Three Good, Four Better; Is Eight Enough?

Northrop Grumman Corporation's Integrated Systems sector and teammate Schweizer Aircraft Corp. have extended their string of successes in developing a new four-blade rotor for the U.S. Navy's RQ-8 Fire Scout vertical tactical unmanned aerial vehicle (VTUAV).

The two companies conducted a successful test flight of the new rotor on a Fire Scout manned prototype helicopter April 18 at Schweizer's Elmira (NY), facility, including ground, hover, taxi and flight evaluations.

The new four-blade rotor will extend Fire Scout's range, payload and endurance. To date, the Northrop/Schweizer team has conducted 20 test flights with the new rotor hub mounted on a Schweizer Model 333 helicopter.

For the latest flight, the rotor hub with four Fire Scout blades flew a 45-minute test flight that included hover in and out of ground effect, traffic pattern flight, and an up-and-away flight to 2500 feet at 108 knots.

"The performance and flight properties of the aircraft were exactly as predicted," said Carl Olson, Schweizer's test pilot. "We set a speed limit of 108 knots for this first flight and at that speed, the helicopter was definitely more stable and more responsive with the four-blade system."

Upgrading the Fire Scout system with the four-blade rotor will not require any major mechanical or structural changes. The new configuration operates with the VTUAV's existing transmission and engine.

The Navy and Northrop Grumman's Unmanned Systems operating unit began the Fire Scout system's flight test program in May 2002. To date, they have conducted 40 successful flights, with the 3-blade design (lower photo). Preparations are now being made to begin land-based take-off and recovery flight-testing with the UAV Common Automatic Recovery System. This testing, scheduled to occur in May at the Webster Field UAV test facility at Naval Air Station Patuxent River (MD), is a precursor to shipboard testing in August this year.

The Fire Scout flight test program continues to expand the air vehicle's flight envelope and refine its collection and dissemination of imagery from the onboard sensor payload. Flight tests to demonstrate laser targeting and designation are also scheduled in May. A weapons delivery demonstration is planned for later this year.

FMI: www.northropgrumman.com