83-03-03 GARLICK HELICOPTERS, HAWKINS & POWERS AVIATION, INC., WILCO AVIATION (BELL): Amendment 39-4556. Applies to Model UH-1 series helicopters certificated in restricted category. \n\n\tCompliance is required as indicated, unless already accomplished. \n\n\tTo detect cracks and to prevent possible failure of the tail boom and fin, accomplish the following: \n\n\tWithin the next 30 hours' time in service after the effective date of this AD: \n\n\ta.\tConduct the following inspections: \n\n\t\t(1)\tVisually inspect the tail boom skin joint at tail boom Station 194 for fretting or cracking (inspect 10 inches forward and 10 inches aft of Station 194). \n\n\t\t(2)\tVisually inspect the vertical fin front spar cap at its intersection with the tail rotor gear box support fitting for cracks. \n\n\t\t(3)\tThe areas to be inspected are shown in Figure 1. \n\n\tb.\tFor aircraft found to have fretting or cracks by the inspections of paragraph a. above and for aircraft with more than 1,000 hours' time inservice, conduct a radiographic inspection of the tail boom Station 194 splice joint in accordance with Advisory Circulars 43-3 (Chapter 2) and 43-13-1A (paragraph 298) to MIL-STD-453 requirements, or FAA approved equivalent. \n\n\tc.\tAfter the initial inspections - \n\n\t\t(1)\tVisually inspect the tail boom skin and fin spar cap area in accordance with paragraph a. above, at intervals not to exceed 100 hours' time in service from the last radiographic inspection. \n\n\t\t(2)\tRadiographically inspect the tail boom skin in accordance with paragraph b. above at intervals not to exceed 500 hours' time in service from the last radiographic inspection. \n\n\td.\tReplace cracked skin panels with serviceable panels. \n\n\te.\tReplace cracked fin spar caps with serviceable parts. \n\n\tf.\tAny equivalent method of compliance with this AD must be approved by the Manager, Aircraft Certification Division, Southwest Region, Federal Aviation Administration. \n\n\tg.\tUpon request of the operator, an FAA maintenance inspector, subject to prior approval of the Manager, Aircraft Certification Division, FAA Southwest 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 for that operator. \n\n\th.\tIn accordance with FAR 21.197, flight is permitted to a base where the inspections required by this AD may be accomplished. \n\n\tThis amendment becomes effective March 14, 1983.