All Beech T-34s used for mock air-combat "thrill" flights should be grounded until they are inspected for serious structural faults, says the US National Transportation Safety Board (NTSB). The recommendation follows the board's investigation of a T-34A Mentor crash on 19 April last year involving wing failure.

The former US military trainer aircraft, operated by Atlanta-based Sky Warriors, was being flown by a pilot and a passenger who were participating in a mock "dogfight". Both were killed when their aircraft hit the ground after the T-34's right wing separated. Metallurgical examination showed wing spar fatigue cracking.

As a result the NTSB is pressing the US Federal Aviation Administration to ground all Beech T-34s, T-34As and T-34Bs used for commercially operated "air combat" flights. It also urges the FAA to develop operational and inspection criteria for the critical flight control surfaces and structural elements of any aircraft used for mock combat flying because the activity "induces a larger number of high positive wing loading events per flight hour than other operations".

Over 450 T-34A/Bs were built. No longer in US military service, they are used for personal flying, aerobatics and air-combat simulation flights. Sky Warrior owns two more T-34As. There are at least two other companies in the USA using the Mentor for mock air combat, including Texas Air Aces, which found cracks in a left wing in early 1998.

Source: Flight International