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73-26-07 R3: 73-26-07 R3 AIRESEARCH MANUFACTURING COMPANY OF ARIZONA: Amendment 39-1761 as amended by Amendments 39-1778 and 39-2954 is further amended by Amendment 39-3850. Applies to Model TPE331-1, -2, -3, -5, -6, -25, -29, -43, -45, -47, -51, -55, -57, -61, and TSE331-3 Series Engines. Compliance required as indicated. To detect abnormal wear of the fuel pump shaft internal drive splines and coupling shaft external splines, accomplish the following: (a) Model TPE331-3, -5, -6, and TSE331-3 Series engines which contain the grease lubricated fuel pump drive coupling spline configuration. (1) Clean, visually inspect, and lubricate the pump and coupling shaft drive splines of all engines with more than 200 hours time in service, within the next 25 hours additional time in service, unless previously accomplished within the last 375 hours time in service, and at intervals not to exceed 400 hours time in service thereafter, per the instructions and procedures described in AiResearch Service Bulletin TPE331-72-0027, Revision 4, dated November 30, 1973, or later FAA-approved revisions. If the extent of the wear is observed to exceed .003 inch, either replace the shaft with a new P/N 869911-3, or perform the additional dimensional inspection described in the Service Bulletin. If the latter inspection indicates wear beyond .005 inch, the shaft must be replaced prior to further flight. (Note: Drive Couplings, P/N 869911-1 or -2 and 895216-1, found in a serviceable condition, may be continued in service.) (2) For engines with less than 200 hours time in service since new or overhaul, clean, visually inspect and lubricate the engine by the procedures described in (a)(1) above, within 25 hours time in service after the effective date of this AD, or, prior to exceeding 200 hours time in service, whichever occurs later, and at intervals not to exceed 400 hours time in service thereafter. Replace shafts as required by the inspections. (b) Model TPE331-1, -2, -25, -29, -43, -45, -47, -51, -55, -57 and -61 Series engines which contain the grease lubricated fuel pump drive coupling spline configuration. (1) Clean, visually inspect, and lubricate the pump and coupling shaft drive splines of all engines with more than 200 hours time in service, within the next 25 hours additional time in service, unless previously accomplished within the last 775 hours, and at intervals not to exceed 800 hours time in service thereafter, per the instructions and procedures described in AiResearch Service Bulletin TPE331-72-0027, Revision 4, dated November 30, 1973, or later FAA-approved revisions. If the extent of wear is observed to exceed .003 inch, either replace the shaft with a new P/N 869911-3, or perform the additional dimensional inspection described in the Service Bulletin. If the latter inspection indicates wear beyond .005 inch, the shaft must be replaced prior to further flight. (Note: Drive Couplings, P/N 869911-1 or -2 and 895216-1, found in a serviceable condition, may be continued in service.) (2) For engines with less than 200 hours time in service since new or overhaul, clean, visually inspect and lubricate the engine by the procedures described in (b)(1) above, within 25 hours time in service after the effective date of this AD, or, prior to exceeding 200 hours time in service, whichever occurs later, and at intervals not to exceed 800 hours time in service thereafter. Replace shafts as required by the inspections. (c) If either the fuel pump, oil pump, or couplings defined in (a)(1) or (b)(1) above are replaced for any reason, a serviceable Drive Coupling, P/N 869911-3, or later FAA approved designs must be installed. (d) The initial and recurring cleaning, visual inspection and lubrication of the fuel pump and coupling shaft drive splines described in paragraph (a) and (b) above may be discontinued after incorporation of improved fuel pump shaft alignment features described in AiResearchService Bulletin TPE/TSE331-73-0051 dated April 29, 1977; TPE331-73-0054 dated April 29, 1977; TPE331-73-0056 dated May 6, 1977; or TPE331-73-0091 dated October 11, 1979; or later FAA approved revisions (as appropriate for various engine models). (e) Equivalent procedures may be approved by the Chief, Aircraft Engineering Division, FAA Western Region, upon submission of adequate substantiating data. (f) Special flight permits may be issued per FAR's 21.197 and 21.199 to authorize operation of aircraft to a base where these inspections or modifications required by this AD may be performed. Amendment 39-1761 became effective January 28, 1974. Amendment 39-1778 became effective February 1, 1974. Amendment 39-2954 became effective July 11, 1977. This Amendment 39-3850 becomes effective July 31, 1980.
2014-26-53: We are adopting a new airworthiness directive (AD) for certain Airbus Model A319-115, A319-133, A320-214, A320-232, and A320-233 airplanes. This emergency AD was sent previously to all known U.S. owners and operators of these airplanes. This AD requires repetitive detailed visual inspections to detect discrepancies of the wing lower skin surface and inboard main landing gear (MLG) support rib lower flange location fasteners and, depending on findings, accomplishment of applicable corrective action(s). This AD was prompted by reports of failure of certain fasteners located at the wing lower skin surface and inboard MLG support rib lower flange. We are issuing this AD to detect and correct discrepancies of the fasteners at the external surface of the lower wing skin and inboard MLG support rib lower flange, which could result in an airplane not meeting its maximum loads expected in service. This condition could result in structural failure.
2015-01-01: We are superseding Airworthiness Directive (AD) 2011-09-11, for certain The Boeing Company Model 777-200 and -300 series airplanes. AD 2011-09-11 required repetitive inspections for hydraulic fluid contamination of the interior of the strut disconnect assembly; repetitive inspections for discrepancies of the interior of the strut disconnect assembly, if necessary; repetitive inspections of the exterior of the strut disconnect assembly for cracks, if necessary; corrective action if necessary; and an optional terminating action for the inspections. This new AD adds, for certain airplanes, an inspection of the side and top cover plates to determine if all cover plate attach fasteners have been installed, and installing any missing fasteners including doing an inspection for damage, and repair if necessary. This AD was prompted by reports of side and top cover plates installed with missing fastener bolts, which results in an unsealed opening on the system disconnect assembly. We are issuing this AD to detect and correct hydraulic fluid contamination, which can cause cracking of titanium parts in the system disconnect assembly; and also to detect and correct missing fasteners, which results in unsealed openings on the system disconnect assembly. Both unsafe conditions can compromise the engine firewall and result in fire hazards for both the engine compartment and the strut.
74-16-03: 74-16-03 BEECH: Amendment 39-1907. Applies to 99 series airplanes (Serial Numbers U-1 through U-151) and 100 and A100 series (Serial Numbers B-1 through B-177) airplanes. \n\n\tCompliance: Required as indicated unless already accomplished. \n\n\tTo prevent restricted elevator travel, within the next 100 hours' time in service after the effective date of this AD, accomplish the following: \n\n\tA)\tIn accordance with the attached sketch and Part II of Beech Service Instruction 0618-152 or subsequent revisions, remove the elevator stop bolts and drill a .046 inch diameter hole in each bolt, or in the alternative, replace the bolts with NAS 428H4-7 bolts which have predrilled heads. Drill a .062 inch diameter hole in each stop bolt mount. Reinstall and safety the installation in accordance with said service instructions. \n\n\tB)\tAny equivalent method of compliance with this AD must be approved by Chief, Engineering and Manufacturing Branch, FAA, Central Region. \n\n\tNOTE: Beechcraft Service Instruction 0618-152 replaces Beechcraft Service Instruction 0374-152, Rev. I and Beechcraft Service Instruction 0455-152, Rev. I. \n\n\tThis amendment supersedes AD 71-26-02, Amendment 39-1364. \n\n\tThis amendment becomes effective August 6, 1974.
2025-04-01: The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD was prompted by two engine fan blade-out (FBO) events that resulted in the separation of engine inlet cowl and fan cowl parts from the airplane. In one event, fan cowl parts damaged the fuselage, which caused loss of pressurization and subsequent emergency descent. This AD requires replacing specified inlet cowl aft bulkhead fasteners for certain airplanes; for certain other airplanes, inspecting the inlet cowl aft bulkhead fastener and replacing the fasteners if rivets are found, and, for all airplanes, replacement of the crushable spacers used in the attachment of the inlet cowl to the engine fan case; or as an option, installing a serviceable inlet cowl. This AD also requires revising the existing maintenance or inspection program, as applicable, to incorporate new airworthiness limitations (AWLs). The FAA is issuing this AD to address the unsafe condition on these products.
2018-08-03: We are adopting a new airworthiness directive (AD) for The Boeing Company Model 787-8 and 787-9 airplanes powered by Rolls-Royce plc (RR) Trent 1000-A2, Trent 1000-AE2, Trent 1000-C2, Trent 1000-CE2, Trent 1000-D2, Trent 1000-E2, Trent 1000-G2, Trent 1000-H2, Trent 1000- J2, Trent 1000-K2, and Trent 1000-L2 turbofan engines. This AD requires revising the airplane flight manual to limit extended operations (ETOPS). This AD was prompted by a report from the engine manufacturer indicating that after an engine failure, prolonged operation at high thrust settings on the remaining engine during an ETOPS diversion may result in failure of the remaining engine before the diversion can be safely completed. We are issuing this AD to address the unsafe condition on these products.
2014-25-52: We are adopting a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter, -200, and -300 series airplanes and Model A340-200, -300, -500, and -600 series airplanes. This emergency AD was sent previously to all known U.S. owners and operators of these airplanes. This AD requires revising the airplane flight manual to advise the flightcrew of emergency procedures for abnormal Alpha Protection (Alpha Prot). This AD was prompted by a report of Angle of Attack (AoA) probes jamming on an in-service Airbus Model A321 airplane. We are issuing this AD to ensure that the flightcrew has procedures to counteract the pitch down order due to abnormal activation of the Alpha Prot. An abnormal Alpha Prot, if not corrected, could result in loss of control of the airplane.
2003-14-05: This amendment adopts a new airworthiness directive (AD) that is applicable to all McDonnell Douglas Model 717 airplanes. This action requires repetitive inspections for cracking of the support fitting assemblies and stop pads of the main spoiler actuators, and follow-on actions. This action is necessary to find and correct cracking of the support fitting assemblies of the main spoiler actuators, which could result in damage of adjacent structure such as the rear spar or upper skin panel, and consequent reduced structural integrity of the airplane. This action is intended to address the identified unsafe condition.
2025-04-13: The FAA is adopting a new airworthiness directive (AD) for certain Pratt & Whitney (PW) Model PW1519G, PW1521G, PW1521GA, PW1521G- 3, PW1524G, PW1524G-3, PW1525G, PW1525G-3, PW1919G, PW1921G, PW1922G, PW1923G, and PW1923G-A engines with a certain high-pressure compressor (HPC) 7th-stage axial rotor installed. This AD was prompted by an analysis of an event involving an International Aero Engines, LLC (IAE LLC) Model PW1127GA-JM engine, which experienced an HPC 7th-stage integrally bladed rotor (IBR-7) separation that resulted in an aborted takeoff. This AD requires performing initial and repetitive angled ultrasonic inspections (AUSI) of certain HPC 7th-stage axial rotors for cracks and replacing the HPC 7th-stage axial rotors if necessary. The FAA is issuing this AD to address the unsafe condition on these products.
2014-26-10: We are adopting a new airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series airplanes. This AD was prompted by a determination that the maintenance actions for airplane systems susceptible to aging must be mandated. This AD requires revising the maintenance or inspection program to incorporate more restrictive maintenance requirements and airworthiness limitations. We are issuing this AD to mitigate the risks associated with aging effects of airplane systems. Such aging effects could change the characteristics leading to an increased potential for failure, which could result in failure of certain life-limited parts, and could reduce the structural integrity or reduce controllability of the airplane.
2014-26-07: We are adopting a new airworthiness directive (AD) for all Dassault Aviation Model FAN JET FALCON and FAN JET FALCON SERIES C, D, E, F, and G airplanes. This AD was prompted by our determination of the need for a revision to the airplane airworthiness limitations to introduce changes to the maintenance requirements and airworthiness limitations. This AD requires revising the maintenance or inspection program, as applicable, to incorporate a new airworthiness limitations section. We are issuing this AD to prevent reduced structural integrity of the airplane.
73-06-02: 73-06-02 AERO COMMANDER: Amdt. 39-1606. Applies to all Models 500, 500A, 500B, 500U, 520, 560, 560A, 560E, 560F, 680, 680E, 680F, 680F(P), 680FL, 680FL(P) and 720 series airplanes certificated in all categories. Compliance required within the next 200 hours' time in service after the effective date of this AD, unless already accomplished. To prevent siphoning of fuel from the fuel tanks and thereby contribute to fuel exhaustion with resultant stoppage of both engines, accomplish the following: a. On Models 520 and 560, serial numbers 1 through 230, replace the standard fuel cap assemblies with non-siphoning fuel cap assemblies, Aero Commander Kit No. 87A-1. b. On the following models, replace the standard fuel cap assemblies with non- siphoning fuel cap assemblies, Aero Commander Kit No. 87A-2 (optional fuel caps already installed by use of Aero Commander Kit No. 87 are acceptable): (1) Models 500, 500A, 500B, 500U, 560A, 560E, 560F, 680, 680E, 680F, 680F(P), 680FL(P) and 720, serial numbers 231 through 1854. (2) Model 680FL, serial numbers 1261 through 1738. c. The compliance time for this AD may be adjusted up to a maximum of 50 hours to coincide with the aircraft's annual or 100 hour scheduled inspection. Aero Commander Custom Kit No. 87A contains the hardware and instructions necessary to accomplish this modification. Equivalent replacement parts approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration, Fort Worth, Texas, may be used. This amendment becomes effective March 19, 1973.
62-26-02: 62-26-02 GRUMMAN: Amdt. 513 Part 507 Federal Register December 6, 1962. Applies to Model G-159 Aircraft Serial Numbers 1 through 93, Except Numbers 75 and 76, and to Aircraft Serial Number 114. Compliance required as indicated. Abnormal fuel system operation has caused structural damage to the wing area of Grumman Model G-159 airplanes. As this condition is likely to exist on other airplanes of the same type design, accomplish the following: (a) Unless already accomplished, the following inspection is required prior to further flight, except that if the airplane is presently located at a base where the equipment and personnel necessary to conduct such an inspection are not available, the airplane may be ferried without passengers to a base where such equipment and personnel are available: (1) Defuel the left and right wing tanks. (2) Remove the inspection covers in the upper surface of the wings between the fuselage and the nacelle and between the nacelle and the fuel filler caps. (3) Inspect for damage to the wing structure in the integral tanks. Pay particular attention to the three top and three bottom rivets in the vertical stiffeners on the ribs. (b) Unless already accomplished, the following repair for damaged aircraft and the following modification for all aircraft are required prior to further flight except that if the damage is confined to the stiffener and rib attachments, the airplane may be operated under a special flight permit (CAR 1.76) to a base where the repair and modification may be made: (1) Repair damage in accordance with Grumman FAA approved instructions or equivalent approved by Chief, Engineering and Manufacturing Branch, FAA Eastern Region, New York International Airport, New York. (2) Modifying by removing the fuel vent flow valve Parker P/N 119-578735 from each tank and drilling a 5/32-inch diameter hole in the valve body in accordance with Grumman Gulfstream Service Change No. 154. After brush-coating the hole with EC-776 or FAA approved equivalent, reinstall the valve. NOTE. - Aircraft Serial Nos. 1, 7, 12, 26 and 91 already incorporate this modification. (Grumman telegram dated November 12, 1962, to all Gulfstream operators and Grumman Service Change No. 154 cover this same subject.) This directive effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated November 15, 1962.
2014-26-09: We are superseding Airworthiness Directive (AD) 2014-03-05, for certain Bombardier, Inc. Model BD-700-1A10 airplanes. AD 2014-03-05 required modification of the air data probes and sensors. This new AD continues to require modification of the air data probes and sensors. This new AD also adds airplanes to the applicability. This AD was prompted by a report that the manufacturer has determined that some completion centers used the heater current/brake temperature monitor unit (HBMU) logic circuit to control the line voltage of the drain mast heaters. We are issuing this AD to detect and correct an unannunciated failure of two pitot static probe heaters, which could affect controllability of the airplane in icing conditions.
2025-04-11: The FAA is adopting a new airworthiness directive (AD) for all Bombardier, Inc., Model BD-700-2A12 airplanes. This AD was prompted by the discovery that a partial loss of thrust after an engine failure during a required navigation performance authorization required (RNP- AR) approach under certain weight, altitude and temperature (WAT) conditions, may lead to a descent below the specified path guidance. This AD requires a revision to the existing airplane flight manual (AFM), to incorporate updated WAT tables for RNP-AR approach operations. The FAA is issuing this AD to address the unsafe condition on these products.
2014-23-01: We are superseding airworthiness directive (AD) 2013-15-09 for all Pratt & Whitney Division (PW) PW4074, PW4074D, PW4077, PW4077D, PW4084D, PW4090, and PW4090-3 turbofan engine models with certain second-stage high-pressure turbine (HPT) air seals installed. AD 2013- 15-09 required initial and repetitive inspections for cracks in second- stage HPT air seals. This new AD expands the applicability of AD 2013- 15-09 to include additional part numbers (P/Ns), requires removal of the mating hardware if the second-stage HPT air seal is found with a through-crack, and adds a mandatory terminating action. This AD was prompted by reports of cracking in the original location on two additional P/Ns and reports of through-cracks in a new location in the second-stage HPT air seal. We are issuing this AD to prevent failure of the second-stage HPT air seal, which could lead to uncontained engine failure and damage to the airplane.
66-27-03: 66-27-03\tBOEING: Amdt. 39-307 Part 39 Federal Register November 5, 1966. Applies to Models 707 and 720 Series Airplanes Equipped With Nylon Tube Conduit in the Tail Cone. \n\n\tCompliance required as indicated, unless already accomplished. \n\n\tTo prevent fire in the tail cone due to shorted tail navigation light wires, accomplish the following: \n\n\t(a)\tWithin the next 300 hours' time in service after October 12, 1966, unless already accomplished, inspect tail navigation light wiring for frayed or deteriorated wires and inspect protective nylon tube to ensure that it is secured to bulkhead. Replace frayed or deteriorated wires and secure nylon tube to bulkhead as necessary before further flight. \n\n\t(b)\tRepeat the inspection described in (a) every 300 hours' time in service until the following modifications or equivalent modifications approved by the Chief, Aircraft Engineering Division, FAA Western Region are accomplished but not later than 2,250 hours' time in service from theeffective date of this AD\n\n\t\t(1)\tTrim nylon tube flush with bulkhead 65-14660-3 at Fuselage Station 1653; \n\n\t\t(2)\tInstall cover plate and angle fabricated in accordance with Boeing Service Bulletin No. 2395(R-1) or later FAA-approved revision using a clamp and grommet in accordance with that Bulletin; and \n\n\t\t(3)\tReplace all frayed or chafed tail cone light wiring. \n\n\tThis supersedes AD 66-24-02. \n\n\tThis directive effective November 5, 1966.
2025-04-07: The FAA is adopting a new airworthiness directive (AD) for certain Airbus SAS Model A330-200, A330-200 Freighter, and A330-300 series airplanes. This AD was prompted by a report of contamination of the advanced pneumatic detector pressure switch of engine pylon fire detectors. This AD requires require replacement of the affected parts and prohibits installation of affected parts, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.
2014-24-05: We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-300, 747-400, 747-400D, and 747SR series airplanes. This AD was prompted by a report of a cracked reveal made from a casting found within a group of airplanes that should have machined reveals made only from 6061 aluminum. This AD requires an inspection to determine the material of the number 3 main entry door (MED) corner reveal, repetitive inspections of certain reveals for cracking, and corrective action if necessary. This AD also requires repetitive inspections for cracking of 6061 machined aluminum one-piece corner reveals, and replacement with 6061 machined aluminum two-piece corner reveals if necessary, which terminates certain repetitive inspections. We are issuing this AD to detect and correct fatigue cracking of the lower forward corner reveal of the number 3 MEDs, which could lead to the door escape slide departing the airplane when the door is opened and the slide is deployed, and consequent injuries to passengers and crew using the door escape slide during an emergency evacuation.
2014-25-08: We are adopting a new airworthiness directive (AD) for certain Dassault Aviation Model FALCON 2000 and FALCON 2000EX airplanes. This AD was prompted by a design review, which revealed that the forward servicing compartment (FSC) is configured with tie-down points. This AD requires inspecting the FSC for installed tie-down points, and removing those tie-down points. We are issuing this AD to detect and correct installed tie-down points, which could lead to inadvertent use of the FSC as a cargo compartment, which could result in damage to the structure of the airplane or potential risk of fire.
76-01-01: 76-01-01 CESSNA and REIMS AVIATION: Amendment 39-2483. Applies to Cessna Models A150K and A150L and Reims Aviation Models FA150K and FA150L airplanes certified in the acrobatic category, which have been modified in accordance with STC SA1809WE, incorporating Flint Aero auxiliary fuel tanks in the outboard wing panels. \n\n\tCompliance is required within ten days after the effective date of this AD, unless already accomplished. \n\n\tTo prevent the possibility of encountering high speed flutter with fuel in these auxiliary fuel tanks, accomplish the following: \n\n\t(a)\tAdjacent to the airspeed indicator and in full view of the pilot, attach a placard which reads: \n\n\t\tAirspeed Limits when auxiliary tanks contain any amount of fuel: \n\n\nVne (never exceed)\n= 162 MPH (141 knots) \nVno (max. structural cruising)\n= 120 MPH (104 knots) \nVa (maneuvering)\n= 109 MPH ( 95 knots) \n\t\n\t(b)\tAny equivalent method of showing compliance with this AD or any demonstration of freedom from flutter of this design must be approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tThis amendment becomes effective January 9, 1976.
2018-07-21: We are superseding Airworthiness Directive (AD) 2005-12-16, which applied to all Fokker Services B.V. Model F28 Mark 0100 airplanes. AD 2005-12-16 required an inspection to determine the part number of the passenger service unit (PSU) panels for the PSU modification status, and corrective actions if applicable. This new AD requires an inspection of the PSU panels and the PSU panel/airplane interface connectors for discrepancies, and corrective actions if necessary. This AD also removes airplanes from the applicability. This AD was prompted by reports of smoke in the passenger compartment during ground operations and in-flight, and a determination that the modification actions required by AD 2005-12-16 might not have been implemented correctly. We are issuing this AD to address the unsafe condition on these products.
2014-25-06: We are adopting a new airworthiness directive (AD) for all Airbus Model A300 series airplanes; Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300 C4-605R Variant F airplanes (collectively called Model A300-600 series airplanes); and Airbus Model A310 series airplanes. This AD was prompted by a report of early ruptures on the levers of the nose landing gear (NLG) sequence valve. This AD requires a one-time inspection for damage of the landing gear sequence valve levers and pin shearing indicating areas on the NLG and the main landing gears (MLGs); and depending on findings, replacing the sequence valve and lever, or doing a one-time inspection to detect interference between control rods and sequence valves and corrective actions if necessary. We are issuing this AD to detect and correct interference between a landing gear leg and door, which could result in failure of that landing gear to extend and could damage the airplane and injure occupants.
2014-25-07: We are adopting a new airworthiness directive (AD) for certain Airbus Model A320-211, -212, -214, -231, -232, and -233 airplanes. This AD was prompted by a report of cracking at the splice plate of the frame (FR) 47 butt joint crossing area found during full-scale fatigue testing. This AD requires repetitive inspections for cracking of both sides of the splice plate of that frame butt joint crossing area, and corrective action if necessary. This AD also provides for an optional modification, which terminates the repetitive inspections. We are issuing this AD to detect and correct fatigue cracking of the splice plate of the FR 47 butt joint crossing area, which could result in reduced structural integrity of the airplane.
70-25-07: 70-25-07 BOEING: Amdt. 39-1125. Applies to Model 707 and 720 Series airplanes listed in Boeing Service Bulletin 2998, dated October 1, 1970, or later FAA approved revisions. \n\n\tTo prevent fluid bypassing within the Rudder Power Control Unit (PCU) accomplish the following: \n\n\tWithin the next 300 hours' time in service after the effective date of this AD, unless previously accomplished, modify the Rudder PCU in accordance with Boeing Service Bulletin 2998, dated October 1, 1970, or later FAA approved revision or an equivalent method approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tThis amendment becomes effective December 11, 1970.