| AD Number | 87-09-03 | Status | Active |
| Effective Date | August 26, 1988 | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | 39-5995 |
| Product Type | ["Aircraft"] | Product Subtype | ["Rotorcraft"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Airbus Helicopters Deutschland GmbH |
| Model(s) | BO-105A BO-105C BO-105LS A-1 BO-105LS A-3 BO-105S MBB-BK 117 A-1 MBB-BK 117 A-3 MBB-BK 117 A-4 MBB-BK 117 B-1 |
87-09-03 MESSERSCHMITT-BOLKOW-BLOHM GMBH: Amendment 39-5995. Final copy of priority letter AD issued May 7, 1987. Applies to Model BO-105, BO-105LS, and BK-117 series helicopters certificated in any category with main rotor blade secondary bolt P/N's 105-14101.35, 105-14101.79, 105-14101.11, and 105-141021.05 installed.
Compliance is required as indicated, unless already accomplished.
To prevent failure of the secondary main rotor blade retention bolt and possible loss of control of the main rotor blade, accomplish the following:
(a) Inspect all bolts having more than 100 hours' time in service for cracks at the junction of the head and shank using a magnetic particle inspection or a dye penetrant inspection method prior to further flight. If the dye penetrant inspection method is used, bolts with solid film lubricant coating shall have the coating removed in the affected area (to approximately 5 MM below the bolt head) using Scotch Brite or equivalent. Use MEK or equivalent to clean the surface prior to dye checking. Coated crack-free bolts need not be recoated prior to reinstallation.
(b) Inspect bolts with less than 100 hours' time in service in accordance with paragraph (a) prior to accumulating 100 hours' time in service.
(c) If cracks are found, remove bolt from service and replace with an airworthy bolt prior to further flight.
(d) Conduct the inspection of paragraph (a) at intervals not to exceed 100 hours' time in service since last inspection.
(e) Reinstall bolts in accordance with the following instructions. Lubricate crack-free bolts (per MBB Maintenance Manual) with Molykte BR2 (MBB Maintenance Manual item CM- 102) or Aeroshell grease #22 (MBB Maintenance Manual item CM-101) and install per the applicable MBB Maintenance Manual with the following exceptions:
(1) Make certain that no lubricant is on the threaded area of the bolt;
(2) Before installing the nut, lightly tap the head of the bolt with aplastic or rubber mallet to seat the bolt in the hole;
(3) Install nut, and torque to 70-90 inch pounds (8-11 Newton meters); and
(4) If required to install cotter pin, back off the nut to next available cotter pin hole, and install cotter pin.
(f) Upon request, an alternate means of compliance which provides an equivalent level of safety with the requirements of this AD may be used when approved by the Manager, Aircraft Certification Division, Department of Transportation, Federal Aviation Administration, Fort Worth, Texas 76193-0100.
(g) Special flight permits may be issued in accordance with Sections 21.197 and 21.199 to operate helicopters to a base for the accomplishment of inspections required by this AD.
This amendment, 39-5995, becomes effective August 26, 1988, as to all persons except those persons to whom it was made immediately effective by priority letter AD No. 87-09-03, issued May 7, 1987, which contained this amendment.