GUY NORRIS / LOS ANGELES
The US Navy will begin modernising its first squadron of Northrop Grumman E-2C Hawkeye airborne early warning aircraft with a new eight-bladed propeller in April or May. Vibration problems that delayed the programme by around a year have been overcome.
Carrier-suitability trials of the new propeller, which will also be fitted to the navy's C-2AGreyhound turboprop transports, were conducted from the USS John F Kennedy last November. Supplied by Hamilton Sundstrand, the NP2000 propeller is based on the Ratier Figeac six-bladed unit used on ATR 42/72-500 regional airliners. They will replace the four-bladed Hamilton Sundstrand 54460 design now used by the E-2 and C-2 fleets.
Naval Air Systems Command, which began flight tests of the eight-bladed propeller at its Patuxent River base in Maryland in mid-2000, will modify all E-2C Hawkeye 2000s and C-2 transports by the end of 2006. The new composite propellers will also be installed on those Advanced Hawkeye aircraft due for procurement through 2009.
Despite the greater number of individual blades, the navy says the upgraded set has a reduced parts count. Other benefits of the design include the ability to replace individual blades on-wing, and a maintenance control device that allows the propellers to be balanced from inside the aircraft.
As well as being compatible with the navy's Rolls-Royce T56-427 engines, the new propeller is also compatible with possible future replacements, such as the Rolls-Royce AE2100 and Pratt & Whitney Canada's PW150. The likelihood of an engine replacement for the E-2 appears to have receded, however, since the cost of the Advanced Hawkeye system development and demonstration programme has escalated to over $2.1 billion.
Source: Flight International
