Van Horn Aviation recently shifted its development priorities to focus on the 206 main rotor blade program after the MD500 main blade flight test program was cut short by unexpected unavailability of the test aircraft.
From May through August 2013, VHA and MD Helicopters personnel prepared the loaned MD530F for flight test, installing strain gages and other instrumentation on the aircraft and the VHA composite main rotor blades. Following successful hover tests at the VHA facility in August, the instrumented MD530F returned to the MD Helicopters facility for forward flight tests. Over the next four months, the VHA flight test team achieved successful track and balancing of newly redesigned blades, high-g maneuvers, and forward flights to 130 kts.
VHA had expected to complete flight test testing on the loaned MD530F to FAA certification standards and bring the rotor blades to market early in 2014. However, MD Helicopters determined they had other priorities for the loaned aircraft and terminated the flight test program in early December.
This was the third round of flight testing since the program began in April 2011. VHA’s challenge was to replace the current metal symmetrical airfoil main rotor blades with a NASA-developed laminar flow composite airfoil while implementing minimal control system modifications. The MD500 series’ non-hydraulically boosted control system and tailored collective stick balance spring proved to be particularly sensitive to changes in main rotor blade design. During the VHA MD500 main rotor blade development program, VHA engineers completed several design modifications including trim tab alteration, root fitting changes and center of gravity (CG) adjustments.
The ability to fly the latest iteration of the VHA composite blades to 130 kts on a helicopter with a maximum cruise speed of 134 kts proved the success of the VHA design. The knowledge and experience gained from the MD530F flight test program will be carried over to the 206 main blade program. While the loss of the MD530F test ship forces refocusing of VHA priorities, VHA intends to resume certification testing of the MD500 series main and tail rotor blades after purchasing its own test helicopter in fourth quarter 2014.