title-14-part-25-sec25-775

278

14 CFR Ch. I (1–1–24 Edition)

§ 25.775

section when the cabin is not pressur-
ized;

(ii) Provides the view specified in

paragraph (b)(1) of this section; and

(iii) Provides sufficient protection

from the elements against impairment
of the pilot’s vision.

(4) The openable window specified in

paragraph (b)(3) of this section need
not be provided if it is shown that an
area of the transparent surface will re-
main clear sufficient for at least one
pilot to land the airplane safely in the
event of—

(i) Any system failure or combina-

tion of failures which is not extremely
improbable, in accordance with
§ 25.1309, under the precipitation condi-
tions specified in paragraph (b)(1) of
this section.

(ii) An encounter with severe hail,

birds, or insects.

(c)

Internal windshield and window

fogging. The airplane must have a
means to prevent fogging of the inter-
nal portions of the windshield and win-
dow panels over an area which would
provide the visibility specified in para-
graph (a) of this section under all in-
ternal and external ambient condi-
tions, including precipitation condi-
tions, in which the airplane is intended
to be operated.

(d) Fixed markers or other guides

must be installed at each pilot station
to enable the pilots to position them-
selves in their seats for an optimum
combination of outside visibility and
instrument scan. If lighted markers or
guides are used they must comply with
the requirements specified in § 25.1381.

(e)

Vision systems with transparent dis-

plays. A vision system with a trans-
parent display surface located in the
pilot’s outside field of view, such as a
head up-display, head mounted display,
or other equivalent display, must meet
the following requirements in non-
precipitation and precipitation condi-
tions:

(1) While the vision system display is

in operation, it must compensate for
interference with the pilot’s outside
field of view such that the combination
of what is visible in the display and
what remains visible through and
around it, enables the pilot to perform
the maneuvers and normal duties of
paragraph (a) of this section.

(2) The pilot’s view of the external

scene may not be distorted by the
transparent display surface or by the
vision system imagery. When the vi-
sion system displays imagery or any
symbology that is referenced to the im-
agery and outside scene topography,
including attitude symbology, flight
path vector, and flight path angle ref-
erence cue, that imagery and sym-
bology must be aligned with, and
scaled to, the external scene.

(3) The vision system must provide a

means to allow the pilot using the dis-
play to immediately deactivate and re-
activate the vision system imagery, on
demand, without removing the pilot’s
hands from the primary flight controls
or thrust controls.

(4) When the vision system is not in

operation it may not restrict the pilot
from performing the maneuvers speci-
fied in paragraph (a)(1) of this section
or the pilot compartment from meet-
ing the provisions of paragraph (a)(2) of
this section.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–23, 35 FR 5676, Apr. 8,
1970; Amdt. 25–46, 43 FR 50595, Oct. 30, 1978;
Amdt. 25–72, 55 FR 29778, July 20, 1990; Amdt.
25–108, 67 FR 70827, Nov. 26, 2002; Amdt. 25–
121, 72 FR 44669, Aug. 8, 2007; Amdt. 25–136, 77
FR 1618, Jan. 11, 2012; Amdt. 25–140, 79 FR
65525, Nov. 4, 2014; Docket FAA–2013–0485,
Amdt. 25–144, 81 FR 90169, Dec. 13, 2016]

§ 25.775

Windshields and windows.

(a) Internal panes must be made of

nonsplintering material.

(b) Windshield panes directly in front

of the pilots in the normal conduct of
their duties, and the supporting struc-
tures for these panes, must withstand,
without penetration, the impact of a
four-pound bird when the velocity of
the airplane (relative to the bird along
the airplane’s flight path) is equal to
the value of

at sea level, selected

under § 25.335(a).

or tests that the probability of occur-
rence of a critical windshield frag-
mentation condition is of a low order,
the airplane must have a means to
minimize the danger to the pilots from
flying windshield fragments due to bird
impact. This must be shown for each
transparent pane in the cockpit that—

(1) Appears in the front view of the

airplane;

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§ 25.779

(2) Is inclined 15 degrees or more to

the longitudinal axis of the airplane;
and

(3) Has any part of the pane located

where its fragmentation will constitute
a hazard to the pilots.

(d) The design of windshields and

windows in pressurized airplanes must
be based on factors peculiar to high al-
titude operation, including the effects
of continuous and cyclic pressurization
loadings, the inherent characteristics
of the material used, and the effects of
temperatures and temperature dif-
ferentials. The windshield and window
panels must be capable of withstanding
the maximum cabin pressure differen-
tial loads combined with critical aero-
dynamic pressure and temperature ef-
fects after any single failure in the in-
stallation or associated systems. It
may be assumed that, after a single
failure that is obvious to the flight
crew (established under § 25.1523), the
cabin pressure differential is reduced
from the maximum, in accordance with
appropriate operating limitations, to
allow continued safe flight of the air-
plane with a cabin pressure altitude of
not more than 15,000 feet.

(e) The windshield panels in front of

the pilots must be arranged so that, as-
suming the loss of vision through any
one panel, one or more panels remain
available for use by a pilot seated at a
pilot station to permit continued safe
flight and landing.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–23, 35 FR 5676, Apr. 8,
1970; Amdt. 25–38, 41 FR 55466, Dec. 20, 1976]

§ 25.777

Cockpit controls.

(a) Each cockpit control must be lo-

cated to provide convenient operation
and to prevent confusion and inad-
vertent operation.

(b) The direction of movement of

cockpit controls must meet the re-
quirements of § 25.779. Wherever prac-
ticable, the sense of motion involved in
the operation of other controls must
correspond to the sense of the effect of
the operation upon the airplane or
upon the part operated. Controls of a
variable nature using a rotary motion
must move clockwise from the off posi-
tion, through an increasing range, to
the full on position.

arranged, with respect to the pilots’
seats, so that there is full and unre-
stricted movement of each control
without interference from the cockpit
structure or the clothing of the min-
imum flight crew (established under
§ 25.1523) when any member of this
flight crew, from 5

′

″

to 6

′

″

in height,

is seated with the seat belt and shoul-
der harness (if provided) fastened.

(d) Identical powerplant controls for

each engine must be located to prevent
confusion as to the engines they con-
trol.

(e) Wing flap controls and other aux-

iliary lift device controls must be lo-
cated on top of the pedestal, aft of the
throttles, centrally or to the right of
the pedestal centerline, and not less
than 10 inches aft of the landing gear
control.

(f) The landing gear control must be

located forward of the throttles and
must be operable by each pilot when
seated with seat belt and shoulder har-
ness (if provided) fastened.

(g) Control knobs must be shaped in

accordance with § 25.781. In addition,
the knobs must be of the same color,
and this color must contrast with the
color of control knobs for other pur-
poses and the surrounding cockpit.

(h) If a flight engineer is required as

part of the minimum flight crew (es-
tablished under § 25.1523), the airplane
must have a flight engineer station lo-
cated and arranged so that the flight
crewmembers can perform their func-
tions efficiently and without inter-
fering with each other.

[Doc. No. 5066, 29 FR 18291, Dec. 24, 1964, as
amended by Amdt. 25–46, 43 FR 50596, Oct. 30,
1978]

§ 25.779

Motion and effect of cockpit

controls.

Cockpit controls must be designed so

that they operate in accordance with
the following movement and actuation:

(a) Aerodynamic controls:
(1)

Primary.

Controls

Motion and effect

Aileron .........................

Right (clockwise) for right wing

down.

Elevator .......................

Rearward for nose up.

Rudder .........................

Right pedal forward for nose right.

(2)

Secondary.