Lockheed Martin and Chico, California-based Aero Union are in early talks over the possibility of using the US Navy's shrinking fleet of Lockheed Martin S-3B Vikings as waterbombers as they retire from active service.

"We're currently talking to several operators about possible roles and missions for the S-3s that are currently undergoing the sundown plan with the [US] Navy," says a Lockheed Martin spokesman at Farnborough. "Firefighting is one of those particular missions we're looking at."

Terry Unsworth, Aero Union's president and chief executive, says: ""We've done some preliminary work with Lockheed Martin, but still have a lot to do yet. We've done some basic feasibility work."

The number of aircraft in which Aero Union would be interested has not been fixed but would be "probably up to 40", says Unsworth.

He sees certain qualities in the S-3B that would potentially suit it for the waterbombing role, which can involve tight manoeuvring at low altitudes so as to dump loads of water or fire-retardant slurry accurately.

"It's built for operations in medium turbulence and obviously, being a carrier aircraft, it's built for strength."

He says that a converted S-3B would probably carry around 7,600 litres (2,000 US gallons), either in the existing bomb bay area or in a belly tank. Aero Union has its own manufacturing division, which has carried out similar conversions on other types in the past. From the time of receiving an S-3B, "we would need 12 months before roll-out of the prototype," says Unsworth.

Aero Union, in common with other US firebombing companies, was affected by April's ruling by the National Transportation Safety Board - investigating three in-flight break-ups of large air tankers since 1994 - that no mechanism existed to ensure the airworthiness of the waterbombers.

Although the fleets of ageing Douglas DC-4s, DC-6s, DC-7s and Lockheed P2V Neptunes and P-3 Orions were not grounded, many are unlikely to fly again for the firefighting branches of the US Bureau of Land Management and the US Forest Service. (Flight International, June 22-28)

The carrier-based S-3B fleet, whose role moved from anti-submarine missions to anti-surface warfare and aerial refuelling, is being wound down over the next five years. Most still have substantial fatigue life remaining.

Source: Flight Daily News