# AD 53-15-02: Wing Lower Front Spar Cap

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed 149-46, 49-46, 649-79, 649A-79, 749-79 and 749A-79
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 2 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/5E03AC3BD6D4DE178625696D0071A9EC.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/53-15-02

## The airworthiness directive

53-15-02 LOCKHEED: Applies to All Models 049, 149, 649 and 749 Series Aircraft.

Compliance required as indicated.

At the first arrival at the main base, unless already accomplished, inspect for cracks in the forward flange of the lower front spar cap at wing Station 326, left and right, with particular reference to spar cap joggle areas using dye penetrant inspection method or equivalent.

1. If crack is found in the forward flange and does not extend into the vertical leg, stop drill the crack unless it terminates in a rivet hole and make permanent repair or install the serviceable repair in accordance with LAC Drawing 325800. When serviceable repair is used, a visual inspection must be conducted at periodic intervals not to exceed 50 hours with dye penetrant inspection or equivalent method to be used at periods not to exceed every 200 hours until incorporation of the reinforcement per LAC Drawing 325667, change A or equivalent.

2. If crack in the front spar flange extends into the vertical leg, remove tank sealant as necessary for skin and web inspection using dye penetrant inspection method or equivalent. Reinforcement per LAC Drawing 325667, change A or equivalent is necessary before resuming commercial operation and normal inspection procedures.

3. If no cracks are found, reinspect using dye penetrant inspection method or equivalent on all aircraft with 10,000 hours or more total flight time, at intervals not to exceed 200 hours, and on all other aircraft at each major airframe inspection period until such time as reinforcement per LAC Drawing 325667, change A or equivalent is accomplished.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A-763](https://openairdocs.org/tcds/A-763): Lockheed Martin Aeronautics Company; names 6 of 6 models: 149-46, 649-79, 749A-79, 749-79, 649A-79, 49-46

## Registered aircraft it may apply to (OpenAirDocs)

Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment.

- Aircraft: 2 (2 by airframe model, 0 by engine model)
- Makers: Lockheed 2

Models with the most aircraft:

- [Lockheed 49-46](https://openairdocs.org/model/lockheed-49-46): 1 aircraft (airframe model)
- [Lockheed 749-79](https://openairdocs.org/model/lockheed-749-79): 1 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/53-15-02/models.md
Every aircraft: https://openairdocs.org/ad/53-15-02/aircraft.md

Its text cites no advisory circulars or STCs.

---
OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.