US Forest Service's fleet renewal plans stuck in limbo as two-thirds of its multi-engined fleet remains inactive

Two-thirds of the US Forest Service's multi-engine air tanker fleet is likely to remain inactive for wildland firefighting next year.

At most, nine of the 33 large air tankers owned by US operators eligible to respond to a contract tender expected to be issued this month will be available for next year's firefighting season. Seven Lockheed P-3s operated by AeroUnion and two Lockheed P2Vs, operated by Neptune Aviation and Minden Air, are cleared for flight operations to date.

The rest of the fleet remains inactive seven months after the US National Transportation Safety Board concluded that there was no means to verify the airworthiness of the large air tanker fleet, which has suffered three in-flight break-ups since 1994.

That ruling prompted the Forest Service to sever contracts with the multi-engine fleet operators on 10 May, effectively grounding the aircraft unless operators could provide evidence the aircraft meet airworthiness standards.

DynCorp Technical Services has been contracted to perform inspections and analyse operations and maintenance records for the entire air tanker fleet. The Forest Service is still waiting for the final report, but a senior agency official says he is not optimistic about the results for the remainder of the fleet.

US aerial firefighting operations also rely on hundreds of single-engine air tankers and helicopters that fall under the authority of the Bureau of Land Management. BLM added dozens of these smaller aircraft, with payloads ranging from 1,150-4,550 litres (300-1,200USgal), to compensate during an unexpectedly mild firefighting season last summer. Four privately owned Bombardier CL-215 amphibians were also enlisted to help contain the worst of the blazes in Alaska.

But the loss of the 6,100-9,100 litres-capacity payloads of the large air tankers was seen as a major blow to the government's ability to attack fires in their early stages. US firefighting tactics focus on dumping retardant around the perimeter of a fire as a containment method, which requires aircraft capable of dousing the ground in long strips.

The forest service also is considering an option to equip the active P-3 fleet with structural health monitoring systems before wildland firefighting operations begin next year. The goal is to gather data on how the low-altitude, turbulent characteristics of aerial firefighting affect the mostly 1950s-era large air tanker fleet.



Source: Flight International