Unlike its sister ship the EC225, the EC175’s main gearbox has no backup lubrication system, which could present a problem should it experience a total loss of oil. To compensate for this, its components have been designed to withstand the absence of lubricant for a limited period of time. Airbus Helicopters so far has certified a 15-minute dry-run capability (which involved a 30-minute demonstration). Further tests are scheduled for 2015 in a bid to increase the certified duration to at least 30 minutes.
Egypt’s Nesma Airlines, which operates two leased Airbus A320-200s, has announced a change of lubricant manufacturer as it seeks to combat the hot desert conditions involved in flying in the Middle East.
Three years ago, Nesma started using Air BP Lubricants’s High Performance Capable Turbine Oil 2197. According to Air BP Lubricants, “The recommendation to switch oils came from the aircraft’s former operator, who had previously experienced the added benefits of using BPTO 2197 in other aircraft.”
Loss of lubrication to the main gearbox (MGB) has been responsible for several crashes, ditchings and precautionary landings in large transport category helicopters in recent years. These accidents set off broad debate as to exactly what is required of main gearboxes under Part 29 certification of the U.S.
Sikorsky is developing a next-generation main gearbox (MGB) with enhanced lubrication capabilities with built-in redundancy systems such as chip detectors and oil scavenge systems, according to Spencer Elani, Sikorsky’s S-92 program manager. “We are continuing to make a lot of improvements to the current gearbox, and to automate some of the features,” Elani said.