The US Army's Aviation Applied Technology Division (AATD) has been asked to look at developing an in-flight refuelling probe and a transportability kit for a Special Operations Force (SOF) version of the Boeing Sikorsky RAH-66 Comanche, as well as assisting in further reducing the weight of the future armed scout helicopter.
The army has provisionally set aside 16 RAH-66s for the SOF out of the planned purchase of 650 machines, possibly as an eventual replacement for its AH-6M Little Bird armed helicopters. Although the SOF has yet to decide how it will employ Comanche or even confirm it will take the helicopter, the programme office is trying to anticipate its need while the helicopter is still in development.
"We recognise that SOF requirements for Comanche are a little bit different in terms of transportability and range," says Col Bob Birmingham, US Army RAH-66 programme manager.
"One of the things I've asked AATD to do is look with the contractor at alternatives and possibilities for a refuelling probe to be developed and integrated on to the aircraft and also a transportability kit that allows for a folding [rotor] flexbeam."
The RAH-66 five-blade rotor is designed around a hingeless flexbeam and adding a fold mechanism will present more of a technical challenge than on the Boeing AH-64 Apache in terms of weight and low observability penalties. Finding an in-flight refuelling probe for the helicopter will present AATD with a similar challenge. The results will go to the army for trade studies and a decision on incorporating the changes into a future Comanche block version.
AATD has also been asked to help identify weight savings on the helicopter, such as the development of lighter armour and replacement of titanium with new material. "We're meeting key performance parameters, but I do have some concerns for Block 3 as aircraft weight continues to grow, as I expect it will. We're going to get very close on the vertical rate of climb of 500ft/min [2.54m/s]," says Birmingham.
Source: Flight International