30 June 2001
IMPROVING SKID RESISTANCE/REDUCING HYDROPLANING POTENTIAL OF RUNWAYS
1. GENERAL. This chapter presents procedures for improving skid resistance and reducing
hydroplaning tendency of runways. It applies to the Army and Air Force. Navy guidance is
contained in NAVFAC Criteria Office Memorandum dated 24 March 1999, Subject: INTERIM
TECHNICAL GUIDANCE (ITG)-SKID RESISTANCE CRITERIA FOR AIRFIELD PAVEMENTS.
a. Skid resistance is the resistance to sliding by aircraft tires on a pavement surface. Skid
resistance is related to the frictional resistance of the pavements. A high coefficient of friction is
indicative of high skid resistance. Low friction resistance may result from polishing of the surface
aggregate, rubber buildup, improper seal coating, or poor drainage.
b. Hydroplaning occurs when a tire looses contact with the surface as a result of the buildup
of water pressure in the tire-ground contact area. The potential for hydroplaning is a function of
speed, water depth, pavement texture, tire inflation pressure, and tread design.
c. Procedures for conducting friction testing and an approved equipment list are contained in
Federal Aviation Administration Advisory Circular, AC 150/5320-12C, "Measurement,
Construction, and Maintenance of Skid-Resistant Airport Pavement Surfaces".
2. IMPROVING RUNWAY FRACTION CHARACTERISTICS. New, reconstructed, or resurfaced
runways must be grooved except when resurfaced with a Porous Friction Surface (PFS). The
grooving is required to provide an acceptable surface for safe operation of aircraft. Friction
characteristics of existing runways need to be improved when tests indicate the surface has a
potential for hydroplaning. Considerations for improving the friction characteristics include
grooving, Porous Friction Surfaces, retexturing, improving runway slopes, and rubber removal.
Table 21-1, developed by the National Aeronautics and Space Administration, provides guidance on
friction ratings for friction measuring equipment. Improving friction characteristics of existing
runways should be considered when friction ratings are less than Good.
Nominal Test Speed, 65 km/h (40 mph)
Ground Vehicle Readings
0.34-0.49 0.40-0.58 0.35-0.50 0.38-0.54 0.35-0.51 0.42-0.59 0.37-0.53 0.37-0.51
0.16-0.33 0.20-0.39 0.15-0.34 0.18-0.37 0.18-0.34 0.21-0.41 0.17-0.36 0.18-0.36