| AD Number | 47-51-03 | 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 |
47-51-03 CURTISS-WRIGHT Applies to Model C-46 Series Aircraft Equipped with Aileron Closure Rib Assembly, Curtiss-Wright P/N 20-030-5039.
Compliance required within every 100 hours' time in service after the effective date of this amendment until rework is accomplished.
The aileron closure rib assembly 20-030-5039 has failed on some aircraft by cracking at the point of attachment to gusset and adjacent to the bolts which secure the aileron hinge assembly.
1. The rib assembly should be inspected and if cracks are found the following rework should be accomplished:
(a) Remove the aileron from the airplane.
(b) Remove aileron hinge assembly 20-030-5042 from the aileron closure rib 20-030-5039 located at wing station 273.875.
(c) Drill out the ten 671D-5AD-5 rivets and two C71D-5AD-8 rivets which secure gusset 20-030-5039-6 to the bottom of ribs 20-030-5039-504 and 20-030-5039-505.
(d) Drill out the eight AN 442AD-5 rivets which secure gusset 20-030-5039- 6 to the sides of ribs 20-030-5039-504L and 20-030-5039-505.
(e) Open the inspection doors nearest each side of the aileron closure rib assembly.
(f) Working through these inspection doors drill out the fourteen AN 442AD4-4 rivets which secure angles 20-030-5039-3 to the sides of the ribs 20-030-5039-504 and 20-030-5039-505. It will not be necessary to remove the twenty-eight 671D-4AD-4 rivets which secure the angles 20-030-5039-3 to the wing trailing edge closure skin.
(g) Working through same inspection doors drill out the eighteen AN 442AD4-4 rivets which secure the angles 20-030-5039-506 to ribs 20-030-5039-504 and 20-030- 5039-505. The ribs are now free and can be removed from the airplane.
(h) Fabricate new lower ribs 20-030-5037-504 and 20-030-5039-505 using the removed ribs as templates.
(i) Fabricate one left-hand and one right-hand angle "A" 7.06 inches long x 0.90-inch leg x 0.70-inch leg, bend radius 0.09, from 0.064-24SO - ALC (AN-A-13Condition A) and heat treat to 56,000 p.s.i. (Spec. AN-QQ-H-186).
(j) Fabricate one left-hand and one right-hand angle "B" 9.25 inches long x .90-inch leg x 0.70-inch leg, bend radius 0.09, from 0.064-24SO-ALC (AN-A-13 Condition A) and heat treat to 56,000 p.s.i. (Spec. AN-QQ-H-186).
(k) Working through the inspection doors located in the trailing edge closure skin secure the ribs 20-030-5039-504 and 20-030-5039-505 to angles 20-030-5039-506 and 20- 030-5039-3.
(l) Install angle "B" with a 0.90-inch leg against ribs 20-030-5039-504 and 20-030-5039-505 in upper inside corners of assembly using six AN 442 AD4-4 rivets for each angle. Rivet the 0.70-inch flange to top gusset using four AN 442 AD6-8 rivets outboard and five LS 1127-6-8 rivets inboard of opening in gusset. Trim angle to match openings in rib and gusset and end curvature of ribs.
(m) Install angles "A" with 0.90-inch leg against ribs 20-030-5039-504 and 20-030-5039-505 in lower inside corners of assembly using two AN 442 AD4-4 rivets at inboard end and four AN 442 AD5-6 rivets to pick up leg of gusset 20-030-5039-6L and 6R and 671D- 5AD rivets on bottom. Trim end of angle to curvature of rib.
(n) Drill the necessary bolt holes in ribs 20-030-5039-504 and 20-030-5039- 505 for attaching hinge assembly 20-030-5042 and install same using AN 24-8A bolts, AN 960D416 washer and AN 364-428 nuts.
(o) Install the aileron.
(Curtiss-Wright Service Information Letter SBS:GS:wd-1482 dated January 6, 1947, and its enclosures, also cover this same subject. This letter and its enclosures may be obtained from the Curtiss-Wright Corp., Airplane Division, Columbus, Ohio, upon request.)
(p) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Southern Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase.
Revised December 28, 1964.