# AD 78-26-04: Tail Rotor Hub Assembly - Type: Airworthiness directive - Status: Current - Products: Schweizer 269A, 269A-1, 269B, 269C, 369D, 369H, 369HE, 369HM and 369HS - Effective: December 27, 1978 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-3374 - Registered aircraft: 620 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/926D7E5EA186984586256A3A006C0F60.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/78-26-04 ## The airworthiness directive 78-26-04 HUGHES HELICOPTERS: Amendment 39-3374. Applies to Hughes Model 269C, Serial Number 0004 through 0716, and Models 269A, 269A-1, and 269B certificated in all categories, equipped with LTS Tail Rotor Assembly P/N 269A6034, including Military Model TH-55A equipped with LTS Tail Rotor Assembly P/N 269A6034, equipped with Tail Rotor Hub Assembly Part No. 369A1725 or Tail Rotor Hub Assembly Part No. 369A1725-5, Serial No. 001 through 862. Also, applies to Hughes Model 369H, 369HM, 369HS, 369HE and 369D, Serial Numbers 0001D through 0324D and 0331D through 0333D certificated in all categories, equipped with Tail Rotor Hub Assembly Part No. 369A1725 or Tail Rotor Hub Assembly Part No. 369A1725-5, Serial No. 001 through 862 or Tail Rotor Hub Assembly Part No. 369A1725- 501. Compliance required as indicated. To prevent failure of Tail Rotor Hub Assembly, Hughes P/N 369A1725, 369A1725-5, Serial No. 001 through 862 and 369A1725-501, which could result in a loss of the rotorcraft, accomplish the following: (a) Within 100 hours time in service or six months after the effective date of this AD, whichever occurs sooner, unless already accomplished, inspect the tail rotor hub for cracks, corrosion or other damage and rework the tail rotor hub in accordance with Part II - Hub Inspection and Rework Paragraphs a through h of the following FAA approved Hughes Service Information Notices: (1) For Hughes Model 269 Series Helicopter use Hughes Service Information Notice No. N-153, dated September 1, 1978. (2) For Hughes Model 369H Series Helicopter use Hughes Service Information Notice No. HN-128.1, dated December 8, 1978. (3) For Hughes Model 369D Series Helicopter use Hughes Service Information Notice No. DN-27.1, dated December 8, 1978. NOTE: Hughes Service Information Notices of the above listed dates are the only versions of S.I.N.s suitable for compliance with this AD. (b) Remove all cracked hubs from service prior to further flight and replace with like serviceable part. If replacement part has part number suffix identification SP, no further action is required by this AD. If replaced with part number hub affected by this AD, revert to the inspection requirements of Paragraph (c). (c) Reinspect the tail rotor hub with a 10 power magnifying glass at each annual inspection or 300 additional hours time in service since the last inspection, whichever occurs earlier. If cracks, pits, corrosion or other damage is found, inspect and rework, per the instructions of Paragraphs (a) and (b). (d) Equivalent inspection procedures and repairs may be used when approved by the Chief, Aircraft Engineering Division, FAA Western Region. This amendment becomes effective December 27, 1978. ## Affected data sheets (2) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H3WE](https://openairdocs.org/tcds/H3WE): MD Helicopters LLC; names 5 of 12 models: 369D, 369HS, 369HM, 369HE, 369H - [TCDS 4H12](https://openairdocs.org/tcds/4H12): Schweizer RSG LLC; names 4 of 6 models: 269B, 269A-1, 269A, 269C ## 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: 620 (620 by airframe model, 0 by engine model) - Makers: Hughes 280, Hughes Helicopters 207, Schweizer 120, MD Helicopters 5, Summa 5, Schweizer RSG 3 Models with the most aircraft: - [Hughes Helicopters HUGHES 369D](https://openairdocs.org/model/hughes-helicopters-hughes-369d): 207 aircraft (airframe model) - [Schweizer 269C](https://openairdocs.org/model/schweizer-269c): 115 aircraft (airframe model) - [Hughes 269A](https://openairdocs.org/model/hughes-269a): 97 aircraft (airframe model) - [Hughes 269C](https://openairdocs.org/model/hughes-269c): 74 aircraft (airframe model) - [Hughes 369HS](https://openairdocs.org/model/hughes-369hs): 69 aircraft (airframe model) - [Hughes 269B](https://openairdocs.org/model/hughes-269b): 31 aircraft (airframe model) - [Hughes 269A-1](https://openairdocs.org/model/hughes-269a-1): 5 aircraft (airframe model) - [Summa 369D](https://openairdocs.org/model/summa-369d): 4 aircraft (airframe model) - [Schweizer HUGHES 269C](https://openairdocs.org/model/schweizer-hughes-269c): 4 aircraft (airframe model) - [MD Helicopters 369HS](https://openairdocs.org/model/md-helicopters-369hs): 3 aircraft (airframe model) - [Hughes 369HE](https://openairdocs.org/model/hughes-369he): 3 aircraft (airframe model) - [Schweizer RSG 269C](https://openairdocs.org/model/schweizer-rsg-269c): 3 aircraft (airframe model) - [MD Helicopters 369HM](https://openairdocs.org/model/md-helicopters-369hm): 2 aircraft (airframe model) - [Summa 369HS](https://openairdocs.org/model/summa-369hs): 1 aircraft (airframe model) - [Hughes 369H](https://openairdocs.org/model/hughes-369h): 1 aircraft (airframe model) - [Schweizer 269A](https://openairdocs.org/model/schweizer-269a): 1 aircraft (airframe model) All 16 models: https://openairdocs.org/ad/78-26-04/models.md Every aircraft: https://openairdocs.org/ad/78-26-04/aircraft.md Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.