# AD 74-23-04: Rib Flanges

- Type: Airworthiness directive
- Status: Current
- Products: American Champion 8KCAB
- Effective: March 6, 1975
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-2111
- Registered aircraft: 825 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/FB7EBBEA72375F4A86256E520053AE8A.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/74-23-04

## The airworthiness directive

74-23-04 BELLANCA: Amendment 39-2001 as amended by Amendment 39-2111. Applies to Bellanca Models 8KCAB aircraft S/N's 4-71 thru 159-74.

To detect evidence of fatigue cracks and/or distortion of rib flanges, accomplish the following before further flight:

A. Visually inspect the wing ribs for evidence of fatigue cracks and/or distortion of the rib flanges as follows:

1. Remove fabric from each of four doped-on round reinforcing rings located on lower surface of each wing adjacent to front spar. Use a sharp knife.

2. Using a flashlight (and mirror as necessary) inspect all ribs beginning at first rib outboard of fuel tank and each other rib outboard, to and including last outboard full rib, for general condition.

3. Examine particularly the area approximately 2" aft of front spar (just aft of rib reinforcing gusset) on rib top flange for evidence of cracks, distortion, and fabric holdown rivet looseness.

B. If, as a result of inspection per ParagraphA, cracks, distortion or fabric rivet looseness are found in any of the inspected ribs, repair and reinforce all 30 ribs, 15 ribs per wing, per Bellanca Kit No. 243. Equivalent repairs are to be approved by the Chief, Engineering and Manufacturing Branch, Great Lakes Region, before further flight.

A special flight permit per FAR 21.197 may be issued after accomplishment of Paragraph A to allow repairs in accordance with this Airworthiness Directive.

C. If, as a result of inspection per Paragraph A, no evidence of any cracks, distortion or fabric rivet looseness is found, repeat the required inspection after every 25 hours of flight.

D. The inspection required by Service Letter #113 may be discontinued after installation of Bellanca Kit No. 243. Amendment 39-2001 was effective November 7, 1974. The telegraphic inspection portion was effective August 20, 1974; for all recipients of the air mail letter of August 20, 1974, which is contained in this amendment.

This amendment 39-2111 becomes effective March 6, 1975.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS A21CE](https://openairdocs.org/tcds/A21CE): American Champion Aircraft Corp.; names 1 of 2 models: 8KCAB

## 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: 825 (825 by airframe model, 0 by engine model)
- Makers: American Champion 449, Bellanca 371, Champion 5

Models with the most aircraft:

- [American Champion 8KCAB](https://openairdocs.org/model/american-champion-8kcab): 449 aircraft (airframe model)
- [Bellanca 8KCAB](https://openairdocs.org/model/bellanca-8kcab): 371 aircraft (airframe model)
- [Champion 8KCAB](https://openairdocs.org/model/champion-8kcab): 5 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/74-23-04/models.md
Every aircraft: https://openairdocs.org/ad/74-23-04/aircraft.md

Its text cites no advisory circulars or STCs.

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