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A supersonic combustion ramjet. An engine in which the air is not compressed below Mach 1, which prevents dissociation (i.e., the breakdown of oxygen, nitrogen, and carbon molecules into individual atoms). The air is practically compressed and the fuel is burned at supersonic speeds, permitting operation in the hypersonic range. Scram operations begin at about Mach 5 to Mach 7.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved