Raisbeck Engineering (Booth No. C7326) is highlighting its new swept-blade propellers for all King Air C90-series turboprop twins here at NBAA 2013. Deliveries of the blades, which sweep on both the leading and trailing edges, will begin in January. Raisbeck has been delivering swept blades for the King Air 200 series since the beginning of this year.
Blade quarter-chord sweep on the King Air 90-series propellers has been increased to 30 degrees at its outer diameter and the diameter has been lengthened by six inches, to 96 inches. These changes are so stark that Raisbeck said the new blades are the “most visible” of the King Air improvements it has done over the past 31 years.
Besides its visual appeal, the propeller blade sweep allows the increase in diameter while simultaneously reducing noise and improving thrust and efficiency. According to Raisbeck, cabin noise levels have been reduced on the C90GTx by 1.6 dBA to 74.6 dBA with the new propellers. Meanwhile, at a mtow of 10,500 pounds, takeoff distance over a 50-foot obstacle is 2,150 feet flaps-up, an 850-foot reduction from the stock C90GTx. Landing distance over a 50-foot obstacle is similarly reduced by 360 feet to 2,120 feet at maximum landing weight without propeller reverse; with reverse, it is only 1,580 feet.
Raisbeck is also showcasing a prototype of its 28-cu-ft aft-fuselage locker for the Learjet 60 at its NBAA booth. Currently in development and expected to be certified early next year, the modification adds up to 300 pounds of extra cargo capacity without any performance penalties. The space is large enough to carry full-size golf bags and large luggage outside of the cabin, Raisbeck said.