AD 56-15-02

56-15-02 BELL: Applies to All Model 47 Series Helicopters Having the 47-150-184-1 or 47-150-184-3 Swashplate Control Ring Installed, Except the Following: Model 47G, Serial Numbers 1378, 1524, 1529 Through 1533 and 1687 and Subsequent. Model 47G2, Serial Numbers 1467, 1469 Through 1471, 1478, 1479, 1481, 1483, 1484, 1487 Through 1499 and 1500 and Subsequent. Model 47H1, Serial Numbers 1347, 1348, 1361, 1366 and Subsequent.

Compliance required as indicated.

Cracking of the control ring horns in the area of the control horn ears has been found. It is necessary that the following action for the 47-150-184-1 and 47-150-184-3 swashplate control ring, lateral, fore and aft control horns be taken as soon as possible but not later than August 15, 1956: Disconnect the control rods from the swashplate control ring horns and using a 10-power magnifying glass inspect the area around the control horn ears for evidence of cracks. If cracks are found, remove the swashplate and replace immediately. If no cracks are found, remove the sharp edge from the top of the fore and aft control horn between the ears and file a 0.062 inch radius in each corner of the fore and after control horn between the ears before replacing.

(Bell Mandatory Service Bulletin No. 108, dated May 1, 1956 covers this same subject.)