Probably too late to make a difference, but... Back in the late 40s the French flew a subsonic ramjet powered research aircraft called the Leduc 0.10. It was air launched from the back of a propeller driven airliner at about 200 mph. At half power the aircraft accelerated to about 420 mph. Later flights at full power expanded the speed envelope to M=0.85.
The tip-jet powered "Hiller Hornet" helicopter developed by Stanley Helicopter during the 50s usually lit its little ramjet engines when they were spinning at about 150 fps. Tip speed in flight was generally about 600 fps. At that speed the ramjets had an Isp of about 400 sec. The same engines were tested at higher velocities on ground based rotor test stands. At 900 fps (M=0.8) they had an Isp of 1,500 sec.
