# AD 73-07-01: Wing Front Spar Lower Cap Cracks

- Type: Airworthiness directive
- Status: Current
- Products: Kelowna Flightcraft R & D 340, 440 and Military C-131E with STC SA1096WE or SA4-1100
- Effective: March 26, 1973
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-1608
- Registered aircraft: 12 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/C7D7C88FAA112273862569B2007591DC.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/73-07-01

## The airworthiness directive

73-07-01 GENERAL DYNAMICS: Amdt. 39-1608. Applies to Model 340, 440 and C- 131E and all such model airplanes converted to turbopropeller power in accordance with STC SA1096WE and SA4-1100 known as Model 640 and Model 580, respectively, certificated in all categories.

Compliance as indicated required on all airplanes with 30,000 hours or more total time in service unless already accomplished.

To detect cracks in the wing front spar lower caps, accomplish the following:

  (1) As soon as practicable, but not to exceed 10 hours' time in service following the effective date of this AD, if the airplane is to be flown, visually inspect, on a daily basis, from the exterior of the wing, both left and right wing front spar lower caps in areas adjacent to each side of main landing gear drag strut attachment fittings for cracks until inspection in (2) below is accomplished.

  (2) Within the next 100 hours' time in service after the effective date of this A.D., unless already accomplished within the last 500 hours' time in service, and thereafter at intervals not to exceed 600 hours' time in service from the last inspection, accomplish the following:

  (a) Gain access to the wing interior in the area described in (1) above by removal of lower wing skin access cover.

  (b) Perform inspection described in (1) above from the interior of the wing.

  (3) If cracks are found as the result of the inspections described in (1) or (2) above, repair before further flight in a manner approved by the Chief, Aircraft Engineering Division FAA Western Region.

This amendment becomes effective March 26, 1973.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 6A6](https://openairdocs.org/tcds/6A6): Kelowna Flightcraft R & D Ltd.; names 3 of 6 models: 340, Military C-131E, 440

## 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: 12 (12 by airframe model, 0 by engine model)
- Makers: Convair 12

Models with the most aircraft:

- [Convair 340](https://openairdocs.org/model/convair-340): 7 aircraft (airframe model)
- [Convair 440](https://openairdocs.org/model/convair-440): 5 aircraft (airframe model)

All 2 models: https://openairdocs.org/ad/73-07-01/models.md
Every aircraft: https://openairdocs.org/ad/73-07-01/aircraft.md

## Related documents

- [STC SA1096WE](https://openairdocs.org/stc/SA1096WE): Rolls Royce Dart 542-4 engines with Dowty Rotol (c) R245/4-40-4.5/13 or (c) R259/4-40-4.5/17 propellers and associated modifications.. Kelowna Flightcraft Ltd, Named in the applicability
- [STC SA4-1100](https://openairdocs.org/stc/SA4-1100): Installation of Allison model 501-D13D, 501-D13H, or 501-D22G engines and related changes.. Kelowna Flightcraft Ltd, Named in the applicability

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