Text in force at 25-153: from 25-38, effective 1 Feb 1977.
[For airplanes equipped with an accessory gearbox that is not certificated as part of an engine--
(a) The engine with gearbox and connecting transmissions and shafts attached must be subjected to the tests specified in Secs. 33.49 or 33.87 of this chapter as applicable;
(b) The accessory gearbox must meet the requirements of Secs. 33.25 and 33.53 or 33.91 of this chapter, as applicable; and
(c) Possible misalignments and torsional loadings of the gearbox, transmission, and shaft system, expected to result under normal operating conditions must be evaluated.]
41 FR 55467 · Source