(a) If certification with ditching provisions is requested, the
rotorcraft must meet the requirements of this section and §§29.807(d),
29.1411 and 29.1415.
(b) Each practicable design measure, compatible with the general
characteristics of the rotorcraft, must be taken to minimize the
probability that in an emergency landing on water, the behavior of the
rotorcraft would cause immediate injury to the occupants or would make it
impossible for them to escape.
(c) The probable behavior of the rotorcraft in a water landing must be
investigated by model tests or by comparison with rotorcraft of similar
configuration for which the ditching characteristics are known. Scoops,
flaps, projections, and any other factors likely to affect the
hydrodynamic characteristics of the rotorcraft must be considered.
(d) It must be shown that, under reasonably probable water conditions,
the flotation time and trim of the rotorcraft will allow the occupants to
leave the rotorcraft and enter the liferafts required by §29.1415. If
compliance with this provision is shown by bouyancy and trim computations,
appropriate allowances must be made for probable structural damage and
leakage. If the rotorcraft has fuel tanks (with fuel jettisoning
provisions) that can reasonably be expected to withstand a ditching
without leakage, the jettisonable volume of fuel may be considered as
(e) Unless the effects of the collapse of external doors and windows
are accounted for in the investigation of the probable behavior of the
rotorcraft in a water landing (as prescribed in paragraphs (c) and (d) of
this section), the external doors and windows must be designed to
withstand the probable maximum local pressures.