As reported first in AINalerts on September 20, the U.S. Air Force and Navy’s suspension of deliveries of the Hawker Beechcraft T-6A Texan II single-engine turboprop trainer resulted from an unapproved change to the manufacturing process of the airplane’s wing spar, according to a Hawker Beechcraft spokesman. Deliveries of the Joint Primary Aircraft Training System (JPATS) T-6A were suspended in July and should resume shortly, he said. “There is no safety-of-flight issue, and our testing has shown no impact on fatigue life of the aircraft or any other structural concerns. A revised process approval is being finalized with the FAA. The Air Force is conducting its own separate approval process, which will be completed shortly.”
During the suspension, the Air Force’s Air Education & Training Command (AETC) has limited the g loading on its fleet of 320 T-6As. “AETC continues to execute its primary mission of undergraduate pilot training under a g limitation suggested by the program office,” an AETC spokesman said.
Other T-6A operators include the Navy’s Air Test and Evaluation Squadron Two Zero (Nav Air), Hellenic Air Force of Greece and NATO Flying Training in Canada. More than 435 T-6As have been delivered and have logged more than 625,000 flying hours. Currently, only the U.S. Air Force and Navy have T-6A deliveries pending.
While resolution of the spar process approval is under way, Hawker Beechcraft continues to build airplanes for the Air Force and Navy contracts and is working with the FAA and the Air Force to resume deliveries, according to the spokesman. The JPATS contract required an FAA-certified aircraft, he added, hence the FAA’s involvement in approving the spar manufacturing process.
“Hawker Beechcraft examined the T-6A’s forward and main spar caps using static strength analysis and determined that the wing could carry the plus 7-g load. Conservative fatigue and damage tolerance analysis showed no impact to the JPATS service life,” he said.
The manufacturer also demonstrated that “worst-case” forward spar caps “fabricated under FAA surveillance [the T-6A is also FAA approved] for a series of mechanical properties testing…showed that the forward spar test specimens met the requirements for material hardness, conductivity and metallurgical and chemical composition. Static and fatigue testing by an independent mechanical testing laboratory, in accordance with the FAA-concurred test plan, determined the forward spars met the material requirements for yield and ultimate strengths. Analysis of the fatigue testing showed that the fatigue life of the spars will meet the design service life of the T-6A without repair or additional inspections.”