# AD 50-26-01: Landing Gear Side Braces

- Type: Airworthiness directive
- Status: Current
- Products: Airlift International C-46A, C-46D, C-46F, C-46R, C-46E, C-46A, C-46D, C-46E, C-46F, C-46A, C-46D, C-46F and 3 more
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Registered aircraft: 7 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/A13DF12C31BDFD5686256CC4006ADB80.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/50-26-01

## The airworthiness directive

50-26-01 CURTISS-WRIGHT Applies to Model C-46 Series Aircraft equipped with landing gear side braces, Curtiss-Wright P/N's 20-310-1028 and 20-310-1029.

Compliance required within 100 hours' time in service after the effective date of this amendment, unless already accomplished within the last 400 hours' time in service, and at intervals thereafter not to exceed 500 hours' time in service from the last inspection.

Thoroughly inspect the landing gear side braces P/N 20-310-1028 and 20-310-1029 for cracks in the vicinity of the welds at either end of the struts, using magnetic or X-ray inspection.

If cracks are found, the following will apply:

1. For one crack only in the weld proper less than 1/2 inch in length and 0.060-inch deep that does not penetrate into the tube member itself, stress relieve by grinding out the crack and polishing to remove all grinding marks. No rewelding required.

2. For more than one crack in the weld proper or cracks larger thanthose mentioned in item 1 that do not penetrate into the tube member itself, repair by grinding out the cracks and rewelding in a welding jig (using the oxyacetylene torch method) and reheat treat the tube assembly to 180,000 p.s.i. and Rockwell C-38.

3. If cracks are found in the tube member itself, the part should be replaced by a completely new assembly or repaired by replacing the tube and refabricating to the original specifications.

4. P/N S51E105 is considered a satisfactory replacement for P/N 20-310-1028. When P/N S51E105 is installed it should be inspected by magnetic particle or X-ray method of inspection prior to initial installation and at periods not to exceed 1,000 hours of operation thereafter.

5. Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Southern 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.

This supersedes AD 50-19-1.

Revised December 28, 1964.

## Affected data sheets (2) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 2A5](https://openairdocs.org/tcds/2A5): Tempo Design Corporation; names 2 of 2 models: C-46/CW20-T, Super C-46/CW20-T
- [TCDS 3A2](https://openairdocs.org/tcds/3A2): Airlift International Inc.; names 1 of 4 models: C-46R

## 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: 7 (7 by airframe model, 0 by engine model)
- Makers: Curtiss Wright 7

Models with the most aircraft:

- [Curtiss Wright C-46F](https://openairdocs.org/model/curtiss-wright-c-46f): 4 aircraft (airframe model)
- [Curtiss Wright C-46A](https://openairdocs.org/model/curtiss-wright-c-46a): 1 aircraft (airframe model)
- [Curtiss Wright C-46D](https://openairdocs.org/model/curtiss-wright-c-46d): 1 aircraft (airframe model)
- [Curtiss Wright C-46R](https://openairdocs.org/model/curtiss-wright-c-46r): 1 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/50-26-01/models.md
Every aircraft: https://openairdocs.org/ad/50-26-01/aircraft.md

Its text cites no advisory circulars or STCs.

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