Results
99-25-12: This amendment supersedes an existing airworthiness directive (AD), applicable to Bell Helicopter Textron (Bell)-manufactured Model HH-1K, TH-1F, TH-1L, UH-1A, UH-1B, UH-1E, UH-1F, UH-1H, UH-1L, and UH-1P helicopters; and Southwest Florida Aviation SW204, SW204HP, SW205, and SW205A-1 helicopters, that currently requires modification and inspections of the tailboom vertical fin spar (vertical fin spar). This amendment requires the same modification and inspections plus two additional inspections and replacement of the vertical fin spar. This amendment is prompted by 6 accidents, 2 of which involved fatalities, involving fatigue cracks in the vertical fin spar that have occurred since the issuance of AD 97-20-09. The actions specified by this AD are intended to prevent in-flight failure of the vertical fin spar and subsequent loss of control of the helicopter.
96-11-16: This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0100 series airplanes, that requires a one-time measurement during refueling to determine the pressure in each collector tank; for certain airplanes, non-destructive test (NDT) inspections to detect cracking or deformations of the collector tank ribs on each wing, and repair, if necessary; and modification of top-hat stringers in each outer wing tank. This amendment is prompted by a report of damage to the ribs of the wing collector tank caused by over-pressure in the collector tank during refueling. The actions specified by this AD are intended to prevent cracking and deformation of the wing collector tanks due to over-pressure, which could result in reduced structural integrity of the wing.
2020-16-17: The FAA is adopting a new airworthiness directive (AD) for all Rolls-Royce Deutschland Ltd. & Co KG (RRD) Trent XWB-75, Trent XWB-79, Trent XWB-79B, and Trent XWB-84 model turbofan engines. This AD was prompted by reports of a lack of weld fusion on the resistance welding during manufacturing, which could result in air leakage through the low-pressure turbine (LPT) rear support seal panel assembly (''LPT seal panel''). This AD requires replacement of the LPT seal panel. The FAA is issuing this AD to address the unsafe condition on these products.
2008-22-13: 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: Two operators of A300 aircraft fitted with General Electric (GE) CF6-50 engine series have reported cracks on the lower side of Rib 5 in the pylon box. * * * * * Investigations disclosed that these cracks are due to the stresses resulting from the pressure applied by the thrust reverser cowl bumpers. * * * * * Cracking of the engine pylons could result in reduced structural integrity of the engine support structure. We are issuing this AD to require actions to correct the unsafe condition on these products.
2006-10-05: The FAA is adopting a new airworthiness directive (AD) for certain Saab Model SAAB-Fairchild SF340A (SAAB/SF340A) and SAAB 340B airplanes. This AD requires a one-time inspection to see if a faulty uplock axle for the shock strut of the main landing gear (MLG) is installed, and replacing the uplock axle with a new uplock axle if necessary. This AD results from a report of a cracked uplock axle caused by hydrogen embrittlement during the manufacturing process. We are issuing this AD to prevent failure of the uplock mechanism, which, combined with a loss of hydraulic pressure, could result in an uncommanded extension of the MLG.
2020-16-12: The FAA is adopting a new airworthiness directive (AD) for Pacific Aerospace Limited Model 750XL airplanes. 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 inadvertent fuel shut-off to the engine during the operation of the flaps due to the fuel and flap control levers being located too closely together. The FAA is issuing this AD to address the unsafe condition on these products.
56-13-02: 56-13-02 SIKORSKY: Applies to All Model S-51 Helicopters. Compliance required as indicated. As a result of recent service experience, the main rotor hubs are to be retired from service at the times indicated. 1. Main rotor hubs, S10-10-1015 and S510117, are to be replaced every 480 hours. Magnaflux inspections are to be conducted at the 200-240 hour interval. 2. Main rotor hubs, S10-10-1033, with 1/16 inch or larger chamfer at the base on the outer edge of each arm, with 240 hours of service, must be replaced by September 15, 1956, or prior to the accumulation of 480 hours, whichever occurs first. The S510122 outer arm locknuts are to be checked for looseness every 30 hours on hubs continuing in service beyond 240 hours. With any indication of looseness, the hub is to be removed and a Magnaflux inspection for cracks at the root radius of the threads on the outer arm is to be conducted. Any hub with a crack is to be replaced. Hubs with 480 hours or more must be replaced prior to further service. After September 15, 1956, all hubs are to be replaced every 240 hours. 3. Main rotor hubs, S10-10-1033, with chamfer less than 1/16 inch at the base on the outer edge of each arm are to be replaced every 960 hours. Magnaflux inspections are to be conducted every 200-240 hours of service. (Service Information Circular No. 76 Revisions D & F cover the same subject.) This supersedes AD 49-44-01.
99-24-09: This amendment adopts a new airworthiness directive (AD) that applies to certain Pilatus Aircraft Ltd. (Pilatus) Models PC-12 and PC-12/45 airplanes. This AD requires modifying the flap inboard attachment fittings through the installation of a reinforcement angle bracket on the inside of the center web of both flap inner attachment fittings. 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 the potential of the inboard flap attachment fittings buckling while operating at full flaps with full power into a head-on wind gust, which could result in loss of control of the airplane.
2020-16-19: The FAA is adopting a new airworthiness directive (AD) for certain Sikorsky Aircraft Corporation (Sikorsky) Model S-92A helicopters. This AD was prompted by two incidents of erroneous low oil pressure caution cockpit indications and unintended actuation of the main gearbox (MGB) auto bypass valve. This AD requires installing auxiliary circuit breaker modification (MOD) kits and inserting a Rotorcraft Flight Manual (RFM) Supplement into the existing RFM for your helicopter. The FAA is issuing this AD to address the unsafe condition on these products.
2020-17-05: The FAA is adopting a new airworthiness directive (AD) for certain Airbus Helicopters Deutschland GmbH Model MBB-BK 117 D-2 helicopters. This AD was prompted by the discovery that certain longitudinal trim actuators, lateral trim actuators, and yaw trim actuators, which are certified for installation on MBB-BK 117 C-2 helicopters, were erroneously listed as eligible for installation on MBB-BK 117 D-2 helicopters. This AD requires removing the affected parts from service and prohibits installing the affected parts on MBB- BK 117 D-2 helicopters. The FAA is issuing this AD to address the unsafe condition on these products.
68-08-07: 68-08-07 LOCKHEED: Amendment 39-585. Applies to Model 1329 Airplanes, Serial Numbers 5001 through 5092, 5094 through 5096. Compliance required as indicated. Recent calibration of several airplanes has revealed a difference in the airspeed and altimeter system static position error from the values presented in the AFM. These differences are in excess of tolerances which can be accepted as normal deviation from an Airplane Flight Manual calibration curve. To detect similar discrepancies, the following is required unless the system has previously been calibrated in accordance with the referenced manufacturer's instructions. Within the next 100 hours' time in service after the effective date of this AD, calibrate the pitot static system in accordance with the instructions given in Lockheed-Georgia Service Bulletin 329-250, Section 2a through 2p, or later FAA approved revision; or in an equivalent manner approved by the Chief, Engineering and Manufacturing Branch, FAA Southern Region. This amendment becomes effective April 19, 1968.
48-06-03: 48-06-03 NAVION: Applies to All models Equipped With Hartzell Propeller Blade Models 8428, 8428C, 8428R Having Serial Numbers Below 61000. Compliance required by April 15, 1948. Examine all Model 8428, 8428C, and 8428R blades having Serial Numbers below 61000 in bright daylight or strong artificial light on the front face in the area approximately 4 inches outboard of the blade clamp. Any fillers used in the blade will be discernible to the naked eye. If fillers are found in this area, the paint should be carefully removed and the fillers removed from the blade. Defects that can be eliminated by removing material to form a shallow saucer not over 1/8 inch at its deepest point, 3/8 inch in width overall, and 1 inch in length overall, should be repaired. Following removal of the defects, the area from which paint has been removed should be repainted and the propeller rebalanced before being returned to service. Blades having defects that cannot be repaired by the above methodor by methods described in the applicable portions of CAM 18, should be returned to the propeller manufacturer. The exact location and the extent of rework necessary to remove any defect should be recorded in the log book. Areas having maximum material removed may not have additional material removed for subsequent injuries.
2002-11-05 R1: The FAA is adopting a new airworthiness directive (AD) to revise AD 2002-11-05, which applies to certain Air Tractor, Inc. (Air Tractor) AT-400 series and Models AT-501, AT-802, and AT-802A airplanes. AD 2002-11-05 establishes a safe life for the wing lower spar cap. Since we issued AD 2002-11-05, we have received reports of cracks found prior to the established safe life on AT-400 series airplanes and on Model AT-802A airplanes. We are issuing separate AD actions for AT-400 series and Models AT-802 and AT-802A airplanes to address the unsafe condition of those airplanes. This AD retains the actions required in AD 2002-11-05 for Model AT-501 airplanes and removes AT-400 series and Models AT-802 and AT-802A airplanes from the applicability of AD 2002-11-05.
2003-13-11: The FAA is adopting a new airworthiness directive (AD) for Pratt & Whitney (PW) PW4074, PW4074D, PW4077, PW4077D, PW4090, and PW4090-3 turbofan engines with high pressure compressor (HPC) rear cases, part numbers (P/Ns) 55H425-01, 55H385-01, and 56H396-01 installed. This AD requires initial and repetitive visual or fluorescent penetrant inspections (FPI) of the J flange on the HPC rear case, and removal from service of the rear case based on certain inspection results. This AD is prompted by reports of cracks propagating from bolt holes in the HPC rear case J flange, and reports of high-cycle HPC rear cases exhibiting cracks propagating into the shell wall. The actions specified in this AD are intended to prevent fracturing and rupturing of the HPC rear case, resulting in uncontained engine failure.
2001-24-11: This amendment adopts a new airworthiness directive (AD) that is applicable to all Raytheon Model Beech 400, 400A, and 400T series airplanes, Model Mitsubishi MU-300 airplanes, and Model Beech MU-300-10 airplanes. This action requires revising the Emergency Procedures Section of the Airplane Flight Manual to ensure the flightcrew is advised of in-flight procedures in the event of loss of airspeed indication. Such loss of airspeed indication and the resulting adverse effects on certain connecting systems could result in reduced controllability of the airplane.
2006-10-03: The FAA is adopting a new airworthiness directive (AD) for certain Airbus Model A319-100 and A320-200 series airplanes, and Model A320-111 airplanes. This AD requires modifying the wiring to the fuel pump control of the center fuel tank. This AD results from reports that the low-pressure warning for the fuel pumps of the center fuel tank has come on in flight. We are issuing this AD to ensure that the fuel pumps do not run while dry, which could result in a potential ignition source inside the center fuel tank, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.
69-09-01: 69-09-01 EISEMANN: Amdt. 39-784. Applies to all type AM-4, AM-6, LA-4, and LA-6 Eisemann magnetos installed on, but not necessarily limited to: Continental A-50 Series Continental A-65 Series Continental A-75 Series Continental A-80 Series Continental C-75 Series Continental C-85 Series Continental C-115 Series Continental C-125 Series Continental E-165 Series Continental E-185 Series Franklin (Aircooled Motors) 2A4 Series Franklin (Aircooled Motors) 4AC Series Franklin (Aircooled Motors) 4A4 Series Franklin (Aircooled Motors) 6AC Series Franklin (Aircooled Motors) 6AL Series Franklin (Aircooled Motors) 6A8 Series Franklin (Aircooled Motors) 6A4 Series Franklin (Aircooled Motors) 6V4 Series Franklin (Aircooled Motors) 6AG4 Series Menasco C4, D4, D4-87 Compliance required within the next 50 hours' time in service after the effective date of this AD, unless already accomplished. To prevent the possibility of loss of engine power in flight caused by electrically shorted windings in the magneto coil, accomplish the following: (a) Inspect the coils P/N H27-958 used in Eisemann Type LA-4, LA-6, AM-4 and AM-6 magnetos for a yellow inspection stamp consisting of a letter and a numeral. (b) Remove from further service those coils inspected in (a) bearing the following stamps: A76, B76, C76, D76, F76, G76, H76, J76, K76, L76, M76, D86, E86, F86, G86, H86, J86, K86. (c) Install coils P/N H27-958 bearing yellow inspection stamp symbols other than those listed under (b) above or an equivalent approved by Chief, Engineering and Manufacturing Branch, FAA, Southern Region. (d) This airworthiness directive affects only coils with the green plastic covering and does not affect: (1) Taped coils. (2) Those covered in black plastic. (3) Those bearing inspection stamps of any type or color (other than those listed under (b) above). (4) Those bearing no inspection stamp. The compliance time may be adjusted up to a maximum of 10 hours to coincide with aircraft annual or 100-hour scheduled inspections. (American Industrial Sales Bulletin dated November 1, 1968, pertains to this same subject.) Effective May 1, 1969. Revised June 24, 1969.
2020-16-02: The FAA is adopting a new airworthiness directive (AD) for Pilatus Aircraft Ltd. Models PC-6, PC-6/350, PC-6/350-H1, PC-6/350-H2, PC-6/A, PC-6/A-H1, PC-6/A-H2, PC-6/B-H2, PC-6/B1-H2, PC-6/B2-H2, PC-6/ B2-H4, PC-6/C-H2, PC-6/C1-H2, PC-6-H1, and PC-6-H2 airplanes. This AD results from mandatory continuing airworthiness information (MCAI) issued 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 rudder shaft assemblies with incorrect rivet configurations. The FAA is issuing this AD to address the unsafe condition on these products.
99-19-07: This amendment adopts a new airworthiness directive (AD), applicable to certain Gulfstream American (Frakes Aviation) Model G-73 (Mallard) and G-73T series airplanes, that requires revising the Airplane Flight Manual (AFM) to include requirements for activation of the airframe pneumatic deicing boots. This amendment is prompted by reports of inflight incidents and an accident that occurred in icing conditions where the airframe pneumatic deicing boots were not activated. The actions specified by this AD are intended to ensure that flightcrews activate the pneumatic wing and tail deicing boots at the first signs of ice accumulation. This action will prevent reduced controllability of the aircraft due to adverse aerodynamic effects of ice adhering to the airplane prior to the first deicing cycle.
74-10-05 R1: 74-10-05 R1 PRATT & WHITNEY AIRCRAFT: Amendment 39-1834 as amended by Amendment 39-3972. Applies to all Pratt & Whitney Aircraft JT9D-7, JT9D-7A, and JT9D-20 turbofan engines. Compliance required as follows unless already accomplished. To preclude possible turbine blade or disc failures resulting from deflection of the second stage turbine nozzle guide vane inner support, perform a radioisotope inspection in accordance with paragraph 8 below per the following schedule: 1. Engines containing second stage vanes, P/N 708952. a. For vanes with less than 4000 hours total time in service or less than 4000 hours since the fuel nozzles and supports were last cleaned, as of June 7, 1974, inspect prior to the accumulation of 4000 hours total time, or 4000 hours since the fuel nozzles and supports were last cleaned, or 400 hours time in service after June 7, 1974, whichever occurs later. b. For vanes with 4000 or more hours total time in service and 4000 or more hours since the fuel nozzles and supports were last cleaned, as of June 7, 1974, inspect within the next 400 hours time in service. c. Repeat the above inspection every 700 hours time in service thereafter. 2. Engines containing second stage vanes, P/N 708952, that were reworked per Pratt & Whitney Service Bulletin 3946 and reidentified to P/N 728752 and operated in engines prior to rework. a. Inspect within the next 400 hours time in service after June 7, 1974. b. Repeat the above inspection every 700 hours time in service thereafter. 3. For engines containing new production second stage vanes 719552, 728752, 731552, 735882, 740292, 747082, 746492, and 747172, not reworked in accordance with Service Bulletin 3946 and operated prior to the incorporation of Pratt & Whitney Service Bulletin 4146. a. For vanes with less than 5000 hours total time in service or less than 4000 hours since the fuel nozzles and supports were last cleaned, as of June 7, 1974, inspect prior to the accumulation of 5000 hours total time, or 4000 hours since the fuel nozzles and supports were last cleaned, or 400 hours time in service after June 7, 1974, whichever occurs later. b. For vanes with 5000 or more hours total time in service and 4000 or more hours since the fuel nozzles and supports were last cleaned, as of June 7, 1974, inspect within the next 400 hours time in service. c. Repeat the above inspection every 2500 hours time in service thereafter. 4. For engines containing second stage vanes, 719552, 728752, 731552, 740292, and 747172, that have incorporated Pratt & Whitney Service Bulletin 4146 before operation. a. For vanes with less than 5000 hours total time in service or less than 5000 hours since the fuel nozzles and supports were cleaned, as of June 7, 1974, inspect prior to the accumulation of 5000 hours total time or 5000 hours since the fuel nozzles and supports were cleaned, or 400 hours time in service after June 7, 1974, whichever occurs later. b. For vanes with more than 5000 hours total time in service and 5000 or more hours since the fuel nozzles and supports were cleaned, as of June 7, 1974, inspect within the next 400 hours time in service. c. Repeat the above inspection every 2500 hours time in service thereafter. 5. If any radioisotope inspection mentioned above indicates a deflection which exceeds .070 inch, remove the affected engine from service prior to further flight. 6. For engines containing a complete set of second stage vanes 735882, 746492, 747082, 772572, or 785992 that have incorporated Pratt & Whitney Service Bulletin 4146 before operation. a. For vanes with less than 5000 hours total time in service or less than 5000 hours since the fuel nozzles and supports were cleaned, as of May 10, 1974, inspect prior to the accumulation of 5000 hours total time or 5000 hours since the fuel nozzles and supports were cleaned, or 400 hours time in service after May 10, 1974, whichever occurs later. b. For vanes with more than 5000 hours total time in service and 5000 or more hours since the fuel nozzles and supports were cleaned, as of May 10, 1974, inspect within the next 400 hours time in service. c. Repeat the above inspection every 2500 hours time in service thereafter. 7. If the radioisotope inspection in accordance with paragraph 6 above indicates vane deflection which exceeds 0.130 inches, remove the affected engine from service prior to further flight. Engines with vane deflection greater than 0.070 inches and up to 0.130 inches must be reinspected every 1250 hours time in service thereafter. Engines with vane deflection of 0.070 inches and less must be reinspected every 2500 hours time in service thereafter. 8. The inspections required above are radioisotope inspections conducted as follows: a. For JT9D-7 and JT9D-7A engines, inspect in accordance with radioisotope inspection procedures specified in the Boeing Maintenance Manual, Section 72-00-00, Paragraph E(7), Pages 680N and 680P, revision dated March 1974, for those engines, or later Federal Aviation Administration approved revision. b. For JT9D-20 engines, inspect in accordance with radioisotope inspection procedures specified in the McDonnell-Douglas Maintenance Manual, Section 72-00-00, Paragraph 2.G., Pages 631 and 633, revision dated May 1973, for this engine, or later Federal Aviation Administration approved revision. 9. Upon submittal of substantiating data through a Federal Aviation Administration Inspector, the Chief, Engineering and Manufacturing Branch, Federal Aviation Administration, New England Region, may adjust the compliance time. 10. For cases where vanes are mixed, if ten or more vanes of any one of the above part numbered categories are installed in an engine, the most restrictive category will apply. The manufacturer's specifications and procedures identified and described in this directive areincorporated herein and made a part hereof pursuant to 5 U.S.C. 552(a)(1). All persons affected by this directive who have not already received these documents from the manufacturer may obtain copies upon request to The Boeing Company, Post Office Box 3707, Seattle, Washington 98124 and McDonnell- Douglas Corporation, Douglas Aircraft Company, 3855 Lakewood Boulevard, Long Beach, California 90801. These documents may also be examined at the Office of the Regional Counsel, New England Region, Federal Aviation Administration, 12 New England Executive Park, Burlington, Massachusetts 01803 and at Federal Aviation Administration Headquarters, 800 Independence Avenue, S.W., Washington, D.C. A historical file on this AD which includes the incorporated material in full is maintained by the Federal Aviation Administration at its headquarters in Washington, D.C., and at the New England Regional Office in Burlington, Massachusetts. Note: Pratt & Whitney Alert Service Bulletin 4304 pertains to this subject. Amendment 39-1834 became effective June 7, 1974. This amendment 39-3972 becomes effective November 17, 1980.
72-02-05: 72-02-05 BELL: Amdt. 39-1380. Applies to: Bell Models 47G-2A, 47G-2A-1, 47G-3, 47G-3B, 47G-3B-1, 47G-3B-2, 47G-4, 47G-4A, 47G-5, 47J-2, and 47J-2A helicopters certificated in all categories; Bell Model 47J helicopters, S/N 1777 and subsequent, certificated in all categories; and Bell Models 47G, 47G-2, and 47J helicopters, S/N 1420 through 1776, certificated in all categories incorporating Bell Mast Controls Kit No. 47-3411-1, Service Instruction No. 333. Compliance required as indicated. To detect possible cracks in the tube surface of control rod assembly, P/N 47-150-255-1, accomplish the following: (a) Inspect both control tubes within 100 hours time in service after the effective date of this AD, unless already accomplished, in accordance with the procedures listed below and accomplish repetitive inspections at intervals of not more than 1200 hours time in service from the last inspection. (b) Inspect the complete external surface of the tube for indications of cracks using a dye penetrant or equivalent inspection method. (c) If crack indications are found polish out and blend all indications into the adjacent areas and reinspect as follows: (1) Use 240 or 320 grit paper then use 400 grit paper for final polish. Sand only in the lengthwise direction of the tube. (2) Do not exceed .005 inch deep removal of material. Circumferential (transverse) cleanup of indication is limited to one-fourth of the tube circumference. There is no restriction of the longitudinal length limit. (3) Reinspect the polished surface of the tube for cracks using a dye penetrant or equivalent inspection method. (4) If cracks are found remove the cracked tube before further flight. (d) If no crack indications are found protect any exposed surfaces of the tube using zinc chromate primer or equivalent. (Bell Helicopter Service Bulletin No. 47-146 dated August 26, 1971 pertains to this subject.) This amendment becomes effective February 22, 1972.
2017-12-10: We are adopting a new airworthiness directive (AD) for certain Airbus Model A321-111, -112, -131, -211, -212, -213, -231, and -232 airplanes. This AD was prompted by a full scale fatigue test campaign on these airplanes in the context of the extended service goal. This AD requires inspections of the affected frame locations, and repair if necessary. We are issuing this AD to address the unsafe condition on these products.
2006-09-07: The FAA is adopting a new airworthiness directive (AD) for all Airbus Model A330-200, A330-300, A340-200, and A340-300 series airplanes; and A340-541 and A340-642 airplanes. This AD requires operators to revise the Airworthiness Limitations section of the Instructions for Continued Airworthiness to incorporate new information. This information includes, for all affected airplanes, decreased life limit values for certain components; and for Model A330- 200 and -300 series airplanes, new inspections, compliance times, and new repetitive intervals to detect fatigue cracking, accidental damage, or corrosion in certain structures. This AD results from a revision to subsection 9-1 of the Airbus A330 and A340 Maintenance Planning Documents (MPD) for Life limits/Monitored parts, and subsection 9-2 of the Airbus A330 MPD for Airworthiness Limitations Items. We are issuing this AD to prevent fatigue cracking, damage, or corrosion, which could result in reduced structural integrity of these airplanes.
99-19-08: This amendment adopts a new airworthiness directive (AD), applicable to certain Lockheed Model L-14 and L-18 series airplanes, that requires revising the Airplane Flight Manual (AFM) to include requirements for activation of the airframe pneumatic deicing boots. This amendment is prompted by reports of inflight incidents and an accident that occurred in icing conditions where the airframe pneumatic deicing boots were not activated. The actions specified by this AD are intended to ensure that flightcrews activate the pneumatic wing and tail deicing boots at the first signs of ice accumulation. This action will prevent reduced controllability of the aircraft due to adverse aerodynamic effects of ice adhering to the airplane prior to the first deicing cycle.
66-16-03: 66-16-03 BRITISH AIRCRAFT CORPORATION: Amdt. 39-255 Part 39 Federal Register July 1, 1966. Applies to Model BAC 1-11 Series Airplanes Equipped with Aluminum Alloy Rocking Lever, P/N CH504-008, in the Rudder Feel Simulator Unit. Compliance required as indicated. To prevent fatigue failure of the rocking lever in the rudder feel simulator unit, accomplish the following: (a) Replace aluminum alloy rocking levers, P/N CH504-008, with 2,900 or more hours' time in service on the effective date of this AD with an unused part of the same part number or with steel rocking lever, P/N CH504-020 or CH504-021, within the next 100 hours' time in service. (b) Replace aluminum alloy rocking levers, P/N CH504-008, with less than 2,900 hours' time in service on the effective date of this AD with an unused part of the same part number or with steel rocking lever, P/N CH504-020 or CH-504-021, before the accumulation of 3,000 hours' time in service. (British Aircraft Corporation (BAC) One-Eleven Alert Service Bulletin 27-A-PM 1248 pertains to this subject.) This directive effective July 31, 1966.