# 12.4: Point mass model

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##### Theorem 12.5 Point mass model

The translational equations (12.3.1.10)-(12.3.1.12) are uncoupled from the rotational equations (12.3.1.13)-(12.3.1.15) by assuming that the airplane rotational rates are small and that control surface deflections do not affect forces. This leads to consider a 3 Degree Of Freedom (DOF) dynamic model that describes the point variable-mass motion of the aircraft.

Under this hypothesis, the translational problem (performances) can be studied separately from the rotational problem (control and stability).

12.4: Point mass model is shared under a CC BY-SA 3.0 license and was authored, remixed, and/or curated by Manuel Soler Arnedo via source content that was edited to conform to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.