# AD 62-21-04: Wing Lower Skin

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed Martin Aeronautics 1649A-98
- Effective: November 2, 1962
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 1 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/90C1FC3230679063862569B60055A0D9.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/62-21-04

## The airworthiness directive

62-21-04 LOCKHEED: Amdt. 489 Part 507 Federal Register October 3, 1962. Applies to All Model 1649A Aircraft.

Compliance required as indicated.

As a result of chordwise cracks on the wing lower milled skin at wing Station 590, the following shall be accomplished:

  (a) Within the next 400 hours' time in service after the effective date of this AD, unless already accomplished within the past 600 hours' time in service, and at periods thereafter not exceeding 1,000 hours' time in service following that initial inspection, inspect from wing Station 580 through wing Station 600, the external lower surface of the aft skin panels, P/N 472066, for any evidence of cracks emanating from the aft edge of the panel through the rear beam attachment holes. Inspection shall be by close visual or dye penetrant means.

  (b) Any cracks shall be repaired prior to further flight in accordance with Lockheed 1649 Service Bulletin No. 73, Section 1, "Modification Data," and Lockheed Drawing SED61- 9004, or an equivalent method approved by the Chief, Engineering and Manufacturing Branch, FAA Western Region.

  (c) The periodic inspections may be discontinued following repair per (b) or when an uncracked skin panel has been reinforced in accordance with Lockheed 1649 Service Bulletin No. 73.

  (d) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Western Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator.

(Lockheed Field Service Letter FS/240893L, dated April 14, 1960, and Lockheed 1649 Service Bulletin No. 73 cover this same subject.)

This directive effective November 2, 1962.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 4A17](https://openairdocs.org/tcds/4A17): Lockheed Martin Aeronautics Company; names 1 of 1 models: 1649A-98

## 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: 1 (1 by airframe model, 0 by engine model)
- Makers: Lockheed 1

Models with the most aircraft:

- [Lockheed 1649A-98](https://openairdocs.org/model/lockheed-1649a-98): 1 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/62-21-04/models.md
Every aircraft: https://openairdocs.org/ad/62-21-04/aircraft.md

Its text cites no advisory circulars or STCs.

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