83-02-51 BELL HELICOPTER TEXTRON, INC: Amendment 39-4842. Applies to Bell Helicopter Textron Models 222 and 222B helicopters certified in all categories equipped with main rotor controls walking beam assembly Part Numbers 222-010-415-5 and -9. Note that the -5 assembly contains a -7 detail beam and the -9 assembly contains a -11 detail beam. Beam assemblies may be identified in the area of their serial numbers by their detail numbers instead of their assembly numbers. The -7 and -11 details are included in this AD. (Airworthiness Docket No. 83-ASW-6.)
Compliance is required as indicated (unless already accomplished).
To prevent failure of the walking beam, accomplish the following:
(a) Before further flight, remove and inspect walking beam assemblies Serial Numbers VN07-1O7 through VN07-140, VN06-057, VN06-060, VN06-061, VNO6-065, VN06- 069, VN06-089 through VN06-092, VN06-095, VN06-096, VNO6-100, EA-004, and EA-008 as follows:
(1) Remove all grease fittings from the walking beam.
(2) Using a magnifying glass of at least 10-power magnification and a bright light, inspect each one of the threaded holes from which the grease fittings were removed for evidence of corrosion, trapped foreign material, or thread indentations caused by foreign material having been trapped between the grease fittings and the threads. Of special interest is the presence of shot-peening residue. This residue will have the appearance of small round balls similar to shotgun pellets. These balls may be as small as 0.012 inch in diameter and are difficult to see unless a magnifying glass and bright light are used.
(3) If any of the above defects are present, remove the part from service and replace it with a serviceable part.
(4) If no defects are found, reinstall the grease fittings with wet zinc chromate primer on the threads.
(b) Before further flight and prior to the first flight of each day, conduct the following inspections of all walking beam assembly Part Numbers 222-010-415-5 and -9, regardless of serial number, with emphasis on the area around the grease fittings in the portion of the beams through which the drive links are attached by bolts part number 20-057-9-95D. Remove cracked parts from service before further flight and replace with serviceable parts.
(c) Within 10 hours time in service following the effective date of this AD, and each 25 hours thereafter, conduct a dye penetrant inspection of a 2-inch diameter area around the grease fittings described in paragraph (b) above. The area shall be prepared for penetrant inspection by thorough cleaning using Stoddard solvent or equivalent. Do not use methyl-ethyl- ketone (MEK) or paint stripper. Remove cracked parts from service before further flight and replace with serviceable parts.
NOTE: Bell Alert Service Bulletin (ASB) 222-83-18 is an equivalent means of compliance with paragraph (b) of this AD. The inspections required in paragraph (b) maybe performed with the parts installed on the helicopter. Any other equivalent means of compliance with this AD must be approved by the Manager, Helicopter Certification Branch, Federal Aviation Administration, Southwest Region.
(d) The helicopter may be flown to a repair base for the above inspections under the provisions of FAR 21.197.
This amendment becomes effective May 15, 1984, as to all persons except those to whom it was made immediately effective by telegraphic AD T83-O2-51 issued January 21, 1983, which contained this amendment.