Osprey crashes leave open wound with flights to resume soon

Amber Sax’s frustration grew each time she saw a new report of a U.S. military Osprey aircraft crashing over the past two years, often taking service members down with it.

Sax, the wife of Capt. John Sax, who was among five Marines who died in a 2022 crash in California, decided earlier this year that she had to do something about it. She joined others in a lawsuit against the manufacturers of the Osprey, formally called the V-22, accusing Bell Textron, Boeing and Rolls-Royce of failing to address known issues with the aircraft.

Amber Sax, who is raising two children, said she was worried that other families could lose their loved ones in an Osprey.

“And so that also carries with it some additional grief, and even just trauma in general, of living in fear that this could happen to another family and wondering if everything is being done to prevent it,” she said.

“It's scary if another Osprey were to go down, and it were to be the same cause,” she continued. “I want to know that I did everything I could to speak up and make noise.”

The Osprey, flown by the Marines, Navy and Air Force, has crashed or been involved in an accident dozens of times, killing more than 60 people since it was rolled out nearly 40 years ago.

The latest deadly crash, near Japan in November 2023, killed eight U.S. service members, forcing the Pentagon to ground the fleet for months before lifting the order, with a plan to fully resume flights in spring 2025.

Another crash this November, a minor accident in which no one died, temporarily grounded flights again. It bore similarities to the Japan crash.

But the Pentagon is adamant that the Osprey is safe and has continued to operate it despite mounting public concerns from family members, experts and lawmakers.

On Capitol Hill, the House Oversight and Accountability Committee is investigating the controversial aircraft and its propensity to crash. And Democratic senators recently urged the Pentagon to ground the Osprey after an Associated Press investigation found that safety issues with the aircraft have spiked over the past five years. The federal watchdog group the Government Accountability Office is also investigating the aircraft.

The Hill examined several mishap reports, spoke with multiple experts and reviewed key crash data on the Osprey that underscores its troubled history.

While there does not appear to be one common fault in the Osprey crashes that stretch back to the early 1990s, the aircraft has unique problems that are not found in many other similar aircraft operated by the U.S. military, raising questions about whether it can ever overcome those issues.

“There are long-standing safety issues that have never been addressed,” said a congressional staffer who spoke on the condition of anonymity. “The fact that they're still having problems with them crashing 20 years or so after it became operational is significant.”

“There are multiple design flaws in the aircraft,” the official continued. “This is not a broken widget or gadget, this is a fundamental design flaw.”

The Hill reached out to the Pentagon’s V-22 office and the two military services that have seen the most crashes, the Marines and the Air Force Special Operations Command. None of them provided comment for this article.

A troubling history

When it was unveiled in the late 1980s, the Osprey was touted as a hybrid aircraft that can take off and land like a helicopter and fly like a plane.

Its birth reportedly came out of the 1979 Iran hostage crisis and the failure of Operation Eagle Claw, as the military weighed whether a more versatile aircraft could have helped secretly transport hostages out of Iran.

The promise was that it could navigate harsh environments much faster and longer than a helicopter, helping troops move quickly into and out of combat zones, with enough space to seat up to 24 people.

However, it faced skepticism from the start, with then-Defense Secretary Dick Cheney looking to cancel the costly program in the mid-1980s.

Prototype aircraft crashed in 1991 and 1992, the latter of which caused seven fatalities. It crashed twice in 2000, killing 23 service members.

Still, by 2007, the Osprey had been cleared for combat deployment.

There have since been deadly crashes all over the world: Morocco, Hawaii, Australia and Japan twice.

Since 2022, Ospreys have crashed in fatal incidents four times, including the California crash that killed Sax’s husband, the son of retired Los Angeles Dodgers player Steve Sax.

“Anytime an aircraft goes down, it's like the world freezes again,” Amber Sax said. “Everything stops again, and it brings back memories from that day, knowing what those family members are going through.”

The Marines plan to fly the Osprey at least through 2050.

What’s to blame?

The $78 million Osprey stretches 57 feet long and 22 feet high. There are more than 400 Ospreys that have collectively flown more than 750,000 flight hours.

The Osprey is a tiltrotor aircraft, meaning it uses powered rotors on top of a fixed wing to lift vertically like a helicopter, and those rotors are then angled horizontally during flight to operate like a plane.

The large rotors, run on two powerful engines, make it more vulnerable to “rotor wash,” or a powerful downward swing of air. A 2012 crash was attributed to powerful downwash from one Osprey that forced another to crash.

The Osprey is hard to fly, especially if the aircraft enters a vortex ring state (VRS), a condition that affects helicopters and forces them to lose lift when entering their own downwash. Researchers have found that the Osprey can struggle with VRS more suddenly and more violently than helicopters, but the issue can be overcome with experience and training.

In recent years, experts have wondered if the gearbox is to blame. The 2023 Japan crash cause was traced earlier this year to a crack in a gearbox part and pilot error, because the pilot ignored warning signs that the aircraft was failing.

The full investigation said a part of the proprotor gearbox, known as a pinion gear, had cracked and was the contributing factor to the crash, though the Air Force does not know why it failed.

A November crash in New Mexico had a similar fault with a crack in the gearbox.

The Hill confirmed the U.S. military is now putting restrictions on Ospreys with proprotor gearboxes that have flown for a a lower number of flight hours, reportedly to get at the problem sooner.

The Associated Press reported 609 proprotor gearboxes have been removed for repair in the past 10 years and the military has reported 60 incidents involving the gearbox.

The gearbox is the aircraft’s transmission and contains five pinion gears that spin to send energy from the engine to the Osprey’s masts and rotor blades.

The 2022 crash that killed John Sax was attributed to dual hard clutch engagement (HCE), which created a gearbox malfunction and drive system failure. HCE, when the clutch dis-engages and then reengages, has also been listed as a recurring problem.

To date, the Pentagon and manufacturers don’t know what the cause of HCE is, but it is one part of a Government Accountability Office (GAO) investigation.

“The hard clutch engagement has definitely been a present and contributing factor to accidents,” an official familiar with the matter said.

The person added that the GAO is looking at a wide range of issues, including human error, environmental and mechanical issues.

“The causal factors are typically associated with human factors more than they are mechanical factors, and so it would not be surprising to see that there's some percentage of the accidents that have occurred with the Osprey that are more human-factor related,” the person said.

Several mishap reports The Hill reviewed have blamed pilot error, a conclusion that families of the victims have often been resistant to accept. Amber Sax said she was upset that some reports have listed pilot error as the reason for a crash.

A loss of power in either of the engines creates serious challenges for a pilot. The gearbox is meant to ensure that one engine at least can keep the aircraft flying, but a clutch problem can cause a failure to switch the transmission.

There has been some speculation that a common failing part is the input quill assembly connecting an engine to the drive system. This issue was identified in the lawsuit this year for the 2022 California crash.

A 2010 crash in Afghanistan that killed four could not find a clear contributing fault for the mishap, but the accident investigation board president determined that “an unanticipated high rate of descent and engine power loss” were contributing factors.

Vice Adm. Carl Chebi, commander of Naval Air Systems Command, said at a House Oversight hearing on the Osprey earlier this year that there’s been 22 known HCE events over the aircraft’s lifetime.

“The failure mode that we are seeing is called a wear-out mode, over time the clutch wears out and has a higher susceptibility to slipping,” he said.

Supply chain issues are also persistent. The GAO has previously found issues with parts and maintenance for the Osprey, and there are concerns that at least one supplier, Universal Stainless, has provided alloys that have weakened and failed over the years.

Ivan Eland, a defense analyst and senior fellow at the Independent Institute, said the Osprey crashes are a “symptom of a larger issue with the defense industrial base because there's not much competition.”

“There's so many regulations and so little competition,” he said. “The whole system is messed up.”

Debate over crash rates

Although the Osprey’s crashes have sparked concern for years, the Marines and other military officials who operate the aircraft have argued it is actually safer than other similar types.

But an analysis of Air Force crash rate data shows that the Osprey has an average class A mishap rate — meaning the incident results in severe damage or fatalities — of 6.23 over its lifetime. That’s higher than the Black Hawk helicopter, the best available comparison, which has an average of 3.52.

The Osprey has an average fatal rate of 2.97, but it only has around 5,600 average annual hours, compared to the Black Hawk’s 6.50 at more than 21,000 annual hours.

The Osprey has largely been involved in accidents outside of combat zones. The Black Hawk is more frequently in combat, but military officials have said that in general, most mishaps involve training accidents.

The Air Force does not have comparable data for the Chinook, the most similar helicopter to the Osprey, but as of 2019 the Chinook had an average Class A mishap rate of 1.37.

Winslow Wheeler, a former researcher at the Project on Government Oversight who has studied the Osprey over decades, said “the innate design” of the Osprey “is so complex that it's prone to failure and it has high maintenance costs.”

“Never should have been built,” he said. “Too complex, too expensive, too unreliable. The performance is too limited.”

While the Pentagon and the Marines fiercely defend the aircraft’s unique abilities for special and combat operations, Wheeler argued a “properly designed helicopter” could do a better job with less risk.

“Advocates keep on saying it flies like an airplane and lands like a helicopter. Neither statements are true,” he said. “It flies like a slow, sluggish, maneuverable airplane. And lands like an incompetently designed helicopter.”

Bell is currently making a successor to the Black Hawk helicopter called the Valor, which is supposed to be a new tiltrotor aircraft. The Valor makes a critical change that could help a pilot: In flight, the engine does not tip forward, only the rotors do, as opposed to the Osprey, in which the engine leans in as well.

Designs are tricky and often criticized after the fact. But Dan Grazier, senior fellow and director of the national security reform program at the Stimson Center, said the Osprey is such a complicated aircraft it requires a very experienced pilot to “instantaneously respond” when something goes wrong.

Grazier added there are “obvious mechanical design issues with the Osprey.”

“The Department of Defense really owes it to not just the American people but [also] the young men and women who have to trust their lives it to this aircraft,” he said. “It's just important for the DoD to fully explain what the issues are and what steps they've taken to mitigate them, and to explain a clear path forward.”

Families want justice

Despite the widespread concern about the aircraft — and the repeated incidents — the military has no plans to halt the flights. And families of crash victims have few options for recourse.

The lawsuit for the California crash is the most action victims and families have taken yet. It accuses the manufacturers of making “recklessly false statements” for an “unsafe and unairworthy aircraft.”

The victims in the 2022 crash were Sax, Capt. Nicholas P. Losapio, Cpl. Nathan E. Carlson, Cpl. Seth D. Rasmuson, and Lance Cpl. Evan A. Strickland.

In an interview, Timothy Loranger, the attorney who filed the lawsuit, said the manufacturers have known about HCE and the gearbox issues but have failed to address them.

“There's a flaw in the design of the whole system,” he said. “The problem has been known for a long time, and now, all of a sudden they figured it out. So what is it that prompted this [and] ... were enough resources given over to this problem in the past?”

Loranger hopes more evidence will come out in discovery. As to whether the U.S. military knows of the flaws, Loranger noted it can’t be sued because there is a prohibition on civil suits involving active-duty deaths.

Michelle and Brett Strickland, who lost their son, Lance Cpl. Evan Strickland, in the 2022 California crash, said they are frustrated that known issues with the aircraft have gone unaddressed for years.

“There isn't a day that goes by that we don't miss and think of our son,” Michelle Strickland said. “I don't want to see another family go through this.”

Brett Strickland said he wanted “accountability and answers” through the lawsuit after receiving few answers to his questions from a military briefing after his son’s death that failed to include engineers from the manufacturers of the Osprey.

“Just hearing them say 'we know what's happening, we just don't understand why it's happening' ... it stuck with us,” he said. “We can't bring Evan back. What we can do, all we can hope for, is that this will improve the safety and reliability of the airframe.”

For Amber Sax, the lawsuit is the best way to get answers and justice. It was filed near the second anniversary of the crash that killed her husband.

“I want to make sure I get all the answers, not just for me, but for my kids,” she said. “I want to be able to tell my daughters I fought for every answer I could.”