# AD 75-04-12: Markings on Tachometer

- Type: Airworthiness directive
- Status: Current
- Products: American Champion 8GCBC
- Effective: February 21, 1975
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Small airplane
- Amendment: 39-2093
- Registered aircraft: 400 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/F73D9F73D444C2DE86256A3400591552.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/75-04-12

## The airworthiness directive

75-04-12 BELLANCA: Amendment 39-2093. Applies to Model 8GCBC Airplanes, Serial Numbers 1-74 through 119-74, 120-75 through 153-75 certificated in all categories.

Compliance required within the next 10 hours time in service after the effective date of this airworthiness directive, unless already accomplished.

To prevent possible resonant vibratory conditions with McCauley Model 1A200/HFA fixed pitch propellers installed on Lycoming 0-360-C2A, or -C2E type engines, accomplish the following in accordance with Bellanca Service Letter Number 115 and Bellanca Service Kit Number 245.

  (a) Remove existing markings on the tachometer instrument glass and affix Mylar decal, Bellanca P/N 1-10443. The decal is properly affixed when: a green arc extends from 500 to 1700 RPM; a yellow arc from 1700 to 2100 RPM; a green arc from 2100 RPM to 2700 RPM; and a red radial is positioned at 2700 RPM.

  (b) Install Bellanca P/N 1-10437, placard "AVOID 1700-2100 DURING DESCENT", on thetachometer instrument glass below the hour meter.

  (c) Accomplish Revision Number 1 to existing FAA Approved Airplane Flight Manual (AFM) in accordance with AFM revisions page.

This amendment becomes effective February 21, 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: 8GCBC

## 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: 400 (400 by airframe model, 0 by engine model)
- Makers: American Champion 218, Bellanca 182

Models with the most aircraft:

- [American Champion 8GCBC](https://openairdocs.org/model/american-champion-8gcbc): 218 aircraft (airframe model)
- [Bellanca 8GCBC](https://openairdocs.org/model/bellanca-8gcbc): 182 aircraft (airframe model)

All 3 models: https://openairdocs.org/ad/75-04-12/models.md
Every aircraft: https://openairdocs.org/ad/75-04-12/aircraft.md

Its text cites no advisory circulars or STCs.

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