The Bell Boeing V-22 Osprey is an American military tiltrotor aircraft whose history of accidents has provoked concerns about its safety. The aircraft was developed by Bell Helicopter and Boeing Helicopters, which build and support the aircraft.

, sixteen V-22 Ospreys have been damaged beyond repair in incidents that have killed a total of sixty-two people. Four of the crashes occurred during developmental flight tests; these killed a total of thirty people from 1991 to 2000. Since the V-22 became operational in 2007, twelve crashes and several other incidents have killed a total of thirty-two people."Bell Boeing MV-22 Osprey accidents and incidents" Aviation Safety Network Database

Most of the crashes have involved the most numerous of the aircraft's three variants: the MV-22B, procured and flown by the U.S. Marine Corps. A handful of crashes have involved CV-22Bs, flown by U.S. Air Force Special Operations Command. No crashes have involved the CMV-22B, the carrier onboard delivery variant flown by the U.S. Navy.

Crashes and hull–loss accidents

June 1991 On 11 June 1991, a miswired flight control system led to two minor injuries when the left nacelle struck the ground while the aircraft was hovering in the air, causing it to bounce and catch fire at the New Castle County Airport in Delaware. The pilot, Grady Wilson, suspected that he may have accidentally set the throttle lever the opposite direction to that intended, exacerbating the crash if not causing it.Whittle 2010, pp. 200–202.

July 1992 On 20 July 1992, pre-production V-22 #4's right engine failed and caused the aircraft to drop into the Potomac River by Marine Corps Base Quantico with an audience of Department of Defense and industry officials watching. Flammable liquids collected in the right nacelle and led to an engine fire and subsequent failure. All seven on board were killed and the V-22 fleet was grounded for eleven months following the accident."V-22 Osprey crash kills 7 Aircraft second of 5 prototypes to go down." Fort Worth Star-Telegram, 21 July 1992.Norton 2004, pp. 46–47. A titanium firewall now protects the composite propshaft.Whittle 2010, p. 246.

April 2000

A V-22 loaded with Marines, to simulate a rescue, attempted to land at Marana Northwest Regional Airport in Arizona on 8 April 2000. It descended faster than normal (over ) from an unusually high altitude with a forward speed of under when it suddenly stalled its right rotor at , rolled over, crashed, and exploded, killing all nineteen on board.Cox, Bob. "V-22 Pilots Not To Blame For Crash, Widows Say", Fort Worth Star-Telegram, 4 June 2011.

The cause was determined to be vortex ring state (VRS), a fundamental limitation on vertical descent that is common to helicopters. At the time of the mishap, the V-22's flight operations rules restricted the Osprey to a descent rate of at airspeeds below (restrictions typical of helicopters); the crew of the accident aircraft had descended at over twice this rate.Norton 2004, pp. 62–63. Another factor that may have triggered VRS was the operation of multiple aircraft in close proximity, also believed to be a risk factor for VRS in helicopters.

Subsequent testing showed that the V-22 and other tiltrotors are generally less susceptible to VRS than helicopters; VRS entry is more easily recognized, recovery is more intuitive for the pilot, altitude loss is significantly less, and, with sufficient altitude ( or more), VRS recovery is relatively easy. The V-22 has a safe descent envelope as large as or larger than most helicopters, further enhancing its ability to enter and depart hostile landing zones quickly and safely. The project team also dealt with the problem by adding a simultaneous warning light and voice that says "Sink Rate" when the V-22 approaches half of the VRS-vulnerable descent rate.

December 2000 On 11 December 2000, a V-22 had a flight control error and crashed near Jacksonville, North Carolina at Marine Corps Air Station New River, killing all four aboard. Vibration-induced chafing from an adjacent wiring bundle caused a leak in the hydraulic line, which fed the primary side of the swashplate actuators to the right side rotor blade controls. The leak caused a Primary Flight Control System (PFCS) alert. A previously undiscovered error in the aircraft's control software caused it to decelerate in response to each of the pilot's eight attempts to reset the software as a result of the PFCS alert. The uncontrollable aircraft fell and crashed in a forest. The wiring harnesses and hydraulic line routing in the nacelles were subsequently modified. This caused the Marine Corps to ground its fleet of eight V-22s, the second grounding in 2000.Dao, James. "After North Carolina Crash, Marines Ground Osprey Program." New York Times, 13 December 2000."Marine V-22 Ospreys cleared to soar again." Spokesman-Review, 6 September 2000.

March 2006 A MV-22B experienced an uncommanded engine acceleration while turning on the ground at Marine Corps Air Station New River, NC. Since the aircraft regulates power turbine speed with blade pitch, the reaction caused the aircraft to go airborne with the Torque Control Lever (TCL, or throttle) at idle. The aircraft rose into the air (initial estimates suggested twenty to thirty feet) and then fell to the ground, causing damage to its starboard wing; the damage was valued at approximately US$7 million."V22 Osprey's 3.2 second accident Flight". iasa.com.au, accessed 14 October 2013."Osprey Down: Marines Shift Story on Controversial Warplane's Safety Record". Condé Nast, 13 October 2011. It was later found that a miswired cannon plug to one of the engine's two Full Authority Digital Engine Controls (FADEC) was the cause. The FADEC software was also modified to decrease the time needed for switching between the redundant FADECs to eliminate the possibility of a similar mishap occurring in the future. The aircraft was found to be damaged beyond repair and stricken from Navy's list in July 2009.Bell-Boeing MV-22B Osprey 27-MAR-2006. Aviation Safety NetworkBell MV-22B Osprey c/n D0056. Helis.com

April 2010 In April 2010, a CV-22 crashed near the city of Qalat in Zabul Province, Afghanistan. Three US service members and one civilian were killed and sixteen were injured in the crash. Initially, it was unclear if the accident was caused by enemy fire. The loaded CV-22B was at its hovering capability limit, landing at night near Qalat (altitude approx. 5,000 feet) in brownout conditions, in turbulence due to the location in a gully.McIntyre, Jamie. "CV-22 Lost Due to Pilot Error" . dodbuzz.com, 18 May 2010. The USAF investigation ruled out brownout conditions, enemy fire, and vortex ring state as causes. The investigation found several factors that significantly contributed to the crash: These include low visibility, a poorly executed approach, loss of situational awareness, and a high descent rate."CV-22B Accident Investigation Board" , "CV-22 Accident Investigation Board Results Released" . U.S. Air Force, 16 December 2010.

Brig. Gen. Donald Harvel, board president of the first investigation into the crash, fingered the "unidentified contrails" during the last seventeen seconds of flight as indications of engine troubles.Rolfsen, Bruce. "Generals clash on cause of April Osprey crash." Airforce Times, 22 January 2011. Harvel has become a critic of the aircraft since his retirement and states that his retirement was placed on hold for two years to silence him from speaking publicly about his concerns about the aircraft's safety.Axe, David. "General: 'My Career Was Done' When I Criticized Flawed Warplane" . Wired, 4 October 2012 The actual causes of the crash may never be known because US military aircraft destroyed the wreckage and black-box recorder.Thompson, Mark. "So Why Did That V-22 Crash?" . Time. 18 December 2010. Former USAF chief V-22 systems engineer Eric Braganca stated that the V-22's engines normally emit puffs of smoke and the data recorders showed that the engines were operating normally at that time.Axe, David. "Air Force Engineer Takes on General Over Controversial Warplane Crash." Wired Magazine, 15 October 2012.

April 2012 An MV-22B belonging to the 2nd Marine Aircraft Wing, VMM-261, was participating in Exercise African Lion when it crashed near Tan-Tan and Agadir, Morocco, on 11 April 2012, killing two Marines. Two others were seriously injured, and the aircraft was lost.Majumdar, Dave. "Two killed in USMC MV-22 accident in Morocco." Flight International, 11 April 2012. Retrieved: 13 April 2012."Two U.S. Marines killed in Morocco helicopter crash" . BNO News, 12 April 2012. Retrieved: 16 April 2012."ASN Wikibase Occurrence # 144945" Aviation Safety Network, 15 April 2012. Retrieved: 16 April 2012. U.S. investigators found no mechanical flaw with the aircraft,"MV-22 Osprey that crashed in Morocco was mechanically perfect" Yomiuri Shimbun, 9 June 2012. Retrieved: 15 June 2012. and human error was determined to be the cause.Whittle, Richard. "Marines Peg 'Bad Flying' As Cause of April V-22 Crash in Morocco" . AOL Defense, 9 July 2012. Retrieved: 10 July 2012.

June 2012

On 13 June 2012, a USAF CV-22B crashed at Eglin Air Force Base in Florida during training. All five aboard were injured; two were released from the hospital shortly after."Two airmen injured in Osprey crash released from hospital". Northwest Florida Daily News, 15 June 2012. Retrieved: 16 June 2012. The aircraft came to rest upside down and received major damage."5 airmen hurt in Osprey crash near Navarre". Pensacola News Journal, 14 June 2012. Retrieved: 16 June 2012. The cause of the crash was determined to be pilot error, with the CV-22 flying through the proprotor wash of another aircraft. The USAF restarted formation flight training in response.

May 2015 An MV-22B Osprey participating in a training exercise at Bellows Air Force Station, Oahu, Hawaii, sustained a hard landing that killed two Marines and injured twenty. The aircraft sustained fuselage damage and a fire onboard. The aircraft was determined to have suffered dust intake to the right engine, leading the Marine Corps to recommend improved air filters, and reduced allowed hover time in dust from sixty to thirty seconds.Fatal MV-22 crash in Hawaii linked to excessive debris ingestion 25 November 2015Whittle, Richard. "Fatal Crash Prompts Marines To Change Osprey Flight Rules" Breaking Defense, 16 July 2015.

December 2016