UH-1F Eglin AFB 1966   UH-1F DMAFB, AZ 1967   UH-1F Malmstrom AFB 1967   UH-1F Eglin AFB 1969   UH-1F Edwards AFB 1971   UH-1F Ellisworth AFB 1971   UH-1N FT. Bragg 1973   HH-1H Hill AFB 1974   UH-1F F.E. Warren 1975   UH-1F Ellsworth AFB 1982   UH-1F Whiteman AFB 1982   UH-1N Bahamas 1984   UH-1 Ellsworth AFB 1986   UH-1N Edwards-Jan-1991   UH-1N Edwards-Oct-1991   UH-1N Kirtland AFB 1996   UH-1N 1998   UH-1N F.E. Warren AFB 1999   UH-1N Kirtland AFB 2002   TH-lH Ft. Rucker 2009   UH-1N Malmstrom AFB 2010   UH-1N Kirtland AFB 2011   UH-1N Minot AFB 2013   CH-3C Malmstrom AFB 1965   CH-3C Sheppard AFB Mar. 1967   CH-3 Sheppard AFB Nov. 1967   CH-3E Midair in Laos 1970   HH-3E Korea 1973   HH-3E Elmendorf AFB 1974   HH-3E Iceland 1979   CH-3E Patrick AFB, 1984   HH-3E Osan 1984   HH-3E 29-Palms 1988   HH-3E Kadena 1989   CH-3E DMAFB 1989   H-5G Ladd AFB 1951   H-5H Maxwell AFB 1953   H-5 New York 1958   H-13G Niagara Falls 1955   H-13 Bryan AFB, TX 1957   H-19A San Marcos 1952   H-19A O'Neill, NB. 1953   H-19B Alexandria, LA. 1954   H-19B Austria 1954   H-19B France 1954   H-19B Korea 1954   H-19B March AFB 1954   H-19B Rhine Main AB 1955   H-19B Eglin AFB 1955   H-19 Skaneateles Lake, NY 1956   H-19 Ashiya Japan 1957   H-19 Edwards AFB 1957   H-19 Niagra Falls 1959   H-19 Sheppard   H-19B Loring AFB 1960   H-19 Beal AFB 1963   H-19 Larson AFB 1963   H-19 Saigon, RVN 1964   YH-21 Thule AB 1953   H-21 Goose Bay 1954   H-21A San Marcos TX 1955   H-21B Tennesse 1955   H-21 San Diego, CA 1956   H-21 Alaska 1957   H-21 Goose Bay 1958.   SH-21 Greenland 1958   H-21 Elmendorf AFB 1958   H-21 Dugway Proving Grnd. 1958   H-21 Goose Bay 1959   H-21 Greenland 1959   CH-21B Otis AFB 1959   H-21 Indian Springs AAF 1961   H-21 Luke AFB 1961   H-23B Moody AFB 1953   H-43A James Connally AFB 1959   H-43B Loring AFB 1961   H-43B Westover AFB 1961   HH-43B MacDill AFB, FL 1964   HH-43B Stead AFB 1965   HH-43B Clark AB, PI 1966   H-43 Sheppard AFC, TX 1966   HH-43B Phan Rang 1968   HH-43B MacDill AFB 1969   HH-43B Hill AFB 1973   HH-53C Eglin AFB 1969   CH-53C Germany 1975   CH-53C Germany 1976   HH-53C Woodbridge 1977   HH-53C Kadena AB 1979   HH-53B Kirtland AFB 1981   HH-53C Kirtland AFB 1982   MH-53 Philippines 1984   CH-53C Pope AFB 1984   HH-53C Hickam AFB, HI 1985   HH-53C Hill AFB 1986   HH-53H Nellis AFB 1986   MH-53J Korea 1995   HH-53B Vance AFB 1996   HH-53B Cherry Point 1998   MH-53J Ft. Bragg 1999   MH-53M RAF Mildenhall 2000   MH-53 Durango CO 2002   MH-53M USNS Kanawha 2002   MH-53M Afghanistan 2003   MH-53M FOL Hurlburt Fld 2003   MH-53M Kuwait 2003   MH-53M Hurlburt Fld. 2007   UH-60A Pope AFB 1987   HH-60G New York 1991   MH-60G Antigua 1991   HH-60G Great Salt Lake 1992   HH-60G Davis-Monthan AFB 1994   HH-60G Korea 1994   HH-60G Indian Springs 1998   HH-60G Al Jabar AB 1999   HH-60G Avon Park 2001   HH-60G Mt. Hood 2002   HH-60G Afghanistan 2002   HH-60G Afghanistan 2003   HH-60G Afghanistan 2004   HH-60G Angel Fire, NM 2005   HH-60G Kandahar 2007   HH-60G Afghanistan 2009   HH-60G Okinawa 2013   HH-60G Lakenheath 2014   HH-60G Lakenheath 2014 1   HH-60G Lakenheath 2014 2   Ellsworth AFB 1955   Hawaii crash 1963   Patuxent River NAS 1960   Randolph AFB 1957   Spokane River, WA 1959   Tyndall AFB 1961   Wright-Patterson 1956   Spokane River 1972  

TH-1H S/N 73-21840

Fort Rucker, AL

30 June 2009



During a night training sortie on 30 June 2009, a TH-l H aircraft, tail number (TIN) 73-21840, experienced a hard landing due to loss of tail rotor thrust at 2140 local time (L) in Conecuh National Forrest near remote training site 406 (RT-406), 43 miles west of Cairns Army Airfield (KOZR). Following the hard landing, the mishap pilot (MP) and two student pilots egressed the aircraft and were subsequently picked up by a local U.S. Army Search and Rescue helicopter. The three pilots were transported to Southeast Alabama Medical  Center for medical evaluation where they were treated for minor injuries associated with the force of the impact. The mishap aircraft (MA) was based at Fort Rucker, Alabama and assigned to the 23rd Flying Training Squadron, of the 58th Special Operations Wing, to provide undergraduate helicopter pilot training for the United States Air Force. The mishap occurred within the lateral boundaries of Alert Area 211 (A-211) in South Central Alabama. A-211 is specially designated airspace which may contain a high volume of rotary and fixed wing training. The MA sustained $6.7M in damage.  There was no damage to private property.


The MA departed  KOZR at 2052L to conduct night vision goggle (NVG) remote procedures training. Approximately 48 minutes after takeoff, while conducting high reconnaissance of RT- 406, at 300' above ground level (AGL) and approximately 65 knots with a 15 knot right quartering tailwind, the aircraft experienced a loss of tail rotor thrust, yawed right, and entered an uncontrollable right rotation about its vertical axis. The MP managed to make it to an open field upon which he entered a near vertical autorotation and the aircraft landed hard, impacting the ground in a level attitude at over 1,500 fpm (24 to 38 Gs). Investigation revealed that the number one tail rotor drive shaft hanger bearing assembly failed. The aft splines of the shaft and coupling had deteriorated to the point that they no longer meshed, causing complete loss of tail rotor thrust.  The failure of the number one hanger bearing assembly spline shaft and aft coupling is the root cause of the mishap. Sufficient evidence exists to conclude that a misalignment somewhere within the tail rotor drive system and flawed assembly of the bearing to the shaft contributed to the spline shaft and coupling failure.


The MP was rested, current, and qualified. Given the flight parameters where the tail rotor lost thrust, he performed admirably to land the aircraft without fatality. All maintenance personnel who worked on the MA were well trained, experienced, and qualified. A thorough review of maintenance documentation and procedures revealed no adverse trends which could have contributed to the accident. The misalignment and flawed assembly were not readily identifiable due to lack of vibration analysis and inadequate maintenance technical data.