# AD 68-09-02: Wing Skin Risers

- Type: Airworthiness directive
- Status: Current
- Products: Lockheed Martin 1329-23A, 1329-23D and 1329-23E
- Effective: November 19, 1968
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-593
- Registered aircraft: 1 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/10028C805522386686256E0100546ADD.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/68-09-02

## The airworthiness directive

68-09-02 LOCKHEED: Amdt. 39-593. Applies to Model 1329 airplanes, serial numbers 5001 through 5029 and 5031 through 5055.

Compliance required as indicated.

Lockheed Model 1329 and military C-140 series airplanes have experienced a number of stress corrosion cracks in the wing skin risers at the riser-skin intersection. To detect cracking of risers on these airplanes, accomplish the following:

  (a) Within 15 days after the effective date of this AD, inspect all aircraft in accordance with the instructions contained in Lockheed-Georgia Company Service Bulletin No. 329-257, dated April 11, 1968, and Service Bulletin Supplement No. 329-257A, dated April 26, 1968, or later FAA approved revision, or in an equivalent manner approved by the Chief, Engineering and Manufacturing Branch, FAA, Southern Region.

NOTE. - Aircraft which have been inspected by representatives of Lockheed-Georgia Company are considered to comply with paragraph (a) above.

  (b) If cracks are detectedin the riser-skin intersections, reinspect at intervals not to exceed 180 days in accordance with the instructions contained in Lockheed-Georgia Company Service Bulletin No. 329-257, dated April 11, 1968, and Service Bulletin Supplement No. 329- 257A dated April 26, 1968, or later FAA approved revision, or in an equivalent manner approved by the Chief, Engineering and Manufacturing Branch, FAA, Southern Region.

  (c) If, as a result of the initial inspection or any subsequent inspections, it is determined that more frequent inspections are required, individual airplane owners will be so notified by the Chief, Engineering and Manufacturing Branch, FAA, Southern Region.

  (d) If no cracks are found, or if cracks are repaired in a manner approved by the Chief, Engineering and Manufacturing Branch, FAA, Southern Region, the repetitive inspections required by paragraphs (b) and (c), above, may be discontinued.

  (e) Repeat the inspection required by paragraph (a), above, at each annual inspection, or each twelve months. These inspections need only consist of Phase I and Phase II inspections as explained in Lockheed-Georgia Company Service Bulletin No. 329-257, dated April 11, 1968, and Service Bulletin Supplement No. 329-257A dated April 26, 1968, or later FAA approved revision, or in an equivalent manner approved by the Chief, Engineering and Manufacturing Branch, FAA, Southern Region.

This amendment becomes effective May 7, 1968.

Revised Nov. 19, 1968.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 2A15](https://openairdocs.org/tcds/2A15): Lockheed Martin Corporation; names 3 of 4 models: 1329-23D, 1329-23A, 1329-23E

## 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 1329-23E](https://openairdocs.org/model/lockheed-1329-23e): 1 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/68-09-02/models.md
Every aircraft: https://openairdocs.org/ad/68-09-02/aircraft.md

Its text cites no advisory circulars or STCs.

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