Abstract: This paper presents a study of how to use the ground loads specification GJB 67.4-85 and MIL-A-8862A correctly to minimize landing dynamic loads and structure weight oflanding gear and aircraft To minimize landing dynamic load5,we must use a rational analysis method to simulate the landing impact dynamics by optimizing the various parameters of shock absober of landing gear.To calculate the effect of struct servicing tolerance on landing loads,also must a ra- tional analysis method be used.Any empirical analysis method is conservative and results in larg- er structure weight This paper also indicates that some of the recent conservative calculations of the landing loads do not conform to GJB67.4-85 and MIL-A-8862A requirement.For example,the choice of the friction coefficient of 0.8 between tyre and ground in spin-up case instead of 0.55 implied by specification GJB 67.4-85 and MIL-A-8862A leads to an increase in spin-up load by 0.455 times.In summary,the advantage of a correct use is that the design load and the structure weight will be smaller.

Key words: anding loads, impact-test, shock absorbers