Sikorsky announced yesterday that the third prototype of the S-76D medium-twin helicopter joined the test fleet, having made its first flight probably in July or August, AIN understands. Sikorsky had planned to reach this milestone early this year. “D3” will be used for avionics and electrical system certification.
Flight tests of the Lockheed Martin F-35 resumed after a two-week grounding. The Joint Program Office (JPO) said that the failure of a control valve had led to the malfunction of the aircraft’s Integrated Power Package (IPP), supplied by Honeywell. But an investigation continues, while a permanent resolution of the problem is being worked, the JPO added.
Sikorsky’s X2 technology demonstrator, a high-speed semi-compound helicopter, flew for the last time on July 14 at the company’s West Palm Beach, Fla. test center, in front of a number of the manufacturer’s military and commercial customers. The sortie took place without the central hub fairing (also known as an “aero sail”), which will not be tested in flight.
Sikorsky flew its X2 technology demonstrator for the last time at its West Palm Beach, Fla. test center last week in front of some of the company’s military and commercial customers. Contrary to previously announced plans, the semi-compound helicopter, which features two contra-rotating main rotors and a pusher propeller, flew without its central hub fairing.
A report by the UK’s National Audit Office (NAO) has listed some risks arising from the decision by the UK Ministry of Defence (MoD) to switch its Joint Strike Fighter selection from the F-35B STOVL (short takeoff and vertical landing) version to the F-35C carrier version.
They both deny it, but helicopter manufacturers Sikorsky and Eurocopter have clearly reignited the speed race between their respective semi-compound X2 and compound X3 demonstrators. The X2 will fly again this summer, this time with its full rotor hub fairing. Sikorsky officials last week said that the test will be oriented primarily toward understanding how the “aero sail” behaves in certain conditions.
Goodrich has been recognized for its role on the 2010 Robert J. Collier Trophy-winning Sikorsky X2 Technology demonstrator team. The company provided the SmartProbe air data systems and engine controls on the record-breaking aircraft.
The Lockheed Martin F-35 development program has met or exceeded the revised flight-test schedule that was written following a technical baseline restructuring (TBR) last August, according to Lockheed Martin officials. But some significant technical issues remain, and affordability continues to be a key concern for the new-generation combat aircraft.
Both the Sikorsky X2 and the Eurocopter X3 have propellers and both are targeting higher cruise speeds; however, their respective designers have not been working to the same principles.
The X2 is effectively a semi-compound helicopter, having contra-rotating main rotors and one aft propeller, while the X3 is a true compound with a single main rotor, wing stubs and two side-mounted propellers.