U.S. Sonic Boom Study

Press, Volume CVIII, Issue 31621, 6 March 1968, Page 17

U.S. Sonic Boom Study

(N.Z.P. A.Reuter—Copyright) WASHINGTON, Mar. 5. The probability of supersonic airliners causing serious damage to buildings and other structures is very small, according to a sub-committee of the special National Academy of Sciences committee set up in 19 6 4 at President Johnson’s request. The sub-committee spent a year studying the results of sonic boom test flights, including preliminary data from recent flights of the SR--71 strategic reconnaissance plane.

The group assumed that supe r -jets would eventually fly over land and that the sonic booms along their flight paths would be low enough in intensity to be acceptable to the public.

“Given those conditions, the sub-committee wishes to emphasise the fact that the probability of serious material damage being caused by a sonic boom generated by an aircraft operating in a safe, normal manner is very small” the report says. But, the sub-committee found that there was too little accurate statistical informaion to be certain about some aspects of the problem, which it said, needed further study. It urged the building of large simulators in which pressure waves could be directed against structures, simulating in a day the number of booms a home or office

building might be subjected to in a year. The sub-committee recommended that a “physical response” research programme should be undertaken and vigorously pursued. It would include simulator studies, laboratory test of glass, and studies of the atmosphere’s bending and magnifying effects on the shock waves of sonic booms.

A group including engineers and lawyers should be appointed to study other considerations, says the report, which also proposes that several companies should be asked to study the feasibility of setting up a nation-wide boom-monitoring network. When legal problems arise, it will be necessary to know whether damaging booms actually occurred, what path they covered and why they occurred, the sub-committee says.