Text in force at 25-153: from 25-91, effective 28 Aug 1997.
[For the one-gear landing conditions, the airplane is assumed to be in the level attitude and to contact the ground on one main landing gear, in accordance with Figure 4 of Appendix A of this part. In this attitude--
(a) The ground reactions must be the same as those obtained on that side under Sec. 25.479(d)(1), and]
(b) Each unbalanced external load must be reacted by airplane inertia in a rational or conservative manner.
62 FR 40705 · Source