A GROWING DEBATE is emerging over the impact of weight increases on the Boeing Sikorsky RAH-66 Comanche scout/ attack helicopter, with one critic claiming that the problem needs to addressed urgently if the helicopter's operational capability is to be unaffected.

Boeing Sikorsky and Pentagon programme managers claim that, despite a weight growth of more than 450kg, the aircraft can still meet "performance parameters".

A US Department of Defense-funded independent report into the project warns that, "-if the programme is to be continued, it should be restructured with additional funding so that weight problems can be addressed promptly".

The RAH-66 was originally designed around a 3,400kg maximum empty weight. The prototype now weighs nearly 4,000kg. Brig Gen James Snider, the US Army's Comanche programme manager, says that 4,000kg is the "top limit" in terms of weight increase before the helicopter's performance is adversely affected.

Art Linden, Boeing Sikorsky programme director, says that the weight growth since 1991 is not a major concern because the aircraft is still 90kg below the maximum empty weight. He believes that there are many options to recover performance and reduce weight on the production aircraft.

Linden says that the weight increase is caused by the addition to the aircraft of the Longbow fire-control radar, cockpit-safety enhancements and an image intensifier. The assessment runs counter to a report written by a long-time critic of the project, Robert McDaniel, a consultant with Analytic Engineering Services, of Alexandria, Virginia.

"Continuing with the current programme-would result in increasingly more evident failures and schedule delays to the detriment of the acquisition process, with little likelihood that a satisfactory operational system would result," warns his Pentagon-funded report. "If a management shake-up is not forthcoming, the Comanche should be terminated and a new concept addressing the needs of the next century should be defined in concert with the Marine Corps," he contends.

McDaniel says that "-the overweight condition of this magnitude is without modern precedent" and that experience shows that "-we will almost certainly have further weight increases".

Source: Flight International