초록 ▼

A system is provided for existing three-engine jet aircraft to reduce the noise levels at take-off and landing in order to meet governmental noise regulations. The system is particularly suitable for 727-200 aircraft having three JT8D engines. A hush kit is formed of the modified components for inst

A system is provided for existing three-engine jet aircraft to reduce the noise levels at take-off and landing in order to meet governmental noise regulations. The system is particularly suitable for 727-200 aircraft having three JT8D engines. A hush kit is formed of the modified components for installation in existing airplanes.

대표청구항 ▼

A method for quieting jet engine noise produced by an airplane having three jet engines upon take-off and landing, comprising: (a) replacing two outboard-mounted jet engines at the rear of the fuselage with jet engines which produce lower noise and greater thrust; (b) retaining a center fuselage-mou

A method for quieting jet engine noise produced by an airplane having three jet engines upon take-off and landing, comprising: (a) replacing two outboard-mounted jet engines at the rear of the fuselage with jet engines which produce lower noise and greater thrust; (b) retaining a center fuselage-mounted jet engine, and removing a thrust reverser from the aft position thereof; (c) mounting a forced-air mixer on the center engine at the position from which the thrust reverser was removed, the mixer being adapted to combine cold air passing around the engine with hot air passing through the engine, to reduce engine noise emitted by the center engine; and (d) mounting an acoustic nozzle comprised of sound-attenuating material aft of the forced-air mixer on the center engine, whereby the noise level produced the airplane is reduced to a sufficiently quiet level to meet governmental noise regulations while remaining airworthy and permitting operation without reduced payloads or thrust.