Heavy Lift Helicopters is close to finalizing the design of the tank system for its ex-U.S. Marine Corps CH-53D Sea Stallion conversion. However, the U.S. Navy has withdrawn from an agreement to supply up to six airframes that would have provided components to keep the two “Fire Stallions” operational.

Chief pilot Mike Gilpin told AIN that, in spite of this setback, the company is continuing to work on the pair it has at Victorville, Calif. According to Gilpin, the company was ready to cut metal at the end of last month and planned to have an STC in place by June next year. “We will try to fly both helicopters and buy spares as we need them,” he added.

Heavy Lift, a division of Rogers Helicopters, is reducing the weight of the -53D by about 1,000 pounds to fit a 2,400-gallon tank and snorkel system, designed with the help of Oregon-based Simplex Manufacturing. The weight reduction comes as a result of “removing military-specific avionics and wiring, and substituting a lighter, non-folding rotor head for the installed Navy unit,” said Gilpin.

He added, “One of the advantages of having an internal system is that its speed is not affected, and the -53D flies faster than the larger CH-54 anyway. We will also retain the external hook, giving it the flexibility to carry Bambi buckets if the situation dictates.”

Heavy Lift acquired the CH-53Ds from a U.S. Navy storage facility in Arizona last year. Certified by the FAA under its recently amended restricted category, the Fire Stallion will remain a converted ex-military helicopter rather than a “standard” S-65. (Sikorsky built only one of the helicopters.)

Heavy Lift president Robin Rogers said, “The CH-53 gives us a lot more speed for initial attack and, because it also has a nice range, we can stay on site longer because we haven’t burned all of our gas getting there. The CH-53 can fly for 3.5 hours; the Skycrane has only around two hours.”

The conversion progresses as the CH-53 celebrates 50 years in front-line service. It started flying with the U.S. Marine Corps in September 1955.