Commentary
The Osprey’s dismal safety history was once again in the spotlight with the death of eight marines off the coast of Japan in November. And despite not having resolved the issues that caused the crash, the U.S. military resumed Osprey operations in March.
This is not the first time Osprey operations have been resumed with no resolution of the issue(s) that caused a fatal crash. Apparently, the Osprey’s versatility makes it irreplaceable, trumping the fact more than 50 crew and passengers have been killed in crashes.
But is all the hype about its versatility really justified? Can it really do what a helicopter can?
Well for one thing, the Osprey, a tiltrotor aircraft, can’t land safely in fields and other landing sites that are no issue for a real helicopter. And when it comes to search and rescue, a JFCCOM study found that its ability to pull people out of the water is inferior to a helicopter and that it is “ill suited” for search and rescue. It’s very hot exhaust damages ship decks. And its vicious rotor/propeller (proprotor) downwash has interfered with safe landings on ships.
While this has not been widely reported, its problems with heat and gearboxes almost certainly combine to give the Osprey a far more limited ability to hover for extended periods of time than a real helicopter. Its turboprop engines are much more vulnerable to foreign object ingestion than are helicopters. Consequently, if hovering over sand, its hover time is limited to 35 seconds.
The above problems, and others, stem from the fact that a tiltrotor is more mechanically complex than a helicopter and has issues that are unique to it. The first of these issues is that the two proprotors it uses to lift itself vertically have much less lifting surface than standard helicopter rotors and are shaped differently so they can function as propellers as well. Hence, unlike the rotors of helicopters, the Osprey’s proprotors are not optimized for hovering. This means to take off and land vertically they have to spin faster and produce a more concentrated, higher velocity downwash than standard helicopters.
A 2009 GAO report found that the V-22’s “significantly greater” downwash created a plethora of problems that impacted troop debarkation and embarkation, hooking up external loads, and dislodging of equipment and men. In general, the report concluded that the downwash had “various negative effects on land-based missions.”
Exacerbating the high-velocity downwash produced by the proprotors when landing, taking off, or hovering is the very hot downwash that comes from the engine’s exhaust. This very hot exhaust, unlike that of a standard helicopter, points straight down and has a history of damaging decks and runway surfaces. Because there is nothing that can be done to modify the Osprey’s downwash, costly deck modifications have had to be made and/or will have to be made to our amphibious warships, which were designed to support helicopters. Hence, there are many places a helicopter can safely land that an Osprey cannot.
Also, the engines, along with the proprotor gearboxes, tilt-axis gearboxes, proprotor controls, and infrared suppressors, are all housed in the rotating nacelle at the end of each wing. Consequently, when hovering, the engine heat travels back up along the engine into the nacelles. In particular, the extra heat goes into complex gearboxes that have been implicated in a number of incidents, including fatal accidents.
One such incident occurred in June 2022 when Captain John J. Sax, an Osprey co-pilot, reported a problem with an overheating gearbox, and then moments later the Osprey crashed, killing all five aboard. The most recent November 2023 crash that killed eight marines off the coast of Japan is also thought to be a gearbox failure, the proprotor gearbox to be specific.
Given all the above, it is clear that the Osprey is not a very good helicopter; however, with a light load it will be faster and be able to outrange most helicopters. But with medium-heavy to heavy loads, the Osprey’s range and speed drop dramatically, and in some cases it actually falls behind comparably sized helicopters.
Finally, unlike a helicopter, the Osprey is not capable of effective autorotation after losing power, making it much harder to land safely than a helicopter. And at more than $40,000 in operating and support costs per hour, it costs far more to operate than the helicopters and airplanes it is replacing.
Yes, if the takeoff and landing zone conditions are right, the Osprey can get troops to a location that an unrefueled helicopter cannot. But with many military helicopters being capable of inflight refueling, the question becomes does it really make sense to displace helicopters with Ospreys that are not as safe, cost far more to operate, and aren’t really nearly as versatile as their hype might lead one to believe?
Views expressed in this article are opinions of the author and do not necessarily reflect the views of The Epoch Times.
