# AD 81-13-09 R2: Tail Rotor Blades Pitch Horn - Type: Airworthiness directive - Status: Current - Products: Airbus Helicopters AS355E, AS355F, AS350B, AS350C, AS350D and AS350D1 - Effective: December 18, 1981 - Published: December 17, 1981 - Issued: December 17, 1981 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-4280 - Docket: 81-ASW-28 - Registered aircraft: 25 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/2293A1A14A83188586256A4E00552925.0001 - DRS record last changed: November 21, 2025 - Page: https://openairdocs.org/ad/81-13-09-R2 ## The airworthiness directive 81-13-09 R2 SOCIETE NATIONALE INDUSTRIELLE AEROSPATIALE: Amendment 39-4175 as amended by Amendment 39-4280. Applies to Models AS350 and AS355 Series Helicopters, certificated in all categories, that are equipped with tail rotor blade pitch horns, P/N 350A12-1368-01 or -02 (Airworthiness Docket No. 81-ASW-28). Compliance required as indicated. To detect possible cracks and prevent failure of the tail rotor blade pitch horns, accomplish the following: (a) Within 10 hours' time in service after the effective date of this AD, unless already accomplished per Aerospatiale Telex Service No. 01.07A dated June 5, 1981, remove each pitch horn, clean and remove paint, inspect for flatness and inspect for cracks as specified in Aerospatiale Telex Service No. 01.07A. (b) Replace horns before further flight if not flat or if cracked. (c) Serviceable pitch horns that comply with this AD must be reinstalled as specified in the Aerospatiale Telex Service No. 01.07A. (d) For pitch horns, P/N 350A-12-1368-01, after initial compliance with paragraphs (a) and (c) of this AD and prior to the first flight of each day, conduct the following: (1) Clean thoroughly, the surface of each horn at the two-mounting bolts. (2) Inspect each horn for cracks using a five power or higher magnifying glass and light in the area of the mounting bolt countersink or spotface and adjacent radii of the yoke. (3) If a crack is found, remove the affected horn prior to further flight and install a serviceable horn as specified in paragraph (c) of this AD. (e) Equivalent means of compliance must be approved by the Chief, Aircraft Certification Staff, FAA, Europe, Africa, and Middle East Office, c/o American Embassy, Brussels, Belgium. (f) Special flight permits may be issued in accordance with Sections 21.197 and 21.199 of the Federal Aviation Regulations to fly aircraft to a base where paragraphs (a) through (c) of this AD can be accomplished. (g) For pitch horns, P/N 350A12-1368-01, accomplish the following: (1) Horns with 400 hours' or more total time in service on July 31, 1981, remove from service within the next 50 hours' time in service. (2) Horns with less than 400 hours' total time in service on July 31, 1981, remove from service before attaining 450 hours' total time in service. (h) For pitch horns, P/N 350A-12-1368-02, remove from service on or before attaining 1,250 hours' total time in service. (i) AS350 Service Bulletin No. 01.07 Revision 2 and AS355 Service Bulletin No. 01.01 Revision 1 may be used instead of TELEX Service No. 01.07A. (Aerospatiale Telex Service No. 01.07B dated June 30, 1981, pertains to the 450 hour' limit.) Amendment 39-4175 became effective July 31, 1981, to all persons including those persons to whom it was made effective by priority mail AD No. 81-13-09 issued June 16, 1981, and to whom part of the amendment was made effective by priority mail AD 81-13-09 issued June 16, 1981. This amendment 39-4280 becomes effective December 18, 1981. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H9EU](https://openairdocs.org/tcds/H9EU): Airbus Helicopters; names 4 of 10 models: AS350C, AS350B, AS350D1, AS350D - [TCDS H11EU](https://openairdocs.org/tcds/H11EU): Airbus Helicopters; names 2 of 6 models: AS355E, AS355F ## 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: 25 (25 by airframe model, 0 by engine model) - Makers: Aerospatiale 16, S N I A S 7, Eurocopter 1, Eurocopter France 1 Models with the most aircraft: - [Aerospatiale AS350B](https://openairdocs.org/model/aerospatiale-as350b): 13 aircraft (airframe model) - [S N I A S AS-350B ECUREUIL](https://openairdocs.org/model/s-n-i-a-s-as-350b-ecureuil): 5 aircraft (airframe model) - [Aerospatiale AS355F TWINSTAR](https://openairdocs.org/model/aerospatiale-as355f-twinstar): 2 aircraft (airframe model) - [S N I A S AS350D ASTAR](https://openairdocs.org/model/s-n-i-a-s-as350d-astar): 1 aircraft (airframe model) - [Aerospatiale AS-355E TWIN STAR](https://openairdocs.org/model/aerospatiale-as-355e-twin-star): 1 aircraft (airframe model) - [S N I A S AS 355F](https://openairdocs.org/model/s-n-i-a-s-as-355f): 1 aircraft (airframe model) - [Eurocopter AS350B](https://openairdocs.org/model/eurocopter-as350b): 1 aircraft (airframe model) - [Eurocopter France AS350B](https://openairdocs.org/model/eurocopter-france-as350b): 1 aircraft (airframe model) All 8 models: https://openairdocs.org/ad/81-13-09-R2/models.md Every aircraft: https://openairdocs.org/ad/81-13-09-R2/aircraft.md Its text cites no advisory circulars or STCs. --- From OpenAirDocs.org, an independent open copy of FAA and NTSB data. Only the Federal Register edition on govinfo.gov is the official legal text of an AD.