# Approach index file — file signature 03 00 00 00 41 50 50 52 at offset 0

For Approach index file, hex signature is 03 00 00 00 41 50 50 52; offset is 0; extension is adx, verified against its source on 2026-09-22.

- **Hex signature:** 03 00 00 00 41 50 50 52 _(verified: appears in the quote below)_
- **Offset:** 0 _(verified: appears in the quote below)_
- **Extension:** adx _(verified: appears in the quote below)_
- **Format:** Approach index file _(verified: appears in the quote below)_

## What the source says

> 03 00 00 00 41 50 50 52 | ␃␀␀␀APPR | 0 | adx | Approach index file |

## Source

- https://en.wikipedia.org/wiki/List_of_file_signatures

Last verified: 2026-09-22. Review by: 2027-09-22.
Part of [File format magic numbers](https://referencesource.org/file-format-signatures/).