# AD 70-16-07: Main Rotor Blade - Type: Airworthiness directive - Status: Current - Products: MD Helicopters 369, 369A, 369H, 369HE, 369HM and 369HS - Effective: August 8, 1970 - Superseded by: Nothing supersedes this AD - Product type: Aircraft, Rotorcraft - Amendment: 39-1059 - Registered aircraft: 130 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/E4648EEF0C6DFFEE86256A39004758AC.0001 - DRS record last changed: May 30, 2024 - Page: https://openairdocs.org/ad/70-16-07 ## The airworthiness directive 70-16-07 HUGHES: Amendment 39-1059. Applies to Model 369 Series helicopters, certificated in all categories, which incorporate P/N 369A1100 and P/N 369A1100-501 main rotor blade serial numbers listed in Hughes Service Information Notice No. HN-8, dated November 19, 1969, or later FAA approved revision and serial numbers listed in OH-6A Information Notice Numbers, 120, 120A, and 120B dated October 24, 1969; November 5, 1969; and December 19, 1969, respectively. Compliance required as indicated: To prevent failure of the main rotor blade P/N 369A1100 and P/N 369A1100-501 accomplish the following or an equivalent inspection procedure approved by the Chief, Aircraft Engineering Division, FAA Western Region: Within 25 hours time in service after the effective date of this AD, unless already accomplished, determine the identification notation on the blade top and bottom doublers in accordance with the procedures in Part I a, b, and c of Hughes Service Information Notice No. HN-8, dated November 19, 1969, or later FAA approved revision. (a) For blades displaying "PR-12" ink stamps or blades lacking ink stamps below the part number on either of the doublers: (1) Inspect prior to further flight in accordance with Part I d of Hughes Service Information Notice No. HN-8, above. (2) If indications of cracks or doubler peeling or separation are found, remove the blade from service prior to further flight. (3) If indications of cracks or doubler peeling or separation are not found, repeat the inspection required under (1) above, at periods not to exceed 25 hours time in service from the last inspection until the blades are removed from service as specified in (4), below. (4) Remove from service prior to the accumulation of 100 hours time in service from the effective date of this AD. (b) Blades displaying ink stamp letters and numerals other than "PR-12" below the part number on both doublers may be returned to service with no further inspection, following refinishing and identification per Hughes Service Information Notice No. HN-8, dated November 19, 1969, or later FAA approved revision. This amendment becomes effective August 8, 1970. ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS H3WE](https://openairdocs.org/tcds/H3WE): MD Helicopters LLC; names 6 of 12 models: 369HS, 369HM, 369HE, 369H, 369 (Army YOH-6A), 369A (Army OH-6A) ## 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: 130 (130 by airframe model, 0 by engine model) - Makers: Hughes 121, MD Helicopters 6, Hughes/Batto John 1, Hughes/Helicopter Assocs 1, Summa 1 Models with the most aircraft: - [Hughes 369HS](https://openairdocs.org/model/hughes-369hs): 69 aircraft (airframe model) - [Hughes 369A](https://openairdocs.org/model/hughes-369a): 32 aircraft (airframe model) - [Hughes 369A (OH-6A)](https://openairdocs.org/model/hughes-369a-oh-6a): 11 aircraft (airframe model) - [Hughes 369](https://openairdocs.org/model/hughes-369): 5 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) - [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) - [MD Helicopters 369A](https://openairdocs.org/model/md-helicopters-369a): 1 aircraft (airframe model) - [Hughes/Helicopter Assocs 369A](https://openairdocs.org/model/hughes-helicopter-assocs-369a): 1 aircraft (airframe model) - [Hughes/Batto John 369A (OH-6A)](https://openairdocs.org/model/hughes-batto-john-369a-oh-6a): 1 aircraft (airframe model) - [Hughes 369H](https://openairdocs.org/model/hughes-369h): 1 aircraft (airframe model) All 12 models: https://openairdocs.org/ad/70-16-07/models.md Every aircraft: https://openairdocs.org/ad/70-16-07/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.