AD 98-12353

[Federal Register Volume 63, Number 90 (Monday, May 11, 1998)] [Proposed Rules] [Pages 25781-25787] From the Federal Register Online via the Government Publishing Office [www.gpo.gov] [FR Doc No: 98-12353]

======================================================================== Proposed Rules Federal Register ________________________________________________________________________ This section of the FEDERAL REGISTER contains notices to the public of the proposed issuance of rules and regulations. The purpose of these notices is to give interested persons an opportunity to participate in the rule making prior to the adoption of the final rules. ========================================================================

Federal Register / Vol. 63, No. 90 / Monday, May 11, 1998 / Proposed Rules

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-27-AD] RIN 2120-AA64

Airworthiness Directives; Textron Lycoming and Teledyne Continental Motors Reciprocating Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Textron Lycoming and Teledyne Continental Motors reciprocating engines that had crankshafts repaired by Nelson Balancing Service, Repair Station Certificate No. NB7R820J, Bedford, Massachusetts. This proposal would require removal from service of affected crankshafts, or a visual inspection, magnetic particle inspection, and dimensional check of the crankshaft journals, and, if necessary, rework or removal from service of affected crankshafts and replacement with serviceable parts. This proposal is prompted by reports of crankshafts exhibiting heat check cracking of the nitrided bearing surfaces which led to crankshaft cracking and subsequent failure. The actions specified by the proposed AD are intended to prevent crankshaft failure due to cracking, which could result in an inflight engine failure and possible forced landing.

DATES: Comments must be received by June 10, 1998.

ADDRESSES: Submit comments in triplicate to the Federal Aviation Administration (FAA), New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-27-AD, 12 New England Executive Park, Burlington, MA 01803-5299. Comments may also be sent via the Internet using the following address: ``9-ad- [email protected]''. Comments sent via the Internet must contain the docket number in the subject line. Comments may be inspected at this location between 8:00 a.m. and 4:30 p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Rocco Viselli, Aerospace Engineer (assigned to Textron Lycoming), New York Aircraft Certification Office, FAA, Engine and Propeller Directorate, 10 Fifth St., 3rd Floor, Valley Stream, NY 11581-1200; telephone (516) 256-7531, fax (516) 568-2716; or Jerry Robinette, Aerospace Engineer (assigned to Teledyne Continental Motors), Atlanta Aircraft Certification Office, FAA, Small Airplane Directorate, 1895 Phoenix Boulevard, One Crown Center, Suite 450, Atlanta, GA 30349; telephone (770) 703-6096, fax (770) 703-6097.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this notice may be changed in light of the comments received. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 98-ANE-27-AD.'' The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, New England Region, Office of the Regional Counsel, Attention: Rules Docket No. 98-ANE-27-AD, 12 New England Executive Park, Burlington, MA 01803-5299.

Discussion

The Federal Aviation Administration (FAA) has received reports of crankshafts installed in certain Textron Lycoming and Teledyne Continental Motors (TCM) reciprocating engines cracking after repair by Nelson Balancing Service, Repair Stations Certificate No. NB7R820J, Bedford, Massachusetts. The investigation revealed that the crankshafts exhibit heat check cracking of the nitrided bearing surfaces. The cracking of the nitride surface is believed to be due to improper grinding procedures. Grinding occurred as part of the engine overhaul process. Improper grinding can result in overheating the crankshaft, which, in turn, results in cracking of the nitride surface. If the crankshaft is returned to service with the nitride surface cracked, the crankshaft will fail. The cracks occur in the forward and/or aft fillet of the main bearing journals and/or crankpin journals. The time to failure depends on the severity of the cracking but the crankshaft will not complete the overhaul cycle. There have been 28 cases of crankshafts installed on certain Textron Lycoming reciprocating engines that have been classified as cracked, 3 broken, and 2 later rejected by Nelson Balancing Service; and 3 reports of crankshaft failure and 7 cases of crankshafts being rejected when reinspected, due to heat check cracking, on certain TCM engines. This condition, if not corrected, could result in crankshaft failure due to cracking, which could result in an inflight engine failure and possible forced landing. Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require removal from service of affected crankshafts, or a visual inspection, magnetic particle inspection, and dimensional check of the crankshaft journals, and, if necessary, rework or removal from service of affected crankshafts and replacement with serviceable parts.

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There are approximately 250,000 engines of the designs listed in the applicability section of this AD in the worldwide fleet. The FAA estimates that 200,000 of those engines are installed on aircraft of U. S. registry. Of these it is estimated that 30% or 60,000 engines will have had an overhaul in the time frame of interest; however, only 291 would be required to take compliance action. Of this 60,000 it is estimated that 10,000 will require removal of the propeller spinner to determine applicability of the AD. The cost associated with the spinner removal/replacement is estimated to be $60 per work hour average labor rate times one hour. It will take approximately 90 work hours per engine to accomplish the proposed action and the average labor rate is $60 per work hour. Required parts would cost $115 per engine for gaskets, seals, etc. In addition, it is estimated that half of the 291 affected engines can be reworked at a cost of $1,800 per engine and that the other half of the 291 affected engines will be rejected, plus purchasing another crankshaft which will cost $4,000 per engine. Based on these figures, the total cost impact of the proposed AD on U.S. operators is estimated to be $3,048,765. The regulations proposed herein would not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this proposal would not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. For the reasons discussed above, I certify that this proposed regulation (1) is not a ``significant regulatory action'' under Executive Order 12866; (2) is not a ``significant rule'' under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

Sec. 39.13 [Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

Textron Lycoming and Teledyne Continental Motors: Docket No. 98-ANE- 27-AD.

Applicability: Textron Lycoming (LYC) O-235, O-235-C1, -235-C2C, O-235-L2C, O-235-N2C, O-290, O-290-D2, 0-320, O-320-A, O-320-A1A, O- 320-A2B, O-320-B2B, O-320-B2C, O-320-D2J, O-320-D3G, O-320-E2A, O- 320-E2D, O-320-E2G, O-320-E3D, -320-H2AD, O-360, O-360-A1A, O-360- A1D, O-360-A3A, O-360-A4A, O-360-A4K, O-360-B1B, IO-360-F1A6, AEIO- 320-E1B, HIO-360-C1A, IO-320, IO-320-B1A, IO-360, IO-360-A1A, IO- 360-A1B6, IO-360-B1E, IO-360-C, IO-360-CIC, IO-360-C1C6, IO-360- C1D6, IO-360-D, O-540-A1B5, O-540-A1D5, O-540-R2AD, IO-540, IO-540- C4B5, IO-540-S1A5, TIO-540-A2, LIO-320-C1A, LIO-360-C1E6, and O-720 reciprocating engines; and Teledyne Continental Motors (TCM) A-65, A65-3, A65-8, A75, A75-8, C75-12, C85, C85-8, C85-12, C90-8FJ, C90- 12, O-200, O-200-A, O-300, O-300-D, IO-360-C, E-185-4, E-225-8, O- 470, O-470-K, O-470-L, O-470-R, O-470-11, IO-470, IO-470-N, IO-470- S, IO-520, IO-520-D, GTSIO-520, and TSIO-520-VB reciprocating engines, with installed crankshafts repaired by Nelson Balancing Service, Bedford, Massachusetts, Repair Station Certificate No. NB7R820J, between February 1, 1995, and December 31, 1997, inclusive, as listed (by work order (W/O)) in Table 1 of this AD.

Table 1 ---------------------------------------------------------------------------------------------------------------- Engine Model W/O Date Engine SER# ---------------------------------------------------------------------------------------------------------------- LYC........................... AEIO-320-E1B 1134 2/17/96 L-5653-55A LYC........................... HIO-360-C1A 1155 2/7/96 L-12126-51A LYC........................... IO-320 1141 1/17/96 LYC........................... IO-320-B1A 1525 11/14/97 LYC........................... IO-360 1314 12/17/96 LYC........................... IO-360 IN6137 8/7/97 LYC........................... IO-360-A1A 1230 6/10/96 L-474-51 LYC........................... IO-360-A1A 1289 10/23/96 L-4085-5174 LYC........................... IO-360-A1A 1415b 5/23/97 RL-3920-51A LYC........................... IO-360-A1B6 1463 7/31/97 LYC........................... IO-360-B1E 1312 12/12/96 L-4453-51A LYC........................... IO-360-C 1146 1/23/96 R-51448-9-C LYC........................... IO-360-C1C 1336 2/10/97 LYC........................... IO-360-C1C 1518 12/9/97 LYC........................... IO-360-C1C6 1530 11/25/97 LYC........................... IO-360-C1C6 1537 12/9/97 L-19294-51A LYC........................... IO-360-C1D6 1286 4/28/97 LYC........................... IO-360-D 1540 12/2/97 LYC........................... IO-360-F1A6 1176 3/7/96 L-27423-36A LYC........................... IO-540 1014 2/8/95 LYC........................... IO-540 1056 6/13/95 LYC........................... IO-540 1302 12/5/96 LYC........................... IO-540-C4B5 1313 12/17/96 L-19547-48 LYC........................... IO-540-S1A5 1513 10/27/97 L-19597-48A LYC........................... IVO-435-G1A 1271 LYC........................... LIO-320-C1A 1158 2/8/96 LYC........................... LIO-360-C1E6 1280 10/7/96

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LYC........................... LIO-360-C1E6 1281 10/9/96 LYC........................... O-235 1013 2/21/95 LYC........................... O-235 1051 6/2/95 LYC........................... O-235 1054 6/9/95 LYC........................... O-235 1057 6/14/95 L-9041-15 LYC........................... O-235 1058 6/29/95 LYC........................... O-235 1060 6/30/95 LYC........................... O-235 1069 8/10/95 LYC........................... O-235 1110 2/20/96 LYC........................... O-235 1145 1/23/96 LYC........................... O-235 1151 1/25/96 LYC........................... O-235 1160 2/9/96 RL-24636-15 LYC........................... O-235 1305 12/5/96 L-22542-15 LYC........................... O-235 1329 2/11/97 LYC........................... O-235 1332 2/11/97 LYC........................... O-235 1481 9/2/97 LYC........................... O-235-C1 1089 10/8/95 L-6475-15 LYC........................... O-235-C1 1188 4/2/96 L-7143-15 LYC........................... O-235-C1 1335 3/12/97 L-5569-15 LYC........................... O-235-C1 1367 3/24/97 LYC........................... O-235-C2C 1019 2/24/95 L-12284-15 LYC........................... O-235-C2C 1040 5/8/95 LYC........................... O-235-C2C 1105 12/1/95 L-12273-15 LYC........................... O-235-L2C 1030 4/6/95 L-14545-15 LYC........................... O-235-L2C 1036 4/24/95 LYC........................... O-235-L2C 1037 4/24/95 L-23012-15 LYC........................... O-235-L2C 1050 6/2/95 L-15542-15 LYC........................... O-235-L2C 1062 7/5/95 L-18306-15 LYC........................... O-235-L2C 1067 8/8/95 LYC........................... O-235-L2C 1070 8/10/95 L-16005-15 LYC........................... O-235-L2C 1095 11/14/95 RL-023227-15 LYC........................... O-235-L2C 1101 11/4/95 L-15300-15 LYC........................... O-235-L2C 1102 11/15/95 L-20183-15 LYC........................... O-235-L2C 1162 2/14/96 L-16114-15 LYC........................... O-235-L2C 1179 3/11/96 L-21215-15 LYC........................... O-235-L2C 1219 5/16/96 L-21215-15 LYC........................... O-235-L2C 1251 8/22/96 LYC........................... O-235-L2C 1285 10/19/96 LYC........................... O-235-L2C 1365 3/24/97 LYC........................... O-235-L2C 1400 4/28/97 LYC........................... O-235-L2C 1414 8/5/97 LYC........................... O-235-L2C 1417 12/5/97 LYC........................... O-235-L2C 1433 6/26/97 L-17074-15 LYC........................... O-235-L2C 1435 6/9/97 LYC........................... O-235-L2C 1504 10/31/97 LYC........................... O-235-L2C 1508 11/18/97 LYC........................... O-235-L2C 1524 11/12/97 LYC........................... O-235-L2C 1536 11/24/97 LYC........................... O-235-L2C 2010 11/19/97 LYC........................... O-235-N2C 1511 10/29/97 L-23857-15 LYC........................... O-290 1257 9/4/96 LYC........................... O-290 1326 3/26/97 LYC........................... O-290-D2 1082 9/26/95 L-6019-21 LYC........................... O-320 1018 2/22/95 LYC........................... O-320 1024 3/17/95 LYC........................... O-320 1038 5/3/95 L-39272-27A LYC........................... O-320 1045 5/24/95 LYC........................... O-320 1084 9/28/95 LYC........................... O-320 1116 1/8/96 LYC........................... O-320 1125 1/8/96 LYC........................... O-320 1169 2/28/96 LYC........................... O-320 1175 3/7/96 LYC........................... O-320 1184 3/28/96 LYC........................... O-320 1189 8/27/96 LYC........................... O-320 1202 4/30/96 LYC........................... O-320 1212 5/10/96 LYC........................... O-320 1283 10/17/96 LYC........................... O-320 1316 12/21/96 LYC........................... O-320 1340 2/25/97 L-24367 LYC........................... O-320 1347 2/18/97 LYC........................... O-320 1360 3/10/97 LYC........................... O-320 1361 3/10/97

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LYC........................... O-320 1436 5/29/97 ...................... LYC........................... O-320 1468 8/14/97 ...................... LYC........................... O-320 1474 8/22/97 L-13130-39A LYC........................... O-320 1477 9/13/97 LYC........................... O-320 1477 9/13/97 LYC........................... O-320 1507 LYC........................... O-320 1519 11/21/97 LYC........................... O-320 1546 12/7/97 ...................... LYC........................... O-320 1171 3/1/96 ...................... LYC........................... O-320-A 1192 4/13/96 ...................... LYC........................... O-320-A 1194 4/13/96 ...................... LYC........................... O-320-A 1196 4/13/96 ...................... LYC........................... O-320-A1A 1244 8/13/96 L-5270-27 LYC........................... O-320-A2B 1081 9/22/95 ...................... LYC........................... O-320-A2B 1461 9/9/97 L-12626-27 LYC........................... O-320-B2B 1452 7/10/97 L-2977-39 LYC........................... O-320-B2C 1315 12/17/96 ...................... LYC........................... O-320-D2J 1172 3/4/96 L-13039-39A LYC........................... O-320-D2J 1173 3/7/96 L-123412-39A LYC........................... O-320-D2J 1253 9/4/96 ...................... LYC........................... O-320-D2J 1534 11/25/97 ...................... LYC........................... O-320-D2J 1539 12/3/97 ...................... LYC........................... O-320-D3G 1077 9/17/95 ...................... LYC........................... O-320-D3G 1114 1/8/96 L-10983-39A LYC........................... O-320-D3G 1354 2/25/97 ...................... LYC........................... O-320-D3G 1370 3/26/97 H45247 LYC........................... O-320-D3G 1544 12/3/97 ...................... LYC........................... O-320-E2A 1103 11/10/95 L-26363-27A LYC........................... O-320-E2A 1191 4/13/96 L-19377-27A LYC........................... O-320-E2A 1317 12/21/96 L-15219-27A LYC........................... O-320-E2A 1439 6/9/97 L-38003-55A LYC........................... O-320-E2D 1068 8/10/95 L-35528-27A LYC........................... O-320-E2D 1078 9/17/95 ...................... LYC........................... O-320-E2D 1177 3/9/96 L-44732-27A LYC........................... O-320-E2D 1181 3/14/96 ...................... LYC........................... O-320-E2D 1241 8/9/96 L-42691-27A LYC........................... O-320-E2D 1245 8/13/96 L-40483-27A LYC........................... O-320-E2D 1260 9/9/96 L-15300-15 LYC........................... O-320-E2D 1343 2/17/97 ...................... LYC........................... O-320-E2D 1346 3/2/97 L-44320-27A LYC........................... O-320-E2D 1385 4/16/97 ...................... LYC........................... O-320-E2D 1458 7/18/97 ...................... LYC........................... O-320-E2D 1533 11/25/97 ...................... LYC........................... O-320-E2D 1549 12/12/97 ...................... LYC........................... O-320-E2G 1338 3/10/97 L-38264-27A LYC........................... O-320-E3D 1034 4/18/95 L-29668-27A LYC........................... O-320-E3D 1074 8/24/95 L-29495-27A LYC........................... O-320-E3D 1431 6/9/97 L-33770-27A LYC........................... O-320-E3D 1444 6/13/97 ...................... LYC........................... O-320-E3D 1500 10/7/97 L-33841-27A LYC........................... O-320-H2AD 1322 1/22/97 L-1530-78T LYC........................... O-360 1025 3/17/95 LYC........................... O-360 1157 2/7/96 ...................... LYC........................... O-360 1199 4/18/96 ...................... LYC........................... O-360 1362 3/10/97 ...................... LYC........................... O-360 1386 4/17/97 ...................... LYC........................... O-360 1394 5/6/97 ...................... LYC........................... O-360 1528 11/19/97 ...................... LYC........................... O-360-A1A 1170 2/28/96 L-20677-36A LYC........................... O-360-A1A 1214 5/14/96 L-20190-36A LYC........................... O-360-A1A 1239 8/5/96 ...................... LYC........................... O-360-A1D 1411 5/5/97 ...................... LYC........................... O-360-A3A 1531 11/25/97 ...................... LYC........................... O-360-A4A 1270 9/27/96 L-14008-36A LYC........................... O-360-A4A 1464 7/30/97 L-24796-36A LYC........................... O-360-A4A 1486 9/6/97 ...................... LYC........................... O-360-A4A 1529 11/25/7 ...................... LYC........................... O-360-A4K 1166 2/22/96 L-26455-36A LYC........................... O-360-B1B 1262 9/9/96 L-5261-51A LYC........................... O-540-A1B5 1129 12/29/95 ...................... LYC........................... O-540-A1B5 1132 1/9/96 L-1165-40 LYC........................... O-540-A1D5 1462 7/28/97 L-5661-40

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LYC........................... O-720 1510 10/26/97 ...................... LYC........................... TIO-540-A2 1064 7/13/95 ...................... LYC........................... TIO-540-A2 1111 1/10/96 ...................... LYC........................... TIO-540-R2AD 1106 11/27/95 L-5949-61A TCM........................... A-65 1152 1/25/96 ...................... TCM........................... A-65 1154 2/7/96 7187 TCM........................... A-65 1183 2/22/96 ...................... TCM........................... A-65 1185 3/28/96 ...................... TCM........................... A-65 1233 6/23/96 ...................... TCM........................... A-65 1290 10/29/96 ...................... TCM........................... A-65 1296 11/14/96 4933868 TCM........................... A-65 1299 11/19/96 ...................... TCM........................... A-65 1325 3/26/97 ...................... TCM........................... A-65 1326 3/26/97 ...................... TCM........................... A-65 1376 4/29/97 ...................... TCM........................... A-65 1438 6/17/97 5890178 TCM........................... A-65-3 1243 8/13/96 324993 TCM........................... A-65-8 1541 12/2/97 ...................... TCM........................... A65-8 1276 10/5/96 5762568 TCM........................... A75 1156 2/7/96 5321868 TCM........................... A75 1255 9/3/96 ...................... TCM........................... A75 1256 9/4/96 ...................... TCM........................... A75-8 1275 10/5/96 5162868 TCM........................... C75-12F 1293 11/4/96 3316-6-12 TCM........................... C85 1088 10/4/95 ...................... TCM........................... C85 1092 10/18/95 ...................... TCM........................... C-85 1198 4/17/96 29652-7-8 TCM........................... C-85 1297 11/14/96 ...................... TCM........................... C-85 1352 3/10/97 ...................... TCM........................... C-85 1381 4/28/97 ...................... TCM........................... C-85 1391 4/19/97 ...................... TCM........................... C-85 1392 4/19/97 ...................... TCM........................... C-85 1484 9/4/97 28487-6-12 TCM........................... C-85-8FJ 1139 1/17/96 29845-7-8 TCM........................... C-85-8FJ 1420 5/12/97 29465-7-8 TCM........................... C-85-12 1031 4/6/95 TCM........................... C-85-12 1182 3/18/96 21596-6-12 TCM........................... C-85-12 1217 5/15/96 TCM........................... C-85-12 1265 9/12/96 14657 TCM........................... C-85-12 1298 11/14/96 23610-6-12 TCM........................... C-90-8F 1471 9/6/97 42838-1-8 TCM........................... C-90-12 1279 10/7/96 44747-6-12 TCM........................... E-185-4 1124 1/16/96 25700D-1-9 TCM........................... E-225-8 1505 10/28/97 35477-D-9-8-P TCM........................... GTSIO-520 1208 5/7/96 210114-70H TCM........................... IO-360-C 1126 12/28/95 F-51439-9-C TCM........................... IO-470 1028 3/23/95 87329-R TCM........................... IO-470-N 1421 5/13/97 95271-1-N TCM........................... IO-470-S 1331 3/11/97 102412-2-S-I TCM........................... IO-520 1174 3/4/96 TCM........................... IO-520-D 1167 2/22/96 TCM........................... O-200 1033 4/18/95 TCM........................... O-200 1043 5/12/95 TCM........................... O-200 1049 6/2/95 TCM........................... O-200 1076 9/11/95 214668-27A TCM........................... O-200 1104 11/21/95 213830-71A TCM........................... O-200 1131 1/5/96 TCM........................... O-200 1142 1/18/96 265349-R TCM........................... O-200 1147 1/23/96 TCM........................... O-200 1190 4/13/96 TCM........................... O-200 1193 4/13/96 TCM........................... O-200 1195 4/13/96 TCM........................... O-200 1197 4/17/96 TCM........................... O-200 1213 5/13/96 TCM........................... O-200 1261 9/9/96 TCM........................... O-200 1303 12/5/96 TCM........................... O-200 1321 2/7/97 28115 TCM........................... O-200 1324 2/6/97 TCM........................... O-200 1344 3/2/97 TCM........................... O-200 1393 5/5/97 TCM........................... O-200 1413 5/7/97 61001-5-4 TCM........................... O-200 1430 5/23/97

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TCM........................... O-200 1437 6/17/97 255759A-48 TCM........................... O-200 1488 9/7/97 TCM........................... O-200 1506 11/18/97 TCM........................... O-200 1522 11/11/97 TCM........................... O-200-A 1052 6/21/95 254150-A-48 TCM........................... O-200-A 1085 9/29/95 TCM........................... O-200-A 1120 12/29/95 253971 TCM........................... O-200-A 1161 2/9/96 24R-469 TCM........................... O-200-A 1215 5/15/96 TCM........................... O-200-A 1240 8/5/96 69589-8-A TCM........................... O-200-A 1254 9/3/96 6105-71-A-R TCM........................... O-200-A 1264 9/12/96 TCM........................... O-200-A 1356 3/10/97 ...................... TCM........................... O-300 1027 3/20/95 ...................... TCM........................... O-300 1042 5/12/95 34012-D-6-D TCM........................... O-300 1083 9/26/95 ...................... TCM........................... O-300 1096 10/23/95 464481 TCM........................... O-300 1137 1/17/96 ...................... TCM........................... O-300 1259 9/4/96 ...................... TCM........................... O-300 1387 4/22/97 ...................... TCM........................... O-300 1397 4/26/97 5928-9A TCM........................... O-300 1403 4/28/97 ...................... TCM........................... O-300 1423 6/9/97 3834D8Z TCM........................... O-300 1555 1/13/98 ...................... TCM........................... O-300-A 1446 6/27/97 ...................... TCM........................... O-300-D 1022 3/17/95 35110-D-6-D TCM........................... O-300-D 1079 9/17/95 24276-D-0-D TCM........................... O-300-D 1487 9/6/97 ...................... TCM........................... O-300-D 1543 12/3/97 ...................... TCM........................... O-470 1046 6/1/95 ...................... TCM........................... O-470 1383 4/4/97 ...................... TCM........................... O-470-11 1017 2/22/95 ...................... TCM........................... O-470-11 1491 10/19/97 ...................... TCM........................... O-470-11 1492 10/19/97 ...................... TCM........................... O-470-11 1493 10/19/97 ...................... TCM........................... O-470-11 1494 10/19/97 ...................... TCM........................... O-470-F 1236 7/25/96 76956-4-F TCM........................... O-470-K 1087 10/3/95 47172-6-K TCM........................... O-470-L 1128 1/10/96 68681-8-L TCM........................... O-470-L 1359 5/19/97 68245-8-L TCM........................... O-470-L 1399 4/28/97 ...................... TCM........................... O-470-R 1016 2/10/95 133087-6-R TCM........................... O-470-R 1086 10/3/95 ...................... TCM........................... O-470-R 1165 2/22/96 ...................... TCM........................... O-470-R 1178 3/10/96 ...................... TCM........................... O-470-R 1201 6/2/96 83164-1-R TCM........................... O-470-R 1319 1/6/97 459408 TCM........................... TSIO-520-VB 1055 6/9/95 ...................... ----------------------------------------------------------------------------------------------------------------

Note 1: Blank spaces indicate unknown data. Where the engine serial no. is blank in this table, it is either unknown or the crankshaft may not be installed in an engine. Note 2: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously. To prevent crankshaft failure due to cracking, which could result in an inflight engine failure and possible forced landing, accomplish the following: (a) Within 10 hours time in service after the effective date of this AD, determine if this AD applies, as follows: (1) Determine if any repair was conducted on the engine that required crankshaft removal during the February 1, 1995, to December 31, 1997, time frame; if the engine was not disassembled for crankshaft removal and repair in this time frame, no further action is required. (2) If the engine and crankshaft was repaired during this time frame, determine from the maintenance records (engine log book), and Table 1 of this AD if the crankshaft was repaired by Nelson Balancing Service, Repair Station Certificate No. NB7R820J, Bedford, Massachusetts. The maintenance records should contain the Return to Service (Yellow) tag for the crankshaft that will identify the company performing the repair. Also the work order number contained in Table 1 of this AD was etched on the crankshaft propeller flange, adjacent to the closest connecting rod journal. Because some etched numbers will be difficult to see, if necessary, use a 10X magnifying glass with an appropriate light source to view the work order number. In addition, the propeller spinner, if installed, will have to be removed in order to see this. (3) A person with a private pilot or higher rated certificate may make the determination of applicability of this AD provided the

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propeller spinner does not have to be removed. (4) If it cannot be determined who repaired the crankshaft, compliance with this AD is required. (b) Within 10 hours time in service after the effective date of this AD, accomplish the following: (1) Perform a visual inspection as defined in paragraph (b)(2) of this AD, magnetic particle inspection, and a dimensional check of the crankshaft journals, or remove from service affected crankshafts and replace with serviceable parts. (2) For the purpose of this AD, a visual inspection of the crankshaft is defined as the inspection of all surfaces of the crankshaft for cracks which include heat check cracking of the nitrided bearing surfaces, cracking in the main or aft fillet of the main bearing journal and crankpin journal, including checking the bearing surfaces for scoring, galling, corrosion, or pitting.

Note 3: Further guidance on all inspection and acceptance criteria is contained in applicable TCM or LYC Overhaul or Maintenance Manuals, or other FAA-approved data.

(3) Replace any crankshaft that fails the visual inspection, magnetic particle inspection, or the dimensional check with a serviceable crankshaft, unless the crankshaft can be reworked to bring it in compliance with: (i) All the overhaul requirements of the appropriate TCM or LYC Overhaul/Maintenance Manuals; or (ii) All of the FAA-approved requirements for any repair station which currently has approval for limits other than those in the appropriate TCM or LYC Overhaul/Maintenance Manuals. (4) For the purpose of this AD, a serviceable crankshaft is one which meets the requirements of paragraph (b)(3)(i) or (b)(3)(ii) of this AD.

Note 4: Crankshafts removed from TCM engine models IO-360, IO- 520, and TSIO-520 series engines are also subject to compliance with AD 97-26-17.

(c) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, New York (LYC) or Atlanta (TCM) Aircraft Certification Offices. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, New York or Atlanta Aircraft Certification Offices.

Note 5: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Atlanta Aircraft Certification or New York Aircraft Certification Office, as applicable.

(d) Special flight permits may be issued in accordance with Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.

Issued in Burlington, Massachusetts, on May 1, 1998. Thomas A. Boudreau, Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service. [FR Doc. 98-12353 Filed 5-8-98; 8:45 am] BILLING CODE 4910-13-U