ACCESS - DESCRIPTION AND OPERATION

** ON A/C NOT FOR ALL

1. General
The components below have an identification of access panels or doors:

access doors for maintenance,
service doors,
fillets,
fairings,
removable access panels of the radio rack,
removable floor panels,
removable cargo compartment panels,
removable ceiling panels.

NOTE: This list does not include the electrical panels. Their identification since they are covered by a specific rule.

A. Identification Method
The identification includes:

(1) Three figures which identify the zone of the door.

(2) A suffix of two letters:

The first or identification letter identifies the door in a logical sequence, ie. from the inside to the outside, or from forward to aft. The first identification letter is an 'A' for each zone.
The second or location letter, gives the location of the door on the aircraft if necessary.
T = Top (Upper Surface)
B = Bottom (Lower Surface)
L = Left
R = Right
Z = Internal
F = Floor panel
W = Sidewall panel
C = Ceiling panel

When all the letters of the alphabet are used, panels are identified as follows:
the letter A is the identification letter
letters U, D, P, S, G, X, Y are the location letters:
U = Top (Upper Surface)
D = Bottom (Lower Surface)
P = Left
S = Right
G = Floor panel
X = Sidewall panel
Y = Ceiling panel

NOTE: The letters I and O are not used.

Examples for the identification of an access door:

121 AL is the first panel in zone 121 on Left side (forward fuselage)
191 AT is the first panel in zone 191 at Top (belly fairing)

B. General Rules

(1) The cabin passenger/crew doors, cargo compartment and main landing gear doors are only identified by the zone number, since each of these doors is a zone in itself.

(2) The letters I and O are not used.

(3) Pressure relief doors or air vents have no identification numbers.

(4) Doors along the aircraft centerline have the left side zone number.

(5) The vertical stabilizer and rudder doors are numbered from the bottom to the upper part.

(6) Identical doors on either side of the aircraft have the same identification letter even if the zone numbers are different.

(7) When a door is on a larger door it is identified with two letters after the identification of the large door.

(8) When a door is in more than one zone, use the smallest zone number.

(9) A door on a zone boundary is numbered according to the zone in which it is removed.

NOTE: The various access doors are in the subject of the related ATA reference.

[Rev.10 from 2021] 2026.03.31 22:52:33 UTC