Flight-testing of new
advanced composite rotor blades for the Boeing-built AH-64D Apache
Longbow logged an important milestone on Thursday, Nov. 6, as part
of a program designed to enhance the performance of the aircraft
while reducing its overall operating costs.
The flight test was a key milestone in the proposed Block III
upgrades for the U.S. Army. Lasting 30 minutes, the test included a
variety of forward, rearward and sideward maneuvers to confirm the
structural integrity of the blades. All points on the test card
were successfully completed. Produced by Boeing in Mesa, Ariz., the
advanced composite rotor blades are designed to have longer service
lives than the standard metal blades now in service on the
The test flight followed four years of development by Boeing and
the U.S. Army/Industry Apache team. The new blades, flown by PVD001
the first production Apache Longbow, use advanced composites that
were not available when the Apache Longbow was introduced in the
Use of advanced analytical tools led to significant cost
reductions in the composite blade manufacturing process. In
addition, the new blade is designed to result in a much longer
operational life As a result the new main rotor blades will cost
approximately 25 percent less than the current blades, and have
almost double the operational life. That means an estimated 50
percent reduction in O&S costs.
The advantages of composite construction allowed the designers
to incorporate more aerodynamically efficient airfoil shapes and a
higher overall twist rate that will result in improved hover and
forward flight performance for Apaches equipped with the new
To further enhance the performance capability of the proposed
Block III Apache, the new blade has been designed to the higher
3,400 maximum horsepower limit of the Block III upgraded drive
system design. The composite blade has been extensively evaluated
with full-scale component live fire tests to confirm that the new
design will meet the same stringent ballistic tolerance
requirements of the current design.
Flight testing is expected to confirm analytical predictions
that the vibrations transmitted to the airframe from the new rotor
design are at least as good as the current rotor and likely better
in many operating regimes. The new blade design is expected to
complete qualification testing in time for incorporation on the
first Block III production aircraft.
Additional key elements of the U.S. Army’s proposed Block
III upgrades for the Apache Longbow include enhanced engines and
drive systems, the Joint Tactical Radio System, increased
situational awareness, improved target detection and acquisition
and other enhancements that would enter production after the
completion of the Block II upgrades in 2006.
The blade has been design to fit all fielded aircraft (AH-64A
Boeing is delivering 269 AH-64Ds to the U.S. Army through the
year 2006 under the second of two multi-year contracts. The first
contract, Multi-Year I covered 232 Apache Longbows for a total of
501. Boeing builds AH-64D Apache Longbow helicopters for the U.S.
Army and for several international defense forces.