16-Inch Diameter Ramjet Prepared for Flight Test

A NACA researcher prepares a 16-inch diameter and 16-foot long ramjet for a launch over Wallops Island in July 1947. The Lewis Flight Propulsion Laboratory conducted a wide variety of studies on ramjets in the 1940s and 1960s to determine the basic operational data necessary to design missiles. Although wind tunnel and test stand investigations were important first steps in determining these factors, actual flight tests were required. Lewis possessed several aircraft for the ramjet studies, including North American F-82 Mustangs, a Northrup P-61 Black Widow, and a Boeing B-29 Superfortress, which was used for this particular ramjet. This was Lewis’ first flight at over the experimental testing ground at Wallops Island. The NACA’s Langley laboratory established the station on the Virginia coast in 1945 to conduct early missile tests.

This ramjet-powered missile was affixed underneath the B-29’s left wing and flown up to 29,000 feet. The ramjet was ignited as the aircraft reached Mach 0.5 and released. The flight went well, but a problem with the data recording prevented a successful mission. Nonetheless additional flights in November 1947 provided researchers with data on the engine’s combustion efficiency at different levels of fuel-air ratios, thrust coefficients, temperatures, and drag. Transonic flight data such as the rapid acceleration through varying flight conditions could not be easily captured in wind tunnels.