78-09-05 CESSNA: Amendment 39-3202. Applies to the following models and serial number airplanes certificated in all categories: \n\n\n\nMODELS\nSERIAL NUMBERS\n336\n336-0001 through 336-0195 \n337, 337A, 337B, T337B,\t\n 337C, T337C, 337D and T337D\n337-0001 through 337-1193\n \n337E, T337E, 337F, T337F,\n 337G, 337H and T337H \n33701194 through 33701852\nT337G and P337H\nP3370001 through P3370313\nM337B\nAll serial numbers\n\n\tCompliance: Required as indicated in accordance with Compliance Table I set forth in this AD or as otherwise set forth herein, unless already accomplished. \n\n\tTo detect cracking of the wing front and rear spar lower caps, front spar web and web doubler - In accordance with instructions set forth herein and in Cessna Multi-Engine Service Letter ME78-2, dated February 13, 1978, or later revisions: \n\n\tI.\tAt time intervals noted in Table I of this AD, inspect the right and left wing front and rear spar lower cap and front spar web and web doubler onairplanes having model and serial numbers shown below; \n\n\n\n\n\n\n\n\n\nTABLE 1\nCOMPLIANCE TIMES\n\nAirplane Type/\nOperation\nTotal Time in\nService for each of the following:\n\nInspection Times for Spar\nCap - Inspections required\nby Paragraph I.A.\n\nInspection Times for \nFront Spar Web - Inspections\nRequired by Paragraph I.B. \n\n\n1) Front Spar\n Lower Cap\nInitial Inspection\nin accordance\nwith this AD \nInterval for\nRepetitive\nInspections\nInitial\nInspection\nInterval for\nRepetitive\nInspections*\n\n2) Rear Spar\n Lower Cap\n3) Front Spar\n Web & Web\n Doubler\n\n\n\n\n\n\n\n\n\n\nNon-Pressurized\n(See Note 1)\n0 to 4999\nNone\nNone\nNone\nNone \n\n5,000 & up\nWithin 25 hours time-in-service after the effective date\nof this AD for those airplanes which \nhave not yet been inspected in accordance with \nAD 76-10-11\nor 73-04-02 or;\nwithin 500 hours\ntime-in-service \nafter the last\ninspection in\naccordance with\nAD 76-10-11 or\n73-04-02.\n500 hoursWithin 25 hours time-in-service\nafter the effective date of this AD.\n\n500 hours\n\n\n\n\n\n\nPressurized\n(See Note 1)\n0 to 9,999\n\nNone\nNone\nNone\nNone \n\n10,000 & up\nWithin 25 hours\ntime-in-service\nafter the effective\ndate of this AD\nfor those airplanes\nwhich have not yet\nbeen inspected in\naccordance with \nAD 76-10-11 or\n73-04-02 or;\nwithin 500 hours\ntime-in-service \nafter the last inspections\nin accordance with\nAD 76-10-11 or 73-04-02.\n500 hours\nWithin 25 hours time-in-service\nafter the effective date of this AD.\n\n\n500 hours\n\n\n\n\n\nNOTE 1: \nFor those airplanes\nwhich have engaged\n in contour or\nterrain following\noperations at low\naltitudes, such \nas power/pipeline\npatrol, fish or\ngame spotting,\naerial applications,\npolice patrol, live-\nstock management,\netc., Cessna \nrecommends and FAA strongly urges\ninspections at \nintervals shown to\nthe right of this\nnote.\n0 to 2,999\n\n3,000 & up\nNone\n\nWithin 25 hours\ntime-in-service\nafterthe effective\ndate of this AD\nfor those airplanes which have\nnot yet been \ninspected in \naccordance with the\nsuggestion in \nAD 76-10-11 or\n73-04-02 or, within 300 hours time-\nin-service after the last inspection in accordance with\nAD 76-10-11 or\n73-04-02.\nNone\n\n300 hours\nNone\n\nWithin 25 hours time-in-service\nafter the effective date of this AD.\n\nNone \n\n300 hours\n\n\n*After initial inspection in\naccordance\nwith this AD the compliance\ntime for\nrepetitive\ninspections\nmay be adjusted to \nallow compliance at the same\ntime as the\ninspections\nrequired by\nparagraph\n1A of this AD.\n\n\t\tA.\tFront and rear spar lower cap inspection;\n\n\nModel\nSerial Numbers\n336\n336-0001 through 336-0195\n337, 337A, 337B, T337B, 337C,\n T337C, 337D, and T337D\n337-0001 through 337-1193\n337E, T337E, 337F, T337F, and 337G\n33701194 through 33701548\nT337G\nP3370001 through P3370138\nM337B\nAll serial numbers\n\n\t\t\t1.\tFront spar lower cap inspection. \n\t\t\t\n\t\t\t\ta.\tInspect three fastener holes on the left wing and three fastener holes on the right wing for wing spar cracks using eddy current inspection procedures outlined in the above noted Cessna Service Letter. Figure 1 shows the area involved and the three fasteners (two NAS 221 screws at W.S. 64.41 and the jack point bolt hole at W.S. 68.45) that are to be inspected. \n\t\t\t\n\t\t\t\tb.\tRemove the two NAS 221 screws at Wing Station 64.41 one at a time for this inspection and hold the boom fairing firmly against underlying thicknesses of material to insure proper eddy current probe depth settings during this inspection. A cross-section with the screws at W.S. 64.41 removed is shown in Figure 2. Figure 3 shows the spar assembly (less boom and wing skins) and the relationship of the lower cap to the other parts at the strut attachment. Figure 4 shows the spar cross-section thru the jack point bolt hole. \n\n\n\n\n\n\n\n\n\n\n\t\t\t\tc.\tIf cracks are found in either the right or left wing front spar lower cap during any inspection required by this AD, prior to approving the airplane for return to service replace the front spar lower cap in both the right and left wing with new spar caps. \n\n\t\t\t2.\tRear spar lower cap inspection. \n\n\t\t\t\ta.\tDye penetrant inspect the lower spar cap area between two and three inches (2nd rivet outboard of W.S. 66.00 rib) outboard of wing station 66.00 rib for spar cap cracks originating in the rivet hole in accordance with inspection provisions in the above noted Cessna Service Letter. Figures 5, 6 and 7 show the location of the area on the rear spar lower cap to be inspected. \n\n\n\n\n\n\n\n\n\n\t\t\t\tb.\tIf cracks are found in either the right or left wing rear spar lower cap during any inspection required by this AD, prior to approving the airplane for return to service replace the rear spar lower cap in both the right and left wing. \n\t\n\t\tB.\tFront spar web and web doubler inspection; \n\n\nModel\nSerial Numbers\n336\n336-0001 through 336-0195\n337, 337A, 337B,T337B, 337C,\n T337C, 337D and T337D\n337-0001 through 337-1193\n337E, T337E, 337F, T337F, 337G,\n 337H and T337H\n33701194 through 33701852\nT337G and P337H\nP3370001 through P3370313\nM337B\nAll serial numbers\n\n\t\t\t1.\tRemove wing root access panels and wing root fairings. \n\n\t\t\t2.\tVisually inspect the radii of both the spar web and web doubler for cracks in the shaded critical area shown in Figure 8 of this AD. \n\n\t\t\t3.\tIf cracks are found in either the right or left wing front spar web or web doubler during any inspection required by this AD, prior to approving the airplane for return to service, replace the discrepant components. \n\n\tII.\tAirplanes found to have cracked spar caps, webs or web doublers during inspections required by this AD may be flown in accordance with FAR 21.197 to a base where the component replacement can be accomplished. \n\n\tIII.\tAccomplish the repetitive inspections made mandatory by this AD on those spar caps, webs and web doublers replaced in accordance with this AD upon accumulation of the total times-in-service shown in Table I of this AD. Repetitive inspections "strongly urged" via Note 1 in Table I of this AD should also be accomplished on spar caps, webs and web doublers replaced in accordance with this AD upon accumulation of the total times-in-service shown in Note 1, Table I, of this AD. \n\n\tIV.\tNotify in writing the Chief, Engineering and Manufacturing Branch, FAA, Central Region, of the location and length of any crack found during inspections required by this AD and also the total time in service of the component at the time the crack was discovered. (Reporting approved by the Office of Management and Budget under OMB NO. 04-R0174.) \n\n\tV.\tThe time interval for repetitive inspections required by this AD, after compliance with initial inspection requirements, can be adjusted up to 25 hours to allow accomplishment of these inspections at regular scheduled maintenance periods. \n\n\tVI.\tEquivalent methods of compliance with this AD must be approved by the Chief, Engineering and Manufacturing Branch, FAA, Central Region. \n\n\tThis AD supersedes AD 76-10-11, Amendment 39-2621 (41 FR 22045, 22046, 22047 and 22048). \n\n\tThis Amendment becomes effective May 11, 1978.