First Flight Completed By Van Horn Aviation

Rotor blade manufacturer Van Horn Aviation (VHA) successfully completed a series of ground and flight tests of its composite MD 500 main rotor blades during a four-hour test session at the MD Helicopters Inc. (MDHI) facility in Mesa, Arizona aboard a MD 530F test aircraft. According to VHA president James R. Van Horn, the April 7, 2011 flight test featured the first commercially-developed composite main rotor blades flown on the MD 500 series helicopter since the aircraft was first developed as the Hughes 369 in 1963.

Composite Rotor Blade Test Flight

"This flight test marks a significant step forward in increasing the capability of a well-respected and productive helicopter," said Van Horn. "Our goals in replacing the current metal blades with more efficient composite blades include increasing the helicopter's internal gross weight and nearly tripling the blade life limit while also decreasing aircraft fuel burn rates, overall aircraft noise and direct operating costs."

Greg Ashe, a retired Boeing experimental test pilot who served as the project test pilot on the Hughes 369F model and has more than 800 experimental flight test hours in the MD 500 series, performed all of the ground and flight tests with assistance from VHA and MDHI ground crew.  The test session had three distinct parts:  track and balance of the VHA blades, hover tests, and low-speed forward flight. "(T)he composite blades performed well enough in initial ground and hover tests to take the aircraft into low-speed forward flight on the blade's first flight test," said Van Horn, a former U.S. Army instructor pilot who served as flight test engineer on the VHA MD 500 test session. "Our blades are very stable, even through transitional flight."

The flight test followed a static pull test performed at VHA's Tempe, AZ, facility on March 28, which showed the composite blade could withstand static load of more than 47,000 lbs. The static pull test provided confidence in moving forward with the flight test program. "Another program goal is to create a blade for the MD 500 series that's easier to track and balance," said Van Horn. "We were able to track and balance our blades in a minimum of iterations. The blades responded as expected when trim tab or pitch link changes were made, and they were resonance-free through the entire RPM range."

The VHA MD 500 main rotor blade shares the same NASA-designed laminar flow airfoil, shaped tip, and composite structure as VHA's successful 206B/L composite tail rotor blade, which received a Supplemental Type Certificate from the Federal Aviation Administration in September 2009 and has been in production since. One of the features of the VHA 206B/L blade is reduced overall aircraft noise, and the initial flight of the VHA MD 500 blades seem to confirm that the new main rotor blades will significantly reduce the overall aircraft noise as well.

"You can hear the difference between the metal and VHA composite blades even at a hover," said VHA general manager Dean Rosenlof, who was one of six VHA employees on hand to witness the flight test.

The April 7 flight test confirms the blade's design, which was built with prototype tooling. Over the next few weeks, VHA personnel will design and build the production tooling required to manufacture conformed blades for FAA certification testing.  Flight testing is estimated to resume with conformed blades in third quarter 2011.

FMI: www.vanhornaviation.com, www.mdhelicopters.com