Noise from low‐altitude military flying

Abstract

Military air tactics rely on increasing use of high‐speed low‐altitude penetration techniques. Training for this type of operation can take place in specially designated low‐altitude military operation areas (MOAs) or along military training routes (MTRs). Environmental assessment of noise from these operations has become an important factor in the design of these special use airspaces. The noise environment is different from commonly studied situations such as airport or highway noise in urban/suburban areas, and it is not obvious that the usual Ldn analysis is appropriate. Individual events are loud (maximum levels in the 100–115 dBA range) and short (10 dB down durations of a few seconds). Noise events are infrequent (typically less than 3 or 4 per day on busy routes) and occur at random times. These operations also take place in quiet rural areas. A discussion is presented of the nature of these operations and the resultant noise environment. This noise is contrasted with well‐understood noise environments. An interim noise metric, Ldnmr (monthly average, onset rate corrected Ldn), developed for the U. S. Air Force is presented. A comprehensive research plan to test Ldnmr, or replace it with a more appropriate metric, is discussed.