66 Airworthiness Directives: 48 airplane, 10 rotorcraft, 6 engine, 1 appliance, 1 various.
AD 98-02-06 R1 · published Nov 2, 1999, effective Dec 7, 1999
Boeing 777-200 Series Airplanes
This amendment revises an existing airworthiness directive (AD), applicable to certain Boeing 777-200 series airplanes, that currently requires repetitive visual inspections to determine the presence and condition of the nut and cotter pin of the lock link mechanism on the side struts and drag struts on the main landing gear (MLG); and corrective action, if necessary. That AD was prompted by reports of missing or damaged components on the lock link mechanism. The actions specified by that AD are intended to prevent failure of the lock link mechanism to lock the MLG in the down position, and consequent collapse of the MLG during ground operation. This amendment provides an optional terminating action for the repetitive inspections.
AD 99-22-15 · published Nov 2, 1999, effective Dec 7, 1999
Dornier Model 328-100 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Dornier Model 328-100 series airplanes, that requires repetitive inspections of the left and right roll spoiler actuators to check for signs of leakage and deformation of the housing, repetitive inspections of the gap between the left roll spoiler actuator housing cap and the actuator housing, repetitive torque checks of the left roll spoiler actuator housing cap attachment screws, and corrective action, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent oil leakage from the roll spoiler actuators, which could result in incorrect roll spoiler operation and reduced controllability of the airplane.
AD 99-22-16 · published Nov 2, 1999, effective Dec 7, 1999
Boeing Model 737 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737 series airplanes, that requires a one-time detailed visual inspection of the upper decompression panel on the flight deck door to verify that a minimum overlap dimension exists, and corrective action, if necessary. This amendment is prompted by reports indicating that, during production, some upper decompression panels were installed incorrectly on the flight deck door. The actions specified by this AD are intended to detect an incorrectly installed upper decompression panel, which could cause the emergency exit panel on the flight deck door to become inoperable, thereby preventing crewmembers from performing essential duties during an emergency evacuation.
AD 99-22-17 · published Nov 2, 1999, effective Dec 7, 1999
Saab Model SAAB SF340A and 340B Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Saab Model SAAB SF340A and 340B series airplanes, that requires removal of certain main landing gear downlock and brake hydraulic swivel brackets and replacement with new, redesigned brackets. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent failure of the downlock or brake swivels. Brake swivel failure could cause the loss of inboard or outboard brakes. Downlock swivel failure could cause the loss of hydraulic fluid in the main hydraulic system, as well as the loss of nose wheel steering operation, extension and retraction capability of landing gear and flaps, and operation of the propeller brake (if installed).
AD 99-23-05 · published Nov 12, 1999, effective Dec 17, 1999
Bombardier Model DHC-8-101, -102, -103, -106, -201, -202, -301, -311, and -315 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Bombardier Model DHC-8-101, -102, -103, -106, -201, - 202, -301, -311, and -315 series airplanes, that requires repetitive detailed visual inspections and high frequency eddy current inspections to detect cracking of the wing upper skin and ladder plates at over wing access panels between certain stations; and repair, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to detect and correct fatigue cracking of the wing ladder plates, which, if not corrected, could reduce the structural integrity of the wing.
AD 99-23-06 · published Nov 12, 1999, effective Dec 17, 1999
Aerospatiale Model SN-601 (Corvette) Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Aerospatiale Model SN-601 (Corvette) series airplanes, that requires repetitive inspections, and repair if necessary, of the locking indication system of the drag strut jack on the main landing gear (MLG) to detect corrosion and damage resulting from its operation. This proposal also requires replacement of seals and backup rings with new parts. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent failure of the locking indication system of the drag strut jack on the MLG due to corrosion. Such corrosion could prevent the MLG from locking and result in the subsequent collapse of the MLG.
AD 99-23-08 · published Nov 12, 1999, effective Dec 17, 1999
McDonnell Douglas Model DC-9-10, -20, - 30, -40, and -50 Series Airplanes, and C-9 (Military) Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes, and C-9 (military) airplanes, that requires a one-time general visual inspection to detect certain discrepancies in the wiring of the fuel quantity indicating system (FQIS) in the forward cargo compartment; and corrective actions, if necessary. This amendment is prompted by a report indicating that several discrepancies were found in the wiring of the FQIS due to maintenance or alteration practices. The actions specified by this AD are intended to prevent excessive electrical energy from entering the fuel tanks through the FQIS wiring, which could result in a potential ignition source in the fuel tanks.
AD 99-23-09 · published Nov 12, 1999, effective Dec 17, 1999
Airbus Model A319, A320, and A321 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A319, A320, and A321 series airplanes, that requires modification of the electro-distributor for the nose wheel steering servo-control. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent uncommanded nose landing gear wheel rotation, due to defective seals in the wheel steering selector valve of the hydraulic control unit for the nose landing gear, which could result in reduced controllability of the airplane.
AD 99-23-10 · published Nov 12, 1999, effective Dec 17, 1999
Raytheon Model Hawker 1000 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Raytheon Model Hawker 1000 series airplanes, that requires a visual inspection of the PS wire bundle, shielded wires going to fuel probe `G,' and any other wire or wire bundle for chafing in the forward wing spar and forward ventral tank area; and corrective actions, if necessary. This amendment is prompted by reports indicating that, due to improper routing of a wire bundle, the wire bundle chafed against the forward ventral tank transfer/crossfeed valve, which caused an electrical short and resulted in failure of the landing light. The actions specified by this AD are intended to prevent a short circuit due to wire chafing, which can cause a fire in the ventral fuel tank area.
AD 99-23-12 · published Nov 12, 1999, effective Dec 17, 1999
Dornier Model 328-100 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Dornier Model 328-100 series airplanes, that requires repetitive inspections to detect damage and discrepancies of various control cables and certain fairleads/swivel guides for the autopilot, elevator, rudder, aileron, and engine; and corrective actions, if necessary. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent failure of the pilot's control cables for the autopilot, elevator, rudder, aileron, and engine, which could result in reduced controllability of the airplane.
AD 99-23-13 · published Nov 12, 1999, effective Dec 17, 1999
Boeing Model 727-200 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Boeing Model 727-200 series airplanes, that requires repetitive inspections to detect cracks in certain areas between the upper and lower sills of the number 1 cargo door, and repair, if necessary. This amendment is prompted by reports indicating that fatigue cracks were found in certain structures adjacent to the number 1 cargo door cutout at the forward and aft doorway frames. The actions specified by this AD are intended to detect and correct such fatigue cracking, which could result in rapid decompression of the fuselage and consequent reduced structural integrity of the airplane.
AD 99-23-14 · published Nov 12, 1999, effective Dec 17, 1999
Airbus Model A300, A310, and A300-600 Series Airplane
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Airbus Model A300, series airplanes, that currently requires certain changes to the procedures in the Airplane Flight Manual (AFM) related to operation of the emergency lighting system. This action requires modification of the emergency lighting system and a revision to the AFM to ensure the preservation of the airplane batteries. This action also provides, for certain airplanes, terminating action for the existing AFM revision, and replacement with a different AFM revision. This action also expands the applicability to include certain model A310 and A300-600 series airplanes. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to ensure that the emergency lighting is available for evacuation in an emergency situation.
AD 99-23-15 · published Nov 12, 1999, effective Dec 17, 1999
Dornier Model 328-100 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Dornier Model 328-100 series airplanes, that requires replacement of a flight attendant panel and modification of its associated wiring. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent the disabling of the ``Fasten Seat Belt'' and ``No Smoking'' signs when they are required to be illuminated. Such disabling could result in the inability to instruct the passengers to extinguish their cigarettes and fasten their seat belts when required, which may contribute to passenger injury should a hard landing or in-flight turbulence be experienced.
AD 99-23-16 · published Nov 12, 1999, effective Dec 17, 1999
Airbus Model A330 and A340 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A330 and A340 series airplanes, that requires repetitive detailed visual inspections to detect cracking of the vertical flange of the inboard Z-stiffeners of the centerline panel of the fuselage belly fairing; and corrective actions, if necessary. This amendment also provides for optional terminating action for the repetitive inspections. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to detect and correct fatigue cracking of the vertical flange of the inboard Z-stiffeners of the centerline panel of the fuselage belly fairing, which could result in reduced structural integrity of the belly fairing.
AD 99-23-11 · published Nov 15, 1999, effective Dec 20, 1999
British Aerospace Model BAe 146 and Avro 146-RJ Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace Model BAe 146 and Avro 146-RJ series airplanes, that requires repetitive inspections to detect signs of chafing to the fuel feed pipe, and repair or replacement of the fuel feed pipe with a serviceable part, if necessary; and ensuring that responder units, electrical connector backshells, and associated wiring are undamaged and are positioned correctly to provide maximum clearance with the fuel pipe. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent damage to the fuel feed pipe, which could result in fuel leaks and an increased potential for fire on the airplane.
AD 99-23-19 · published Nov 16, 1999, effective Dec 21, 1999
Learjet Model 31, 31A, 35, 35A, and 60 Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Learjet Model 31, 31A, 35, 35A, and 60 airplanes, that requires a visual inspection of the spoiler actuators to determine the serial number of the spoiler actuators; and replacement of the spoiler actuators with new actuators, if necessary. This amendment is prompted by failure of a spoiler actuator piston rod during the first production flight of a Model 60 airplane due to an incomplete heat treatment process. The actions specified by this AD are intended to prevent failure of the spoiler actuator, which could result in the spoiler panel floating and inducing an uncommanded roll of the airplane.
AD 99-23-21 · published Nov 16, 1999, effective Dec 21, 1999
Boeing Model 757 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes, that requires a modification of the reverse thrust lever assemblies and replacement of the spring bumper assemblies of the thrust reverser sleeves with new assemblies. This amendment is prompted by an FAA review of the thrust reverser system on all transport category airplanes including the Boeing Model 757 series airplane. The actions specified by this AD are intended to prevent operation with an energized sync lock or malfunctioning sleeve locking devices, which could result in the deployment of a thrust reverser in flight and subsequent reduced controllability of the airplane.
AD 99-23-20 · published Nov 19, 1999, effective Dec 27, 1999
Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-100, -200, -300, -400, and -500 series airplanes. For certain airplanes, this AD requires installation of a transient suppression diode in the wiring circuit of the refueling valve-to-float switch of each fuel tank. For certain other airplanes, this AD requires replacement of the existing transient suppression diode with an improved diode. This AD also requires a functional test to verify proper installation of each diode, and corrective action, if necessary. This amendment is prompted by incidents of electrical fire during fueling of the airplane, due to a short circuit and overheating of a transient suppression diode. The actions specified by this AD are intended to prevent such conditions, which could result in electrical arcing and ignition of fuel vapors at the refueling receptacle for the fuel tanks, and consequent fire during airplane fueling.
AD 99-23-24 · published Nov 19, 1999, effective Dec 6, 1999
AlliedSignal, Instrument Landing System Navigation Receivers, as Installed in, but Not Limited to, Airbus Model A300 Series Airplanes and Boeing Model 747-100, -100B, -100B SUD, - 200B, -200F, -200C, -300, 747SR, and 747SP Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain instrument landing system (ILS) navigation receivers manufactured by AlliedSignal. This action requires replacement of certain resistors in the ILS navigation receiver with higher ohm resistors and replacement of the nameplate on the receiver with a new nameplate. This amendment is prompted by reports of ILS navigation receivers incorrectly indicating signals from the glideslope ground station during final approach. The actions specified in this AD are intended to ensure the ILS receiver provides the flight crew with accurate glideslope data. Inaccurate glideslope data could result in an approach off the glideslope, and, consequently, a landing short of the runway or a runway overrun.
AD 99-23-25 · published Nov 19, 1999, effective Dec 6, 1999
Fokker Model F27 Mark 050 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F27 Mark 050 series airplanes. This action requires replacement of the lighting plates of the fuel control panel and the electrical power control panel with new, improved lighting plates. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent internal short circuits in the fuel control and electrical power control panels, which could result in burning of the panels and consequent smoke in the flight deck area.
AD 99-24-02 · published Nov 19, 1999, effective Dec 6, 1999
Boeing Model 767-200 and -300 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 767-200 and -300 series airplanes. This action requires a one-time visual inspection to determine the part number and serial number of the lower drag strut of the nose landing gear (NLG); and corrective actions, if necessary. This amendment is prompted by reports of a fracture of the lower drag strut of the NLG, which was caused by a thin wall thickness condition that occurred during the manufacturing process. The actions specified in this AD are intended to prevent a fracture of the lower drag strut, which could result in collapse of the NLG.
AD 99-24-03 · published Nov 19, 1999, effective Dec 27, 1999
McDonnell Douglas Model MD-11 Series Airplanes
This amendment supersedes two existing airworthiness directives (AD), applicable to certain McDonnell Douglas Model MD-11 series airplanes, that currently require inspections in the lower center cargo compartment at frame 1681 to verify that a certain bracket and a certain open face nylon clamp were installed to a specific wire bundle support and to detect damage of the subject wire bundle; and corrective actions, if necessary. This amendment requires a similar inspection and corrective actions required by the existing AD's and removes certain airplanes from the applicability of the existing AD's. This amendment also adds a requirement to install a wire assembly support bracket, clamp, and spacer, or revise the wire assembly support bracket and clamp installation; as applicable. This amendment is prompted by an incident in which the insulation blanket in the lower center cargo compartment was found to be burnt due to a missing wiring harness support bracket/clamp on a wire bundle. The actions specified by this AD are intended to prevent sparks, smoke, and possible fire in the lower center cargo compartment.
AD 99-19-03 · published Nov 22, 1999, effective Dec 27, 1999
Sabreliner Model NA-265-40, NA-265-60, NA-70, and, NA-265-80 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Sabreliner Model NA-265-40, NA-265-60, NA-70, and NA-265-80 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.
AD 99-19-06 · published Nov 22, 1999, effective Dec 27, 1999
Mitsubishi Model YS-11 and YS-11A Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Mitsubishi Model YS-11 and YS-11A 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.
AD 99-19-07 · published Nov 22, 1999, effective Dec 27, 1999
Frakes Aviation Airplanes
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.
AD 99-19-08 · published Nov 22, 1999, effective Dec 27, 1999
Lockheed Model L-14 and L-18 Series Airplanes
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.
AD 99-19-09 · published Nov 22, 1999, effective Dec 27, 1999
Fairchild Model F-27 and FH-227 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Fairchild Model F-27 and FH-227 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.
AD 99-19-10 · published Nov 22, 1999, effective Dec 27, 1999
Aerospatiale Model ATR-42 and ATR-72 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Aerospatiale Model ATR-42 and ATR-72 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.
AD 99-19-11 · published Nov 22, 1999, effective Dec 27, 1999
Jetstream Model BAe ATP Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Jetstream Model BAe ATP 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.
AD 99-19-13 · published Nov 22, 1999, effective Dec 27, 1999
British Aerospace Model HS 748 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain British Aerospace Model HS 748 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.
AD 99-19-14 · published Nov 22, 1999, effective Dec 27, 1999
Saab Model SAAB SF340A, SAAB 340B, and SAAB 2000 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Saab SAAB SF340A, SAAB 340B, and SAAB 2000 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.
AD 99-19-15 · published Nov 22, 1999, effective Dec 27, 1999
CASA C-212 and CN-235 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain CASA C-212 and CN-235 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.
AD 99-19-16 · published Nov 22, 1999, effective Dec 27, 1999
Dornier Model Dornier 328-100 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Dornier Model Dornier 328-100 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.
AD 99-19-17 · published Nov 22, 1999, effective Dec 27, 1999
Lockheed Model 1329-23 and 1329-25 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Lockheed Model 1329-23 and 1329-25 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.
AD 99-19-18 · published Nov 22, 1999, effective Dec 27, 1999
Bombardier Model DHC-7 and DHC-8 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model DHC-7 and DHC-8 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.
AD 99-19-19 · published Nov 22, 1999, effective Dec 27, 1999
Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 Series Airplanes and Model F27 Mark 050 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F27 Mark 100, 200, 300, 400, 500, 600, and 700 series airplanes and Model F27 Mark 050 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.
AD 99-19-20 · published Nov 22, 1999, effective Dec 27, 1999
Short Brothers SD3-30, SD3-60, SD3- SHERPA, and SD3-60 SHERPA Series Airplanes.
This amendment adopts a new airworthiness directive (AD), applicable to certain Short Brothers SD3-30, SD3-60, SD3-SHERPA, and SD3-60 SHERPA 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.
AD 99-24-06 · published Nov 26, 1999, effective Jan 3, 2000
Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes; and Model 727-100 and -200 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 737-100, -200, -300, -400, and -500 series airplanes; and Model 727-100 and -200 series airplanes. This amendment requires a one-time inspection to determine the presence and condition of the breather plug in each fuel tank boost pump; and either installation of a new plug or replacement of the boost pump with a new or serviceable pump, if necessary. This amendment is prompted by a report that breather plugs were missing from fuel tank boost pumps. The actions specified by this AD are intended to prevent possible ignition of fuel vapor in the fuel tank boost pump, which could result in a fuel tank explosion in the event of a boost pump internal failure.
AD 99-24-07 · published Nov 26, 1999, effective Jan 3, 2000
Boeing Model 757 Series Airplanes Equipped With Rolls Royce Engines
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes equipped with Rolls Royce RB211 engines, that requires modification of the nacelle strut and wing structure. This amendment is prompted by reports indicating that the actual operational loads applied to the nacelle are higher than the analytical loads that were used during the initial design. Such an increase in loading can lead to fatigue cracking in primary strut structure prior to an airplane's reaching its design service objective. The actions specified by this AD are intended to prevent fatigue cracking in primary strut structure and consequent reduced structural integrity of the strut.
AD 99-24-08 · published Nov 26, 1999, effective Dec 13, 1999
Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes
This amendment supersedes an existing airworthiness directive (AD), applicable to all Boeing Model 737-100, -200, -300, -400, and - 500 series airplanes, that currently requires, for certain airplanes, repetitive replacements of the airplane battery with a new or reconditioned battery and replacement of the battery charger with a new or serviceable battery charger; performing repetitive tests to determine the condition of a certain diode of the Generator Control Units (GCU); and corrective actions, if necessary. This amendment adds, for certain other airplanes, a requirement for repetitive replacements of the airplane battery with a new or reconditioned battery, and clarifies a diode test requirement. This amendment is prompted by an incident during which all electrical power was lost due to a combination of a weak or depleted battery and the failure of a certain diode of the GCU. The actions specified in this AD are intended to prevent failure of all electrically powered airplane systems, which could result in the inability to continue safe flight and landing.
AD 99-24-09 · published Nov 26, 1999, effective Jan 14, 2000
Pilatus Aircraft Ltd. Models PC-12 and PC-12/45 Airplanes
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.
AD 99-24-11 · published Nov 30, 1999, effective Jan 4, 2000
Boeing Model 757-200 and -300 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 757-200 and -300 series airplanes, that requires modification of the slide/raft evacuation system by installing a girt reinforcement chafing patch. This amendment is prompted by reports of holes in the inflatable area of the slide/raft evacuation system due to chafing against the installation support bracket. The actions specified by this AD are intended to prevent holes in the inflatable portion of the slide/raft evacuation system, which could result in the slide/raft being less effective as a raft during an emergency water landing.
AD 99-24-12 · published Nov 30, 1999, effective Jan 4, 2000
Lockheed Model L-1011-385 Series Airplanes
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Lockheed Model L-1011-385 series airplanes, that currently requires revision of the Airplane Flight Manual (AFM) to prohibit operation of the fuel boost pumps when fuel quantities are below certain levels, and to add maintenance procedures for operating the airplane under certain conditions. That AD also requires the installation of a placard on the engineer's fuel panel to advise the maintenance crew that operation of the fuel boost pumps is prohibited under certain conditions. This amendment adds a terminating modification for the requirements of the existing AD. This amendment is prompted by reports of internal electrical failures in the fuel boost pump of the wing fuel tanks that could result in either electrical arcing or localized overheating. The actions specified by this AD are intended to prevent such electrical arcing or overheating, which could breech the protective housing of the fuel boost pump and expose it to fuel vapors and fumes, and consequent potential fire or explosion in the wing fuel tank.
AD 99-24-13 · published Nov 30, 1999, effective Dec 15, 1999
Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-135 and EMB-145 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to all EMBRAER Model EMB-135 and EMB-145 series airplanes. This action requires a revision to the Airplane Flight Manual (AFM) to prohibit in-flight operations of the autopilot coupled to flight director #2 during certain conditions; and installation of an associated warning placard. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified in this AD are intended to prevent failure of the autopilot to automatically disconnect from flight director #2, as intended, at a low altitude during windshear conditions. Such failure could result in reduced controllability of the airplane.
AD 99-24-16 · published Nov 30, 1999, effective Jan 4, 2000
Boeing Model 747 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that requires removal of cable guards in the lateral control system and replacement with new, improved cable guards. This amendment is prompted by reports of high control wheel forces and restricted control wheel movement. The actions specified by this AD are intended to prevent deterioration of cable guards in the lateral control system, which could result in a jam of the lateral control system and consequent reduced lateral controllability of the airplane.
AD 99-24-17 · published Nov 30, 1999, effective Jan 4, 2000
Saab Model SAAB 2000 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Saab Model SAAB 2000 series airplanes, that requires modification of the airplane by coldworking fastener holes at the front and rear wing spars and by installing modified support angles for the lower trailing edge panel of the wing. This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent fatigue cracking in the lower spar cap of the wing rear spar and in the lower skin at the wing front spar, just outside the nacelle, on the left-hand and right-hand side of the airplane, which could result in fuel leakage and consequent fire in or around the wing.
AD 99-25-01 · published Nov 30, 1999, effective Jan 4, 2000
Raytheon Model BAe.125 Series 1000A and 1000B, and Model Hawker 1000 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Raytheon Model BAe.125 series 1000A and 1000B, and Model Hawker 1000 series airplanes, that requires inspection of P1 pitot pipes for chafing or damage, and various follow-on actions. This amendment is prompted by reports of P1 pitot pipes chafing against adjacent flight control cables. The actions specified by this AD are intended to prevent a hole in the P1 pitot pipes, which would lead to erroneous input to the instrumentation and warning systems associated with the pilot's instruments.
AD 99-25-02 · published Nov 30, 1999, effective Dec 15, 1999
Boeing Model 737-100, -200, -300, -400, and -500 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 737-100, -200, -300, -400, and -500 series airplanes. This action requires a one-time inspection to verify correct installation of the fastener that connects the input rod of the spoiler mixer mechanism to the torque tube crank, and corrective actions, if necessary. For certain airplanes, this action requires replacement of the nut, bolt, and cotter pin that connects the input rod of the spoiler mixer mechanism to the torque tube crank with a new or serviceable nut, bolt, and cotter pin. This amendment is prompted by reports indicating numerous discrepancies in the installation of the fastener that connects the input rod of the spoiler mixer mechanism to the torque tube crank. The actions specified in this AD are intended to prevent the linkage between the ratio changer input rod and the aft aileron control quadrant from becoming disconnected, which could result in reduced controllability of the airplane.
AD 99-23-01 · published Nov 3, 1999, effective Dec 8, 1999
Robinson Helicopter Company (Robinson) Model R44 Helicopters
This amendment supersedes an existing airworthiness directive (AD), applicable to Robinson Model R44 helicopters, that currently requires removing and replacing the pilot's cyclic control grip assembly (grip assembly) with an airworthy grip assembly. This amendment requires the same actions as the current AD but would change a part number (P/N) referenced in the current AD. This amendment is prompted by the discovery of an error in the P/N of the current AD. The actions specified by this AD are intended to prevent use of a grip assembly that may crack, resulting in failure of the grip assembly and subsequent loss of control of the helicopter.
AD 99-23-02 · published Nov 3, 1999, effective Dec 8, 1999
Eurocopter France Model SA-365N, SA- 365N1, and AS-365N2 Helicopters
This amendment adopts a new airworthiness directive (AD), applicable to Eurocopter France Model SA-365N, SA-365N1, and AS-365N2 helicopters, that requires replacing certain defective electrical modules with airworthy electrical modules. This amendment is prompted by the discovery of several defective electrical modules. The actions specified by this AD are intended to prevent loss of electrical continuity, which could cause loss of critical rotorcraft electrical systems and subsequent loss of control of the helicopter.
AD 99-23-03 · published Nov 4, 1999, effective Nov 19, 1999
Bell Helicopter Textron Canada Model 430 Helicopters
This amendment adopts a new airworthiness directive (AD) that is applicable to Bell Helicopter Textron Canada (BHTC) Model 430 helicopters. This action requires verifying the torque on each vertical fin attachment bolt (bolt); modifying the vertical fin and tailboom and replacing the attachment hardware; and re-verifying the torque on the bolts after inspecting the fittings. This amendment is prompted by a report of a loose vertical fin, which was discovered during a post- flight inspection. The actions specified in this AD are intended to prevent loss of torque of the bolts, which could lead to fracture of the bolts, separation of the vertical fin from the helicopter, and subsequent loss of control of the helicopter.
AD 99-23-04 · published Nov 4, 1999, effective Nov 19, 1999
Bell Helicopter Textron Canada Model 222, 222B, and 222U Helicopters
This amendment adopts a new airworthiness directive (AD) that is applicable to Bell Helicopter Textron Canada (BHTC) Model 222, 222B, and 222U helicopters. This action requires verifying the torque on each vertical fin attachment bolt (bolt); inspecting the vertical fin and tailboom fittings for cracks, elongation of bolt holes, distortion and corrosion; and re-verifying the torque on the bolts after inspecting the fittings. This amendment is prompted by a report of a loose vertical fin, which was discovered during a post-flight inspection. The actions specified in this AD are intended to prevent loss of torque of the bolts, which could lead to fracture of the bolts, separation of the vertical fin from the helicopter, and subsequent loss of control of the helicopter.
AD 99-23-23 · published Nov 4, 1999, effective Dec 1, 1999
Bell Helicopter Textron, Inc. Helicopters
This amendment adopts a new airworthiness directive (AD) applicable to Bell Helicopter Textron, Inc. (BHTI) Model 412, 412EP, and 412CF helicopters. This action requires inspecting and measuring the thickness of certain main rotor yoke assemblies. This AD also requires adding 500 hours time-in-service (TIS) to the total time for main rotor yoke assemblies that measure below 0.478-inch thickness and noting the measurement and added TIS on the component history card or equivalent record. This amendment is prompted by a report of an emergency landing due to severe main rotor vibration on a BHTI Model 412 helicopter. Subsequent fatigue analysis indicates that the main rotor yoke assembly (yoke) does not have the anticipated service life when manufactured below 0.478-inch thickness. The actions specified in this AD are intended to prevent a fatigue failure of the yoke, loss of a main rotor blade, and subsequent loss of control of the helicopter.
AD 99-23-07 · published Nov 5, 1999, effective Nov 22, 1999
Eurocopter France Model SA330F, G, J, and AS332C, L, and L1 Helicopters
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Eurocopter France Model SA330F, G, J, and AS332C, L, and L1 helicopters. This action requires inserting statements into the Limitations section of the Rotorcraft Flight Manual (RFM) prohibiting flight under certain atmospheric conditions. This amendment is prompted by one incident in which a Multi-Purpose Air Intake (MPAI) inlet seal deflated after the P2 air system line, which feeds the seal, clogged due to the formation of ice. The actions specified in this AD are intended to prevent clogging of the MPAI seal P2 air system line due to ice formation, which could result in deflation of the MPAI seal, loss of engine power, and subsequent loss of control of the helicopter.
AD 99-23-18 · published Nov 15, 1999, effective Nov 30, 1999
Bell Helicopter Textron Canada Model 407 Helicopters
This amendment adopts a new airworthiness directive (AD) applicable to Bell Helicopter Textron Canada (BHTC) Model 407 helicopters. This action requires, before further flight, revising the life limits for certain parts and replacing each part that has exceeded its life limit. The AD also requires revising the applicable component history cards or equivalent records and the Airworthiness Limitations Schedule of the BHTC Model 407 maintenance manual to reflect these new life limits. This amendment is prompted by an engineering evaluation of additional flight test data, which resulted in redefining the service life for certain parts and revising the Airworthiness Limitations Schedule. The actions specified in this AD are intended to prevent a fatigue failure of certain parts that may have exceeded revised life limits and subsequent loss of control of the helicopter.
AD 99-23-17 · published Nov 16, 1999, effective Dec 21, 1999
Eurocopter France Model AS 332C, L, and L1 Helicopters
This amendment adopts a new airworthiness directive (AD), applicable to Eurocopter France Model AS 332C, L, and L1 helicopters, that requires a one-time inspection of the length of the main gearbox epicyclic module upper casing bearing attachment bolts (attachment bolts), and if they exceed a certain length, replacing the epicyclic module to preclude a potential interference between the attachment bolts and the 2nd stage planet gear cage web. This amendment is prompted by a report of interference between the attachment bolts and the second stage planet gear cage web of the epicyclic module in the main gearbox. The actions specified by this AD are intended to prevent failure of the second stage planet gear of the main gearbox, loss of main rotor drive and subsequent loss of control of the helicopter.
AD 99-24-05 · published Nov 18, 1999, effective Dec 3, 1999
Eurocopter Deutschland GMBH (ECD) Model BO-105CB-5 and BO-105-CBS-5 Helicopters
This amendment supersedes an existing emergency priority letter airworthiness directive (AD), applicable to ECD Model BO-105CB-5 and BO-105-CBS-5 helicopters, that currently requires, before further flight, creating a component log card or equivalent record and determining the calendar age and number of flights on each tension- torsion (TT) strap. This amendment requires the same actions as the emergency priority letter AD and additionally clarifies the compliance time requirements specified in the emergency priority letter AD. This amendment is prompted by an accident in which a main rotor blade (blade) separated from an ECD Model MBB-BK 117 helicopter due to fatigue failure of a TT strap. The same part number TT strap is also used on the ECD Model BO-105 helicopter. The actions specified by this AD are intended to prevent failure of a TT strap, loss of a blade, and subsequent loss of control of the helicopter.
AD 99-24-18 · published Nov 30, 1999, effective Dec 15, 1999
Eurocopter France Model AS-350B, B1, B2, B3, BA, and D, and AS-355E, F, F1, F2, and N Helicopters
This amendment supersedes an existing airworthiness directive (AD), applicable to Eurocopter France Model AS-350B, B1, B2, B3, BA, and D, and AS-355E, F, F1, F2, and N helicopters, that requires inspecting certain versions of the tail rotor spider plate bearing (bearing) for the proper rotational torque, axial play, and any brinelling of the bearing. This amendment has the same inspection requirements as the current AD. Also, this AD expands the applicability to include additional part numbers (P/N's) and reduces the initial and recurring inspection compliance times. This amendment is prompted by additional reports of deterioration of the bearing. The actions specified by this AD are intended to prevent seizure of the bearing, loss of tail rotor control, and subsequent loss of control of the helicopter.
AD 99-23-26 · published Nov 5, 1999, effective Dec 6, 1999
General Electric Aircraft Engines Engines
This amendment supersedes an existing airworthiness directive (AD), applicable to General Electric Aircraft Engines (GE) CF34 series turbofan engines, that currently requires installation of a main fuel control (MFC) that incorporates a flange vent groove and installation of an MFC with improved overspeed protection. This amendment requires replacement of Buna-N O-rings with Viton O-rings or a new location of the vent groove on the MFC mounting flange, or installation of an MFC with improved overspeed protection. This amendment is prompted by the determination that the location of the reworked vent groove was ineffective, and that replacement of Buna-N preformed packings with Viton preformed packings will alleviate the unsafe condition. The actions specified by this AD are intended to prevent uncommanded engine accelerations, which could result in an engine overspeed, uncontained engine failure, and damage to the airplane. The incorporation by reference of GE Alert ServiceBulletins (ASB s) No. A73-33, dated November 21, 1997; A73-33, Revision 1, dated May 29.1998; and A73-19, Revision 1, dated February 20, 1998, was approved by the Director of the Federal Register as of July 27, 1999. The incorporation by reference of GE ASB No. CF34AL 73-A0025, dated July 7, 1999; CF34BJ 73-A0040, dated July 7, 1999; CF34AL S/B 73-0026, dated August 12, 1999; and CF34BJ S/B 73-0041, dated August 12,1999, is approved by the Director of the Federal Register as of December 6, 1999. Comments for inclusion in the Rules Docket must be received on or before January 18, 2000.
AD 99-24-01 · published Nov 17, 1999, effective Jan 18, 2000
Rolls-Royce plc Tay 620-15, Tay 650-15, and Tay 651-54 Series Turbofan Engines
This amendment adopts a new airworthiness directive (AD), applicable to Rolls-Royce plc Tay 620-15, Tay 650-15, and Tay 651-54 series turbofan engines, that requires initial and repetitive visual inspections of the emergency fuel shutoff cable for broken strands or failed cables, and, if necessary, replacement with serviceable parts. This amendment is prompted by reports of broken strands and failed emergency fuel shutoff cables. The actions specified by this AD are intended to prevent emergency fuel shutoff cable failure, which could result in the non-operation of the emergency fuel shut-off system in the event of a low pressure shaft failure.
AD 98-21-22 R1 · published Nov 19, 1999, effective Jan 18, 2000
Pratt & Whitney JT9D Series Turbofan Engines
This amendment revises an existing airworthiness directive (AD), applicable to Pratt & Whitney JT9D series turbofan engines, that currently requires initial and repetitive eddy current inspections (ECI) of 14th and 15th stage high pressure compressor (HPC) disks for cracks, and removal of cracked disks and replacement with serviceable parts. This amendment revises the definition of a shop visit to make compliance less restrictive, and adds references to a Nondestructive Inspection Procedure attached to applicable service bulletins. This amendment is prompted by feedback from operators saying that the shop visit definition in the current AD made AD compliance unnecessarily restrictive. The actions specified by this AD are intended to prevent 14th and 15th stage HPC disk rupture, which could result in an uncontained engine failure and damage to the airplane.
AD 98-24-03 R1 · published Nov 19, 1999, effective Dec 27, 1999
BMW Rolls-Royce GmbH Models BR700- 710A1-10 and BR700-710A2-20 Turbofan Engines
This amendment revises an existing airworthiness directive (AD), applicable to BMW Rolls-Royce GmbH (BRR) Models BR700-710A1-10 and BR700-710A2-20 turbofan engines. The existing AD requires initial and repetitive visual inspections of the engine compressor and combustion core fairings (also referred to as the engine core fairings) and fasteners for correct installation and damage, and verification that the engine core fairing fasteners are torqued to a higher torque value. This amendment increases the repetitive inspection interval to 150 hours time-in-service (TIS) following an initial inspection and follow-on inspection at the current 50 hours TIS interval. This amendment also requires an initial inspection and follow-on inspection at a 50 hours TIS interval following any engine core fairing or fastener removal, repair, or replacement. Repair of engine core fairings has been added as an alternate to engine core fairing replacement, and an inspection for loose engine core fairing(s) has been included to verify correct installation on the engine. Finally, this amendment adds a new paragraph in the compliance section allowing the option to incorporate redesigned core engine fairings as the terminating action to the required repetitive inspections. This amendment is prompted by results of repetitive inspections that indicate that the inspection interval can be increased safely, and by introduction of redesigned engine core fairings. The actions specified by this AD are intended to prevent engine compressor or combustion core fairing detachment and damage to the engine bypass duct, resulting in engine failure and damage to the airplane.
AD 99-24-14 · published Nov 26, 1999, effective Dec 13, 1999
General Electric Company CF6-80E1A2 Series Turbofan Engines
This amendment adopts a new airworthiness directive (AD) that is applicable to General Electric Company (GE) CF6-80E1A2 series turbofan engines. This action requires removing from service stage 2 high pressure turbine (HPT) disks and impeller spacers prior to exceeding new, lower cyclic life limits and imposes a drawdown program for those parts that currently exceed, or will exceed, the new lower limits. This amendment is prompted by the results of a refined low cycle fatigue (LCF) analysis. The actions specified in this AD are intended to prevent LCF cracking and failure of stage 2 HPT disks and impeller spacers, which could result in an uncontained engine failure and damage to the aircraft.
AD 99-24-15 · published Nov 29, 1999, effective Jan 28, 2000
General Electric Company CF6 Series Turbofan Engines
This amendment supersedes an existing airworthiness directive (AD), applicable to General Electric Company (GE) CF6 series turbofan engines, that currently requires initial and repetitive ultrasonic and eddy current inspections of high pressure compressor rotor (HPCR) stage 3-9 spools for cracks. This amendment defines more aggressive inspection intervals for certain HPCR stage 3-9 spools, adds CF6-80E1 engines to the inspection program, adds inspection requirements for spools manufactured from 8 inch diameter billet, adds inspection requirements for stage 3-5 blade slot bottoms, and adds inspection requirements for web and hub-to-web transition areas. This amendment is prompted by analysis of recent HPCR stage 3-9 spool inspection results and separations, and assessment of the adequacy of the existing program to prevent HPCR stage 3-9 spool cracking and separation. As a result of that assessment, the FAA has determined there is a need to make changes to the existing AD. The actions specified by this AD are intended to prevent HPCR stage 3-9 spool cracking and separation, which can result in an uncontained engine failure and aircraft damage.
AD 99-24-10 · published Nov 30, 1999, effective Jan 14, 2000
Precise Flight, Inc. Model SVS III Standby Vacuum Systems
This amendment adopts a new airworthiness directive (AD) that applies to all aircraft equipped with Precise Flight, Inc. Model SVS III standby vacuum systems installed in accordance with the applicable supplemental type certificate (STC) or through field approval. This AD requires incorporating revised operating limitations for the affected standby vacuum systems into the airplane flight manual (AFM), and repetitively inspecting the push-pull cable, vacuum lines, saddle fittings, and shuttle valve for correct installation and damage (wear, chafing, deterioration, etc.). This AD also requires immediately correcting any discrepancy found and conducting a function test of the vacuum system after the inspections. This AD is the result of reports of shuttle valve failure and standby vacuum system malfunction on aircraft. The actions specified by this AD are intended to detect and correct problems with the standby vacuum system before failure or malfunction and to provide operating procedures for the pilot regarding the use and limitations of this system.
AD 99-23-22 · published Nov 12, 1999, effective Nov 29, 1999
Various Transport Category Airplanes Equipped With Mode ``C'' Transponder(s) With Single Gillham Code Altitude Input
This amendment adopts a new airworthiness directive (AD) that is applicable to various transport category airplanes equipped With certain Mode ``C'' transponder(s) with single Gillham code altitude input. This action requires repetitive tests to detect discrepancies of the Mode ``C'' transponder(s), air data computer, and certain wiring connections; and corrective actions, if necessary. This amendment is prompted by reports that, during level flight, the Traffic Alert Collision Avoidance System (TCAS II) issued false advisories that directed the flightcrew to change course and either climb or descend. The actions specified in this AD are intended to prevent such false advisories due to inaccurate airplane altitude reporting, which could result in the flightcrew deviating the airplane from its assigned flight path and a possible mid-air collision.
