The United States last month announced that the MV-22 Osprey transport aircraft will be deployed to U.S. Marine Corps Air Station Futenma in Okinawa as scheduled in October.

The planned deployment has fueled anger among people living in Okinawa, who have long opposed the Futenma base, and Iwakuni, Yamaguchi Prefecture, where the aircraft are to first reach Japanese soil, because crashes involving the planes have raised safety concerns, earning the Osprey, like countless predecessors in aviation history, the nickname “widow maker.”

Following are some questions and answers about the MV-22 Osprey:

What is the Osprey?

The V-22 Osprey is the world’s first operational tilt-rotor transport aircraft, capable of vertical takeoff and landing like a helicopter and relatively fast forward flight like a prop plane. Variants of the V-22 include the marines’ MV-22, the navy’s HV-22 and the air force’s CV-22.

Why are Ospreys being deployed to Futenma?

The U.S. Marine Corps is in the process of replacing its CH-46 Sea Knight helicopters, which are to be retired in 2014. Currently, about 140 Ospreys have been deployed to Marine Corps Air Station New River in North Carolina and at Miramar Air Station in California.

The fast-deployment Osprey will play a major strategic role in connection with the force deployment changes planned for the U.S. military presence in Asia. The changes include deploying marines to Darwin, in northern Australia, and to Guam.

The Osprey are expected to be an indispensable part of the marines’ transport equipment, because the project to develop a next-generation amphibious vehicle has been canceled and one to create a vertical takeoff and landing-capable marine version of the F-35B Joint Strike Fighter has been delayed.

What can the Osprey do?

For the U.S. military, the Osprey is a dream aircraft that provides greater flexibility and capabilities, including flying at higher speeds and offering greater range than the CH-46.

Ospreys have been involved in combat operations in Iraq and Afghanistan and in disaster relief in Haiti.

The standard V-22 has a maximum cruising speed of 275 knots (520 kph), twice that of the CH-46, and with its in-flight refueling capabilities, the aircraft can be launched from carriers out at sea, well beyond the threat of coastal mines.

The Osprey’s operational area is also quadruple that of the CH-46, which has a combat radius of 140 km, barely covering the Okinawan islands.

The Osprey’s combat radius can be extended by as much as eight times farther with aerial refueling, thus any based in Okinawa can reach Osaka, Seoul, Shanghai and the northern Philippines.

In the Middle East, the Osprey’s combat area could cover an area the size of Iraq, Syria and part of Saudi Arabia and Iran if flown from the al-Asad Air Base in western Iraq’s Anbar Province, whereas the CH-46 can basically only operate over an area the size of Iraq.

“If a crisis were to erupt in North Korea, the Osprey would be quicker to respond,” said Narushige Michishita, associate professor at the National Graduate Institute for Policy Studies (GRIPS) in Minato Ward, Tokyo.

How did the Osprey’s development start?

The Osprey has been an expensive project, taking some 25 years to design, build, test and eventually deploy. Development started after the failed mission to rescue U.S. hostages in Iran in 1981 demonstrated that the U.S. military needed aircraft that would give them more options than existing sea-launched assault aircraft.

The initial Osprey program called for production of more than 1,000 aircraft costing less than $40 million each, but the technical hurdles to create the two turboprop engines and rotating nacelles at the end of short, winglike appendages sent the price soaring.

But the helicopter-airplane hybrid has survived many setbacks and even possible cancellation of the entire project, but it was never killed, in part because the U.S. Marines in particular lobbied hard to keep it.

Amid the budget crisis, the Government Accountability Office in 2009 ordered the cost and performance of the V-22 to be clarified and alternatives reconsidered.

According to the GAO, the program’s cost increased over 200 percent from 1986 through 2007 — from $4.2 billion to $12.7 billion — while the cost of procurement increased 24 percent from $34.4 billion to $42.6 billion.

As of 2009, it was estimated that $75.4 billion would be needed for the program’s life cycle, or the costs involved in procuring and operating the aircraft before they are retired.

Is the Osprey accident prone?

The Osprey had three fatal accidents, claiming 30 lives, during its development and early deployment stage. In total, the aircraft had four accidents before the Pentagon authorized full-scale production in September 2005.

But Pentagon investigations ruled out technical or mechanical faults as being the causes of the accidents.

More recently, an MV-22 crashed in Morocco in April, killing two, and an air force CV-22 crashed in June in Florida, injuring its crew.

The causes of the latest accidents have yet to be officially established but they took place when the aircraft were transitioning from helicopter to aircraft mode — the Osprey’s main feature.

Although Defense Minister Satoshi Morimoto admitted an aircraft’s development does not end with the start of full-scale production, the Defense Ministry said the accident rate for the MV-22, which presently stands at 1.93 per 100,000 flight hours, is much lower than that of the U.S. Marine Corps. aircraft average, of 2.45. The rate for the CH-46 is 1.11.

Yet critics point out that these figures only take into account major incidents, not minor ones.

Noboru Yamaguchi, a professor at the National Defense Academy of Japan and a Self-Defense Forces helicopter pilot, cites the so-called bathtub curve, saying the accident rates are high at the start of deployment but go down as flight hours increase. As the aircraft age, however, the rate goes back up.

“It should be hitting the bottom of the curve when it’s deployed in Okinawa,” said Yamaguchi.

Do the Ospreys have any mechanical or material faults?

That question seems to be an open one.

Some news reports say the Osprey is unable, like conventional choppers, to autorotate, or effectively descend at a controllable attitude and speed if the engines fail, just by controlling the prop speeds and angles.

The Pentagon has reportedly said autorotation is not a formal requirement to ensure an Osprey can make a safe power-off landing.

A Defense Ministry brochure meanwhile states that the Osprey has autorotation capability, something Morimoto said the Pentagon confirmed.

All helicopters in Japan are required to be able to autorotate. However, in the U.S., autorotation is only required for civilian helicopters.

Autorotation is performed if both engines fail, as usually if one engine remains on, it can control the other one via in interconnected driveshaft.

The Defense Ministry noted that the loss of both engines is very rare and the Osprey can also enter a steep descending glide akin to that of a C-130 while in airplane mode.

Is the Osprey a better choice than the CH-46?

Deploying the Osprey will not alleviate the burden on the people living near Futenma, an environmental impact assessment concluded.

The report says the noise level is only slightly lower than the CH-46 when the craft is flying in airplane mode and just as noisy in helicopter mode.

“We are in a double bind as we feel we are being forced to choose between Ospreys, whose safety has not really been confirmed, or the CH-46, as aging craft could cause another crash,” said Mikio Shimoji, a member of the House of Representatives from Okinawa. He took a flight on an MV-22 at Miramar Air Station in California in January.

When will the Ospreys come to Okinawa?

Amid the growing opposition to the deployment, especially after two recent crashes, the U.S. made a concession by pledging it will not carry out any test flights in Japan, including at Iwakuni, where the first 12 Ospreys will be offloaded and grounded until the final investigative reports on the accidents are compiled by the end of August.

Morimoto said findings already submitted by the U.S. military indicate the accidents were caused by operational error, but he said his ministry has formed a special team to verify this claim.

The Weekly FYI appears Tuesdays. Readers are encouraged to send ideas, questions and opinions to hodobu@japantimes.co.jp