Kaman and AlliedSignal have completed initial fuel pressure tests on the K-MAX fleet and have found no more fuel-pump driveshaft spline failures. Investigation of the fatal crash of a K-MAX in Germany in early September revealed that both the primary and secondary pump splines had failed in the T5317A-1 turboshaft powering the external-lift helicopter.
The US Federal Aviation Administration has issued a priority airworthiness directive requiring immediate tests to determine whether both fuel pumps are producing pressure. Repetitive tests are required every 50h and will take about 1h to accomplish.
The company is planning to install a caution light system on all K-MAX, to alert pilots to changes in pressure from either fuel pump element. The system is being designed and will be installed in the fleet after certification.
Source: Flight International
