| AD Number | 69-13-07 | Status | Active |
| Effective Date | April 30, 1970 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-970 |
| Product Type | ["Aircraft"] | Product Subtype | ["Rotorcraft"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Hiller Aviation Siam Hiller Holdings, Inc. |
| Model(s) | UH-12D UH-12L UH-12L4 UH-12E UH-12E-L |
69-13-07 FAIRCHILD HILLER: Amdt. 39-789 as amended by Amendment 39-970. Applies to UH-12D, UH-12E, UH-12E-L, UH-12L and UH-12L4 type helicopters certified in all categories.
Compliance required as indicated.
To prevent failure of the attachment of collective yoke support brackets, P/N 31351 or 31483, to upper transmission housings, P/N 23541 or 23541-5, accomplish the following:
(a) Within the next 10 hours time in service after the effective date of this AD, unless already accomplished, inspect the collective yoke support bracket attachment bolts for torque and visually inspect the Rosan inserts in the transmission housing for cracks or any other damage. Replace damaged inserts, and inserts where a bolt torque of less than 50 inch pounds is encountered, prior to further flight in accordance with Fairchild Hiller Service Bulletins SB UH12L-23-1 and SB UH12D thru G-23-1 dated May 20, 1969 or an alternate method approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.
(b) Within the next 100 hours' time in service after the effective date of this AD, unless already accomplished, remove the Rosan R206SB-8 inserts and install Rosan RD206SB-8 inserts in their place, and install MS20073-04-7 bolts in accordance with Fairchild Hiller Service Bulletins SB UH12L-23-1 and SB UH12D thru G-23-1 dated May 20, 1969 or an alternate method approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region. Where oversize Rosan R231SB-8 inserts have been installed, replace with Rosan RD231SB-8 inserts and RL-31-SB-9 locking rings in accordance with Fairchild Hiller Service Bulletins UH12L-23-1 and UH12D through G-23-1 dated 19 January 1970 or an alternate method approved by the Chief, Engineering and Manufacturing Branch, FAA Eastern Region.
Amendment 39-789 effective July 9, 1969.
This Amendment (39-970) is effective April 30, 1970.