wear on several other blowers, and as a result, the blowers will be changed once they reach 100 hours of use and every 100 flight hours thereafter until either additional investigation mitigates the periodicity or the blower design is changed. In either case, there should be no near-term impact to developmental or operational test. The full investigation will take some weeks to complete. In the meantime, V-22 flight operations continue.

In spite of the incident, the shipboard suitability period was deemed a success and included several firsts:

- First time V-22s landed on Spots 5 and 6.

- First time for V-22/V-22 interaction testing (roll-on-deck phenomenon fixed).

- Envelope expansion operating from Spots 2 and 4.