Boeing/Sikorsky is to undertake a $50 million mini-redesign of the RAH-66 Comanche by year-end, aiming to shed nearly 91kg (200lb) from its overall weight. The move, which will produce an increase in vertical climb rate, is designed to pre-empt the US Army's forthcoming review of its aviation portfolio.

Programme officials say the Comanche's design will exceed weight targets during early production lots, with planned enhancements to be introduced with the third lot increasing airframe weight to 4,585kg or about 68kg over target.

Officials say each extra pound (0.454kg) trims 1ft/min (0.005m/s) off the helicopter's vertical rate of climb, a critical performance parameter. Even at its projected weight, the Comanche falls within the army's required 2.28-3.8m/s vertical climb requirement.

About 600 weight saving ideas were proposed during a Comanche "weight summit" in late August, to which helicopter, fixed-wing and spacecraft designers were invited. Solutions included replacing metal components with compo- site items in areas such as the transmission housing and weapon launcher.

Meanwhile, the Comanche's future is subject to a review of army aviation launched by incoming Chief of Staff Gen Peter Schoomaker. A taskforce of doctrine, acquisition and operational experts is due to report by 1 November following a review of the army's fleet mix and possibly a consolidation to two airframes from the army's portfolio, which includes the Boeing AH-64 Apache, CH-47 Chinook, Sikorsky UH-60 Black Hawk and Bell OH-58 Kiowa Warrior.

The army says another focus of the taskforce is to examine the long-range strike doctrine using attack helicopters, a subject of intense debate since an Iraqi ambush on 23 March resulted in the loss of one Apache and rendered 28 more unflyable for several days.

Source: Flight International