# AD 76-25-03: Main Rotor Blade Spars

- Type: Airworthiness directive
- Status: Current
- Products: Columbia Helicopters 107-II
- Effective: December 10, 1976
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-2784
- Registered aircraft: 12 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9A3532217D9A7FBB86256A34005B9E32.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/76-25-03

## The airworthiness directive

76-25-03 BOEING VERTOL: Amendment 39-2784. Applies to Boeing Vertol Model 107-11 Helicopters Certificated in all Categories.

Compliance required as follows:

To detect corrosion which could lead to cracking of the main rotor blade spars accomplish the following within the next 60 days unless already accomplished within the past 34 months and every 36 months thereafter.

a) Inspect for corrosion, and alter if necessary, main rotor blades P/N's 107R1202 and SK24790 series in accordance with Boeing Vertol Company Service Bulletin No. 107-333 (R-1) dated July 1, 1976, Section 2 (Accomplishment Instructions" or Boeing Vertol Company Service Bulletin No. 107-334 dated October 29, 1976, Section 2 "Accomplishment Instructions" or equivalent procedure approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region.

b) If spar corrosion exceeds the limits in either of the above service bulletins or those approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region, replace the main rotor blade with one that has been inspected and altered if necessary, in accordance with one of the above service bulletins and/or an acceptable equivalent procedure.

This amendment is effective December 10, 1976.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS 1H16](https://openairdocs.org/tcds/1H16): Columbia Helicopters Inc.; names 1 of 1 models: 107-II

## 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: Boeing-Vertol 7, Columbia Helicopters 2, Vertol 2, Boeing V-Columbia Helicopters 1

Models with the most aircraft:

- [Boeing-Vertol 107-II](https://openairdocs.org/model/boeing-vertol-107-ii): 7 aircraft (airframe model)
- [Columbia Helicopters 107-II](https://openairdocs.org/model/columbia-helicopters-107-ii): 2 aircraft (airframe model)
- [Vertol 107-II](https://openairdocs.org/model/vertol-107-ii): 2 aircraft (airframe model)
- [Boeing V-Columbia Helicopters 107-II](https://openairdocs.org/model/boeing-v-columbia-helicopters-107-ii): 1 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/76-25-03/models.md
Every aircraft: https://openairdocs.org/ad/76-25-03/aircraft.md

Its text cites no advisory circulars or STCs.

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