Results
99-14-05: This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 777-200 series airplanes, that requires inspections to verify correct installation of certain fasteners located on the trailing edges of the horizontal and vertical stabilizer; replacement of the existing fasteners with new fasteners installed with wet sealant; and follow-on actions, if necessary. This amendment is prompted by reports indicating that, during manufacture of the horizontal and vertical stabilizers, certain fasteners attaching the aluminum ribs and brackets to the trailing edges on the empennage were not correctly installed with wet sealant. The actions specified by this AD are intended to prevent corrosion and possible cracking of those aluminum parts, which could result in loss of the attachment of the elevator and rudder to the empennage and consequent reduced controllability of the airplane.
82-08-01: 82-08-01 DOWTY ROTOL: Amendment 39-4356. Applies to Dowty Rotol Propellers (c)R.209/4-40.5/2, installed on Nihon YS-11 airplanes; (c)R.245/4-40.5/13, installed on Convair Models 600(240D) and 640(340D); and (c)R.259/4-40-4.5/17, installed on Convair Model 640(440D) airplanes, not modified by Dowty Rotol Modification (c)VP2693 in accordance with Dowty Rotol SB No. 61-728, Revision 3, dated July 17, 1981. Compliance required as indicated unless already accomplished. To detect and prevent loosening of the propeller blade groups, accomplish the following: (a) Unless already accomplished, within the next 50 hours' time in service after the effective date of this AD, and thereafter at intervals not to exceed 300 hours' time in service from the last inspection, inspect the locking of the blade groups in the hub group, in accordance with Dowty Rotol Service Bulletin 61-581, Revision 3, dated July 17, 1981, or an FAA-approved equivalent. (b) If, during the inspections required by paragraph (a), it is found that the red line position markings across the bearing center race and the hub have separated by more than 0.100 of an inch, before further flight, replace the propeller with a serviceable propeller of the same model number. (c) If, during the inspections required by paragraph (a), it is found that the lockpieces on the rear of the cylinder are damaged or they are not engaging with and locking the serrations of the bearing center race of the blade group; or that the set bolts securing the lockpieces are not secure or they are bent; or that the shims under the distance blocks on which the lockpieces are mounted have extruded, before further flight, replace the defective parts with serviceable parts of the same part number. This AD supersedes AD 67-32-02. This amendment becomes effective April 12, 1982.
2022-14-09: The FAA is adopting a new airworthiness directive (AD) for certain Saab AB, Support and Services Model 340A (SAAB/SF340A) and SAAB 340B airplanes. This AD was prompted by a report that there is no evidence that post-machining stress relief or de-embrittlement post- cadmium plating treatments were performed on certain torque arm center pins. This AD requires replacing each affected torque arm center pin on the main landing gear (MLG), as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. This AD also prohibits the installation of affected parts. The FAA is issuing this AD to address the unsafe condition on these products.
2013-23-09: We are adopting a new airworthiness directive (AD) for Eurocopter France (Eurocopter) Model AS350B, AS350BA, AS350B1, AS350B2, AS350B3, AS350C, AS350D, AS350D1, AS355E, AS355F, AS355F1, AS355F2, AS355N, and AS355NP helicopters with sliding doors, except those with modification AL.4262. This AD requires removing from service certain part-numbered nuts and washers from the lower ball-joint bolt. This AD was prompted by a report of a sliding door detaching from the helicopter in flight. These actions are intended to prevent loss of the lower ball-joint nut, which could lead to loss of the sliding door and damage to the helicopter.
59-22-01: 59-22-01 PIAGGIO: Applies to All Model P.136-L2 Aircraft. Compliance required by November 30, 1959. In order to preclude the possibility of condensed water vapor from freezing and obstructing the oil tank breather lines, these lines for both the right and left engines should be rerouted to provide an increased slope in accordance with Piaggio & Co. Change Order No. 36- 52 which covers this same subject.
2013-23-02: We are adopting a new airworthiness directive (AD) for all EADS CASA (Type Certificate previously held by Construcciones Aeronauticas, S.A.) Model CN-235, CN-235-100, CN-235-200, CN-235-300, and C-295 airplanes. This AD requires inspection of the feeder cables of certain fuel booster pumps for damage (including, but not limited to, signs of electrical arcing and fuel leaks), and replacement if necessary. This AD was prompted by a report of an in-flight problem with the fuel transfer system. We are issuing this AD to detect and correct damage to certain fuel booster pumps, which could create an ignition source in the fuel tank vapor space, and result in a fuel tank explosion and consequent loss of the airplane.
99-14-01: This amendment supersedes Airworthiness Directive (AD) 98-04-27, which currently requires incorporating certain icing information into the FAA-approved airplane flight manual (AFM) of The New Piper Aircraft, Inc. (Piper) PA-23, PA-30, PA-31, PA-34, PA-39, PA-40, and PA-42 series airplanes. The Federal Aviation Administration (FAA) inadvertently omitted Piper Models PA-31P, PA-31T, PA-31T1, PA-31T2, and PA-31P-350 airplanes from the Applicability section of AD 98-04-27. This AD retains the requirement of incorporating the icing information into the AFM for all airplanes affected by AD 98-04-27, and adds Piper Models PA-31P, PA-31T, PA-31T1, PA-31T2, and PA-31P-350 airplanes to the Applicability section of the AD. The actions specified by this AD are intended to minimize the potential hazards associated with operating these airplanes in severe icing conditions by providing more clearly defined procedures and limitations associated with such conditions.
99-14-02: This amendment adopts a new airworthiness directive (AD) that applies to certain LET Aeronautical Works (LET) Model L33 SOLO sailplanes. This AD requires replacing the main wing attachment and wing spar root pins and modifying the corresponding area. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the Czech Republic. The actions specified by this AD are intended to prevent structural failure of the wing attachments caused by the current design configuration, which could result in the wing separating from the sailplane with consequent loss of control.
2013-22-23: We are adopting a new airworthiness directive (AD) for Aermacchi S.p.A. Models F.260, F.260B, F.260C, F.260D, F.260E, F.260F, S.208, and S.208A airplanes equipped with a Lycoming O-540 wide cylinder flange engine with a front crankcase mounted propeller governor. This AD results from mandatory continuing airworthiness information (MCAI) issued by the aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as the set screw that fixes the setting of the propeller governor idler gear shaft was not in the proper position. We are issuing this AD to require actions to address the unsafe condition on these products. [[Page 68358]]
2010-15-02: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Several cases of corrosion and damage on the Down Drive Shafts (DDS), between the Down Drive Gear Box (DDGB) and the Input Gear Box (IPGB), on all 10 Flap Tracks (5 per wing), have been reported by AIRBUS Long Range Operators. Investigations have revealed that corrosion and wear due to absence of grease in the spline interfaces could cause [DDS] disconnection which could result in a free movable flap surface, potentially leading to aircraft asymmetry or even flap detachment. * * * * * The unsafe condition could reduce the ability of the flightcrew to maintain the safe flight and landing of the airplane. We are issuing this AD to require actionsto correct the unsafe condition on these products.
99-14-03: This amendment supersedes Airworthiness Directive (AD) 98-13-08, which currently requires replacing and re-routing the power return cables on the starter generator and the generator 2 on certain Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. AD 98-13-08 also requires inserting a temporary revision to the pilot operating handbook (POH), and installing a placard near the standby magnetic compass. This AD retains the actions currently required by AD 98-13-08 on all airplanes affected by that AD, and requires replacing the temporary revision to the POH and the placard near the standby magnetic compass with an improved procedural POH revision and placard. This AD also requires the placard and the temporary revision to the POH for additional manufacturer serial number Models PC-12 and PC-12/45 airplanes; and requires accomplishing improved Standby Magnetic Compass Swing procedures and incorporating a temporary revision to the maintenance manual on all of theaffected airplanes. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Switzerland. The actions specified by this AD are intended to prevent directional deviation on the standby magnetic compass caused by modifications made to the airplane since manufacture, which could result in flight-path deviation during critical phases of flight. The incorporation by reference of Pilatus PC-12 Maintenance Manual Temporary Revision No. 34-03, dated July 16, 1998, as specified in Pilatus Service Bulletin No. 34-006, dated September 3, 1998, as listed in the regulations is approved by the Director of the Federal Register as of August 17, 1999. The incorporation by reference of Pilatus PC XII Service Bulletin No. 24-002, Rev. No. 1, dated September 20, 1996, as listed in the regulations was previously approved by the Director of Federal Register as of July 31, 1998 (63 FR 32975, July 17, 1998).
99-13-11: This amendment adopts a new airworthiness directive (AD), applicable to Robinson Model R44 helicopters, that requires installing a shutoff clamp on the auxiliary fuel tank sump drain tube (drain tube) and a placard decal to alert operators as to the proper use of the auxiliary fuel tank drain. This amendment is prompted by a report of fuel leaking from a drain tube opening in the area of the horizontal and vertical firewalls. The actions specified by this AD are intended to prevent fuel leaks from the drain tube that could cause a fire and subsequent loss of control of the helicopter.
2013-19-14: We are superseding Airworthiness Directives (ADs) 2009-04-07 and 2011-02-09 for certain [[Page 68348]] Airbus Model A330-200, A330-200 Freighter, A300-300, A340-200, A340- 300, A340-500, and A340-600 series airplanes. AD 2009-04-07 required revising the airplane flight manual (AFM) to include appropriate operational procedures to prevent the air data inertial reference unit (ADIRU) from providing erroneous data to other airplane systems. AD 2011-02-09 required revising the AFM to provide appropriate operational procedures to prevent the airplane flight directors (FDs), autopilot (AP), and auto-thrust re-engagement in the event of airspeed sources providing similar but erroneous data. This new AD requires that operators modify or replace all three flight control primary computers (FCPCs) with new software standards. Since we issued ADs 2009-04-07 and 2011-02-09, we have determined that new software standards for the FCPCs are necessary to inhibit autopilot re-engagementunder unreliable airspeed conditions. This new AD also removes certain airplanes from the applicability. We are issuing this AD to prevent autopilot engagement under unreliable airspeed conditions, which could result in reduced controllability of the airplane.
99-13-08: This amendment supersedes an existing airworthiness directive (AD), applicable to all Lockheed Model L-1011-385 series airplanes, that currently requires inspections to detect cracking and other discrepancies of certain web-to-cap fasteners of the rear spar between inner wing stations 310 and 343, and of the web area around those fasteners; and various follow-on actions. That AD also provides for an optional modification, which, if accomplished, would defer the initiation of the inspections for a certain period of time. This amendment requires accomplishment of the previously optional modification. This amendment is prompted by an FAA determination that the optional terminating modification specified in the existing AD must be accomplished within a specified period of time to ensure an acceptable level of safety of the affected fleet. The actions specified by this AD are intended to prevent fatigue cracking in the web of the rear spar of the wing, which could result in failure of the rear spar of the wing and consequent fuel spillage.
2013-22-10: We are adopting a new airworthiness directive (AD) for all Dassault Aviation Model Fan Jet Falcon; Model Mystere-Falcon 200 airplanes; and Model Mystere-Falcon 20-C5, 20-D5, 20-E5, and 20-F5 airplanes. This AD was prompted by reports of defective fire extinguisher bottle cartridges. This AD requires checking manufacturing references of pyrotechnical cartridges for batch number and date, repetitive checking of cartridges for electrical continuity, and replacing defective pyrotechnical cartridges if necessary. We are issuing this AD to detect and correct defective fire bottle cartridges, which could impact the capability to extinguish a fire in an engine, auxiliary power unit, or rear compartment, which could result in damage to the airplane and injury to the occupants.
99-13-07: This amendment adopts a new airworthiness directive (AD); applicable to certain McDonnell Douglas Model DC-9-80 series airplanes, Model MD-88 airplanes, and Model MD-90-30 airplanes; that requires repetitive inspections to detect cracking of the main landing gear (MLG) shock strut pistons, and replacement of a cracked piston with a new or serviceable part. This amendment is prompted by reports indicating that, while an airplane was positioned on the taxiway, the right MLG shock strut piston failed due to fatigue cracking. The actions specified by this AD are intended to detect and correct such fatigue cracking, which could result in failure of the piston, and consequent damage to the airplane structure or injury to the passengers and flightcrew.
92-07-01: 92-07-01 SAAB-SCANIA: Amendment 39-8197. Docket No. 91-NM-53-AD. Applicability: Model SF-340 series airplanes, Serial Numbers 003 through 138, certificated in any category. Compliance: Required within one year after the effective date of this AD, unless previously accomplished. To prevent unexpected loss of nose wheel steering and brakes during taxi, accomplish the following: (a) Remove main/emergency dual pressure indicator 3DB, Part Number (P/N) 522796 and install main/emergency dual pressure indicator 3DB, P/N 523250, in accordance with SAAB Service Bulletin SF340-29-004, Revision 1, dated November 9, 1990. (b) An 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, Standardization Branch, ANM- 113, FAA, Transport Airplane Directorate. NOTE: The request shall be forwarded through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Standardization Branch, ANM-113. (c) Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate the airplanes to a location where the requirements of this AD can be accomplished. (d) The installation shall be done in accordance with SAAB-Scania Service Bulletin SF340- 29-004, Revision 1, dated November 9, 1990, which includes the following list of effective pages: Page Number Revision Level Date 1, 2, 4, 5 1 November 9, 1990 3 (Original) September 15, 1988 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 SAAB-Scania AB, Product Support, S- 581.88, Linkoping, Sweden. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, DC. (e) Thisamendment becomes effective on April 28, 1992.
2013-22-12: We are adopting a new airworthiness directive (AD) for all DG Flugzeugbau GmbH Models DG-800A, DG-800B, DG-500MB gliders. This AD results from mandatory continuing airworthiness information (MCAI) issued by the aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as a defective starter motor control unit, which could activate the starter motor without pressing the starter button. We are issuing this AD to require actions to address the unsafe condition on these products. [[Page 67014]]
99-12-52: This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) T99-12-52 that was sent previously to all known U.S. owners and operators of all Boeing Model 727 series airplanes by individual telegrams. This AD requires a boost pump dry bay inspection to detect leakage of fuel through an arced-through conduit, and corrective action, as necessary. This AD also requires repetitive detailed visual inspections of the in-tank fuel boost pump wiring to detect chafing of the wire insulation, evidence of electrical arcing, or arc-through of the conduit wall on Model 727 series airplanes, and applicable corrective action; and installation of sleeving over the in- tank fuel boost pump wires as a method to protect the wiring from chafing. This action is prompted by reports of severe wear of in-tank fuel boost pump wiring, and arc-through of the surrounding conduit on two Model 727 series airplanes. The actions specified by this AD are intended toprevent fuel tank explosion resulting from arc-through of the fuel boost pump wiring conduits.
99-13-05: This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 777 series airplanes. This action requires repetitive inspections to detect cracking of the upper cutout and lower flange of the outboard support assembly of the flaperons on the wings; and corrective actions, if necessary. This amendment also provides an optional terminating action for the repetitive inspections. This amendment is prompted by results of flight testing conducted by the manufacturer indicating that high engine thrust conditions during takeoff cause excessive cyclic loads and could lead to fatigue cracking of the outboard support of the flaperon. The actions specified in this AD are intended to detect and correct such fatigue cracking, which could result in fracture of the flaperon support structure, loss of the flaperon, and consequent reduced controllability of the airplane.
2013-20-13: We are adopting a new airworthiness directive (AD) for certain Bell Model 206B and 206L helicopters. This AD requires installing a placard beneath the engine power dual tachometer and revising the operating limitations section of the rotorcraft flight manual (RFM). This AD was prompted by several incidents of third stage engine turbine wheel failures, which were caused by excessive vibrations at certain engine speeds during steady-state operations. These actions are intended to alert pilots to avoid certain engine speeds during steady- state operations, prevent failure of the third stage engine turbine, engine power loss, and subsequent loss of control of the helicopter.
99-13-02: This amendment supersedes an existing priority letter airworthiness directive (AD), applicable to Eurocopter France Model AS 332C, L, L1, and L2 helicopters, that currently requires conducting a filter clogging warning test, and, if necessary, replacing a jammed valve with an airworthy valve. This amendment requires the same corrective actions required by the existing AD; however, the applicability is reduced to encompass only certain part-numbered fuel filters. This amendment is prompted by jammed fuel filter by-pass valves and new information that justifies a reduction in the applicability of the superseded priority letter AD. The actions specified by this AD are intended to prevent engine power loss due to fuel starvation, which could cause one or both engines to flameout and a subsequent forced landing.
89-22-07: 89-22-07 PRATT & WHITNEY: Amendment 39-6344. Applicability: Pratt & Whitney (PW) JT3D-3B and JT3D-7 turbofan engines approved for return to service by Jet Power, Inc (JPI), FAA Repair Station No. 705-70, located at 4275 Northwest 77th Avenue, Miami, Florida, identified by serial number (S/N) as follows: 630197 631540 631996 632276 632282 632285 632339 632340 632346 632351 632408 632478 632481 632487 632749 632842 632846 632852 632962 632966 632968 632973 633040 633495 633541 633558 633564 633607 633609 633615 633669 633732 633742 633744 634616 642390 642490 642512 642901 642910 642914 643332 643471 642715 643803 643812 643899 643904 643973 644047 644071 644131 644200 644218 644306 644359 644667 644756 644953 644973 645017 645030 645051 645088 645128 645145 645177 645214 645294 645370 645401 645407 645570 645675 645753 645769 645785 645854 645865 645913 645915 645977 645999 646001 667054 667677 667736 667792 667879 667932 667979 668042 668103 668229 668312 668331 668373 668430 668557 668594 668603 668609 668658 668678 668827 668877 669156 669252 669324 669360 669375 669377 669411 669425 669484 669564 669583 669644 669690 669793 669797 669801 670744 671102 671133 671141 671233 671254 671340 671391 671425 675803 678988 678994 678999 688430 Compliance: Required within the next 30 calendar days after the effective date of this AD, unless already accomplished. To ensure the continuing structural integrity and certificated performance capabilities of JT3D-3B and JT3D-7 turbofan engines, accomplish the following: (a) Remove from service those engines identified above. (b) Engines removed from service in accordance with paragraph (a) above may be returned to revenue service by accomplishing either one of the two following requirements: (1) Accomplish the overhaul manual requirements on all parts, sub-assemblies, accessories, and components installed on the engine and, if any of the engines or components of the engines referred in paragraph (a) have been in an accident, accomplish the pertinent overhaul manual special check and inspection requirements. The engine overhaul and special inspection requirement must be accomplished in accordance with the requirements of Pratt & Whitney JT3D-3B Overhaul Manual, Part Number (P/N) 411568, Revision 78, dated December 15, 1988, or Pratt & Whitney JT3D-7 Overhaul Manual P/N 615105, Revision 50, dated December 15, 1988, as applicable. NOTE: The Light Overhaul Manual requirements, included in the above overhaul manuals, are not applicable in this case. (2) Submit to the FAA, Manager, Engine Certification Office, through the cognizant FAA Airworthiness Inspector, all the pertinent records identified below for review, and obtain a written FAA approval prior to returning an engine to service: (i) If the parts, sub-assemblies, accessories, or other components of an engine approved for return to service by JPI were subjected to overhaul or maintenance activities during the last shop visit at JPI, provide records establishing the origin and/or the prior service history of the subject parts. If the determination of the origin of such parts leads to other engines, the records for reason of removal from service, and if available, trend monitoring data for those engines must also be included. Provide records of accomplishment of the required inspections, checks, tests, as applicable in accordance with engine manual requirements that establish the components' airworthiness. (ii) A list of all life limited components by S/N, service history, and current status as required by FAR Part 121, Section 380, or FAR Part 91, Section 173, as appropriate. (iii) All repair or overhaul records, concerning the last shop visit at JPI, as required by FAR Part 121, Section 380, or FAR Part 91, Section 173, as appropriate. (iv) Substantiating evidence that the work performed during the last shop visit at JPI was done in accordance with FAA approved data as required by the FAR's. (v) Engine acceptance test data or engine "on-wing" test data, accomplish after repair or overhaul, whichever is applicable. (vi) Engine operation trend monitoring data, if available, for the current engine installation. (vii) A list by P/N or S/N of any engine, part, sub-assembly, accessory, or component acquired from JPI that has been known to have been involved in an accident. NOTE: If engine owners, operators, or cognizant Civil Aviation Authorities outside the United States wish to have the FAA's assistance in this effort, they may contact the FAA at the following address: Federal Aviation Administration, Engine and Propeller Directorate, Aircraft Certification Service, Attention: Manager, Engine Certification Office, ANE-140, 12 New England Executive Park, Burlington, Massachusetts 01803. Information collection requirements contained in the amendment to Section 39.13 have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (Pub. L. 96-511) and have been assigned OMB Control No. 2120-0056. (c) Aircraft may be ferried in accordance with the provisions of FAR 21.197 and 21.199 to a base where the AD can be accomplished. (d) Upon submission of substantiating data by an owner or operator through an FAA Airworthiness Inspector, an alternate method of compliance with the requirements of this AD or adjustments to the compliance times in this AD, may be approved by the Manager, Engine Certification Office, Engine and Propeller Directorate, Aircraft Certification Service, Federal Aviation Administration, 12 New England ExecutivePark, Burlington, Massachusetts 01803. The engine overhaul and special inspection requirements shall be done in accordance with PW JT3D-3B Overhaul Manual P/N 411568, Revision 78, dated December 15, 1988, or JT3D-7 Overhaul Manual P/N 615105, Revision 50, dated December 15, 1988, as applicable. The sections of these manuals pertinent to Light Overhaul are not applicable. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to Pratt & Whitney, Publications Department, P.O. Box 611, Middletown, Connecticut 06457. Copies may be inspected at the Regional Rules Docket, Office of the Assistant Chief Counsel, Federal Aviation Administration, New England Region, 12 New England Executive Park, Room 311, Burlington, Massachusetts 01803. This amendment (39-6344, AD 89-22-07) becomes effective on October 31, 1989.
99-12-08: This amendment supersedes an existing airworthiness directive (AD), applicable to all Boeing Model 737-200C series airplanes, that currently requires a one-time external detailed visual inspection to detect cracks of the fuselage skin in the lower lobe cargo compartment; repetitive internal detailed visual inspections to detect cracks of the frames in the lower lobe cargo compartment; and repair of cracked parts. That AD also provides for an optional preventative modification that constitutes terminating action for the repetitive inspections. This amendment requires accomplishment of the previously optional terminating modification. This amendment is prompted by reports of cracking in the body frames between stringers 19 left and 25 left and at body stations 360 to 500B. The actions specified by this AD are intended to prevent opening or loss of the cargo door during flight, and consequent rapid decompression of the airplane.
83-07-12 R1: 83-07-12 R1 PILATUS BRITTEN-NORMAN LTD.: Amendment 39-4615. Applies to BN-2, BN2A, and BN-2B Islander Series equipped with wing tip fuel tanks and BN-2A MK. III Trislander Series (all Serial Numbers) airplanes certificated in any category. Compliance: Required as indicated, unless already accomplished. To detect erosion of the wing tip tank fuel transmitter floats, which could restrict fuel flow and result in the loss of power, accomplish the following: a) Within the next 100 hours time-in-service after the effective date of this Airworthiness Directive (AD) and thereafter at intervals not to exceed 100 hours time-in-service: 1) Remove and visually inspect the wing tip tank fuel transmitter floats for evidence of cracking, fretting, or erosion in accordance with the instructions provided in the "Inspection and Rectification" section of Pilatus Britten-Norman Service Bulletin (SB) No. BN- 2/SB.154, Issue 1, dated February 12, 1982, (hereinafter referred to as the SB) or an FAA approved equivalent. 2) If any fuel transmitter float is found with cracks, fretting, or erosion during the accomplishment of the visual inspection in accordance with paragraph a)1) of this AD, prior to further flight, replace the float with a serviceable unit of the same part number and continue the repetitive visual inspections in accordance with paragraph a)1) of this AD. 3) If any fuel transmitter float is found with excessive erosion during accomplishment of the visual inspection in accordance with paragraph a)1) of this AD, prior to further flight, drain the affected tank and clean the filters, including also the fuel supply system, through the auxiliary pumps, to the engine together with all fuel filters enroute. 4) Reinstall wing tip tank fuel transmitters in accordance with instructions provided in the "Inspection and Rectification" section of the SB. b) The intervals between repetitive inspections required by this AD may be adjustedup to 10 percent of the specified inspection intervals to allow them to be accomplished concurrent with other scheduled maintenance on these airplanes. c) Aircraft may be flown in accordance with FAR 21.197 to a location where this Airworthiness Directive (AD) can be accomplished. d) An equivalent method of compliance with this AD, if used, must be approved by the Manager, Aircraft Certification Staff, AEU-100, Europe, Africa and Middle East Office, FAA, c/o American Embassy, 1000 Brussels, Belgium. This amendment becomes effective on April 11, 1983.