75-23-08 R5 CESSNA: Amendment 39-2419 as amended by Amendment 39-2687, 39-2830, 39-3298, and 39-3609, are further amended by Amendment 39-5451. Applies to T310, 320, 340, 401, and 411 series airplanes and Models 402, 402A, 402B, 414, 421, 421A, 421B and 421C (S/N 421C0001 through 421C0683) airplanes, certificated in any category.\n\n\tThis AD is issued to combine in one document inspections and parts replacements required by previous ADs and require modifications now available which will increase the reliability of the exhaust systems on the affected airplanes.\n\n\tCompliance: Required as indicated, unless previously accomplished.\n\n\tTo detect incipient failure and improve reliability of the engine exhaust systems installed on the above-noted airplanes, accomplish the following:\n\n\tI.\tRepetitive General Exhaust System Inspection\n\n\t\tA.\tOn all new and in-service airplanes listed above, visually inspect the exhaust system components per procedures hereafter specified in accordance with the following schedule:\n\n\t\t\t50 HOUR INSPECTION\n\n\t\t\tInspect components not listed in Table II or III within 50 hours time-in-service after the effective date of this AD or last inspection per AD 75-04-01 and within each 50 hours time-in-service thereafter.\n\n\t\t\t100 HOUR INSPECTION\n\n\t\t\tInspect components listed in Table II within 100 hours time-in-service after the effective date of this AD or last inspection in accordance with this AD and within each 100 hours time-in-service thereafter.\n\n\t\t\tEXEMPT COMPONENTS\n\n\t\t\tComponents listed in Table III are exempt from these inspection requirements.\n\n\t\t1.\tCLEANING - In order to properly inspect the exhaust system, components must be clean and free of oil, grease, etc. If required, clean as follows:\n\n\t\t\ta.\tSpray engine exhaust components with a suitable solvent (such as Stoddard Solvent), allow to drain, and then wipe dry with a clean cloth. \n\nWARNING \nNEVER USE HIGHLY FLAMMABLE SOLVENTS ON ENGINE EXHAUST SYSTEMS. \nNEVERUSE A WIRE BRUSH OR ABRASIVES TO CLEAN EXHAUST SYSTEMS OR MARK ON THE SYSTEM WITH LEAD PENCILS.\n\n\t\t\tb.\tRemove the heat shields from the turbocharger in accordance with heat shield removal procedures in the Service Manual.\n\n\t\t\tc.\tRemove shields around the exhaust bellows or slip joints, multi-segment "V" band clamps at joints, and other items which might hinder inspection of the system.\n\nNOTE \nDo not remove clamps.\n\n\t\t2.\tVISUAL INSPECTION OF COMPLETE SYSTEM \n\nNOTE \nConduct this inspection when the engine is cool\n\n\t\t\ta.\tVisually inspect exhaust stacks for burned areas, cracks and looseness. Insure that attach bolts are properly torqued in accordance with the aircraft Service Manual.\n\nNOTE\n\tDuring this inspection give special attention to condition of bellows and welded areas along seams and around bellows, and weld seams around exhaust system components.\n\n\t\t\tb.\tVisually inspect the flexible connection between the waste-gate and overboard duct (when applicable) for cracks and security.\n\n\t\t\tc.\tCorrect any major leaks in all areas of the exhaust system except waste-gate to tailpipe flexible coupling (when applicable) by replacement of defective parts or by repair in accordance with Part 43 of the FARs.\n\n\t\t\td.\tVisually inspect exhaust joint springs for correct compression. If the joint is disturbed or if springs are obviously loose, proceed with the following inspection. (See Figure 1).\n\n\n\n\t\t\t\ti.\tBefore removal of exhaust joint springs, measure installed length of each spring. Those compressed to less than 0.45 inch must be replaced.\n\n\t\t\t\tii.\tRemove all springs and measure free length. Springs having a free length of less than 0.57 inch must be replaced.\n\nNOTE\n\tAdd AN960-10 washers under head of joint bolts as required to obtain correct dimension. During installation, joint bolts should be tightened gradually and spring length checked frequently to prevent over compression of springs.\n\n\t\t\t\tiii.\tReinstall springs and measure installed length. Length must be 0.51 plus .00, -.03 inch.\n\n\t\t\te.\tIf installed, visually inspect the slipjoint(s) for bulges beyond normal manufacturing irregularities of .03 inches and/or cracks. If any bulges and/or cracks are present, replace bulged or cracked slipjoint(s) (refer to Service Manual). See Figure 2.\n\n\n\nNOTE\n\tThis inspection was previously required on Model 421B airplanes, S/N 421B0001 through 421B0935 by AD 75-17-38 effective August 22, 1975.\n\n\t\t\tf.\tInspection of multi-segment "V" band clamp(s) (Between engine and turbocharger).\n\n\t\t\t\ti.\tUsing crocus cloth, clean the outer band of the multi-segment "V" band clamp(s). Pay particular attention to the spot weld area on the clamp(s).\n\n\t\t\t\tii.\tWith clamp(s) properly torqued:\n\n\t\t\t\t\t(1)\tVisually inspect the outer band in the area of the spot weld for cracks (see Figure 3). If cracks are found, replace the clamp(s) with new multi-segment "V" band clamp(s).\n\n\t\t\t\t\t(2)\tVisually inspect the corner radii of clamp innersegments for cracks (See figure 3). This inspection requires careful use of artificial light and inspection mirrors.\n\n\n\n\nNOTE\n\tWhen replacement is required, install the new multi-segment "V" band clamp over the exhaust flanges and torque to the correct value (see Torque Value Chart, Table 1 to this AD). As the clamp is tightened, lightly tap it circumferentially in a radial direction with a rawhide or soft plastic mallet.\n\n\t\t\t\t\t(3)\tVisually inspect flatness of the outer band, especially within two inches of the spot welded tabs which retain the T-bolt fastener. This can be done by placing a straight edge across the flat part of the outer band as shown in Figure 4, then checking the gap between the straight edge and the outer band. This gap should be less than 0.062 inch. If deformation exceeds 0.062 inch limit, replace clamp(s) with new multi-segment clamp(s). (See Note preceding this step).\n\n\n\n\t\t\tg.\tOne-piece "V" band clamp inspection (Overboard exhaust to turbocharger).\n\n\t\t\tVisually inspect with a light and mirror, the clamp surfaces adjacent to the intersection of the "V" apex and bolt clips, and the entire length of the "V" apex of the clamp for signs of cracks or fractures. If cracks or fractures are visible, replace the clamp. (See Figure 5).\n\nNOTE\n\tThe above inspections, except for Paragraph e. and f., were previously required by AD 75-04-01 effective February 11, 1975. Inspections per Paragraph e. were previously required by AD 75-17-38 effective August 22, 1975. Inspections per Paragraph f. were previously required by AD 75-04-01 as amended by Amendment 39-2338 effective August 15, 1975.\n\n\tTABLE I\nEXHAUST COUPLING APPLICABILITY CHART\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\nAIRCRAFT APPLICABILITY\n\n\n\n\n\n\n\n\n\n\n\n\n\nSingle Piece "V" Coupling\nCoupling\nPart Number\nQty \nPer\nAcft\nTorque\nIn-Lbs\nT310P\nQ, R\n320\n320A,\nB,C\n320D\nE, F\n340\n340A\n401/402\nA, B\n414\n421\nA, B\n421\nC\nLocation\nLife Limited\nNH1000897-20\n4\n40*\n\n\n\n\nX\n\nX\n\n\nCollector (Wye)\nInlet\nNo\nNH1000897-30\n2\n40\n**\n\n\n\n\n\n\n\nX\n\nWastegate\nInlet\nNo\nNH1000897-40\n or\nV57A4234\n or\n41195AA423\n2\n40\n*\nX\n\n\nX\n\nX\n\n\n\nTurbine\nOutlet\nNo\nNH1000897-50\n or\nV57A5019\n or\n41195AA502\n2\n40\n*\n\n\n\n\nX\n\nX\nX\nX\nTurbine\nOutlet\nNo\n\n\n\n\n\n\n\n\n\n\n\n\n\nMulti-Segment "V" Band Clamps\n51394H250\n(51134-2505\nGasket)\n3\n35\n\nX\n\n\n\n\n\n\n\nCollector\nInlet\nYes\n838037\nAlternates:\n4309AL\n4309AF\n3\n35\n\n\nX\n\n\n\n\n\n\nCollector\nInlet\nYes\nMVT64832\nAlternates:\n4309AL\n4309F\n3\n35\nX\n\n\nX\n\nX\n\n\n\nCollector\nInlet\nYes\nMVT68892-250\nAlternate\n4301BT250\n4\n45\n\n\n\n\nX\n\nX\n\n\nCollector (Wye)\nInlet\nYes\n4256AB200\nAlternate\nMVT68892-200\n2\n45-50\n\n\n\n\nX\n\nX\nX\n\nWastegate Inlet 340A (414) & Wastegate Exit (421)\nYes\n\n4356AA300\n\n2\n\n70-90\n\n\n\n\n\n\n\n\nX\n\nWastegate Inlet (421)\nYes\n\n\t* Initial installation of single piece couplings must be madein strict adherence to the specified 40 inch-pounds torque value. However, periodic retorquing is required only if coupling shows torque values below 30 inch-pounds.\n\n\t**The 24096-300-N gasket is not required at the exhaust wastegate inlet of 421, 421A, and 421B aircraft when the NH 1000897-30 Single-piece coupling is installed.\n\nNOTES FOR TABLE II \nGENERAL NOTES:\n\t0850XXX and 5654XXX dash numbers shown in parentheses are earlier part numbers for the corresponding 9910XXX dash numbers..\n\n\tBall joint attaching parts (springs, bolts, nuts, washers and cotter pins) are subject to the 100-hour inspection instead of the 50-hour, only if installed in combination with the components listed in Table II.\n\n\t1.\tComponents incorporate formed sheet metal coupling flanges.\n\n\t2.\tComponents incorporate external safety ring.\n\n\t3.\tComponents incorporate internal safety sleeve.\n\n\t4.\tComponents require seals at coupling flange.\n\n\t5.\tAlternate for MVT68892-250 and 4301BT250 couplings.6.\tNH1000897-30 supersedes 4356AA300. Gasket P/N 24096-300-N is not required with the NH1000897-30 clamp.\n\n\t7.\tExhaust stack assemblies are sealed type, and the part numbers shown include risers for both cylinder banks and the crossover pipes.\n\nTABLE II\n100 HOUR INSPECTION EXHAUST SYSTEM COMPONENTS\n\n\nDescription &\nPart Number\nQty\nPer Eng\nT310 P,Q,R,\n320\nD,E,F\n340\n340A\n401/402\nA,B\n414\n421\nA,B\n421\nC\nNotes\nExhaust Stack Assy\n9910379-1 L.H. Eng\n(Inconel 601)\n\n1 (LH)\n\n\n\n\n\n\n\nX\n\n\n7\n9910379-2 R.H. Eng\n(Inconel 601)\n1 (RH)\n\n\n\n\n\n\nX\n\n7\n9910295-11 L.H.\n(5155184-1)\n1\n\n\n\n\n\n\n\nX\n\n9910295-12 R.H.\n(5155184-2)\n1\n\n\n\n\n\n\n\nX\n\nAft Slip Joints\n9910314-1\n(Inconel 601)\n\n1\n\n\n\n\n\n\n\nX\n\n\nAft Elbows\n9910299-3 L.H.\n(5654551-5)\n\n1\n\n\n\nX\n\nX\n\n\nX\n\n\n\n1 & 4\n9910299-4 R.H.\n(5654551-6)\n1\n\n\nX\nX\n\nX\n\n\n1 & 4\n9910301-1\n(0850712-39)\n1 L.H.\nX\nX\n\n\nX\n\n\n\n1\n9910301-3\n(0850712-41)\n1 R.H.\nX\nX\n\n\nX1\n9910301-5\n(0850712-40)\n1 L.H.\nX\nX\n\n\nX\n\n\n\n1\n9910379-19\n(Inconel 601)\n1 L.H.\n\n\n\n\n\n\nX\n\n\n9910379-20\n(Inconel 601)\n1 R.H.\n\n\n\n\n\n\nX\n\n\nWye Collector Assy\n9910299-8\n(Inconel 601)\n\n1\n\n\n\n\nX\n\n\n\n\n\n1,3, & 4\n9910301-4\n(0850732-3)\n1 L.H.\nX\nX\n\n\nX\n\n\n\n1 & 2\n9910301-6\n(0850732-18)\n1 R.H.\nX\nX\n\n\nX\n\n\n\n1 & 2\n9910341-1\n(Inconel 601)\n1\n\n\nX\n\n\n\n\n\n1,3, & 4\n9910300-6\n(5155100-1)\n1\n\n\n\n\n\n\n\nX\n\nWastegate \nInlet Elbow\n9910299-5\n(5654551-4)\n\n1\n\n\n\n\nX\n\n\nX\n\n\n\nCouplings \n (One Piece)\nWastegate Inlet\nNH1000897-30\n\n1\n\n\n\n\n\n\n\nX\n\n\n6\nWye Collector Inlet\nNH1000897-20\n2\n\n\nX\nX\n\nX\n\n\n5\n\nNOTES FOR TABLE III \nGENERAL NOTES:\n\t5155XXX, 5355XXX, and 5654XXX dash numbers shown in parentheses are earlier part numbers for the corresponding 9910XXX dash numbers.\n\n\tBall joint attaching parts (springs, bolts, nuts, washers and cotter pins) are exempt from mandatory inspections only if installed in combination with the components listed in Table III.\n\n\t1.\tExhaust stack assemblies are seal-less type, and part numbers shown are complete bank assemblies.\n\n\t2.\tOn aircraft prior to 1979 Models, the initial replacement must include the aft elbow, wye collector assemblies and clamps since they are not interchangeable with earlier components.\n\n\t3.\tAttach 5155156-5 Elbow to overboard stack using one each 5155157-1 Flex Joint and two each U84C200 SH Clamps.\n\n\tII.\tParts Replacement\n\n\t\tA.\tReplacement of multi-segment "V" band clamps between aft engine cylinders and turbocharger inlet.\n\n\t\t\tOn all airplanes listed above within 50 hours time in service after February 11, 1975, for those clamps having more than 350 hours time in service as of that date or prior to 400 hours time in service for those clamps having less than 350 hours time in service as of that date, and at or prior to each additional 400 hours time in service thereafter, replace existing multi-segment "V"band exhaust system clamps located between aft engine cylinders and the turbocharger inlet (except for waste-gate to exhaust overboard pipe clamp on 421 airplanes) with new parts having Cessna part numbers in accordance with Attachment 4 to Cessna Service Letter ME-75-17 dated July 14, 1975, or later revisions. Use aircraft total time for clamp time in service unless aircraft maintenance records establish location and time in service on previously replaced clamps. See Figure 3 for multi-segment type clamp configuration.\n\nNOTE\n\t\tThe above clamp replacement was previously required by AD 75-04-01 effective February 11, 1975.\n\n\t\tB.\tReplacement of multi-segment turbocharger to overboard tail pipe clamps.\n\n\t\t\tWithin 200 hours time in service after August 15, 1975, replace presently installed multi-segment type turbocharger to overboard tailpipe clamps on Model T310, 320, 401, 402, 340, 414 and 421 airplanes with the clamps specified below:\n\nTABLE III\nEXEMPT EXHAUST SYSTEM COMPONENTS\n\n\nDescription &\nPart Number\nQty\nPer Eng\nT310 P,Q,R,\n320\nD,E,F\n340\n340A\n401/402\nA,B\n414\n421\nA,B\n421\nC\nNotes\nExhaust Stack Assy\n9910295-13 L.H. \n(Inconel 601)\nor\n9910295-9 L.H.\n(5155166-1)\n\n\n\n1\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\n\n\n1\n9910295-14 R.H.\n(Inconel 601)\nor\n9910295-10 R.H.\n(5155166-2)\n\n\n1\n\n\nX\n\n\nX\n\n\nX\n\n\nX\n\n\nX\n\n\nX\n\n\n\n\n1\n9910295-15\n(Inconel 601)\n1\n\n\n\n\n\n\n\nX\n\n9910295-16\n(Inconel 601)\n1\n\n\n\n\n\n\n\nX\n\nAft Slip Joints\n9910296-2\n(Inconel 601)\nor\n9910296-1\n(5355108-4)\n(Stainless Steel)\n\n\n\n2\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\n\nX\n\nAft Elbows\n(Inconel 601 mat'l, seal-less style machined coupling, flanges & internal safety sleeves)\n9910299-15 L.H.\n\n\n\n\n\n\n1\n\n\n\n\n\n\n\n\nX\n\n\n\n\n\n\nX\n\n\n\n\n\n\n\nX\n\n\n\n\n\n\n\n\n2\n9910299-16 R.H.\n1\n\n\nX\nX\n\nX\n\n\n2\n9910301-14\n1 L.H.\nX\nX\n\n\nX\n\n\n\n2\n9910301-16\n1 L.H.\nX\nXX\n\n\n\n2\n9910301-17\n1 R.H.\nX\nX\n\n\nX\n\n\n\n2\nWye Collector Assy\n(Inconel 601 mat'l & seal-less style maintained coupling flanges)\n99102099-9\n\n\n\n\n\n1\n\n\n\n\n\n\n\n\nX\n\n\n\n\n\n\nX\n\n\n\n\n\n\n\n2\n9910301-15\n1 L.H.\nX\nX\n\n\nX\n\n\n\n2\n9910301-18\n1 R.H.\nX\nX\n\n\nX\n\n\n\n2\n9910341-2\n1\n\n\nX\n\n\n\n\n\n2\n9910300-7\n1\n\n\n\n\n\n\n\nX\n\n\n\nDescription &\nPart Number\nQty\nPer Eng\nT310 P,Q,R,\n320\nD,E,F\n340\n340A\n401/402\nA,B\n414\n421\nA,B\n421\nC\nNotes\nOverboard Exhaust Stack Assembly\n0850711-33 & -31\n\n\n1 L.H.\n\n\nX\n\n\nX\n\n\n\n\nX\n\n\n\n\n0850711-34, -40, -42\n1 R.H.\nX\nX\n\n\nX\n\n\n\n\n9910299-1\n(5654551-7)\n1 L.H.\n\n\nX\nX\n\nX\n\n\n\n9910299-2\n(5654551-8)\n1 R.H.\n\n\nX\nX\n\nX\n\n\n\n5155156-3\n1 L.H.\n\n\n\n\n\n\nX\n\n\n5155156-4\n1 R.H.\n\n\n\n\n\n\nX\n\n\n9910300-1\n(5155100-7)\n1 L.H.\n\n\n\n\n\n\n\nX\n\n9910300-2\n(5155100-8)\n1 R.H.\n\n\n\n\n\n\n\nX\n\nWastegate Inlet Elbow\n9910299-10\n\n1\n\n\n\n\nX\n\n\nX\n\n\n\nWastegateOverboard Pipe\n0850713-1\n\n\n1\n\n\nX\n\n\nX\n\n\n\n\nX\n\n\n\n\n5355100-64\n1\n\n\nX\n\n\n\n\n\n\n9910299-6\n(5654551-3)\n1\n\n\n\nX\n\nX\n\n\n\nWastegate Outlet Elbow\n5155156-5\n\n\n1\n\n\n\n\n\n\n\n\nX\n\n\n\n3\n9910300-3\n(5155100-20)\n1\n\n\n\n\n\n\n\nX\n\nTurbo Shield\n0850902-1\n\n1\n\nX\n\nX\n\n\n\nX\n\n\n\n\n5155154-3\n1\n\n\n\n\n\n\nX\n\n\n5354005-1\n1\n\n\nX\nX\n\nX\n\n\n\nCouplings \n (One Piece)\n\nWye Collector Inlet \nNH1000897-60\n2 L.H.\n(All)\n2 R.H.\n(340,414)\n1 R.H.\n(T310, 320 & \n401/402)\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\nX\n\n\n\n\n\n2\nWastegate Inlet\nNH1000897-70\n1\n\n\n\nX\n\nX\n\n\n2\nTurbine Outlet\nNH1000897-40\n1\nX\nX\n\n\nX\n\n\n\n\nTurbine Outlet\nNH1000897-50\n1\n\n\nX\nX\n\nX\nX\nX\n\n\n\t\t\tOn T310 (all aircraft through S/N 310Q0600), 320D (all aircraft), 320E (all aircraft), 320F (all aircraft), 401 (all aircraft), and 402 (all aircraft through S/N 402B0300 series airplanes, replace the existing multisegment "V" band turbocharger to overboard tailpipe clamp with a new Part Number V57A4234 or 41195AA423 clamp. These new clamps are not "life limited".\n\n\t\t\tOn 340 (all aircraft through S/N 3400150, 414 (all aircraft through S/N 4140350), and 421 (all aircraft through 421B0396) series airplanes, replace the existing multi-segment "V" band turbocharger to overboard tailpipe clamp with a Part Number V57A5019 or 41195AA502 clamp. These new clamps are not "life limited".\n\nNOTE\n\t\t\tThe above clamp replacement was previously required by AD 75-04-01 as amended by Amendment 39-2338 effective August 15, 1975.\n\n\tIII.\tSpecial Inspections\n\n\t\tA.\tUnless previously accomplished, within 25 hours time in service after August 15, 1975, the inspection described below is to be conducted on the following aircraft on which the one-piece "V" band tail pipe clamps have been installed. (Clamps bearing a Cessna inspection stamp on the back side (a large C with a number) and installed on airplanes exempted from this inspectionon Attachment No. 2 of Cessna Service Letter ME-75-17 have been inspected by the manufacturer and comply with this requirement).\n\n\t\t\tT310 (All aircraft S/N 310P0001 through 310R0275)\n\t\t\t320D, 320E, 320F (All aircraft)\n\t\t\t340 (All aircraft through S/N 3400550)\n\t\t\t401 (All aircraft)\n\t\t\t402 (All aircraft S/N 4020001 through 402B0912)\n\t\t\t414 (All aircraft through S/N 4140648)\n\t\t\t421 (All aircraft S/N 4210001 through 421B0927)\n\n\t\t\t1.\tRemove upper cowling from LH and RH engine.\n\n\t\t\t\ta.\t(Aircraft Turbo 310, 320, 401, 402, and 421 series equipped with metal heat shield). Detach heat shield from turbocharger turbine housing by cutting safety wire and removing hinge pin located at top of shield assembly securing shield halves together.\n\n\t\t\t\tb.\tThe heat shield does not need to be removed on 320, 340 or 414 and any aircraft equipped with insulation blanket shield.\n\n\t\t\t2.\tClean and visually inspect with a light and mirror, the clamp surfaces adjacent to the intersection of the "V"apex and bolt clips (see Figure 5) for signs of cracks or fractures. If cracks or fractures are visible, replace clamp. (This step allows inspection of the clamp under tension).\n\n\n\n\t\t\t3.\tRemove nut, washer, and bolt from clamp, unseat coupling, and slide clamp down exhaust stack to gain adequate visibility. \n\nCAUTION: DO NOT REMOVE EXPANSION LIMITER.\n\n\t\t\t4.\tVisually inspect for cracks and fractures the entire length of the "V" apex of the clamp (see Figure 5), and pay particular attention to the surfaces adjacent to the intersection of the "V" apex and bolt clips.\n\n\t\t\t\tNOTE: The use of artificial light and at least a 10-power magnifying glass is necessary to detect minute cracks or signs of incipient failure. \n\n\t\t\t\tDo not use dye penetrant inspection procedures since noncritical metal forming folds yield misleading failure indications.\n\n\t\t\t5.\tIf clamp is found to be defective, replace clamp.\n\n\t\t\t6.\tIf clamp has no defects, steel stamp or using a vibrating pencil, mark an "X" on the back side of metal torque tag.\n\n\t\t\t7.\tReinstall clamp on turbocharger turbine housing and overboard exhaust stack and install bolt, washer and nut. Torque nut to 40 inch-pounds. \n\nCAUTION: DO NOT EXCEED NUT TORQUE BY MORE THAN 5 INCH-POUNDS.\n\n\t\t\t8.\tResecure heat shield on turbocharger turbine housing when detached, by aligning shield hinge halves and reinstalling pin previously removed. Secure lower halves of shield using two pieces of .032 monel safety wire twisted together, through opposing eyelets of shield halves, draw shield snug on turbine housing, and safety by twisting end of wire together. Insure heat shield is snug on housing.\n\n\t\t\t9.\tReinstall upper cowling on LH and RH engine.\n\nNOTE\n\t\t\tThis inspection was previously required by AD 75-04-01 as amended by Amendment 39-2338 effective August 15, 1975. Previous inspection per this AD or accomplished by the manufacturer satisfies the above requirement (IIIA).\n\n\tIV.\tModifications\n\n\t\tA.\tOn the following aircraft within 50 hours time in service after the effective date of this AD inspect/modify the overboard exhaust stack flange (turbocharger and exhaust stack interface) in accordance with the instructions below.\n\n\t\t\tT310P0001 through T310R0230, T310R0232 through T310R0254, T310R0256, T310R0257, T310R0259 through T310R0263, T310R0265, T310R0266, T310R0268 through T310R0272, T310R0274, T310R0275, 320D0001 through 320F0045, 3400001 through 3400550, 4010001 through 401B0221, 4020001 through 402B0630, 402B0632 through 402B0909, 402B0911, 402B0912, 4140001 through 4140643, 4140645 through 4140648, 4210001 through 421B0889, 421B0891 through 421B0918, 421B0921, 421B0922, 421B0924, 421B0926 and 421B0927.\n\n\t\t\t1.\tRemove any existing overboard support clamps, and remove overboard exhaust stack. \n\nNOTE\n\t\t\tTake precautions to prevent collection of any dirt or foreign particles in opening of turbocharger turbine housing during modification.\n\n\t\t\t2.\tVisually inspect the mating surfacesof flanges of overboard exhaust stack and turbochargers for uniform contact over their entire perimeter.\n\n\t\t\t3.\tIf such contact is not evident, remove excess material (shaded area) of overboard exhaust stack as required, and as shown typical in Figure 6, by grinding, to allow mating surfaces of flanges of overboard exhaust stack and turbine housing to have uniform contact over their entire perimeter. Exercise care to prevent damage to flange surface of overboard exhaust stack when grinding off excess material.\n\n\n\nFIGURE 6\n\n\t\t\t4.\tReinstall overboard exhaust stack and secure clamps in accordance with turbine outlet exhaust stack one-piece "V" band clamp inspection.\n\nNOTE\n\t\t\tThis one-time inspection/modification may be performed in conjunction with the one-piece "V" bank clamp 25-hour inspection and redundant tail pipe support installation required by IV. B. below.\n\n\t\tB.\tOn the following aircraft, prior to but not later than December 31, 1975, install redundant tail pipe support clamps and brackets in accordance with Cessna Service kits specified below.\n\n\t\t\tT310 (All aircraft through S/N 310Q0600)\n\t\t\t320D0001 through 320F0045\n\t\t\t3400001 through 3400150\n\t\t\t4010001 through 401B0300\n\t\t\t4020001 through 402B0300\n\t\t\t4140001 through 4140350\n\t\t\t4210001 through 421B0300\n\n\t\t\t1.\tKit Number and Applicability\n\n\t\t\t\ta.\tSK402-31 - Turbo 310P0001 through Turbo 310Q0600\n\t\t\t\t\t320D0001 through 320F0045\n\t\t\t\t\t4010001 through 401B0300\n\t\t\t\t\t4020001 through 402B0300\n\n\t\t\t\tb.\tSK414-9-3400001 through 3400150\n\t\t\t\t\t4140001 through 4140350\n\n\t\t\t\tc.\tSK421-67-4210001 through 421B0300\n\n\tV.\tAny equivalent method of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region.\n\n\tVI. The time in service between the repetitive inspections required herein may be adjusted up to plus 10 per cent of any specified inspection interval required by this AD to facilitate accomplishing these inspections concurrent with other scheduled maintenance on the airplane.\n\n\tCessna Service Letter ME75-17 dated July 14, 1975, Cessna Service Letter ME77-1 dated January 24, 1977, and Supplement 2 thereto dated June 26, 1978, and Cessna Multiengine Service Information Letter ME79-32 dated August 17, 1979, pertain to this subject.\n\n\tAmendment 39-2419 supersedes AD 75-04-01, Amendments 39-2083, 39-2130, and 39-2338, and AD 75-17-38, Amendment 39-2341.\n\n\tAmendment 39-2419 became effective November 17, 1975.\n\n\tAmendment 39-2687 became effective August 12, 1976.\n\n\tAmendment 39-2830 became effective February 17, 1977.\n\n\tAmendment 39-3298 became effective September 25, 1978.\n\n\tAmendment 39-3609 became effective November 13, 1979.\n\n\tThis amendment, 39-5451, becomes effective on November 4, 1986.