# AD 59-16-02: Stabilizer Spar

- Type: Airworthiness directive
- Status: Current
- Products: Air Trading Army B-34, Navy PV-1 and 18
- Superseded by: Nothing supersedes this AD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/6CA774B920244FCE8625696F0047EECB.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/59-16-02

## The airworthiness directive

59-16-02 LOCKHEED: Applies to Models 18, PV-1 and B-34 Series Aircraft Except Those Incorporating Spar Reinforcement as Covered in Lockheed Aircraft Service Bulletin 18/SB- 112.

Compliance required as indicated.

Numerous reports have been received wherein fatigue cracks have been found in the horizontal stabilizer spars in the area of the vertical fin attachments. In order to determine if this condition has developed, the following inspection is required.

Within the next 50 hours of flight and at 300-hour intervals thereafter inspect the horizontal stabilizer front and rear spar flanges and webs for cracks in the region of the vertical fin attaching angles. If cracks are found, stop-drill, install spar flange and web doublers and flange filler blocks extending beyond the fin attaching angles. Add doubler plates on the forward face of rear spar in region of rudder hinge bracket attachment holes. Visual inspections of the area with a 10-power glass are adequate. The 300 hour inspection may be discontinued after incorporation of the reinforcements. One approved method of accomplishing the above spar reinforcement is contained in Lockheed Aircraft Service Bulletin 18/SB-112 dated September 18, 1944, pertaining to this same subject.

Revised May 27, 1965.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS LTC AL-13](https://openairdocs.org/tcds/LTC%20AL-13): Air Trading Corporation; names 2 of 3 models: Navy PV-1, Army B-34
- [TCDS A-723](https://openairdocs.org/tcds/A-723): Lockheed Martin Aeronautics Company; names 1 of 1 models: 18

## 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 18](https://openairdocs.org/model/lockheed-18): 2 aircraft (airframe model)

All 1 models: https://openairdocs.org/ad/59-16-02/models.md
Every aircraft: https://openairdocs.org/ad/59-16-02/aircraft.md

Its text cites no advisory circulars or STCs.

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