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75-23-08 R5: 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.
88-03-01: 88-03-01 PRATT & WHITNEY CANADA: Amendment 39-6032. Final copy of priority letter AD issued February 2, 1988. Applies to Pratt & Whitney Canada (PWC) PT6B-36A turboshaft engines incorporating the third stage compressor stator assembly, Part Number (P/N) 3109163-01, installed in Sikorsky Aircraft S-76B helicopters. The third stage compressor stator assembly, P/N 3109163-01 is incorporated in engines, Serial Number PC-E36043 and subsequent, and those engines incorporating PWC Service Bulletin (SB) 11022, dated September 28, 1987. Compliance is required as indicated, unless already accomplished. To prevent failure of the third stage compressor stator vane assembly which could result in loss of engine power or an inflight engine shutdown, accomplish the following: (a) Prior to further flight, accomplish the following: (1) Attach a placard which reads "avoid N1 ranges, 78-80.5 percent, 95.6-97.6 percent", in full view of the pilot and copilot, as close as practicable to the N1 speed indicators. (2) Place a copy of this AD in the appropriate rotorcraft flight manual. (3) Operate the rotorcraft in accordance with these speed range restrictions. (b) For engines which have accumulated 25 hours or less total time in service (TIS) from the effective date of this AD, accomplish the following: (1) Install vibration damping device, Part Number (P/N) 3112128-01, on vane assembly, P/N 3109163-01, in accordance with PWC Alert SB A-11033, dated December 31, 1987, prior to accumulating 25 hours total TIS. (2) Remove vane assembly, P/N 3109163-01, prior to accumulating 600 hours total TIS, and replace with a serviceable part. (c) For engines which have accumulated more than 25 hours total TIS from the effective date of this AD, accomplish the following: (1) Install vibration damping device, P/N 3112128-01, on vane assembly, P/N 3109163-01, in accordance with PWC Alert SB A-11033, dated December 31, 1987, within 25 hours TIS from the effectivedate of this AD. (2) Remove vane assembly, P/N 3109163-01, within 100 hours TIS from the installation of damping device, P/N 3112128-01, and replace with a serviceable part. (d) Thereafter, remove from service vane assembly, P/N 3109163-01, prior to accumulating 600 hours TIS since new, and replace with a serviceable part. NOTE: When vane assembly, P/N 3109163-01, is installed as a serviceable part, it must include damping device, P/N 3112128-01. (e) Aircraft may be ferried in accordance with the provisions of Federal Aviation Regulations 21.197 and 21.199 to a base where the AD can be accomplished. (f) Upon request from an operator, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Engine Certification Office, Engine & Propeller Directorate, Aircraft Certification Service. (g) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, the Manager, Engine Certification Office, Engine & Propeller Directorate, Aircraft Certification Service, may adjust the compliance time specified in this AD. PWC Alert SB 11033, dated December 31, 1987, and PWC SB 11022, dated September 28, 1987, identified and described in this document, are incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to Pratt & Whitney Canada, Box 10, Longueuil, Quebec, Canada J4K 4X9. These documents may also be examined at the Office of the Assistant Chief Counsel, Federal Aviation Administration, New England Region, Rules Docket No. 88-ANE-06, 12 New England Executive Park, Burlington, Massachusetts 01803, Room 311. This amendment, 39-6032, becomes effective November 29, 1988, as to all persons except those persons to whom it was made immediately effective by individual priority letter AD 88-03-01, issued February 2, 1988, which contained this amendment.
2018-25-07: We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc., Model BD-700-1A10 and BD-700-1A11 airplanes. This AD was prompted by reports of drainage holes on the belly fairing forward and middle access panels being obstructed with sealant. This AD requires inspecting for and removing all sealant blocking the drainage holes on the belly fairing forward and middle access panels. We are issuing this AD to address the unsafe condition on these products.
86-14-05: 86-14-05 SHORT BROTHERS, LTD.: Amendment 39-5344. Applies to Model SD3-60 airplanes, serial numbers SH3601 through SH3676 inclusive, certificated in any category. Compliance is required within 90 days after the effective date of this AD. To maintain the structural integrity of the horizontal stabilizer, accomplish the following, unless previously accomplished: 1. Modify the horizontal stabilizer lower skin to spar attachment in accordance with Short Brothers, Ltd., Service Bulletin SD36-55-06, Revision 1, dated May 1985. 2. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Northwest Mountain Region. 3. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base for the accomplishment of inspections and/or modifications required by this AD. All persons affected by this directive who have not already received the appropriate service document from the manufacturer may obtain copies upon request to Shorts Aircraft, 1725 Jefferson Davis Highway, Suite 510, Arlington, Virginia 22202. This document may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, 9010 East Marginal Way South, Seattle, Washington. This amendment becomes effective August 4, 1986.
2000-16-12: This amendment adopts a new airworthiness directive (AD) that is applicable to General Electric Company (GE) CF6-45, -50, -80A, -80C2, and -80E1 turbofan engines with certain high pressure compressor rotor (HPCR) stage 3-9 spools installed. This action requires initial ultrasonic and eddy current inspections of certain HPCR stage 3-9 spools for cracks. This amendment is prompted by an uncontained failure of an HPCR 3-9 spool. The actions specified in this AD are intended to detect cracks which can cause separation of the HPCR stage 3-9 spool and result in an uncontained engine failure.
92-03-02: 92-03-02 MCDONNELL DOUGLAS: Amendment 39-8156. Docket 92-NM-02-AD. \n\n\tApplicability: Model DC-9-81, -82, -83, and -87 series airplanes, and Model MD-88 airplanes, certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent loss of engine thrust, accomplish the following: \n\n\t(a)\tWithin 10 days after the effective date of this AD, revise the Limitations Section of the FAA-approved Airplane Flight Manual (AFM) to include the following. This may be accomplished by inserting a copy of this AD in the AFM. \n\n\t"Ice on Wing Upper Surfaces\t\n\n CAUTION\n\n\t\t Ice shedding from the wing upper surface during takeoff can cause severe damage to one or both engines, leading to surge, vibration, and complete thrust loss. The formation of ice can occur on wing surfaces during exposure of the airplane to normal icing conditions. Clear ice can also occur on the wing upper surfaces when cold-soaked fuel is in the main wing fuel tanks,and the airplane is exposed to conditions of high humidity, rain, drizzle, or fog at ambient temperatures well above freezing. Often, the ice accumulation is clear and difficult to detect visually. The ice forms most frequently on the inboard, aft corner of the main wing tanks. (END OF CAUTIONARY NOTE) \n\nThe wing upper surfaces must be physically checked for ice when the airplane has been exposed to conditions conducive to ice formation. Takeoff may not be initiated unless the flight crew verifies that a visual check and a physical (hands-on) check of the wing upper surfaces have been accomplished, and that the wing is clear of ice accumulation when any of the following conditions occur: \n\n(1)\twhen the ambient temperature is less than 50 degrees F and high humidity or visible moisture (rain, drizzle, sleet, snow, fog, etc.) is present; \n\n(2)\twhen frost or ice is present on the lower surface of either wing; \n\n(3)\tafter completion of de-icing. \n\nWhen tufts and triangular decals are installed in accordance with McDonnell Douglas MD-80 Service Bulletin 30-59, the physical check may be made by assuring that all installed tufts move\nfreely.\n\n\t\t\t\t\tNOTE\n\n \tThis limitation does not relieve the requirement that aircraft surfaces are free of frost, snow, and ice accumulation, as required by Federal Aviation Regulations Sections 91.527 and 121.629. (END OF NOTE)" \n\n\t(b)\tWithin 10 days after the effective date of this AD, revise the Configuration Deviation List (CDL) Appendix of the AFM to include the following. This may be accomplished by inserting a copy of this AD in the AFM.\n \n\t"30-80-01 Triangular Decal and Tuft Assemblies \n\n\tUp to two (2) decals or tufts per side may be missing, provided: \n\n\t\t\ta)\tAt least one decal and tuft on each side is located along the aft spar line; and \n\n\t\t\tb)\tThe tufts are used for performing the physical check to determine that the upper wing is free of ice by observing that the tufts move freely. \n\n\t\tUp to eight (8)decals and/or tufts may be missing, provided: \n\n\t\t\ta)\tTakeoff may not be initiated unless the flight crew verifies that a physical (hands-on) check is made of the upper wing in the location of the missing decals and/or tufts to assure that there is no ice on the wing when icing conditions exist;\n\n\t\t\t\t\t OR \n\n\t\t\tb)\tWhen the ambient temperature is more than 50 degrees F." \n\n\t(c)\tWithin 30 days after the effective date of this AD, install tufts and triangular decals on the inboard side of the wings' upper surfaces, in accordance with McDonnell Douglas Service Bulletin 30-59, dated September 18, 1989; Revision 1, dated January 5, 1990; or Revision 2, dated August 15, 1990. \n\n\t(d)\tAn alternative method of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. The request shall be forwarded through an FAA PrincipalMaintenance or Operations Inspector, as appropriate, who may concur or comment and then send it to the Manager, Los Angeles ACO. \n\n\t(e)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. \n\n\t(f)\tThe installation required by this AD shall be done in accordance with McDonnell Douglas Service Bulletin 30-59, dated September 18, 1989; Revision 1, dated January 5, 1990; or Revision 2, dated August 15, 1990. \n\n\tThis incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from McDonnell Douglas Corporation, P. O. Box 1771, Long Beach, California 90846-0001, Attention: Business Unit Manager, Technical Publications, C1-HDR (54-60). Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C. \n\n\t(g)\tThis amendment (39-8156, AD 92-03-02) becomes effective on January 17, 1992.
88-25-51 R1: 88-25-51 R1 McDONNELL DOUGLAS: Amendment 39-6128. Final copy of, and revision to, telegraphic AD T88-25-51 which was issued December 16, 1988. \n\n\tApplicability: McDonnell Douglas Model DC-9-81, -82, -83, -87, and MD-88 series airplanes, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo ensure that the airplane horizontal stabilizer is configured correctly for takeoff, accomplish the following: \n\n\tA.\tWithin 5 calendar days after the effective date of this AD and daily thereafter, perform a functional test of the horizontal stabilizer takeoff position indicator assembly by selecting a center of gravity setting of 13 and a flap setting of 8, and verifying that the longitudinal trim is correctly displayed as 6 plus or minus 1/2 degrees. If the longitudinal trim displayed is not correct, check the adhesive bond strength of the center of gravity and flap indicator dials as indicated in paragraph B., below. \n\n\t\t1.\tIf both indicator dials are firmly bonded to their respective wheels, re-rig the horizontal stabilizer takeoff position indicator assembly in accordance with McDonnell Douglas MD-80 Maintenance Manual, Chapter 27-40-12, step 3, paragraph A, "Test Module." \n\n\t\t2.\tIf either the flap or center of gravity indicator dials show signs of loose bonding, or if the assembly cannot be re-rigged to bring it within tolerance, replace the horizontal stabilizer takeoff position indicator assembly prior to further flight. \n\n\tB.\tWithin 25 calendar days after the effective date of this AD and thereafter at intervals not to exceed 25 days, accomplish both of the following: \n\n\t\t1.\tCheck the center of gravity and flap indicator dial adhesive bond strength in accordance with the "Accomplishment Instructions," with the exception of paragraphs F and J, of McDonnell Douglas Service Bulletin A27-304, Revision 1, dated December 23, 1988. If the indicator dials are dislodged or loosened, replace the horizontalstabilizer takeoff position indicator assembly prior to further flight. \n\n\t\t2.\tPerform an adjustment/test of the horizontal stabilizer takeoff position indicator assembly in accordance with McDonnell Douglas MD-80 Maintenance Manual, Chapter 27-40-12, step 3, paragraph A, "Test Module." If the adjustment/test is not successful, check the adhesive bond strength of the center of gravity and flap indicator dials as indicated in paragraph B.1., above. \n\n\t\t\ta.\tIf both indicator dials are firmly bonded to their respective wheels, re-rig the horizontal stabilizer position indicator assembly in accordance with McDonnell Douglas MD-80 Maintenance Manual, Chapter 27-40-12, step 3, paragraph A, "Test Module." \n\n\t\t\tb.\tIf either the flap or center of gravity indicator dials show signs of loose bonding, or if the assembly cannot be re-rigged to bring it within tolerance, replace the horizontal stabilizer takeoff position indicator assembly prior to further flight. \n\n\tC.\tModification of theflap and center of gravity dial indicators in the horizontal stabilizer takeoff position indicator assembly, in accordance with "Repair Action II" of McDonnell Douglas Service Rework Drawing SRO9270010, New, dated December 17, 1988, constitutes terminating action for the requirements of this AD. \n\n\tD.\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with inspection requirements of this AD. \n\n\tE.\tAn alternate means of compliance or adjustment of the compliance time which provides an acceptable level of safety may be used when approved by the Manager, Los Angeles Aircraft Office, FAA, Northwest Mountain Region. \n\n\tNOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any comments and then send it to the Manager, Los Angeles Aircraft Certification Office. \n\n\tAll persons affected by this directive who have not already received the appropriate service documents from the manufacturer, may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Director of Publications, CL-100 (54-60). These documents may be examined at the FAA, Northwest Mountain Region, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California. \n\n\tThis AD is the final copy of, and revision to, Telegraphic AD T88-25-51. Portions of this amendment were effective earlier to all recipients of Telegraphic AD T88-25-51, issued December 16, 1988, which was effective immediately upon receipt. \n\n\tThis amendment (39-6128, AD 88-25-51 R1) becomes effective February 15, 1989.
85-03-03 R1: 85-03-03 R1 ROLLS-ROYCE LIMITED: Amendment 39-4987 as amended by Amendment 39-5197. Applies to Rolls-Royce Dart engines series 506, 510, 511, 514, 525, 526, 527, 528, 529, 530, 531, 532, 535, 542, and all variants of these series. Compliance is required as indicated unless already accomplished. To prevent possible uncontained failure of the low pressure impeller, accomplish the following: Inspect certain low pressure impellers in accordance with mandatory Rolls-Royce Alert Service Bulletin (SB) Da72-A488, Revision 1, dated October 18, 1984, and Rolls-Royce SB Da72-480, Revision 4, dated December 1984, or FAA approved equivalent. Remove from service all impellers not ,meeting the inspection criteria per Rolls-Royce SB Da72-480. (a) Inspect low pressure impellers with serial numbers listed in Appendix 1 of Rolls-Royce SB DA72- A488, Revision 1, which have accumulated less than 2,000 flights since new, within the next 200 flights, but not later than March 31, 1985.(b) Inspect low pressure impellers with serial numbers listed in Appendix 2 of Rolls-Royce SB Da72- A488, Revision 1, which have accumulated less than 2,000 flights since new, within the next 600 flights or next shop visit, whichever comes first, but not later than September 30, 1985. NOTE: Shop Visit (as defined in the World Airlines Technical Operations Glossary) is defined as the input of an engine to a repair shop where the subsequent engine maintenance entails: (a) Separation of a major engine flange (lettered or numbered) other than flanges mating with major sections of the nacelle or reverser. Note: Separation of flanges purely for purposes of shipment, without subsequent internal maintenance, is not a "Shop Visit." (b) Removal of a disk or hub or spool. (c) Removal of the main or angle gearbox. (d) Removal of the fuel nozzles. (c) Inspect low pressure impellers with serial numbers listed in Appendix 1 of Rolls-Royce SB Da72- A488, Revision 2, which have not been inspected per (a) above, which have accumulated less than 3,500 flights since new, within the next 100 flights, but not later than February 28, 1986. (d) Inspect low pressure impellers with serial numbers listed in Appendix 1 of Rolls-Royce SB Da72- A488, Revision 2, which have not been inspected per (a) above, which have accumulated 3,500 or more flights since new, within the next 500 flights, but not later than April 30, 1986. For purpose of this AD the term "repair shop" refers to a maintenance station where low compressor overhaul facilities exist. Aircraft may be ferried in accordance with the provisions of Federal Aviation Regulations (FARs) 21.197 and 21.199 to a base where the AD can be accomplished. Upon request, an equivalent means of compliance with the requirements of this AD may be approved by the Manager, Engine Certification Office, Aircraft Certification Division, FAA, New England Region, 12 New England Executive Park, Burlington, Massachusetts 01803. Rolls-Royce SB Da72-A488, Revision 2, dated July 25, 1985, is incorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received this document from the manufacturer may obtain Rolls-Royce Limited, East Kilbride, Glasgow G74 4PY, Scotland. This document also may be examined at the Office of the Regional Counsel, FAA, New England Region, Attention: Rules Docket No. 84-ANE-19, 12 New England Executive Park, Room Number 311, between the hours of 8:00 a.m. and 4:30 p.m., Monday through Friday except Federal holidays. Amendment 39-4987 became effective on February 11, 1985. This Amendment 39-5197 becomes effective on January 6, 1986.
2018-25-02: We are adopting a new airworthiness directive (AD) for certain Airbus SAS Model A318, A319, A320, and A321 series airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the principal structural elements and certain life- limited parts are subject to widespread fatigue damage (WFD). This AD requires revising the existing maintenance or inspection program to incorporate new or more restrictive airworthiness limitations. We are issuing this AD to address the unsafe condition on these products.
91-21-05: 91-21-05 MCDONNELL DOUGLAS: Amendment 39-8052. Docket No. 91-NM-174-AD.\n\n\tApplicability: Model DC-10-10, -10F, and -15 series airplanes, fuselage numbers through 379; and Model DC-10-30, -30F, and -40 series airplanes, fuselage numbers through 275; certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished.\n\n\tTo ensure the structural integrity of these airplanes, accomplish the following:\n\n\t(a)\tExcept as provided in paragraphs (b) through (e) of this AD, prior to the accumulation of 7,000 landings or within 30 days after the effective date of this AD, conduct the initial inspections specified in paragraphs (a)(1), (a)(2), or (a)(3) of this AD.\n\n\t\t(1)\tConduct an eddy current inspection of the wing rear spar lower cap aft tang and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option III of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. In addition, within 1,500 landings after performing these eddy current and dye penetrant inspections, conduct the inspections specified in paragraph (a)(2) or (a)(3) of this AD and repeat thereafter as indicated. Or\n\n\t\t(2)\tConduct an ultrasonic inspection of the area around the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option II of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 1,900 landings. Or\n\n\t\t(3)\tConduct an eddy current inspection of the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option I of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 3,300 landings.\n\n\t(b)\tThe requirements of paragraph (c) of this AD apply to airplanes on which the following actions have been accomplished:\n\n\t\t(1)\tThe dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 422 has been accomplished prior to the effective date of this AD, in accordance with McDonnell Douglas Service Bulletin 57-61, Revision 2, dated August 15, 1990; and\n\n\t\t(2)\tThe eddy current inspection of the wing rear spar lower cap aft tang has been accomplished prior to the effective date of this AD per DC-10 Supplemental Inspection Document, Principal Structural Element (PSE) 57.10.007 and 57.10.008, in accordance with McDonnell Douglas Service Bulletin 57-61, Revision 2, dated August 15, 1990.\n\n\t(c)\tFor airplanes specified in paragraph (b) of this AD, conduct the initial inspections specified in either paragraph (c)(1) or (c)(2) of this AD within 1,500 landings after the inspections (eddy current and dye penetrant) specified in paragraph (b)(1) of this AD, or within 30 days after the effective date of this AD, whichever occurs later.\n\n\t\t(1)\tConduct an ultrasonic inspection of the area around the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424, in accordance with Option II of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 1,900 landings. Or\n\n\t\t(2)\tConduct an eddy current inspection of the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424, in accordance with Option I of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 3,300 landings.\n\n\t(d)\tThe requirements of paragraph (e) of this AD apply to airplanes on which the following actions have been accomplished: \n\n\t\t(1)\tThe dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 422 has been accomplished prior to the effective date of this AD, in accordance with McDonnell Douglas Service Bulletin 57-61, Revision 2, dated August 15, 1990; and\n\n\t\t(2)\tThe eddy current inspection of the wing rear spar lower cap aft tang fastener holes located between stations Xors= 417 and Xors= 422 has been accomplished prior to the effective date of this AD per DPS 4.735-9 in accordance with McDonnell Douglas Service Bulletin 57-61, Revision 2, dated August 15, 1990.\n\n\t(e)\tFor airplanes specified in paragraph (d) of this AD, conduct the initial inspections specified in either paragraph (e)(1) or (e)(2) of this AD within 3,300 landings after the accomplishment of the inspection specified in paragraph (d)(1) of this AD, or within 30 days after the effective date of this AD, whichever occurs later.\n\n\t\t(1)\tConduct an ultrasonic inspection of the area around the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option II of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 1,900 landings. Or\n\n\t\t(2)\tConduct an eddy current inspection of the six wing rear spar lower cap aft tang fastener holes and a dye penetrant inspection of the wing trailing edge access door sill located between stations Xors= 417 and Xors= 424 in accordance with Option I of McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. Repeat these inspections at intervals not to exceed 3,300 landings.\n\n\t(f)\tIf any cracks are found as a result of the inspections conducted in accordance with this AD, prior to further flight, repair ina manner approved by the Manager of the Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate.\n\n\t(g)\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate to a base in order to comply with the requirements of this AD.\n\n\t(h)\tAn alternative method of compliance or adjustment time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate.\n\n\tNOTE: The request should be forwarded through the FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Los Angeles ACO.\n\n\t(i)\tThe inspection requirements shall be done in accordance with McDonnell Douglas Alert Service Bulletin A57-123, dated July 25, 1991. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from McDonnell Douglas Corporation, P.O. Box 1771, Long Beach California 90806-0001, Attention: Business Unit Manager of Technical Publications, Technical Administrative Support C1-L5B (54-60). Copies may be inspected at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington; or the Los Angeles Aircraft Certification Office, 3229 East Spring Street, Long Beach, California; or at the Office of the Federal Register, 1100 L Street N.W., Room 8401, Washington, D.C.\n\n\tThis amendment (39-8052, AD 91-21-05) becomes effective on October 23, 1991.