WASHINGTON — The CH-53K King Stallion, the Marine Corps' next-generation heavy-lift helicopter, took its first flight Tuesday at Sikorsky's test facility in West Palm Beach, Florida.

The entire flight test lasted about 55 minutes including taxiing on the runway, but the helicopter was in the air for about 30 minutes, Stephen McCulley, Sikorsky's chief test pilot for the CH-53K, told reporters in a teleconference.

"This aircraft flew just like we expected it to fly from the simulation, there were no surprises," McCulley said, adding he was "extremely happy with the aircraft response."

The first flight marks a significant and long-awaited milestone for the approximately $25.5 billion CH-53K program. The aircraft will replace the CH-53E Super Stallion helicopters and provide 50 percent more power that will allow it to transport more Marines and gear and at higher altitudes. The plan is to eventually buy 200 aircraft and the program is still on track to reach initial operational capability in 2019.

"When you look at the future of joint warfighting concepts the US military has put together, the 53K is viewed as one of the very key enablers of those warfighting concepts," said Col. Hank Vanderborght, the Marine Corps' heavy-lift helicopters program manager.

But the helicopter's first flight has been pushed back several times. It was supposed to fly in the summer of 2014, but was delayed to late 2014 and then to the summer of 2015. Some of the delay had to do with problems with the helicopter's gearbox.

Neither Sikorsky nor the Marine Corps were able to quantify how much such a delay cost the program, but said the gearbox problem set the program back by seven months and "before that there were other technical issues — probably a half dozen or so technical issues — that we were working collectively as a program," Vanderborght said.

However, "this is probably the most mature in terms of aircraft maturity that we have gone into a first flight inside the history of naval rotorcraft," he added. The aircraft has its fully functioning software on board, according to Vanderborght. The aircraft is more software-intensive than the legacy helicopters.

"We have over 200 hours of turn-time on the ground test vehicle. It is, in essence, a fully flyable aircraft," he said. "We have really wrung out the systems quite a bit, both the hardware and software in that aircraft ... We feel good about going into the flight test program from here on because we have spent all this additional time ... really developing both the software and hardware and I think that is really going to pay off as we progress into the flight test program."

Michael Torok, Sikorsky's vice president in charge of the CH-53K program, added that the delays were "obviously from an event driven process.You need 100 percent of everything to work before you can safely proceed to the next step."

While the program had "a handful of challenges we were working through," Torok said. "The balance of the program was continuing on."

Triple hook lifting capability. Sikorsky Aircraft
Triple hook lifting capability. Sikorsky Aircraft

Sikorsky's CH-53K King Stallion has triple hook lifting capability.

Photo Credit: Sikorsky Aircraft

The team continued to develop software elements that were originally planned to be developed during flight tests, according to Torok, but they are now complete. Also, the program pushed a "huge maintenance demonstration" ahead of schedule that was planned for two years down the road. "We have completed almost a third of that already," he said.

"I think the real total impact, from both a cost perspective and schedule perspective, we won't know until maybe six months to a year from now as we fly the aircraft," Torok said. "If it continues to fly like, granted just the first 30 minutes, but exactly as we expected and no surprises, we have great opportunities to recover some of those impacts as we go through the program."

Torok also noted that the problems so far have not been related to the key technologies required to make the aircraft capable of three times the lift, all within the same or less footprint of the legacy aircraft.

Sikorsky is still building three more test aircraft. The four aircraft will fly a total of 2,000 hours over the course of the next three years.

Torok said one aircraft is sitting in the hangar next to the first test aircraft and is finishing up instrumentation procedures. That aircraft will be ready to fly by the end of the year and will likely have its first flight in January. The other two aircraft are being assembled at a nearby Sikorsky facility. A gearbox for one of the aircraft "should be arriving shortly," Torok said, with the second to follow a couple of months behind.

"By mid-year next year, we will have all four aircraft up and into the test flight program," he added.

The program is expected to reach its production and deployment milestone review period in the second quarter of Fiscal Year 2017. It was originally scheduled for the last quarter of FY16.

Twitter: @JenJudson