By crosscheckpres on March 11, 2018.
The U.S. Marine Corps is a step closer to taking delivery of a new heavy lift helicopter that will make them the envy of rotorcraft aviators around the world. On February 10, 2018, Sikorsky (a division of Lockheed Martin) performed a maximum performance sling load test as part of its envelope expansion testing for the new CH-53K King Stallion heavy-lift helicopter. The King Stallion is destined to supplant the existing Sikorsky CH-53E Super Stallion in the Marine heavy transport role.
The February 10th test—held at Sikorsky’s flight test facility in West Palm Beach, Florida—lifted a 36,000 pound load and successfully maneuvered both in and out of ground effect. This load is triple what the legacy CH-53E can lift. The total gross weight of the helicopter and the load was 91,000 pounds, which is the highest gross weight ever achieved by a Sikorsky helicopter, and second only to the Russian Mi-26 Halo in vertical lift capability among production model helicopters. View the Sikorsky test video below:
According to Wikipedia, the Sikorsky CH-53K King Stallion is powered by three 7,500 shp General Electric GE38-1B turboshaft engines driving a seven-bladed composite rotor. The design cruising speed is 170 knots, and the service ceiling is 14,400 feet MSL.
Interestingly, the tail rotor on both the CH-53E and K models is canted 20° from vertical. Generally this design feature enlarges the allowable cg range and offers nominal improvements in low-speed stability, but at the expense of significant flight control complexity due to the flight control couplings introduced by the tail rotor vertical lift component.
Stay tuned to the CrossCheck Flight Test Services blog for an upcoming article in the Flight Test Best Practices page concerning helicopter and tilt-rotor sling load testing. Thanks for reading!