Helicopter safety - Thank you Finmeccanica - AIN

The "Extremely Remote" waiver to the main 30-minute rule is flawed. I therefore welcome any effort, now demonstrated by Finmeccanica, to gurantee and certificate a dry-run capability of not less than 30 minutes. (Ed.) Finmeccanica Mulls Longer Run-dry Duration for Helos

Finmeccanica Helicopters (formerly AgustaWestland) is studying ways to enhance main gearbox performance in case of loss of lubrication. At the recent EASA rotorcraft symposium, Marco Tamborini, one of the company's experts in transmission system design and development, gave details on Finmeccanica's strategy in gearbox durability. Unless the possibility of such a failure is extremely remote, EASA rules call for continued safe operation for at least 30 minutes. In November, Finmeccanica announced it had demonstrated to the Italian airworthiness authority a “60-plus minute 'run dry' capability” for the AW139's improved main gearbox. Finmeccanica's target is to achieve the longest durability after loss of oil, Tamborini said. It has adopted five ways to prevent or mitigate such an event: minimizing the probability of oil loss, minimizing power losses, maximizing heat rejection, increasing high-temperature capability and managing residual oil. As a result of changes to oil passages and a move to ceramic roller bearings, among others, the company's gearbox has maintained a steady thermal balance during run-dry conditions for more than 50 minutes (AW189) or 60 minutes (AW139) in certification testing.