This Data Item is the second of a series dealing with frictional and retarding forces on aircraft-type tyres. Methods are given for estimating

(i) the coefficient of friction for unyawed tyres in both braked rotating and skidding conditions on prepared, hard runway surfaces,

(ii) the limits placed on the braking force due to brake energy and torque considerations,

(iii) the maximum and locked-wheel tyre-runway braking forces and their appropriateness to a given situation,

(iv) the mean effective braking force developed during a period of braking, either manual or automatic.

The values of braking force may be used in the methods of ESDU 87018 and ESDU EG 6/4 to calculate the landing ground run or the braked portion of a rejected take-off.

This Data Item has been superseded by ESDU 23002.