ASC-II second generation advanced structural composite propeller

Citation

(2007), "ASC-II second generation advanced structural composite propeller", Aircraft Engineering and Aerospace Technology, Vol. 79 No. 1. https://doi.org/10.1108/aeat.2007.12779aad.020

ASC-II second generation advanced structural composite propeller

ASC-II second generation advanced structural composite propeller

Hartzell Propeller, Inc., recently announced that it has received FAA certification for its new ASC-II second generation advanced structural composite propeller system. Hartzell's ASG-II is the first FAA certified advanced structural composite propeller developed specifically for the genera! Aviation market (Figure 2).

Hartzell's ASC-II is the result of the company's nearly 30 year experience in the design and manufacture of advanced structural composite propellers. The Hartzell ASC-II is an optimized design mated to a proprietary, Hartzell-developed manufacturing process. The result is described as an advanced structural composite propeller that delivers all of the advantages provided by Hartzell's first generation of composite propellers – low weight, low inertia, and low life cycle costs – while minimizing the major disadvantage: the high cost manufacturing process.

Figure 2 Hartzell Propeller's second generation advanced structural composite propeller, the ASC-11e

The Hartzell ASC-II consists of a monocoque structure of advanced composite materials. Its carbon/Kevlar laminate is integrated into a co-molded stainless steel shank. The outboard half of the leading edge is protected with a co-molded electroformed nickel erosion shield. Aluminum mesh is embedded into the laminate for lightning protection.

The new design claims numerous benefits to aircraft owners:

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  Lighter weight. Hartzell's ASC-II blades weigh 30 percent less per blade than comparable metal blades, providing greater useful load and moving the aircraft center of gravity away from the propeller, often creating more versatile loading capability.

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  Lower inertia. Propellers with ASC- II blades provide dramatic reductions in inertia, which is vitally important for aerobatic aircraft to minimize the gyroscopic effects of the propeller and often means lower vibration and smoother operation for GA aircraft.

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  More durable. Properly maintained, the Hartzell ASC-II blade will reportedly never require replacement because, unlike a metal blade, its surface can be restored. While erosion of metal blades eventually requires blade replacement, erosion damage to the Hartzell ASC-II blade can be repaired. The durability and repairability of the Hartzell ASC-II results in lower maintenance costs over its life.

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  Higher performance. Typically composite blades cannot quite match the performance of metal blades, since metal blades can be produced with the thin airfoil sections needed for maximum performance. The use of carbon in combination with Hartzell's proprietary manufacturing process yields a strong, yet thin, monocoque structure that permits the use of thinner airfoil sections at the blade tips and performance comparable to metal.

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  Higher strength. The Hartzell ASC-II uses carbon and Kevlar materials to make the structural part of the blade, creating an extremely high strength advanced structural composite blade that is stronger than other composite propeller blades.

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  Proven design. Passing the rigorous certification process provides assurance that the Hartzell ASC-II design is well proven. As the only certified advanced structural composite propeller in the GA market, the Hartzell ASC-II has lived through a simulated encounter with a four pound bird at rotation, taken a direct hit of 200,000 amps of electricity to prove that it can survive an encounter with lightning, and withstood a direct pull of 132,000 pounds reaching the limit of the test fixture without failing (6.8 times the normal Cf load) to demonstrate a safety margin in the event of an engine overspeed. These special tests were performed in addition to the normal battery of fatigue and endurance tests designed to demonstrate that the propeller will have a long useful life and flight tests that ensure stress levels fall within allowable limits for safety.

Details available from: Hartzell Propeller, Inc., Tel: +1 937 778 4200, Fax: +1937 778 4321, web site: www.hartzellprop.com