Definitions
4 Interchangeability Codes (Spares with Different Part Number)
Introduction
When a part is submitted to changes, it is necessary to define the relationship in terms of
interchangeability between the new and the previous part(s) definition, respectively identified by new PN and previous PN linked by a modification.
It may also be necessary to define the relationship in terms of interchangeability between parts not linked by a single modification.
In both cases, the same process applies.
ATA interchangeability codes
ATA defines "one-digit" interchangeability codes in the Common Support Data Dictionary
(CSDD) issued by the ATA, as follows:
CODE TITLE ATA CUSTOMER SUPPORT DATA DICTIONARY
DESCRIPTION
1One-Way
Interchangeable The new PN is an acceptable replacement for either the old or the new PN. The old PN may be used as a replacement only where the old PN was installed
2Two-Way
Interchangeable The old and the new PN are each acceptable replacement for both the old and new PN
3Not Interchangeable When the old part is removed, it must be replaced
with the same PN. When the new PN is removed, it
must be replaced with the new PN
4Interchangeable "as
a set" Replacement requires that the entire quantity of the old part used in an installation be replaced with a complete set of the new PN. For sets comprised of more than one PN, code 5 applies
5Qualified
Interchangeability Applies to replacement situations not described by the above 4 codes or when not applicable to all aircraft or engines specified by the Model of Applicability Code
6Part
Re-identification Corrects the identification of a replacing/replaced part in an established Replacing Part Data Text (RPD) or Replaced Part Data Text (RPE)
Definitions
AIRBUS interchangeability codes
Background
The ATA CSDD interchangeability codes 1, 4 and 5, as shown above do not provide enough information regarding interchangeability possibilities with or without application of conditions.
In case of ATA CSDD interchangeability code 1, Airbus has decided to apply internally the following definition:
CODE TITLE AIRBUS
DESCRIPTION
1One-Way
Interchangeable The new PN is an acceptable replacement for either the old or new PN installed as A/C definition.
The old PN may be used as a replacement only where the old PN was installed as A/C definition.
In case of ATA CSDD interchangeability code 4 and 5, Airbus has decided to apply internally the following coding, based on three digits (e.g. 152, 341). The results of this coding shall be translated in documents provided to end users (Operators, Maintenance Centers, …).
Architecture principles of the Airbus interchangeability codes
The First digit gives the interchangeability code obtained in case there is no associated condition or in case the conditions are not fulfilled.
1: One-way interchangeable
2: Two-way interchangeable
3: Not interchangeable
The Second digit identifies the type of condition that may be associated.
0: No condition applicable
4: Interchangeable as a set of the same PN on the same aircraft (mixing old and new PN is not allowed)
5: Any other condition applicable during maintenance activities
The Third digit identifies the interchangeability code obtained only if conditions are fulfilled.
0: No condition applicable
1: One-way interchangeable
2: Two-way interchangeable
Refer to AP2027.6 for method of selecting interchangeability code.
Definitions
List of 3-digit interchangeability codes
Based on these architecture rules and on the A/C definition (delivery or retrofit after AI SB embodiment), the following codes are defined:
ICY
CODE
TITLE DEFINITION
100One-way interchangeable x When the old PN (A/C definition or Airbus SB
retrofit) is removed, it may be replaced either with
the old or with the new PN.
x The new PN installed as spares, can be replaced
by itself or the old PN (no A/C configuration
changes).
x When the new PN (A/C definition or Airbus SB
retrofit) is removed, it must be replaced with the
new PN.
200Two-way interchangeable x When the old PN (A/C definition or Airbus SB
retrofit) or the new PN (A/C definition or Airbus SB
retrofit) is removed, it may be replaced with the old
or with the new PN.
300Not interchangeable x When the old PN is removed, it must be replaced
with the old PN.
x When the new PN is removed, it must be replaced
with the new PN.
(Equivalent to ATA CSDD definition for code 3)
152One-way Interchangeable, But
Two-way interchangeable
with conditions x When the old PN (A/C definition or Airbus SB retrofit) is removed, it may be replaced either with the old or with the new PN
x When the new PN (A/C definition or Airbus SB retr x ofit) is removed, it may be replaced:
x with the new PN,
x with the old PN only if specified conditions are fulfilled.
341Not interchangeable,
But
One-way interchangeable as
a set x When the old PN (A/C definition or Airbus SB retrofit) is removed, it may be replaced:
x with the old PN,
x with the new PN only if the complete set of old PN is replaced with a set of new PN.
the new PN (A/C definition or Airbus SB
x When
retrofit) is removed, it must be replaced with the new PN.
o te: For se
N ts comprising more than one PN, code 351 applies.
Definitions
ICY
CODE
TITLE DEFINITION
342Not interchangeable
But
Two-way interchangeable as
a set x When the old PN (A/C definition or Airbus SB retrofit) is removed, it may be replaced:
x with the old PN,
x with the new PN only if the complete set of old PN is replaced with a set of new PN.
x When the new PN (A/C definition or Airbus SB retrofit) is removed, it may be replaced:
x with the new PN,
x with the old PN only if the complete set of new PN is replaced with a set of old PN. Note: For sets comprising more than one PN, the code 352 applies.
351Not interchangeable,
But
One-way interchangeable
with conditions x When the old PN (A/C definition or Airbus SB retrofit) is removed, it may be replaced:
x with the old PN,
x with the new PN only if specified conditions are fulfilled.
x When the new PN (A/C definition or Airbus SB retrofit) is removed, it must be replaced with the new PN.
352Not interchangeable,
But
Two-way interchangeable
with conditions x When the old PN (A/C definition or Airbus SB retrofit) is removed, it may be replaced:
x with the old PN,
x with the new PN only if specified conditions are fulfilled.
x When the new PN (A/C definition or Airbus SB retrofit) is removed, it may be replaced:
x with the new PN,
x with the old PN only if specified conditions are fulfilled.
Note 1: 3-digit codes other than the ones defined above shall not be used.
Note 2: The evolutions of the part (PN1, PN 2, PN3, PN4) in accordance with their respective modifications and interchangeability codes (ICY) can be used as spares (transitivity). Transitivity
The interchangeability code authorises the airlines to replace the part defined at the A/C definition by another part without A/C configuration change.
If ICY is 1 or 2 WAY between parts, the PN2, PN3 or PN4 can be used as spares to replace the PN 1 valid on A/C definition.
