A Bell structural test team is preparing to start high-cycle fatigue tests of the UH-1Y Huey after the successful completion of a 20,000h low-cycle, or ground-air-ground, simulated loads fatigue test.

The tests, at Bell's Fort Worth site in Texas represent twice the required 10,000h fatigue life of the AH-1Z SuperCobra and Huey, says US Navy Air Systems Command.

The tests are required as the UH-1Y has new structural elements such as full-length, one-piece machined beams and bulkheads to cope with its extra 545kg (1,200lb) fuel load and 1,820kg (4,000lb) extra maximum useful load.

The tests began in April 2001 and were unaffected by some of the later changes implemented as part of the campaign to save the $6.2 billion-programme from cancellation by the US Department of Defense last year. These included reinforcement of the rotor yoke to prevent delamination, and the resizing of the elevator.

Over 1,284h of flight testing have been amassed by the H-1 upgrades integrated test team on five aircraft - three AH-1Zs and two UH-1Ys. Four of the aircraft are undergoing modification to incorporate the moveable elevator and the Thales Top Owl helmet-mounted display.

Source: Flight International