A DC-10-10 airliner modified for aerial firefighting is making a spectacular debut at this year’s show. The DC-10 Super Tanker dumps 7,000 U.S. gallons of water in only eight seconds along the airshow flightline, from a series of external tanks mounted along the centerline (see picture page 1).
Quietly developed over the past two years by private U.S. investors, the capability could be a crucial counter to devastating wildfires such as those that ravaged southern France and the western U.S. last year.
The 10 Tanker STC company is a joint venture between the principals of Omni Air International, a U.S.-certificated carrier already operating DC-10s, and Cargo Conversions, owned by Rick Hatton. The joint venture hopes to achieve Federal Aviation Administration certification (inclusive of FAR 36 Stage III noise compliance) in July. The tank installation and flight tests have been taking place at Victorville Airport, the former George Air Force Base at the edge of the Mojave Desert in southern California.
Hatton told Aviation International News that the water dump system uses the computerized gravity-feed system favored by the U.S. Forest Service. The drop rate is controlled from the cockpit and is governed by the extent to which the tank doors are opened. It can be adjusted to meet the requirements of firefighters on the ground: the maximum drop is 12,000 U.S. gallons at a rate of 1,500 gallons per second. “Essentially, we’ve taken the system that was proven by Erickson Air-Crane on its S-64 helicopter and scaled it up for the DC-10,” he said.
The aircraft has an operational radius of 500 nm when fully loaded and a ferry range of 3,000 nm. In an area the size of the U.S. or Australia, five aircraft could be positioned so that any fire could be reached within one hour. The tanks can be refilled on the ramp in eight seconds.
Airshow rules limit the drop height here to 300 feet, but this can be as low as 150 feet at a speed of 142 knots, “providing excellent maneuverability, stall margin, and pullout capability,” according to Hatton.
The flying qualities have been tested in a simulator, as well as on this airplane and a DC-10 freighter at “significantly higher weights than the Super Tanker will operate,” he added.
After certification, 10 Tanker intends to offer the firefighting service itself, and Hatton sees an initial market for multiple aircraft. The company will perform aerial demonstration drops here at approximately 3.30 p.m. from today until Thursday.
