Monday, June 1, 2015
Highs and a Low for the V-22
|An MV-22B Osprey with Marine Medium Tiltrotor Squadron 161 (Reinforced) departs the USS Essex during a certification exercise off San Diego April 14. An Osprey from the squadron crashed in Hawaii May 17, killing one Marine.
Photo courtesy of the U.S. Marine Corps/Staff Sgt. Miguel Carrasco
On May 16, U.S. Air Force CV-22s helped fly U.S. Delta Force troops into southeastern Syria, where the commandos killed a senior Islamic State in Syria (ISIS) leader. The Ospreys from the Air Force Special Operations Command joined Sikorsky Aircraft MH-60 Black Hawks from the U.S. Army’s 160th Special Operations Aviation Regiment (Airborne) in carrying the special-operations troops on that mission.
Described as the first successful raid by American ground troops since the military campaign against ISIS began last year, the mission garnered much intelligence material, freed what the Pentagon described as an enslaved woman and saw other ISIS personnel captured. Yet, the Pentagon said, no Americans were injured (despite hand-to-hand combat and aircraft struck by ground fire), nor were there any civilian casualties.
In Nepal, MV-22s from the U.S. Marine Corps’ Marine Medium Tiltrotor Squadron 262 (VMM-262, the “Flying Tigers”) began carrying critical supplies to survivors and aid officials on damage-survey flights shortly after April 25’s magnitude 7.8 earthquake.
But a fatal May 17 MV-22 accident in Hawaii prompted politicians and the public to again ask, “Is the V-22 safe?” (Japan’s Kyodo news service reported that governor of Okinawa in southern Japan, where 24 U.S. V-22s are stationed, demanded that Osprey flights there be suspended until the crash’s cause is determined.)
The Osprey from VMM-161 Reinforced (the “Greyhawks”) crashed after suffering what the USMC described as a hard landing during routine training. The aircraft was one of several that had departed the USS Essex about 100 miles off Oahu, transporting 21 Marines and a U.S. Navy corpsman to Bellows Air Force Station near Waimanalo, Oahu.
As the aircraft transitioned from airplane to helicopter mode at about 1140 local time, it crashed. One Marine was killed and at least one other person onboard was critically injured.
VMM-161 Reinforced also includes USMC McDonnell Douglas AV-8B Harriers and Bell AH-1Z Vipers. It is assigned to the 15th Marine Expeditionary Unit, based at Camp Pendleton, Calif. The 15th MEU departed San Diego May 10 for a seven-month deployment to the Pacific Command and Central Command areas of operation as part of the Essex Amphibious Ready Group. That group consists of the Wasp-class amphibious assault ship USS Essex (LHD 2), the San Antonio-class amphibious transport dock ship USS Anchorage (LPD 23) and the Whidbey Island-class amphibious dock landing ship USS Rushmore (LSD 47). That group and the MEU completed a two-week certification exercise in late April that included a unique training element, a joint recovery force exercise with Army special forces, Marines and U.S. Navy personnel.
Like helicopters, the V-22 is susceptible to vortex ring state, a condition in descent in which vortices normally shed clear of the rotor blades become trapped around the rotor. This essentially prevents the production of rotor thrust and results in a sudden descent.
Because of the V-22’s configuration, vortex ring state also can produce a sudden hard roll if only one of its lateral rotors is affected. This combination is considered a contributing cause of the April 8, 2000 crash at Marana, Ariz. that killed 19 Marines. That crash was one of two that led to a 17-month grounding of
the V-22. The cause of the May 17 crash is under investigation.