A study has been made of the build-up of braking force with increasing slip as an aircraft tyre loaded to 3.5 tons and inflated to 40 or 160 lb/in2 was braked on four wet surfaces of different surface texture at speeds up to 60 mile/h. The main results of the investigations are as follows: 1. In about half the measurements the peak braking force coefficients were reached before 20% slip occurred tending to be at lower slip at the higher speeds. Even with the higher coefficient surfaces peak coefficients were obtained before 50% slip was reached. 2. As found earlier in locked wheel braking tests, higher inflation pressure produced lower peak braking force coefficients on the fine textured surfaces. 3. The ratio of peak to locked wheel braking force coefficient was lowest on the quartzite macadam and highest on the smooth concrete surface.
Abstract