2011 Reno Air Races crash

On September 16, 2011, at the Reno Air Races, a North American P-51D Mustang flown by James K. "Jimmy" Leeward crashed into spectators, killing the pilot and 10 people on the ground, and injuring 69 others. It was the third-deadliest airshow disaster in U.S. history, following accidents in 1972 and 1951, and the deadliest aviation-related disaster in the U.S. in two years.

Accident
Leeward, 74, and his Mustang, The Galloping Ghost, were in third place and had just rounded pylon number 8 when the airplane abruptly pitched up, rolled inverted, then pitched down. The aircraft hit the tarmac in front of the grandstands in an area containing box seating.

Seven people, including the pilot, died at the crash site; four died later in the hospital. The weekend's remaining races at the Reno Air Races were cancelled.

The crash was the worst U.S. aviation-related disaster since a Pilatus PC-12 airplane went down in Montana on March 22, 2009, killing all 14 on board.

The day after the crash, the National Transportation Safety Board (NTSB) began examining whether part of the tail had come off before the crash. A photograph taken just before the crash showed the airplane inverted and part of the left elevator trim tab missing.

On October 21, 2011, Federal crash investigators with the National Transportation Safety Board said that they found no readable onboard video amid the debris of the racing plane. However, they were still attempting to extract information from an onboard data memory card found among damaged aircraft components and other debris scattered over more than two acres following the crash, as well as hundreds of photos and dozens of videos provided by spectators.

In 2012 the NTSB released seven safety recommendations to be applied to future air races. These included course design and layout, pre-race inspections, airworthiness of aircraft modifications, FAA guidance, pilot g-force awareness, and ramp safety.

Aircraft
The Mustang, named The Galloping Ghost, was a highly modified former military plane that in 2010 had come out of retirement after undergoing major modifications, including removal of the underbelly radiator and installation of a "boil off" cooling system, as well as other modifications that the owner describes as designed to make the plane more efficient. The former United States Air Force 44-15651 was owned by Aero Trans Corp., DBA in Ocala, Florida. The wings had been clipped a further 3 ft each side on top of the 4 ft reduction in span earlier in its life.

The aircraft had a long history of successful competition in air races dating back to the National Air Races from 1946 to 1949 in Cleveland. It was flown by a series of pilots under a variety of names, including "Miss Candace" from 1969 to 1978 and "Jeannie" in 1981.

Leeward called the modifications of the plane "radical." He said the oil system was similar to an oil cooling system in the Space Shuttle. The canopy is about the size of the ones on Formula One aircraft. The modifications were meant to improve aerodynamics by reducing drag and hence increase top speed.

Previous incidents
On September 18, 1970, the airplane (then known as Miss Candace Race #69) crashed after an engine failure during an air show at Reno Stead Airport and landed short of the runway, with only minor injuries to pilot Dr. Cliff Cummins.

In 1998, another modified P-51 Mustang, Voodoo Chile, lost a left trim tab during the Reno Air Races. The pilot, "Hurricane" Bob Hannah, reported that the airplane pitched up, subjecting him to more than 10 g and knocking him unconscious. When he regained consciousness, the plane had climbed to more than 9,000 feet, and he brought it in for a safe landing.

In 1999, another highly modified P-51 called Miss Ashley II, piloted by Gary Levitz, experienced rudder flutter during an Unlimited race at the Reno Air Races. The airframe broke up, killing Levitz.

Investigation results
The NTSB thoroughly investigated the extensive modifications made to the airplane. The modifications had made the aircraft lighter and reduced drag, but decreased stability. Leeward took the plane to 530 mph during the race, about 40 mph faster than he had ever gone before. There was evidence of extreme stress on the airframe demonstrated by buckling of the fuselage aft of the wing and gaps appearing between the fuselage and the canopy during flight (clearly visible in high resolution photographs taken by spectators).

However, the investigation (released in August 2012) found that the probable cause of the crash were old reused locknuts in the left elevator trim tab system that loosened. This led to a fatigue crack in an attachment screw and allowed the trim tab to flutter. This flutter caused the trim tab link assembly to fail which led to loss of control of the aircraft. Untested and undocumented modifications to the airplane contributed to the accident. Particularly, the right trim tab had been fixed in place. Had both trim tabs been operational, the loss of the left trim tab alone may not have caused loss of control. When the trim tab failed, Leeward was exposed to 17Gs which quickly incapacitated him and likely rendered him unconscious.