S.S. White Celebrates 175th Year as Flexible Rotary Shaft Supplier

S.S. White Technologies is celebrating its 175th year as a supplier of flexible rotary shafts for the aerospace industry and is currently supplying flexible shafts that transmit power to activate and synchronize the actuation of the Thrust Reverser Actuation Systems (TRAS) on all of the CFM International LEAP-Series turbofan engines that are powering the upgraded Airbus A320neo (LEAP-1A), Boeing B737 MAX (LEAP-1B) and a new O-Duct Thrust Reverser Actuation System (TRAS) developed for the LEAP- 1C turbofan engines to power the new COMAC C919 aircraft.

In addition, S.S. White is also the leading supplier of flexible rotary shafts that activate the Thrust Reverser Actuation Systems on the Pratt & Whitney GTF turbofan engines that power the Airbus A220, upgraded A320neo and Embraer E180-E2 and Mitsubishi MRJ regional jets. S.S. White provides a set of flexible rotary shafts per engine, depending upon the TRAS architecture, that transfer power to synchronize the actuators that expose the “cascade” vanes under the two-piece “D” doors thrust reverser units upon landing and also help lock the TRAS system to prevent any inadvertent deployment during flight.

Also, S.S. White is the leading supplier of flexible rotary shafts that activate the thrust reverser actuation systems (TRAS) on the Rolls-Royce Trent 1000 turbofan engines on the Boeing 787 and XWB engines used on the Airbus A350. The company is supplying two, three, four or six sets of shafts depending on the engine architecture that also precisely transfers power to synchronize the actuators that expose the “cascade” vanes under to two-piece “D” doors thrust reverser units upon landing.

And, the company is also the key supplier of aerospace flexible rotary shafts specifically designed to transmit rotary torque for the manual override on the Honeywell Aerospace Starter Air Valve for the new GE9X turbofan engine which is scheduled for final certification tests this year. The world’s largest and most powerful turbofan engine is designed to power the Boeing 777X aircraft.

On the CFM LEAP-1C TRAS, the advanced thrust reverser concept, uses a one-piece composite O-Duct to replace the traditional thrust reverser’s two-piece “D” doors, and is deployed with new kinematics that transitions the entire O-Duct aftward to the reverse thrust position. The LEAP 1-C system is an electrical thrust reverser actuation system (ETRAS) which was first introduced to commercial aviation on the Airbus A380 turbofan engine nacelles.

The CFM LEAP-1A and LEAP-1B turbofan engines use the more traditional “D” door TRAS configuration which obstructs more (compared to the O duct) by-pass flow area with structure and similarly less thrust reversing capacity. Deployment of the TRAS redirects the turbofan engine thrust by exposing deflecting “cascade” vanes along the sides of the engine nacelles These deflectors force the fan air to exit forward working with the wheel and air braking systems to help slow the ground speed of the aircraft.