14 CFR · Part 27
14 CFR § 27.653
Pressure venting and drainage of rotor blades.
(a)
For each rotor blade—
(1)
There must be means for venting the internal pressure of the blade;
(2)
Drainage holes must be provided for the blade; and
(3)
The blade must be designed to prevent water from becoming trapped in it.
(b)
Paragraphs (a)(1) and (2) of this section does not apply to sealed rotor blades capable of withstanding the maximum pressure differentials expected in service.
Reflects the eCFR edition current as of September 29, 2026. Retrieved from ecfr.gov on October 16, 2026.
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