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14 CFR Ch. I (1–1–19 Edition)
§ 27.562
(2) The wheels are retracted (where
applicable); and
(3) Each occupant and each item of
mass inside the cabin that could injure
an occupant is restrained when sub-
jected to the following ultimate iner-
tial load factors relative to the sur-
rounding structure:
(i) Upward—4g.
(ii) Forward—16g.
(iii) Sideward—8g.
(iv) Downward—20g, after intended
displacement of the seat device.
(v) Rearward—1.5g.
(c) The supporting structure must be
designed to restrain, under any ulti-
mate inertial load up to those specified
in this paragraph, any item of mass
above and/or behind the crew and pas-
senger compartment that could injure
an occupant if it came loose in an
emergency landing. Items of mass to be
considered include, but are not limited
to, rotors, transmissions, and engines.
The items of mass must be restrained
for the following ultimate inertial load
factors:
(1) Upward—1.5g.
(2) Forward—12g.
(3) Sideward—6g.
(4) Downward—12g.
(5) Rearward—1.5g
(d) Any fuselage structure in the area
of internal fuel tanks below the pas-
senger floor level must be designed to
resist the following ultimate inertial
factors and loads and to protect the
fuel tanks from rupture when those
loads are applied to that area:
(i) Upward—1.5g.
(ii) Forward—4.0g.
(iii) Sideward—2.0g.
(iv) Downward—4.0g.
[Doc. No. 5074, 29 FR 15695, Nov. 24, 1964, as
amended by Amdt. 27–25, 54 FR 47318, Nov. 13,
1989; Amdt. 27–30, 59 FR 50386, Oct. 3, 1994;
Amdt. 27–32, 61 FR 10438, Mar. 13, 1996]
§ 27.562
Emergency landing dynamic
conditions.
(a) The rotorcraft, although it may
be damaged in an emergency crash
landing, must be designed to reason-
ably protect each occupant when—
(1) The occupant properly uses the
seats, safety belts, and shoulder har-
nesses provided in the design; and
(2) The occupant is exposed to the
loads resulting from the conditions
prescribed in this section.
(b) Each seat type design or other
seating device approved for crew or
passenger occupancy during takeoff
and landing must successfully com-
plete dynamic tests or be demonstrated
by rational analysis based on dynamic
tests of a similar type seat in accord-
ance with the following criteria. The
tests must be conducted with an occu-
pant, simulated by a 170-pound
anthropomorphic test dummy (ATD),
as defined by 49 CFR 572, subpart B, or
its equivalent, sitting in the normal
upright position.
(1) A change in downward velocity of
not less than 30 feet per second when
the seat or other seating device is ori-
ented in its nominal position with re-
spect to the rotorcraft’s reference sys-
tem, the rotorcraft’s longitudinal axis
is canted upward 60
°
with respect to
the impact velocity vector, and the
rotorcraft’s lateral axis is perpen-
dicular to a vertical plane containing
the impact velocity vector and the
rotorcraft’s longitudinal axis. Peak
floor deceleration must occur in not
more than 0.031 seconds after impact
and must reach a minimum of 30g’s.
(2) A change in forward velocity of
not less than 42 feet per second when
the seat or other seating device is ori-
ented in its nominal position with re-
spect to the rotorcraft’s reference sys-
tem, the rotorcraft’s longitudinal axis
is yawed 10
°
either right or left of the
impact velocity vector (whichever
would cause the greatest load on the
shoulder harness), the rotorcraft’s lat-
eral axis is contained in a horizontal
plane containing the impact velocity
vector, and the rotorcraft’s vertical
axis is perpendicular to a horizontal
plane containing the impact velocity
vector. Peak floor deceleration must
occur in not more than 0.071 seconds
after impact and must reach a min-
imum of 18.4g’s.
(3) Where floor rails or floor or side-
wall attachment devices are used to at-
tach the seating devices to the air-
frame structure for the conditions of
this section, the rails or devices must
be misaligned with respect to each
other by at least 10
°
vertically (i.e.,
pitch out of parallel) and by at least a
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