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Munch, C. L.

Publications and source records attributed to Munch, C. L..

7 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Conceptual design study of 1985 commercial VTOL transports that utilize rotors

Conceptual design studies of pure and compound helicopter commercial short-haul transport aircraft for initial fabrication in 1980 were performed to determine their technical and economic feasibility. One-hundred-passenger configurations were optimized for minimum direct operating cost consistent with producibility and marketability, with emphasis on proper account of mass properties, performance and handling qualities adequacy, and suppression of internal and external noise. The effect of external noise constraints was assessed, in terms of gross weight and direct operating cost, for each aircraft.

Kefford, N. F. K.↗
NASA NTRS1975

A study of noise guidelines for community acceptance of civil-helicopter operations

The Day-Night Noise Level, which takes tonal content, duration, and number of operations into account, and penalizes night-time noise, is found to be the best available index for rating community annoyance caused by aircraft. A Day-Night level of 60 for communities with ambient noise levels up to 58 dBA, and a level of 2 dBA higher than the ambient for communities where it is above 58 dBA, is proposed as acceptable. Evaluation of a large transport helicopter showed that the guidelines do not impose severe economic penalties on helicopter operations.

Munch, C. L.↗
NASA NTRS1974

Community acceptance of helicopter noise: Criteria and application

A study was conducted to define those criteria necessary for civil helicopter operations to be acoustically acceptable to the communities from which they operate and over which they fly. The study involved surveying existing domestic and foreign Federal regulations and guidelines, state and local noise ordinances, results of community noise annoyance studies, and results of individual aircraft noise annoyance studies, and results of individual aircraft noise annoyance studies in order to establish the criteria. The final criteria selection are based on the Day-Night Level, L sub DN, a measure of total noise exposure. The basic rating unit is the A weighted sound pressure level (dbA) which has accuracy comparable to other units currently used for aircraft. An L sub DN of 60 is recommended as a criterion for areas where the ambient noise is below 58 dbA. An L sub DN value 2 dbA above the local ambient is recommended for areas where the ambient is above 58 dbA.

Munch, C. L.↗