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14 CFR Ch. I (1–1–19 Edition) 

§ 29.561 








§ 29.561


(a) The rotorcraft, although it may 

be damaged in emergency landing con-
ditions on land or water, must be de-
signed as prescribed in this section to 
protect the occupants under those con-

(b) The structure must be designed to 

give each occupant every reasonable 
chance of escaping serious injury in a 
crash landing when— 

(1) Proper use is made of seats, belts, 

and other safety design provisions; 

(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 the in-

tended displacement of the seat device. 

(v) Rearward—1.5g. 
(c) The supporting structure must be 

designed to restrain under any ulti-
mate inertial load factor up to those 
specified in this paragraph, any item of 
mass above and/or behind the crew and 
passenger compartment that could in-
jure an occupant if it came loose in an 
emergency landing. Items of mass to be 
considered include, but are not limited 
to, rotors, transmission, and engines. 
The items of mass must be restrained 
for the following ultimate inertial load 

(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, if rupture is 
likely when those loads are applied to 
that area: 

(1) Upward—1.5g. 
(2) Forward—4.0g. 
(3) Sideward—2.0g. 

(4) Downward—4.0g. 

[Doc. No. 5084, 29 FR 16150, Dec. 3, 1964, as 
amended by Amdt. 29–29, 54 FR 47319, Nov. 13, 
1989; Amdt. 29–38, 61 FR 10438, Mar. 13, 1996] 

§ 29.562

Emergency landing dynamic 


(a) The rotorcraft, although it may 

be damaged in a crash landing, must be 
designed to reasonably protect each oc-
cupant 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 loads 

equivalent to those 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 

VerDate Sep<11>2014 

12:50 Apr 30, 2019

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