The Marine Corps said it plans to base 24 MV-22 tilt-rotor Osprey aircraft at Kaneohe Bay, along with 18 Cobra attack helicopters and nine Huey helicopters as part of a larger plan that will radically change the aircraft makeup at the air station.

The distinctive Ospreys, with 38-foot twin rotors that allow the aircraft to take off like a helicopter and then rotate forward to become giant propellers, make it possible for the aircraft to fly much faster than helicopters.

The basing is part of a plan by the Marines to restructure and rebase its forces in the Pacific. Approximately 1,000 personnel and 1,100 dependents would be added starting in 2012, with “full implementation” of the basing plan by 2018.

On Nov. 19, the Navy announced its decision to bring up to 10 MV-22 squadrons, for a total of 120 Ospreys, on the West Coast to replace nine helicopter squadrons.

The replacements in Hawaii and on the West Coast are part of a Marine Corps plan to replace its aging fleet of medium-lift helicopters with the more advanced tilt-rotor Osprey.

The MV-22 is designed to transport 24 fully equipped Marines at a cruising speed of about 250 knots (about 288 mph), exceeding the performance of Marine Corps CH-46 medium-lift assault helicopters.

In Hawaii, the Ospreys would replace older CH-53D Sea Stallions.

The Corps announced it is conducting an environmental impact statement analysis of the Osprey and helicopter basing plan in Hawaii.

The Navy in late 2009 finalized a plan to replace all but three of the 27 propeller-driven P-3C Orion surveillance and reconnaissance aircraft at Kaneohe Bay with 18 P-8A Poseidon multi-mission jet aircraft based on the Boeing 737-800, but with strengthened wings, weapons systems and added fuel tanks.

The move to Poseidon surveillance aircraft would result in fewer airplanes and personnel at the Marine Corps base, slightly more noise, and an investment of $147.5 million for infrastructure upgrades, the Navy said.

The Navy at the time said it wanted to begin replacing the Orions in its fleet no later than 2012 and have the process completed by 2019.