Sikorsky expects a six-month delay in approval to launch development of a replacement for the US Marine Corps' (USMC) ageing CH-53E Super Stallion, but could still begin preliminary design work and an engine selection process next month.

Senior US military officials have pushed back a final go-ahead decision from late 2004 until late April or May 2005. At that point, the US Defense Acquisition Board will decide whether the CH-53X - now renamed the Heavy-Lift Helicopter Replacement (HLR) - programme can be moved immediately into a 10-year development and demonstration phase.

Congress allocated $103 million in fiscal year 2005 to launch risk reduction work on the USMC's projected 154-aircraft order, and Sikorsky is expecting an "imminent" contract award, says David Haines, the company's H-53 programme manager. The money will enable Sikorsky to refine designs for an advanced rotor with a "cathedral"-shaped blade tip, which will add 2,270kg (5,000lb) more lift by using a dihedral-anhedral surface.

Sikorsky also can use the 2005 funds to get an engine competition under way, with a solicitation to be issued by February or March expected to draw at least four contenders. Candidate engines include the General Electric GE38 and Pratt & Whitney Canada PW150, plus uprated versions of Honeywell's T55-715B and the Rolls-Royce AE1107C that powers the USMC's Bell Boeing V-22 Osprey tiltrotor.

The R-R engine would allow the marines to share a logistics and training base between the HLR and V-22 programmes, but Sikorsky has plans to negate that advantage. Haines says one option is to propose that any engine selected for the HLR in early 2006 will also be retrofitted to the V-22.

If the HLR is approved for development in early 2005, Sikorsky has plans to complete a preliminary design review by 30 June 2006 and a critical design review by 30 September 2008.

First flight of the new aircraft would occur in mid-2011, and the first operational unit would be fielded before September 2015.


Source: Flight International