The Marine Corps’ newest Aviation Plan underscored the importance of new sensors to be installed on the V-22 Osprey to better predict when parts need to be replaced to avoid previous incidents.
The document said this new Osprey Drive System Safety and Health Instrumentation (ODSSHI) will install sensors in critical areas of the aircraft’s Proprotor Gearbox (PRGB) and drivetrain “to provide vibration signature data that will allow maintenance to forecast the failure of parts and plan to remove those parts prior to failure.”
It also described that a “more refined Triple-Melt steel” will be the source material for internal components of the PRGB that the service expects will be “material for the internal components of the PRGB which will drastically reduce the likelihood of material defects in critical gears and bearings.”
The V-22 program is also working on a redesigned Input Quill Assembly (IQA) to reduce the “incidence of the wearout mode observed in previous IQA failures that led to aircraft Hard Clutch Engagement (HCE) occurrences.”
On Jan. 31 the Navy awarded the Bell-Boeing Joint Project Office a $46.5 million delivery order for integration and supportability of the V-22 Gearbox Vibration Monitoring/ODSSHI system. It also procures up to 91 ODSSHI kits. The work is expected to be finished by December 2026.
The V-22 has experienced 19 hard clutch engagements that could lead to loss of the aircraft for years. Starting in 2022, there was a jump in serious problems. First, in June 2022, a dual hard clutch engagement led to a fatal crash.
Last June, Vice Adm. Carl Chebi, commander of Naval Air Systems Command (NAVAIR), said that instance led to the V-22 program implementing clutch replacements after 800 flight hours.
Then, last November, eight airmen died in a CV-22 crash off the coast of Japan. Chebi told lawmakers he got data indicating that was caused by a catastrophic material failure not previously seen. He said NAVAIR is replacing engine clutches after 800 flight hours to prevent the previous hard clutch engagement type incidents while also testing a new clutch design.
Currently, the V-22 is operating under flight restrictions and last year Chebi said those were not likely to be removed before the middle of this year.
The Navy and Marine Corps are allowed to fly their V-22s with safety controls like only having flights within 30 minutes of a divert airfield.
Speaking to reporters on Jan. 27, Navy Capt. Andrew Bear, deputy commodore of Fleet Logistics Multi-Mission Wing VRM-30 in San Diego, said they have translated that flight time limitation into 200 miles for the crews, the distance Ospreys can travel when it flies like an airplane. The Navy advertises the Osprey as having a range of about 1,150 miles.
NAVAIR has set a predetermined flight hour threshold for the V-22 gearbox after which they become more susceptible to problems. While Beard did not disclose that, he said the aircraft in his wing are divided into aircraft with gearboxes under and over 400 flight hours.
Beard also noted there is currently a CMV-22B detachment operating off the USS Carl Vinson (CVN-70) and they have worked closely with the ship “to make sure that the ship stays within 200 miles at all times.”
He admitted there are still some days they do not have an opportunity to fly the Ospreys from the carrier based on where it is operating, which “they just incorporate that into their plan.”
Beard said they define a suitable divert field as a “runway with instrument approach, and I think at least 3,000 feet.”
However, pilots have been given some guidance on what that is, they have been trained to know that “if you’re in extremis and there’s a rock and it’s flat, get it done.”
A version of this story originally appeared in affiliate publication Defense Daily.