King Air Propeller

MT 5-Blade Whisper Prop

Natural Composite

The MT Whisper Prop is a Natural Wood composite structure. The core of the blade is a hybrid comprised of Spruce wood and a resin-injected Beech wood at the blade's root. The blade core is protected with carbon face skins that are bonded to the wood core. Unlike traditional composite propellers with a foam core, the wooden core of the BLR/MT propeller is the principle structural element of the blade. With traditional foam core composite propellers the blade's composite skins are the principle structural element. When a foam core composite blade is damaged it generally requires a structural repair which cannot be done in service and often must be returned to the factory for expensive and time-consuming repairs. Since the MT prop skins are only a protective cover for the wood core most damage can be simply and quickly repaired in the field, reducing aircraft downtime.

Infinite Blade Life

Unlike its aluminum counterpart, the MT Natural Composite propeller blade does not get smaller with time in service due to erosion and the regular filing of small nicks in the blades. Eventually, aluminum blades will no longer meet their dimensional limits and will need to be replaced. Nicks in the MT prop can be simply and quickly filled with epoxy resin and hence do not get smaller with time. As a result, the MT natural composite propeller blade has an infinite life. The MT Propeller blade also has a 2-inch wide nickel cobalt erosion sheath providing superior leading-edge protection since nickel is 50% harder than aluminum.

Quite

The MT Whisper Propeller is the quietest propeller available for The King Air 200 or C-12 aircraft. The European Aviation Safety Agency (EASA) maintains a database of certified noise performance for all propellers approved for use within the EASA community of countries. From the EASA database the following are certified noise levels for the available King Air 200 or C-12 propellers:

• Hartzell 4-bladed factory aluminum propeller - 82.2 dB
• Hartzell 4-bladed factory composite propeller - 80.0 dB
• Raisbeck 4-bladed aluminum swept propeller - 81. 7 dB
• MT 5-bladed Natural Composite propeller - 77 .1 dB

The principle reason for the substantial reduction in noise level for the BLR/MT prop is the propeller diameter.

• Hartzell 4-bladed factory aluminum propeller - 93.0 inches
• Hartzell 4-bladed factory composite propeller- 93.0 inches
• Raisbeck 4-bladed aluminum swept propeller - 96.0 inches
• MT 5-bladed Natural Composite propeller- 88.6 inches

In addition to a reduction in noise due to the shorter blade diameter, the MT props have superior foreign object damage (FOO) characteristics since the blade tip is further from the ground.

Less Vibration

The MT 5-bladed Natural Composite Propeller has a 45% high dampening coefficient as compared to its 4-bladed aluminum counterparts. An increase in the dampening coefficient means a decrease in vibration. The combination of reduced vibration and noise results in a significantly improved cabin and cockpit environment. A reduction in vibration also reduces airframe fatigue and avionics and engine maintenance precipitated by propeller vibration.