Third Gulfstream G650 joins test fleet in quest of type certification in 2011

Aircraft incorporates first-ever carbon/PPS rudder and elevators.

Gulfstream Aerospace Corp. (Savannah, Ga.) announced on June 3 that a third aircraft has joined the Gulfstream G650 flight-test program. The first to be fully equipped with the G650’s advanced-avionics system, the plane also is thoroughly instrumented for measurement of aerodynamic loads and to gauge the performance of its ice-protection system. The project was first announced in March 2008, with rollout of the first aircraft in September 2009.

The G650 incorporates innovative composite design and materials in its 4m/13-ft long rudder and 6m/19.7-ft long elevators. The complex, ribbed parts are made with Fortron polyphenylene sulfide (PPS) thermoplastic resin manufactured by Ticona (Florence, Ky.), which is prepregged with carbon fiber by TenCate Aerospace Composites (Nijverdal, The Netherlands and Morgan Hill, Calif.). The parts’ press-formed ribs and two spars are welded to the left-hand and right-hand skins by means of a robotized induction-welding process developed by KVE Composites Group (The Hague, The Netherlands). The method uses the carbon fiber in the part as a heat conductor. Part skins receive an additional autoclave cycle.

The thermoplastic control surfaces weigh 10 percent less and the process results in 20 percent lower cost than the previous composite design, say the suppliers involved. The control surfaces reportedly are the first thermoplastic composite external primary structures to fly. The rudder and elevators recently won the Composites Innovation Award for Aeronautics at the 2010 JEC Composites show in Paris.

Gulstream’s flagship G650 officially entered flight testing on Nov. 25, 2009. As of June 2, this year, the three test aircraft already had completed a total of 75 flights, logging more than 210 flight-test hours. The flight-test program recently achieved two objectives: On May 2, the aircraft flew at its maximum operational Mach number, achieving a top speed of Mach 0.925 at altitude of 42,500 ft/12,954m. Earlier in the year, the aircraft flew at its maximum takeoff weight of 99,600 lb/45,177 kg.

The G650 business jet is designed to offer the longest range at the fastest speed in its class, says Gulfstream. Powered by best-in-class Rolls-Royce BR725 engines, it will be capable of traveling 7,000 nautical miles (12,964 km) at Mach 0.85. The aircraft is expected to receive certification from the Federal Aviation Admin. (FAA) and the European Aviation Safety Agency (EASA) in 2011. Thus far, the G650 is on schedule to enter service in 2012.