StacksVerified U.S. regulatory reference

14 CFR §25.1167

Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗
For airplanes equipped with an accessory gearbox that is not certificated as part of an engine—
  1. (a)The engine with gearbox and connecting transmissions and shafts attached must be subjected to the tests specified in § 33.49 or § 33.87 of this chapter, as applicable;
  2. (b)The accessory gearbox must meet the requirements of §§ 33.25 and 33.53 or 33.91 of this chapter, as applicable; and
  3. (c)Possible misalignments and torsional loadings of the gearbox, transmission, and shaft system, expected to result under normal operating conditions must be evaluated.