(a) Each fuel tank filler connection must prevent the entrance of fuel
into any part of the rotorcraft other than the tank itself during normal
operations and must be crash resistant during a survivable impact in
accordance with §29.952(c). In addition --
(1) Each filler must be marked as prescribed in §29.1557(c)(1);
(2) Each recessed filler connection that can retain any appreciable
quantity of fuel must have a drain that discharges clear of the entire
rotorcraft; and
(3) Each filler cap must provide a fuel-tight seal under the fluid
pressure expected in normal operation and in a survivable impact.
(b) Each filler cap or filler cap cover must warn when the cap is not
fully locked or seated on the filler connection.