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TCH.1C-27J-4

- 3 Indicates an item that has a one way interchangeability with another (ICY code 5) item. The

use of ICY code 3 is always accompanied with an ICY 5 item and is only applied to items
presented at different Configuration Standards. Code 3 is applied to the pre-modified item
and code 5 is applied to the post-modification item. A code 3 item is only used as a
replacement where a code 3 item is installed, but a code 5 item may be used to replace
either a code 3 or a code 5.

- 4 Indicates an item which is fully interchangeable with, but not identical to, other ICY 4 items.

It is used only when the items are presented at the same Configuration Standard. When
items are presented at different Configuration Standards, then codes 1-2 or 3-5 must be
applied.

- 5 Indicates an item which has one way ICY with another (code 3) item. The use of ICY code

5 is always accompanied with an ICY code 3 item and is only applied to items presented at
different Configuration Standards. See code 3 for details of application.

- 6 Indicates an item which has a qualified interchangeability with another ICY 6 item. The

conditions under which this qualified interchangeability is operative is provided in the
Description column (Description For Location content).

- 7 Not used
- 8 Not used
- 9 Indicates an item which is fully interchangeable with, and identical to, other ICY 9 items. It

is used when a secondary Part Number is showing a Vendor allocated identity to a
proprietary item, which can otherwise be supplied direct by the proprietary firm. In such cases
the proprietary item is listed first, followed by the Vendors Part Number. A proprietary item is
one which is identified by a Primary Reference Number as defined in ACodP 1. ICY 9 is used
only when items are presented at the same Configuration Standard.

F. Applicable

The applicable column is made of two columns of numbers wich identify the "Aircraft Number"
the P/N is applicable to.
When the item is applicable to all the "Aircraft Number" of the fleet, the columns are left blank.

1-5 Cross Reference Index

The IPC includes a single Cross Reference Index. This Index is ordered in alphanumeric sequence
and uses four different data elements as its Search Key.
In order to identify the data element which is being used as Search Key for a particular entry, a
Search Key Code has been provided as follows:

Data element

Search Key Code

Part Number

Reference Designator

The data element being used as the Search Key, and provided in the second column of the Cross
Reference Index, is not repeated in its own data element column. However, this is not the case
when a Part Number of more than 20 characters is being used as the Search Key; in this instance
the full Part Number is shown in the Part Number column.

The following data elements have been presented in the Index layout:

- SKC
- SEARCH KEY
- CH-SUBCH-UNIT-FIG-ITEM
- MFRC
- QTY PER ASSY

INTRODUCTION

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