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The CH-53K flight test program is expected to accumulate around 2,000 flight hours over a three-year period. Sikorsky Photo
The CH-53K “King Stallion” helicopter has performed its long-awaited first flight, taking to the air on Tuesday, Oct. 27 at Sikorsky’s Development Flight Center in West Palm Beach, Fla.
The maiden flight involved basic taxi work and hovering maneuvers, lasting a total of around 55 minutes. “This aircraft flew just like we expected it to fly,” Sikorsky CH-53K chief test pilot Stephen McCulley reported in a media conference call shortly after the flight. “There were no surprises.”
The super-heavy-lift CH-53K — which will have a projected maximum gross weight with external load of 88,000 pounds (39,916 kilograms) — is the replacement for the U.S. Marine Corps’ CH-53E Super Stallion. Powered by three 7,500-shaft-horsepower-class T408-GE-400 engines, the CH-53K will be able to lift up to three times more than its predecessor, which is already the largest and heaviest helicopter in the U.S. military fleet. The Marines expect to buy 200 of the new-generation King Stallions.
The CH-53K was originally projected to fly in 2014, but that target was pushed back due to engineering problems, notably with the main gearbox. “We’re an event-driven program, so we do not fly unless we’re ready to fly,” explained USMC Col. Hank Vanderborght, program manager for Heavy-Lift Helicopters. “We did have some technical issues with our main rotor gearbox, and the collective engineering team, program team did a great job in the last five months resolving those issues. Everything has now checked out, as evidenced by the successful first flight today of the aircraft.”
Despite the delays, Vanderborght expressed confidence in the program, telling reporters, “Like any program, we’ve built margin into our schedule. We’ve eaten up some of that margin, but right now we’re still targeting an initial operational capability in 2019.”
Sikorsky’s CH-53K ground test vehicle has already accumulated more than 220 test hours, one reason why the first flight test aircraft took to the air with a high level of maturity. Sikorsky Photo
Tuesday’s milestone marks the beginning of a flight test program that will encompass four flight prototypes, which are expected to accumulate a total of around 2,000 flight test hours. According to Sikorsky’s VP for the CH-53K program, Dr. Michael Torok, The next prototype in the flight test program is currently in the hangar at West Palm Beach having instrumentation work completed. That aircraft will likely fly in January, while the remaining two prototypes should join the flight test program by mid-2016, Torok said. Close behind them on the assembly line are the first two of four aircraft that will be used for operational evaluation at the end of the three-year flight test program.
The program has already logged more than 220 test hours on a non-flying prototype “ground test vehicle” in West Palm Beach, which has been used to resolve engineering issues and validate aircraft systems. That, along with extensive use of simulation throughout the development process, has allowed the program to take to the air with a high level of aircraft maturity, including fully functional software.
“If I personally look at the history of Naval rotorcraft, many many times we’ve gone into first flight without having full functionality software, and a much lower level of maturity,” said Vanderborght. “We’ve really wrung out the systems quite a bit, both the hardware and the software, in [the ground test] aircraft. And so we feel good about going into the flight test program from here on.”