Two Paths Toward Future Helicopters

In the past few days both Eurocopter and Sikorsky have posted videos relating to their work on next generation rotorcraft concepts. Eurocopter was first in posting a video of their X3 compound helicopter in flight with the Airbus Military A400M transport. (Both Eurocopter and Airbus are EADS companies.) A compound helicopter is one with forward propulsion, and often stub wings to offload the rotor during forward flight. The X3 has two propellers mounted on the tips of a high-mounted stub wing.

Sikorsky on the other hand posted a video featurette on Liquid Measurement Systems, a small company that is one of the key suppliers to the S-97 Raider program. Like the X3, the S-97 is a compound helicopter, but Sikorsky is going a different route. While the X3 has a conventional main and tail rotor layout, the S-97 has a coaxial main rotor and a pusher propeller at the end of the tail. The S-97 is based on their record setting X2 technology demonstrator, which reached a speed of 250 knots in level flight.

The S-97 Raider is currently expected to fly in 2014. Sikorsky is developing it on their own in the hopes of interesting the US Army in it for the Armed Aerial Scout requirement to replace the aging OH-58 Kiowa fleet, since the previous Bell ARH-70 Arapaho program was cancelled for being over budget and behind schedule.