Ground Performance at Take‐off and Landing: A Chart for the Estimation of either Unstick or Landing Roll Distance

A simple chart is presented for the rapid evaluation of either unstick or landing roll distance. The method is incomplete in that it docs not deal with the airborne phase of take‐off and landing manoeuvres; it is necessary to estimate this part separately. The chart is strictly applicable only when wing incidence remains constant for the whole of the ground run. In the case of the landing roll, some uncertainty exists as to the precise value of µ, the braking coefficient of friction. An attempt is made to relate an equivalent value of µ to touchdown speed for the standard wet and dry runway as adopted by I.C.A.O. assuming that automatic brakes are fitted, with a maximum braking force equal to 0.35 of the landing weight.