In this video we learn that ‘X3′ is pronounced ‘X-Cube’. I think that’s the first time I’ve heard that, I was mentally reading it as ‘X-Three’, of course.

Eurocopter isn’t the only vendor working on a compound helicopter, of course. Sikorsky continues to develop the S-97 Raider coaxial compound helicopter, based on their earlier X2 demonstrator. Each month they release a program update video, and the June release focuses on Esterline, one of the primary suppliers to the program.

Esterline is providing the Human/Machine Interface technology, which includes the cockpit flight displays and the HOTAS (Hands On Throttle And Stick) fly-by-wire flight controls (the cyclic and collective), as well as the control surface actuators for the elevators and rudders.

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.