AIRCRAFT BRAKING FRICTION TRIALS ON A COARSE OPEN GRADED MACADAM RUNWAY SURFACE.
Abstract
Accelerate-brake trials were made on a coarse open graded macadam runway surface, with a Scimitar Mk.1 aircraft to measure braking friction in wet conditions. For comparison, trials were also made on grooved and ungrooved asphalt surfaces. The grooving was shallow and transverse to the runway. The braking was initially found to be limited by the available brake torque and the performance of the maxaret anti-skid system but was subsequently improved by increasing the brake pressure and modifying the maxarets in order to develop the available tire/runway friction. Although the aircraft had to be given up before the planned test program was completed, a tentative assessment of the surfaces was made from the seven trials carried out. These indicated that the open graded surface realized somewhat higher wet braking force coefficients than either of the other two surfaces, that the wet open graded surface was almost as good as the dry grooved asphalt, and that the grooved surface was no better in wet conditions than the ungrooved. Moreover, the trials showed the necessity of using a test vehicle with a high braking performance and the desirability of nosewheel steering. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1969
- Accession Number
- AD0706679
Entities
People
- E. J. Key
- E. M. Minter
Organizations
- Royal Aircraft Establishment