# AD 73-09-03: Main Rotor Gear Box

- Type: Airworthiness directive
- Status: Current
- Products: Airbus Helicopters SA.315B Alouette III, SA.316B Alouette III, SA.316C Alouette III and SA.319B Alouette III
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Rotorcraft
- Amendment: 39-1626
- Registered aircraft: 11 may be affected, by airframe or engine model (OpenAirDocs)
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/BEAA7FB2396EC55B86256A33006F7B35.0001
- DRS record last changed: May 30, 2024
- Page: https://openairdocs.org/ad/73-09-03

## The airworthiness directive

73-09-03 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE: (S.N.I.A.S.) - formerly SUD Aviation). Amendment 39-1626. Applies to Lama Model SA-315B and Alouette Models SA-316B, SA-316C, and SA- 319B helicopters having main gear box P/N's 319A.62.00.000.1 and .2, serial numbers up to and including 2,000, installed.

Compliance required as follows, unless already accomplished:

  (1) For helicopters that have accumulated 500 or more hours' time in service on the main rotor gear box since new or since overhauled, compliance is required before further flight, except that the aircraft may be flown in accordance with FAR 21.197 to a base where the work can be performed.

  (2) For all other helicopters, compliance is required before the accumulation of 500 hours' time in service on a main rotor gear box since new or since overhauled.

To prevent the possible failure of a main rotor gear box because of defective planetary gears, remove and disassemble gear box P/N's 319A.62.00.000.1 or .2 and inspect the planet pinions of the second stage planetary gear, P/N 3160S.62.05.208, for cracks and evidence of overheat, due to grinding, in accordance with the inspection procedures specified in Aerospatiale Service Letter No. 137-01-72, dated November 30, 1972, or an FAA-approved equivalent and -

  (a) For Lama Model SA-315B helicopters, Aerospatiale Service Bulletin No. 05-02, dated October 27, 1972, as amended on November 30, 1972, or an FAA-approved equivalent; and

  (b) For Alouette Models SA-316B, SA-316C and SA-319B helicopters, Aerospatiale Service Bulletin No. 05-47, dated October 27, 1972, or an FAA-approved equivalent.

  (c) If cracks or evidence of overheat are found in the planet pinions of the second stage planetary gear, P/N 3160S.62.05.208, replace with serviceable planet pinions of the same part number.

This amendment is effective upon publication in the Federal Register as to all persons except those persons to whom it was made immediately effective by the airmail letter dated March 23, 1973, which contained this amendment.

## Affected data sheets (1) (OpenAirDocs)

The type certificate data sheets whose models the AD names.

- [TCDS H1IN](https://openairdocs.org/tcds/H1IN): Airbus Helicopters; names 4 of 5 models: SA.316C Alouette III, SA.316B Alouette III, SA.315B Alouette III, SA.319B Alouette III

## 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: 11 (11 by airframe model, 0 by engine model)
- Makers: Aerospatiale 9, Sud 2

Models with the most aircraft:

- [Aerospatiale SA315B ALOUETTE III](https://openairdocs.org/model/aerospatiale-sa315b-alouette-iii): 4 aircraft (airframe model)
- [Aerospatiale SA319B ALOUETTE III](https://openairdocs.org/model/aerospatiale-sa319b-alouette-iii): 3 aircraft (airframe model)
- [Sud SA316B ALOUETTE III](https://openairdocs.org/model/sud-sa316b-alouette-iii): 2 aircraft (airframe model)
- [Aerospatiale SA316B ALOUETTE III](https://openairdocs.org/model/aerospatiale-sa316b-alouette-iii): 2 aircraft (airframe model)

All 4 models: https://openairdocs.org/ad/73-09-03/models.md
Every aircraft: https://openairdocs.org/ad/73-09-03/aircraft.md

Its text cites no advisory circulars or STCs.

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