title-14-part-23-sec23-2270

185

Federal Aviation Administration, DOT

§ 23.2270

servicing, the applicant must incor-
porate a means into the airplane design
to allow such actions to be accom-
plished.

[Doc. No. FAA–2015–1621, Amdt. 23–64, 81 FR
96689, Dec. 30, 2016, as amended by Doc. No.
FAA–2022–1355, Amdt. 23–65, 87 FR 75710, Dec.
9, 2022]

§ 23.2260

Materials and processes.

(a) The applicant must determine the

suitability and durability of materials
used for parts, articles, and assemblies,
accounting for the effects of likely en-
vironmental conditions expected in
service, the failure of which could pre-
vent continued safe flight and landing.

(b) The methods and processes of fab-

rication and assembly used must
produce consistently sound structures.
If a fabrication process requires close
control to reach this objective, the ap-
plicant must perform the process under
an approved process specification.

(f) and (g) of this section, the applicant
must select design values that ensure
material strength with probabilities
that account for the criticality of the
structural element. Design values must
account for the probability of struc-
tural failure due to material varia-
bility.

(d) If material strength properties

are required, a determination of those
properties must be based on sufficient
tests of material meeting specifica-
tions to establish design values on a
statistical basis.

(e) If thermal effects are significant

on a critical component or structure
under normal operating conditions, the
applicant must determine those effects
on allowable stresses used for design.

(f) Design values, greater than the

minimums specified by this section,
may be used, where only guaranteed
minimum values are normally allowed,
if a specimen of each individual item is
tested before use to determine that the
actual strength properties of that par-
ticular item will equal or exceed those
used in the design.

(g) An applicant may use other mate-

rial design values if approved by the
Administrator.

§ 23.2265

Special factors of safety.

(a) The applicant must determine a

special factor of safety for each critical
design value for each part, article, or
assembly for which that critical design
value is uncertain, and for each part,
article, or assembly that is—

(1) Likely to deteriorate in service

before normal replacement; or

(2) Subject to appreciable variability

because of uncertainties in manufac-
turing processes or inspection methods.

(b) The applicant must determine a

special factor of safety using quality
controls and specifications that ac-
count for each—

(1) Type of application;
(2) Inspection method;
(3) Structural test requirement;
(4) Sampling percentage; and
(5) Process and material control.
(c) The applicant must multiply the

highest pertinent special factor of safe-
ty in the design for each part of the
structure by each limit and ultimate
load, or ultimate load only, if there is
no corresponding limit load, such as
occurs with emergency condition load-
ing.

TRUCTURAL

CCUPANT

ROTECTION

§ 23.2270

Emergency conditions.

(a) The airplane, even when damaged

in an emergency landing, must protect
each occupant against injury that
would preclude egress when—

(1) Properly using safety equipment

and features provided for in the design;

(2) The occupant experiences ulti-

mate static inertia loads likely to
occur in an emergency landing; and

(3) Items of mass, including engines

or auxiliary power units (APUs), with-
in or aft of the cabin, that could injure
an occupant, experience ultimate stat-
ic inertia loads likely to occur in an
emergency landing.

(b) The emergency landing conditions

specified in paragraph (a)(1) and (a)(2)
of this section, must—

(1) Include dynamic conditions that

are likely to occur in an emergency
landing; and

(2) Not generate loads experienced by

the occupants, which exceed estab-
lished human injury criteria for human
tolerance due to restraint or contact
with objects in the airplane.

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186

14 CFR Ch. I (1–1–24 Edition)

§ 23.2300

tion for all occupants, accounting for
likely flight, ground, and emergency
landing conditions.

(d) Each occupant protection system

must perform its intended function and
not create a hazard that could cause a
secondary injury to an occupant. The
occupant protection system must not
prevent occupant egress or interfere
with the operation of the airplane
when not in use.

(e) Each baggage and cargo compart-

ment must—

(1) Be designed for its maximum

weight of contents and for the critical
load distributions at the maximum
load factors corresponding to the flight
and ground load conditions determined
under this part;

(2) Have a means to prevent the con-

tents of the compartment from becom-
ing a hazard by impacting occupants or
shifting; and

(3) Protect any controls, wiring,

lines, equipment, or accessories whose
damage or failure would affect safe op-
erations.

Subpart D—Design and

Construction

§ 23.2300

Flight control systems.

(a) The applicant must design air-

plane flight control systems to:

(1) Operate easily, smoothly, and

positively enough to allow proper per-
formance of their functions.

(2) Protect against likely hazards.
(b) The applicant must design trim

systems, if installed, to:

(1) Protect against inadvertent, in-

correct, or abrupt trim operation.

(2) Provide a means to indicate—
(i) The direction of trim control

movement relative to airplane motion;

(ii) The trim position with respect to

the trim range;

(iii) The neutral position for lateral

and directional trim; and

(iv) The range for takeoff for all ap-

plicant requested center of gravity
ranges and configurations.

§ 23.2305

Landing gear systems.

(a) The landing gear must be de-

signed to—

(1) Provide stable support and control

to the airplane during surface oper-
ation; and

(2) Account for likely system failures

and likely operation environments (in-
cluding anticipated limitation
exceedances and emergency proce-
dures).

(b) All airplanes must have a reliable

means of stopping the airplane with
sufficient kinetic energy absorption to
account for landing. Airplanes that are
required to demonstrate aborted take-
off capability must account for this ad-
ditional kinetic energy.

that actuates the landing gear, there
is—

(1) A positive means to keep the land-

ing gear in the landing position; and

(2) An alternative means available to

bring the landing gear in the landing
position when a non-deployed system
position would be a hazard.

§ 23.2310

Buoyancy for seaplanes and

amphibians.

Airplanes intended for operations on

water, must—

(a) Provide buoyancy of 80 percent in

excess of the buoyancy required to sup-
port the maximum weight of the air-
plane in fresh water; and

(b) Have sufficient margin so the air-

plane will stay afloat at rest in calm
water without capsizing in case of a
likely float or hull flooding.

CCUPANT

YSTEM

ESIGN

ROTECTION

§ 23.2315

Means of egress and emer-

gency exits.

(a) With the cabin configured for

takeoff or landing, the airplane is de-
signed to:

(1) Facilitate rapid and safe evacu-

ation of the airplane in conditions like-
ly to occur following an emergency
landing, excluding ditching for level 1,
level 2, and single-engine level 3 air-
planes.

(2) Have means of egress (openings,

exits, or emergency exits), that can be
readily located and opened from the in-
side and outside. The means of opening
must be simple and obvious and
marked inside and outside the airplane.

(3) Have easy access to emergency

exits when present.