| AD Number | 57-15-02 | Status | Active |
| Effective Date | Not specified | Issue Date | Not specified |
| Docket Number | Unknown | Amendment | N/A |
| Product Type | ["Aircraft"] | Product Subtype | ["Large Airplane"] |
| CFR Part | --- - Part 39 | CFR Section | N/A |
| Citation | This information is not available. | ||
| Manufacturer(s) | Airlift International, Inc. Curtiss-Wright Corporation Flying Tiger Line, Inc. L. B. Smith Aircraft Corporation Skyways International Trading and Transport Co. Tempo Design Corporation |
| Model(s) | C-46A C-46D C-46F C-46R C-46E C-46A C-46D C-46E C-46F C-46A C-46D C-46F C-46F C-46/CW20-T Super C-46/CW20-T |
57-15-02 CURTISS-WRIGHT: Applies to all Model C-46 Series aircraft.
Compliance required as indicated.
Due to repeated service failures of H-3-38-M1 wheel assemblies (Hayes and/or Goodrich Model No. 1900M), the following action is required:
1. At each 100 to 125 hours, conduct a visual inspection of the demountable flange in the area of the lightening holes with the aid of a flashlight or equivalent. If cracks are detected, the flange must be either retired or reworked in accordance with paragraphs 3.5.2.2.1 and 3.5.2.2.2 of Goodrich Manual No. 14932.
2. Unless already inspected within the period specified herein, all H-3-38-M1 wheel assemblies (used or unused) must be disassembled and inspected prior to installation and thereafter at each 85th landing or regular periodic inspection period nearest to 330 hours, whichever occurs first.
(a) Visually inspect the lock ring groove area for corrosion. All corrosion in this area must be removed by hand working with No. 300 sandpaper or equivalent, remachining or grinding away of metal is not permitted. Corrosion in the lock ring groove area of the wheelbase can be removed only to a depth of 0.015 inch from the original surface of the groove. Should corrosion and pitting be in excess of this dimension, the wheelbase must be retired from service. The nominal lock ring groove diameter in the wheel is 17.250 inches. After corrosion cleanup this diameter should not be less than 17.220 inches. The O.D. of the wheelbase in the lock ring groove area and the bottom of the lock ring groove should be concentric within 0.015 inch. The lock ring groove should be retreated to prevent corrosion at every wheel disassembly per treatment specified in B.F. Goodrich Service Letter No. 1022 or equivalent.
Note: The original rim lock ring, P/N G85-30, was of tubular steel construction and cadmium plated for rust prevention. This lock ring causes an electrolitic reaction between the magnesium and steel when exposed to moisture and is therefore conducive to corrosion. These lock rings have been superseded by a new solid aluminum type of the same part number.
(b) Inspect the following critical areas for cracks using Zyglo, dye penetrant or equivalent method. All paint must be removed using a stripping agent of the waxless solvent type that does not react chemically with magnesium.
(1) Brake drum mounting register, (2) tire bead radius of the fixed flange, (3) tire bead seat radius of the demountable flange, (4) radius of the demountable flange step, (5) flange retaining ring groove in the wheel, and (6) rim lock ring.
All parts with cracks in any of the critical areas must be retired from service. Rim lock rings P/N G85-30 with cracks must be replaced with the solid aluminum part or equivalent.
3. The following should be accomplished at the first disassembly of wheel unless already accomplished:
(a) The lock ring groove area should be steam cleaned with high pressure steam to insure that this area had not been previously reworked and refinished by filling corroded areas with metal putty. Corroded areas may only be reworked in accordance with item 2(a) above.
(b) Rework all demountable flanges by removing the sharp edges of the lightening holes in accordance with Goodrich Service Letter No. 1022.
This supersedes AD 56-17-1.