By Tim Kelly

IWAKUNI, Japan (Reuters) - The U.S. military's MV-22 Osprey aircraft has been a lightning rod for opposition to U.S. bases in Japan since 24 of them were deployed on the southern island of Okinawa in 2014.

By sending eight of the tilt-rotor Ospreys to help with relief efforts for survivors of recent earthquakes on Kyushu island, both U.S. and Japanese military planners have been able to showcase an aircraft they see as necessary for Japan's defense.

When an Osprey set down last week on a sports ground in Hakusui village on Kyushu, the first person out was a U.S. Marine Corps photographer taking pictures of Japanese troops unloading supplies. Within hours, the pictures were on social media.

Opposition to U.S. bases in Japan has simmered for years, especially on Okinawa where many people believe the MV-22, which can hover like a helicopter and fly as a fixed wing craft, is prone to crashing.

They say the U.S. military's deployment of the Osprey on Okinawa shows its disregard for their feelings. The U.S. military insists the Osprey is safe but in 2012 it nevertheless agreed to curb flights over heavily populated areas.

Since earthquakes killed about 50 people on Kyushu this month, the aircraft has been seen in a new light, thanks in large part to pictures of it ferrying blankets, food and water to quake survivors, posted on the 31st Marine Expeditionary Unit's Facebook and Twitter feeds.

"We have had no negative reaction," said Colonel Romin Dasmalchi, commander of the unit, which is based in Okinawa.

Visits to the unit's social media sites surged by as much as 10 times after it began flying relief supplies, a spokesman for the U.S. Marine Corps said.

Eight Osprey's were deployed for the relief effort from Okinawa to a USMC air station at Iwakuni near Hiroshima because "of the speed and efficiency of the airframe to get into those places where a traditional aircraft could not land", he said.

JAPAN BUYING OSPREYS

By the time the U.S. military's relief mission ended on Sunday, its posts had earned more than 230,000 hits compared with a normal rate of between 10,000 to 50,000.

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While the publicity is unlikely to placate opponents of U.S. bases, it should improve the Osprey's image.

The deployment has also given the Japanese military a chance to see how the Osprey fits with its kit. Japan ordered five Ospreys last year, making it the first foreign force to buy it.

"The more exposure you get to any weapon system aircraft I think the better it is going to be," Dasmalchi said.

Japan's Ospreys will be based on Kyushu from around 2019, near a new unit of Japanese marines that represent the spearhead of Prime Minister Shinzo Abe's plan to give Japan's military a global security role by making it more mobile and expeditionary.

After leaving Hakusui village on Friday, the Osprey flew to the Hyuga, the first in a new class of Japanese helicopter carriers, which also helps Japan extend its military reach beyond home waters.

Japanese navy officers were given a brief tour of the aircraft before it was loaded with water, chicken curry and beef rice, and topped up with fuel, for another trip back to hungry quake survivors.

(With additional reporting by Nobuhiro Kubo; Editing by Robert Birsel)