Navy to Begin Flight Testing Eight-Blade Composite Propellers for E-2C.

The U.S. Navy plans to begin flight-testing E-2C Hawkeye aircraft equipped with new eight-blade, all-composite propellers. The Hawkeye is the Navy's carrier-based early warning and control radar plane, which has been in the fleet since 1973.

Flight tests originally were scheduled to start last month but were delayed until December.

Officials believe that this new system, called NP2000 (for Navy propeller 2000), will be easier to maintain than the current four-blade, steel-spar propellers. The NP2000 propeller system is controlled digitally and will replace the current Hamilton Sundstrand 54460-model electro-mechanical, steel-spar propeller that currently is used on all Hawkeye and C-2 Greyhound aircraft. The C-2 is a carrier-based transport airplane that can carry 28 passengers or deliver up to 10,000 pounds of cargo. It has been in service since 1985.

Hamilton Sundstrand received a contract award for NP2000 in October 1997. The system has undergone 200 hours of testing since that time, said Rear Adm. J.A. Cook, vice commander of the Naval Air Systems Command, at Patuxent River Naval Air Station, Md. He spoke during a roll-out ceremony for the NP2000 in late August.

The NP2000 will enter service in 2002, he said.

"We bought the [NP2000] props before we actually tested them," said Navy Capt. N.L. Lilly, program manager for the E2-C and the C-2A. "That scared the acquisition people," he added. But he believes that action was necessary, because "lots of money was being spent on prop repairs," with the old system.

A diminishing supply of 54460-model propeller blades in the United States also contributed to the Navy's decision to seek a replacement system. The NP2000 is made by Hamilton Sundstrand Corporation, in Windsor Locks, Conn. The company's vice president for flight and undersea systems, Jim Gingrich, said the new props will enable on-wing blade replacement and field repair of erosion damage.

He said that NP2000 is the first eight-blade propeller system produced by a U.S. contractor. The Sundstrand Company, later acquired by Hamilton Standard, delivered 500,000 props during World War II and built the props used in the famed "Spirit of St. Louis," plane flown by Charles Lindbergh.

Navy Lt. Cmdr. Steve Schmeizer, E-2C project officer, said the old metal propellers are getting "old and cracking." The blades are controlled hydro-mechanically, using pulleys and levers, making them susceptible to oil intrusion and to sea-water corrosion. The new, swept, composite blades, he said, will be operated electronically, making the maintenance less costly and less labor intensive. "They offer a 10-fold increase in mean time between depot repair actions," Schmeizer said in an interview after the rollout ceremony. The new system allows maintenance crews to remove blades individually, versus the old props, where the blades cannot be removed one at a time. The estimated cost for each NP2000 system is $195,000, Schmeizer said.

Lilly said that the new propellers will be in the fleet next year for operational test and evaluation. "We will take the same propellers and put them on the C-2 for the C-2 service life extension program," he said.

In the future, he said, the eight-blade system could be considered for the P-3 Orion aircraft or even the C-130 Hercules, which has a six-blade propeller. The latter option, he said, is considered a "sensitive topic."

Hamilton Sundstrand will deliver 182 propeller systems between 2001 and 2005, said the company's NP2000 project manager, Mike Stewart. The Navy plans to have them installed in the newer versions of the E-2 and the C-2.