14 CFR § 27.991
Fuel pumps
July 13, 2020
Compliance with §27.955 may not be jeopardized by failure of—
(a) Any one pump except pumps that are approved and installed as parts of a type certificated engine; or
(b) Any component required for pump operation except, for engine driven pumps, the engine served by that pump.
[Amdt. 27-23, 53 FR 34213, Sept. 2, 1988]