82-07-02 CESSNA: Amendment 39-4353. Applies to Models 170A, 170B, 172, 172A through 172P, 175, 175A, 175B, 175C, P172D, and R172E (USAF T-41B) airplanes modified in accordance with STCs SA3-13, SA3-126, SA3-571, SA3-672, SA3-674, SA135CE, SA420CE, SA421CE, SA424CE, SA610SW, SA647CE, SA777CE, SA806CE, SA807CE, or SA1324CE, certificated in any category. \n\n\tCOMPLIANCE: Required as indicated, unless already accomplished. \n\n\tTo reduce the possibility of rapid loss of engine oil caused by ice obstruction of the engine crankcase breather, accomplish the following: \n\n\tA)\tWithin the next 50 hours time-in-service after the effective date of this AD: \n\n\t\t1.\tVisually examine the engine crankcase breather to determine if an alternate air outlet is drilled or cut in the tube as shown in Figure 1. If any of these provisions exist, make an appropriate entry in the aircraft maintenance records per paragraph B). No further action is necessary. \n\n\t\t2.\tIf the hole or cutout shown in Figure 1 is not in the engine crankcase breather tube: \n\n\t\t\ta.\tInspect the crankcase to crankshaft seal and ensure that the seal is secure. (This seal is located behind the starter ring gear in the forward most part of the crankcase.) Reinstall or replace this seal if it is not flush with the forward face of the crankcase. \n\n\t\t\tb.\tDrill the engine crankcase breather tube line to include an alternate air outlet as shown in Figure 1. \n\n\tB)\tParagraph A)1 of this AD may be accomplished by the holder of at least a private pilot certificate issued under Part 61 of the Federal Aviation Regulations on any airplane owned or operated by that person. Make the prescribed entry in the aircraft maintenance records, including those airplanes on which it has already been accomplished, indicating compliance with this AD. \n\n\tC)\tThe airplane may be flown in accordance with FAR 21.197 to a location where paragraph A)2 of this AD may be accomplished. \n\n\tD)\tAny equivalent method of compliance with this AD may be used when approved by the Chief, Wichita Aircraft Certification Office, FAA, Room 238, Mid-Continent Airport, Terminal Building No. 2299, Wichita, Kansas 67209; telephone (316) 269-7000. \n\n\tThis amendment becomes effective on April 8, 1982. \n\nTYPICAL INSTALLATION