283 

Federal Aviation Administration, DOT 

§ 25.783 

(6) It must not be possible to unlatch 

the latches with the locks in the 
locked position. Locks must be de-
signed to withstand the limit loads re-
sulting from— 

(i) The maximum operator effort 

when the latches are operated manu-
ally; 

(ii) The powered latch actuators, if 

installed; and 

(iii) The relative motion between the 

latch and the structural counterpart. 

(7) Each door for which unlatching 

would not result in a hazard is not re-
quired to have a locking mechanism 
meeting the requirements of para-
graphs (d)(3) through (d)(6) of this sec-
tion. 

(e) 

Warning, caution, and advisory in-

dications. 

Doors must be provided with 

the following indications: 

(1) There must be a positive means to 

indicate at each door operator’s station 
that all required operations to close, 
latch, and lock the door(s) have been 
completed. 

(2) There must be a positive means 

clearly visible from each operator sta-
tion for any door that could be a haz-
ard if unlatched to indicate if the door 
is not fully closed, latched, and locked. 

(3) There must be a visual means on 

the flight deck to signal the pilots if 
any door is not fully closed, latched, 
and locked. The means must be de-
signed such that any failure or com-
bination of failures that would result 
in an erroneous closed, latched, and 
locked indication is improbable for— 

(i) Each door that is subject to pres-

surization and for which the initial 
opening movement is not inward; or 

(ii) Each door that could be a hazard 

if unlatched. 

(4) There must be an aural warning 

to the pilots prior to or during the ini-
tial portion of takeoff roll if any door 
is not fully closed, latched, and locked, 
and its opening would prevent a safe 
takeoff and return to landing. 

(f) 

Visual inspection provision. 

Each 

door for which unlatching of the door 
could be a hazard must have a provi-
sion for direct visual inspection to de-
termine, without ambiguity, if the 
door is fully closed, latched, and 
locked. The provision must be perma-
nent and discernible under operational 

lighting conditions, or by means of a 
flashlight or equivalent light source. 

(g) 

Certain maintenance doors, remov-

able emergency exits, and access panels. 

Some doors not normally opened ex-
cept for maintenance purposes or emer-
gency evacuation and some access pan-
els need not comply with certain para-
graphs of this section as follows: 

(1) Access panels that are not subject 

to cabin pressurization and would not 
be a hazard if open during flight need 
not comply with paragraphs (a) 
through (f) of this section, but must 
have a means to prevent inadvertent 
opening during flight. 

(2) Inward-opening removable emer-

gency exits that are not normally re-
moved, except for maintenance pur-
poses or emergency evacuation, and 
flight deck-openable windows need not 
comply with paragraphs (c) and (f) of 
this section. 

(3) Maintenance doors that meet the 

conditions of paragraph (h) of this sec-
tion, and for which a placard is pro-
vided limiting use to maintenance ac-
cess, need not comply with paragraphs 
(c) and (f) of this section. 

(h) 

Doors that are not a hazard. 

For 

the purposes of this section, a door is 
considered not to be a hazard in the un-
latched condition during flight, pro-
vided it can be shown to meet all of the 
following conditions: 

(1) Doors in pressurized compart-

ments would remain in the fully closed 
position if not restrained by the 
latches when subject to a pressure 
greater than 

1

⁄

2

psi. Opening by persons, 

either inadvertently or intentionally, 
need not be considered in making this 
determination. 

(2) The door would remain inside the 

airplane or remain attached to the air-
plane if it opens either in pressurized 
or unpressurized portions of the flight. 
This determination must include the 
consideration of inadvertent and inten-
tional opening by persons during either 
pressurized or unpressurized portions 
of the flight. 

(3) The disengagement of the latches 

during flight would not allow depres-
surization of the cabin to an unsafe 
level. This safety assessment must in-
clude the physiological effects on the 
occupants. 

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