# AD 98-18-12: Fuel Pump - Type: Airworthiness directive - Status: Historical - Products: Textron Lycoming, AVCO AEIO-540-D4A5, AEIO-540-D4B5, AEIO-540-D4C5, AEIO-540-L1B5, AEIO-540-L1B5D, GO-435, GO-435-C2, GO-435-C2A, GO-435-C2A2, GO-435-C2B, GO-435-C2B1, GO-435-C2B2 and 240 more - Effective: September 28, 1998 - Published: September 11, 1998, 63 FR 48571–48573 - Issued as: Final rule; request for comments - Superseded by: [AD 2003-14-03](https://openairdocs.org/ad/2003-14-03) - Product type: Engine - Amendment: 39-10728 - Docket: 97-ANE-50-AD - Registered aircraft: 26,673 may be affected, by airframe or engine model (OpenAirDocs) - Official PDF: https://openairdocs.org/files/sha256/34/0b/340bde8238bbc7b9feb4eba31380b1f296f163d44743d56477b2451b511b3dc2 (from https://www.govinfo.gov/content/pkg/FR-1998-09-11/pdf/98-24184.pdf) - Federal Register: https://www.federalregister.gov/documents/1998/09/11/98-24184/airworthiness-directives-textron-lycoming-fuel-injected-reciprocating-engines - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/9AA16D7A981FE9B28625684D006873C1.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/98-18-12 ## Summary This amendment adopts a new airworthiness directive (AD) that is applicable to certain Textron Lycoming fuel injected reciprocating engines with certain Crane/Lear Romec "AN" rotary fuel pumps installed. This action requires initial and repetitive torque check inspections of pump relief valve attaching screws. In addition, if the torque remains within acceptable values after two inspections, the repetitive torque check inspections may be terminated. This amendment is prompted by reports of inflight engine fires caused by leaking rotary fuel pumps. The actions specified in this AD are intended to prevent rotary fuel pump leaks, which could result in an engine failure, engine fire, and damage to or loss of the aircraft. ## The airworthiness directive 98-18-12 Textron Lycoming: Amendment 39-10728. Docket 97-ANE-50-AD. Applicability: Textron Lycoming IO-320, LIO-320, IO-360, HIO-360, TIO-360, LTIO-360, GO-435, GO-480, IGO-480-A1B6, IO-540, IGO-540, AEIO-540, HIO-540, TIO-540, LTIO-540, TIGO-541, IO-720, and TIO-720 fuel injected reciprocating engines, with Crane/Lear Romec "AN" rotary fuel pump model series, RG9080, RG9570, and RG17980 installed. These engines are installed on but not limited to fuel injected, reciprocating engine powered aircraft manufactured by Cessna, The New Piper, Inc., Mooney, Raytheon (Beech), Bellanca, Champion, Partenavia, Rockwell, Schweizer, Enstrom, Aerospatiale (SOCATA), Maule, Aero Commander, Helio, Hiller, and Pacific Aerospace Corp. Note 1: 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 (b) 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 rotary fuel pump leaks, which could result in an engine failure, engine fire, and damage to or loss of the aircraft, accomplish the following: (a) Perform initial and repetitive torque check inspections of pump relief valve attaching screws in accordance with the Accomplishment Instructions of Textron Lycoming Service Bulletin (SB) No. 529, dated December 1, 1997, as follows: (1) Within 10 hours time in service(TIS), or 30 days after the effective date of this AD, whichever occurs first, perform the initial torque check inspection. If the torque does not meet the specifications in Textron Lycoming SB No. 529, dated December 1, 1997, tighten screws to the required torque in accordance with that SB. (2) Perform a follow-up torque check inspection after accumulating 50 hours TIS, or 6 months since the initial torque check inspection, whichever occurs first. If the torque does not meet the specification in Textron Lycoming SB No. 529, dated December 1, 1997, during this follow-up inspection, tighten screws to the required torque in accordance with that SB. (3) Continue the repetitive torque check inspections required by paragraph (a)(2) of this AD until: (i) The accumulation of 100 hours TIS since the initial inspection with the torque remaining within the SB specification for 50 hours TIS; or (ii) The torque meets the SB specification during the initial inspection and a subsequent inspection taking place at least 50 hours TIS later. (b) 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 Aircraft Certification Office. 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 Aircraft Certification Office. Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the New York Aircraft Certification Office. (c) Special flight permits may be issued in accordance with sections 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. (d) The actions required by this AD shall be done in accordance with the following Textron Lycoming SB: Document No. Pages Date 529 1-6 December 1, 1997 Total Pages: 6. 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 Textron Lycoming, 652 Oliver St., Williamsport, PA 17701; telephone (717) 327-7080, fax (717) 327-7100. Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (e) This amendment becomes effective on September 28, 1998. 3rd Floor, Valley Stream, NY 11581-1200; telephone (516) 256-7505, fax (516) 568-2716. ## Rule preamble ### Supplementary information The Federal Aviation Administration (FAA) has received reports of three engine fires and six other fuel leakage events on certain Textron Lycoming fuel injected reciprocating engines with Crane/Lear Romec "AN" rotary fuel pumps, model series RG9080, RG9570, and RG17980, installed. The investigations revealed that the rotary fuel pumps were leaking past the fuel pump relief valve gasket. The fuel pump valve cover screws had become loose, possibly due to gasket compression set (permanent deformation) or screw yield. If the torque loosens due to gasket compression set, once the torque is reset, it may not loosen again. Therefore, this AD allows for termination of repetitive torque checks if the torque meets specifications during two follow-up checks after being reset. This condition, if not corrected, could result in rotary fuel pump leaks, which could result in an engine failure, engine fire, and damage to or loss of the aircraft. The FAA has reviewedand approved the technical contents of Textron Lycoming Service Bulletin (SB) No. 529, dated December 1, 1997, that describes procedures for torque check inspections of pump relief valve attaching screws. Since an unsafe condition has been identified that is likely to exist or develop on other engines of the same type design, this AD is being issued to prevent rotary fuel pump leaks. This AD requires initial and repetitive torque check inspections of pump relief valve attaching screws. In addition, if the torque remains within acceptable values after two inspections, the repetitive torque check inspections may be terminated. The manufacturer is developing a modification to the rotary fuel pump with a more resilient gasket material that does not exhibit these permanent set characteristics, so future rulemaking may be forthcoming requiring this modification as a terminating action to the repetitive inspections required if the torque does not remain within the values stated by the SB. The actions are required to be accomplished in accordance with the SB described previously. Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. Comments Invited Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of thecomments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD 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 97-ANE-50-AD." The postcard will be date stamped and returned to the commenter. The regulations adopted herein will 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 final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 R 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends 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. 39.13 [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: ## Affected data sheets (10) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS 1E4](https://openairdocs.org/tcds/1E4): Lycoming Engines; names 72 of 81 models: IO-540-L1A5D, IO-540-L1C5, IO-540-M2A5D, AEIO-540-L1B5, IO-540-A1A5, IO-540-AA1B5, IO-540-B1C5, IO-540-K1J5D… - [TCDS 1E10](https://openairdocs.org/tcds/1E10): Lycoming Engines; names 53 of 89 models: IO-360-C1D6, HIO-360-B1B, IO-360-B2F6, HIO-360-C1B, HIO-360-E1BD, IO-360-K2A, IO-360-B1G6, IO-360-B2E… - [TCDS E14EA](https://openairdocs.org/tcds/E14EA): Lycoming Engines; names 38 of 40 models: TIO-540-G1A, LTIO-540-N2BD, TIO-540-A1A, TIO-540-AF1B, TIO-540-T2AD, TIO-540-A2A, TIO-540-C1A, TIO-540-V2AD… - [TCDS E-275](https://openairdocs.org/tcds/E-275): Lycoming Engines; names 32 of 33 models: GO-480-F3A6, IGO-480-A1B6, GO-480-C1B6, GO-480-G1J6, GO-480-C2C6, GO-480-F1A6, GO-480-G2F6, GO-480-B1C… - [TCDS 1E12](https://openairdocs.org/tcds/1E12): Lycoming Engines; names 17 of 32 models: IO-320-B1C, IO-320-F1A, LIO-320-B1A, IO-320-B1D, IO-320-E1B, IO-320-B2A, IO-320-E2B, IO-320-E1A… - [TCDS 1E15](https://openairdocs.org/tcds/1E15): Textron Lycoming Subsidiary of Textron Inc.; names 12 of 12 models: IO-720-B1A, IO-720-D1CD, IO-720-A1A, IO-720-B1B, IO-720-D1BD, IO-720-C1BD, IO-720-A1BD, IO-720-A1B… - [TCDS E-228](https://openairdocs.org/tcds/E-228): Lycoming Engines; names 11 of 20 models: GO-435-C2B1, GO-435-C2A, GO-435-C2E, GO-435-C2 (O-435-17), GO-435-C2B, GO-435-C2D, GO-435, GO-435-C2C… - [TCDS 1E11](https://openairdocs.org/tcds/1E11): Lycoming Engines; names 6 of 6 models: IGO-540-B1B, IGO-540-B1A, IGO-540-B1C, IGO-540-A1A, IGO-540-A1C, IGO-540-A1B - [TCDS E19EA](https://openairdocs.org/tcds/E19EA): Lycoming Engines; names 6 of 6 models: TIGO-541-C1A, TIGO-541-G1AD, TIGO-541-D1B, TIGO-541-E1A, TIGO-541-B1A, TIGO-541-D1A - [TCDS E16EA](https://openairdocs.org/tcds/E16EA): Lycoming Engines; names 4 of 4 models: TIO-360-A1B, TIO-360-A1A, TIO-360-C1A6D, TIO-360-A3B6 ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 26,673 (0 by airframe model, 26,673 by engine model) - Makers: Piper 10,248, Cessna 4,814, Mooney 2,194, Textron 1,174, Beech 587, Bellanca 459, Aviat 334, Rockwell International 323, Robinson Helicopter 304, Socata 275 Models with the most aircraft: - [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series): 6,174 aircraft (engine model) - [Lycoming TI0-540 series](https://openairdocs.org/engine/lycoming-ti0-540-series): 4,886 aircraft (engine model) - [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series): 4,219 aircraft (engine model) - [Lycoming IO-360-L2A](https://openairdocs.org/engine/lycoming-io-360-l2a): 2,644 aircraft (engine model) - [Lycoming IO-320 series](https://openairdocs.org/engine/lycoming-io-320-series): 1,707 aircraft (engine model) - [Lycoming IO-360-B4A](https://openairdocs.org/engine/lycoming-io-360-b4a): 985 aircraft (engine model) - [Lycoming IO-360-A1B6D](https://openairdocs.org/engine/lycoming-io-360-a1b6d): 844 aircraft (engine model) - [Lycoming TIO-540-AE2A](https://openairdocs.org/engine/lycoming-tio-540-ae2a): 488 aircraft (engine model) - [Lycoming AEIO-540 series](https://openairdocs.org/engine/lycoming-aeio-540-series): 433 aircraft (engine model) - [Lycoming HIO-360 series](https://openairdocs.org/engine/lycoming-hio-360-series): 336 aircraft (engine model) - [Lycoming GO-480 series](https://openairdocs.org/engine/lycoming-go-480-series): 246 aircraft (engine model) - [Lycoming IO-540-D4A5](https://openairdocs.org/engine/lycoming-io-540-d4a5): 237 aircraft (engine model) - [Lycoming IO-360 series](https://openairdocs.org/engine/lycoming-io-360-series): 217 aircraft (engine model) - [Lycoming IO-360-A1A](https://openairdocs.org/engine/lycoming-io-360-a1a): 196 aircraft (engine model) - [Lycoming IO-360-A1D6](https://openairdocs.org/engine/lycoming-io-360-a1d6): 192 aircraft (engine model) - [Lycoming TIO-540 series](https://openairdocs.org/engine/lycoming-tio-540-series): 190 aircraft (engine model) - [Lycoming IO-540-C4B5](https://openairdocs.org/engine/lycoming-io-540-c4b5): 179 aircraft (engine model) - [Lycoming IO-360-B1G6](https://openairdocs.org/engine/lycoming-io-360-b1g6): 177 aircraft (engine model) - [Lycoming I0-360-B1E](https://openairdocs.org/engine/lycoming-i0-360-b1e): 141 aircraft (engine model) - [Lycoming IO-360-A1B6](https://openairdocs.org/engine/lycoming-io-360-a1b6): 141 aircraft (engine model) All 166 models: https://openairdocs.org/ad/98-18-12/models.md Every aircraft: https://openairdocs.org/ad/98-18-12/aircraft.md ## Related documents - [AD 2003-14-03](https://openairdocs.org/ad/2003-14-03): Rotary fuel pumps · Lycoming Engines AEIO-540-D4A5, AEIO-540-D4B5, AEIO-540-D4C5 and 262 more. Effective Aug 14, 2003. Supersedes this AD No proposed rule in this release led to it. Its text cites no advisory circulars or STCs. ## NTSB investigations that cite this AD (3) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB LAX04FA001](https://openairdocs.org/ntsb/LAX04FA001), Oct 1, 2003: Piper PA-32R-301T (N481CA), Corona, CA, destroyed, 2 fatal. Probable cause: failure of the turbocharger exhaust clamp due to a pre-existing weld crack, which allowed the release of high temperature exhaust gasses in the engine compartment, causing an in-flight fire. - [NTSB LAX01FA207](https://openairdocs.org/ntsb/LAX01FA207), Jun 14, 2001: Piper PA-46-350P (N70SL), Stockton, CA, destroyed. Probable cause: a loss of engine power for undetermined reasons. Also causal was the inadequate supervision of the flight by the CFI for allowing a simulated emergency maneuver to continue below an altitude which… - [NTSB ATL00LA042](https://openairdocs.org/ntsb/ATL00LA042), Apr 19, 2000: Piper PA-31-350 (N41081), Rock Hill, SC, substantial damage. Probable cause: The maintenance personnel's failure to re-torque the engine driven fuel pump in accordance with an Airworthiness Directive that resulted in a fuel leak and a subsequent engine fire. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.