Story ID: 
Bell's 525 Relentless Logs First Flight
By: Mark Huber
Caption: The new super-medium twin features sidestick fly-by-wire controls.
Word Count: 502
After 21 hours of ground testing, Bell Helicopter flew the 525 Relentless super-medium twin for the first time July 1 from its assembly plant in Amarillo, Texas. Despite wind gusting to 20 knots, the 525 taxied, hovered and flew maneuvers to assess low-speed controllability with Bell senior test pilots Troy Caudill and Jeff Greenwood at the controls. Caudill said the helicopter performed “extremely well. It flies better than it does in the simulator.”

The 525 is the first commercial helicopter equipped with sidestick, triple-redundant fly-by-wire controls and the Garmin G5000H touchscreen avionics system. It will be certified to perform Cat-A takeoffs and landings at maximum takeoff weight. Power comes from a pair of GE CT7-2F1 turboshafts (1,800 shp each) driving an all-composite five-blade main rotor and a four-blade tail rotor. The 525 is Bell’s largest civil helicopter, with a rotor disc diameter of 54.5 feet, and features hybrid aluminum/composite construction. It is expected to have a max cruise speed of at least 155 knots, range of 500 nm, an mtow of 19,300 pounds and a useful load of 7,400 pounds. In high-density configuration there will be seating for up to 20 passengers. The 525 features a 4.5-foot-tall cabin with 88 sq ft of floor space and a 128-cu-ft baggage hold.

The 525 will offer various mission kits but is aimed primarily at the offshore energy market. Bell has received orders and letters of intent for more than sixty 525s since it unveiled the program in 2012. While the OEM has not disclosed a price, it is expected to be in the $20- to $24 million range. Two more test aircraft will join the program this year, followed by another two next year. The first two aircraft will be used for flight envelope expansion and the third will assess load levels. Bell expects the five aircraft to log 1,500 hours of flight-testing before certification and deliveries in 2017. It intends to begin assembling production aircraft later this year. Earlier this month the company revealed that supplier issues have caused the program schedule to slip by several months.  

Larry Thimmesch, Bell vice president of the 525 program, said the aircraft has 200 suppliers providing 10,000 parts and that “there were some growing pains getting all the suppliers up to speed and maturing the supply base to production. It’s a learning journey not just for us, but also for our suppliers. We have a great supplier base and we are continually communicating with them.”

Thimmesch said Bell has set aggressive targets for the program “both in terms of performance and schedule. We use our targets to drive best performance, to get best performance out of the team, and the team has done well. It is not a surprise that we are several months behind, but we are well within the realm of [what is expected on] a clean-sheet aircraft with fly-by-wire technology coming together for the first time.”

The next two test aircraft are in assembly, as are a fuel cell drop test article and a fatigue test article, Thimmesch said.