Though the Air Force on Wednesday grounded its fleet of CV-22 Osprey tiltrotor aircraft over safety concerns, the Navy and Marine Corps are continuing to fly their versions.
“The Navy and Marine V-22s are still operational,” Naval Air Systems Command (NAVAIR) spokeswoman Marcia Hart told The War Zone in an email Thursday morning.
The program of record for each variant is 360 for the Marine Corps, 48 for the Navy and 56 for the Air Force, but not all those have been delivered yet. All these airframes largely share the same engines and associated primary systems.
“Naval Air Systems Command and the V-22 Joint Program Office [JPO] have been working with our Bell Boeing industry partners on a known V-22 Aircraft clutch issue. While root cause remains under investigation, we are implementing additional risk mitigation controls to ensure the safety of our Service Members.”
The program office, she said, “continues to communicate and collaborate with all V-22 customers, including allied partners. The safety of pilots and air crews is our number one priority.”
Japan also flies Ospreys.
The NAVAIR review comes in the wake of a decision by Air Force Special Operations Command (AFSOC) on Aug. 16 to ground its fleet of 52 CV-22 Ospreys “due to an increased number of safety incidents,” Lt. Col. Rebecca Heyse, AFSOC Public Affairs Director, said.
The AFSOC grounding decision was first reported by Breaking Defense.
AFSOC commander Lt Gen Jim Slife “directed a safety standdown of the AFSOC CV-22 fleet” because of those concerns, said Heyse.
Since 2017, there have been “four incidents involving hard clutch engagement during flight” with two occurring in the past six weeks, said Heyse.
Heyse told The War Zone that the problems have involved the aircraft’s clutch – located inside the gearbox connecting the rotor to the engine – slipping.
“When that happens, the aircraft, by design, transfers all power to the opposite engine,” said Heyse. That allows the Osprey to fly using one engine.
But sometimes, the clutch re-engages, creating a high-torque transfer back to the original engine, which at that point forces the pilots to immediately land.
The Air Force does not know why this problem is happening, Heyse said.
“In the coming days, the AFSOC staff will work with the Joint Program Office and industry partners to fully understand this issue and develop risk control measures to mitigate the likelihood of catastrophic outcomes. Ultimately, the goal is to determine a viable long-term material solution.”
There have been no injuries to date as a result of this problem, Air Force Capt. Savannah G. Stephens, an AFSOC spokeswoman, said, ”due in large part to the skill and professionalism of our Air Commandos who operate the CV-22. The safety of our Airmen is of the utmost importance, therefore no AFSOC CV-22s will fly until we will determine the cause of the hard clutch engagements and risk control measures are put in place.”
The Marines have known about the clutch issue for years.
“The hard clutch issue has been known to the Marine Corps since 2010, and as such, we have trained our pilots to react with the appropriate emergency control measures should the issue arise during flight,” according to a statement the service published today. “We also remain engaged with the joint program office, NAVAIR engineering, and our industry partners to resolve the issue at the root cause.”
A Marine Corps official told reporters the service has been training its pilots on how to deal with the clutch issue since first discovering it in 2010, according to Breaking Defense.
“The official said since that time, the V-22 program — meaning the Navy, Marine Corps and Air Force variants — have only recorded 15 incidents, and 10 of those incidents involved the Marines. None of the 15 incidents occurred on the Navy’s CMV-22 variant.”
Stephens told The War Zone that the command “has been in close communications” with the NAVAIR JPO about the decision to ground its CV-22 fleet “and will continue to share information for their awareness.”
It is worth noting, she added, that the CV-22 Osprey variants flown by AFSOC differ from the ones flown by the Navy and Marines. In addition, she pointed out that their operating environments and mission profiles differ from AFSOC’s as well.
We asked AFSOC if the problems discovered with its CV-22 fleet might cause it to open new accident investigation boards on the incidents involving the clutch problems, or whether it will reopen previous investigations into crashes – like one from April 9, 2010 near Qalat, Afghanistan, that killed four people and injured 16 of the 20 onboard.
AFSOC could not immediately answer those questions, and we will update this story when they do.
This is just the latest in a long series of problems for the Osprey.
There have been two fatal crashes this year, one in California in June that killed five Marines and one in Norway in March that killed four Marines.
Capt. John J. Sax, 33, of Placer, California, Capt. Nicholas P. Losapio, 31, of Rockingham, New Hampshire, Cpl. Nathan E. Carlson, 21, of Winnebago, Illinois, Cpl. Seth D. Rasmuson, 21, of Johnson, Wyoming and LCpl. Evan A. Strickland, 19, of Valencia, New Mexico, were killed in the June 8 crash in Imperial County, California.
No cause has yet been determined.
Earlier this week, the Marines ruled the MV-22 crash in Norway on March 18 was caused by pilot error.
“Analysis of the recovered aircraft data shows the aircraft, while maneuvering within the valley, made a left turn at 68 degrees angle-of-bank … followed by an overcorrected maneuver with a right turn in excess of 80 degrees from which the aircraft could not recover,” a Marine Corps statement explained, adding that the Osprey is rated to bank a maximum of 60 degrees.
The four Marines killed were Capt. Matthew Tomkiewicz, the aircraft commander; Capt. Ross Reynolds, the co-pilot; Gunnery Sgt. James Speedy, the aerial observer; and Cpl. Jacob Moore, the crew chief.
In 2019, the Pentagon’s top watchdog released a report offering new details and insights into the Navy’s struggle to resolve long-standing issues with the Engine Air Particle Separators, or EAPSs, on U.S. Marine Corps and U.S. Air Force V-22 Ospreys. This includes the revelation that there was never any requirement for the EAPS design to meet specifications from Rolls-Royce, the manufacturer of the aircraft’s two engines, to ensure proper operation in all desert conditions.
We went into great depth about that report, which you can read here.
The Osprey program has a particularly controversial safety record tracing all the way back to the very beginning of the program in 1981 and that the aircraft had to go through a major redesign process before actually entering service. Since then, it has performed better in terms of safety than many critics had predicted.
It is not known yet how long the Air Force CV-22 grounding will last, or whether NAVAIR will institute one for the Navy and Marines.
We will keep you up to speed as this story continues to develop.
Contact the author: howard@thewarzone.com