26 Airworthiness Directives: 20 airplane, 2 rotorcraft, 1 engine, 3 appliance.
AD 96-13-09 · published Oct 1, 1996, effective Jul 15, 1996
Jetstream Model 4101 Airplanes
This amendment clarifies information in an existing airworthiness directive (AD), applicable to all Jetstream 4101 airplanes, that currently requires a review of maintenance records to determine the time-in-service of the bearings in the starter/generators of both engines. It also establishes a new time-in-service limit for the bearings, and requires replacement of the starter/generator unit with a serviceable unit, if necessary. The actions specified in that AD are intended to prevent failure of the bearings of the starter/ generator, which could cause severe vibrations and resultant in-flight shutdown of one or both engines. This amendment clarifies the requirements of the current AD by specifying the name of the manufacturer of the starter/generator units that are affected by the requirements of this AD.
AD 96-21-02 · published Oct 8, 1996, effective Oct 15, 1996
Bombardier Model CL-600-2B19 (Regional Jet Series 100) Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100) series airplanes. This action requires revising the Airplane Flight Manual (AFM) to require the flight crew to check, and reset, if necessary, certain instrument settings prior to each takeoff and after any event during which generators are switched. This amendment is prompted by reports indicating that the co-pilot's air data reference system has intermittently failed following the switching of power between generators. The actions specified in this AD are intended to prevent uncommanded changes in certain instrument settings on the co-pilot's display, which, if not corrected, can result in confusion among the flight crew about the correct position and flight configuration of the airplane.
AD 96-18-10 · published Oct 9, 1996, effective Oct 9, 1996
Airbus SAS Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A300-600 and A310 series airplanes, that requires an inspection to detect defects of the directional pilot valves (DPV); and replacement of any defective DPV with a new DPV, or deactivation of the thrust reverser system, if necessary. This amendment is prompted by a report indicating that, during a maintenance check, an uncommanded deployment and stowage of the thrust reverser occurred due to improperly modified DPV's. The actions specified by this AD are intended to prevent uncommanded deployment and stowage of the thrust reverser during maintenance activities, as a result of improperly modified DPV's, which could result in injury to maintenance personnel or other people on the ground.
AD 96-18-12 · published Oct 9, 1996, effective Oct 9, 1996
Airbus Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that requires an inspection to detect damage to the electrical wiring of the fuel tank of the wings and to verify if the proper P-clip is installed in the electrical wiring. This amendment also requires re-fitting any proper P-clip, replacing any improper P-clip with a new P-clip, and repairing damaged electrical wiring. This amendment is prompted by a report that incorrect P-clips were found installed in the electrical wiring of the fuel system on these airplanes. The actions specified by this AD are intended to ensure that the proper P-clips are installed. Improper P-clips could fail to adequately safeguard the fuel tank of the wing against a lightning strike, which could result in electrical arcing and resultant fire.
AD 96-20-01 · published Oct 10, 1996, effective Oct 25, 1996
Boeing Model 777-200 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 777-200 series airplanes. This action requires a one-time inspection to determine the serial numbers of various switch modules on the overhead panel and control stand, and replacement of switch modules with new improved modules. This AD also requires repetitive tests of the cargo fire extinguishing system, and one-time tests of the fuel crossfeed valve, pack, trim air, and alternate flap control switches; and repair or replacement of switch modules with new improved modules, if necessary. This amendment is prompted by a report indicating that the flight crew received a warning of fire in the forward cargo compartment during flight; later inspection revealed that the metered fire bottles failed to discharge due to suspected contamination of the arming switch contacts of the cargo fire extinguishing system. The actions specified in this AD are intended to minimize contamination of the switch contacts and consequent failure of the switches, which, if not corrected, could result in inability of the flight crew to activate the cargo fire extinguishing, fuel, air conditioning, and alternate flap systems.
AD 96-20-10 · published Oct 10, 1996, effective Oct 25, 1996
Lockheed Aircraft Corporation Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Lockheed Model L-1011-385 series airplanes. This action requires inspections to detect cracking of the canted pressure bulkhead at fuselage station (FS) 1212, and inspections to detect cracking of the web at the fastener rows of the vertical stiffener-to-web; and repair or replacement of the web with a new web, if necessary. This amendment is prompted by a report of fatigue cracking of the canted pressure bulkhead at FS 1212. The actions specified in this AD are intended to detect and correct such fatigue cracking, which could result in blowout of a panel between adjacent stiffeners and consequent cabin depressurization.
AD 96-21-01 · published Oct 10, 1996, effective Nov 14, 1996
McDonnell Douglas Corporation Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-9 series airplanes, that requires either replacement or modification of the hydraulic damper assembly. This amendment is prompted by reports indicating that insufficient damping of the hydraulic shimmy damper in the main landing gear (MLG) can allow high torsional vibration to occur. The actions specified by this AD are intended to prevent such vibration, which can damage the MLG assembly and lead to its collapse.
AD 96-21-03 · published Oct 15, 1996, effective Dec 10, 1996
Piper Aircraft Inc. Airplanes
This amendment adopts a new airworthiness directive (AD) that applies to The New Piper Aircraft, Inc. (Piper) PA31, PA31P, PA31T, and PA42 series airplanes. This action requires inspecting for cracks beneath and in the area of the inboard aileron hinge bracket on the aileron spar and rib using dye penetrant methods, replacing any cracked aileron spar or rib, and replacing the inboard aileron hinge bracket with a hinge bracket of improved design. Several reports of cracks in the vicinity of the inboard aileron hinge bracket, aileron spar, and aileron rib prompted this proposed action. The actions specified by the proposed AD are intended to prevent structural failure of the aileron caused by cracks in the area of the inboard aileron hinge bracket, which, if not detected and corrected, could result in loss of control of the airplane.
AD 96-18-18 · published Oct 16, 1996, effective Oct 16, 1996
Airbus Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Airbus Model A300-600 series airplanes, that requires inspections to detect cracking of the upper radius of the forward fitting of frame 47, and repair, if necessary. This amendment is prompted by results of full-scale fatigue testing, which revealed cracking in the upper radius of frame 47. The actions specified by this AD are intended to prevent such fatigue cracking, which could result in reduced structural integrity of frame 47 of the fuselage.
AD 96-21-10 · published Oct 18, 1996, effective Nov 22, 1996
Short Brothers Model SD3-60 SHERPA Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Short Brothers Model SD3-60 SHERPA series airplanes, that requires revising the Airplane Flight Manual (AFM) to provide the flight crew with recognition cues for, and procedures for exiting from, severe icing conditions, and to limit or prohibit the use of various flight control devices. This amendment is prompted by results of a review of the requirements for certification of the airplane in icing conditions, new information on the icing environment, and icing data provided currently to the flight crews. The actions specified by this AD are intended to minimize the potential hazards associated with operating the airplane in severe icing conditions by providing more clearly defined procedures and limitations associated with such conditions.
AD 88-09-05 R1 · published Oct 21, 1996, effective Oct 21, 1996
Bombardier Inc. Airplanes
AD 96-21-05 · published Oct 21, 1996, effective Nov 29, 1996
Fairchild Aircraft SA226 and SA227 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that applies to certain Fairchild Aircraft SA226 and SA227 series airplanes that do not have a certain elevator torque tube installed. This action requires drilling inspection access holes in the elevator torque tube arm, inspecting the elevator torque tube for corrosion, replacing any corroded elevator torque tube, and applying a corrosion preventive compound. Several reports of corrosion found in the elevator torque tube area on the affected airplanes prompted this action. The actions specified by this AD are intended to prevent failure of the flight control system caused by a corroded elevator torque tube, which could result in loss of control of the airplane.
AD 96-19-12 · published Oct 23, 1996, effective Oct 23, 1996
Various Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0100 series airplanes, that requires inspection and adjustment of the torque value of the attaching parts of the interlock mechanism of the large cargo doors, removal of a spring from that mechanism, and installation of a new microswitch bracket. This amendment is prompted by a report indicating that a spring on the interlock lever of the large cargo doors may become disconnected or the lever may become jammed in the "activated" state. The actions specified by this AD are intended to prevent the spring from becoming disconnected or the lever from jamming. If other failures occur, the flightcrew could dispatch the airplane with improperly locked cargo doors; this condition could result in the opening and/or separation of the cargo doors while the airplane is in flight and subsequent rapid decompression and/or structural damage to the airplane.
AD 96-19-15 · published Oct 23, 1996, effective Oct 23, 1996
Bombardier Inc. Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B16 and CL-600-2B19 series airplanes, that requires a one-time inspection of the spring bungee assembly of the nose landing gear (NLG) to ensure proper torque of the collar and correct clearance between the collar and the body of the bungee, and replacement of the spring bungee assembly with a serviceable unit, if necessary. This amendment is prompted by reports of failure of the NLG to extend when the landing gear selector was placed in the "DOWN" position, and failure of the NLG doors to open when the NLG door switch was set in the "SAFETY/DOOR OPEN" position; these conditions may have been caused by a reduced stroke of the spring bungee. The actions specified by this AD are intended to prevent improper operation of the NLG door and consequent inability to extend the NLG due to a reduced stroke of the spring bungee.
AD 96-21-06 · published Oct 24, 1996, effective Nov 29, 1996
Boeing Model 767 Series Airplanes
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing 767 series airplanes, that currently requires inspections and various follow-on actions to detect cracking and corrosion of the aft trunnion of the outer cylinder of the main landing gear (MLG). That action also provides for the optional termination of the inspections by repairing the outer cylinder and installing new aft trunnion bushings. That AD was prompted by reports of failure of several MLG due to fracture of the aft trunnion outer cylinder. This amendment requires operators to implement the previously optional terminating action. The actions specified by this AD are intended to prevent the collapse of the MLG due to stress corrosion cracking of the aft trunnion of the outer cylinder.
AD 96-21-07 · published Oct 24, 1996, effective Nov 29, 1996
Short Brothers PLC Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Shorts Model SD3-30, -60, and -SHERPA series airplanes, that requires a visual inspection to detect signs of exfoliation corrosion on the brackets of the flap hydraulic units, and rework or replacement of corroded brackets. This amendment is prompted by a report that exfoliation corrosion was found on the brackets of the flap hydraulic units. The actions specified by this AD are intended to prevent such corrosion, and consequent reduced structural integrity of the brackets of the flap hydraulic units, which could result in the loss of the flap control and consequent reduced controllability of the airplane.
AD 96-21-08 · published Oct 24, 1996, effective Nov 29, 1996
Short Brothers PLC Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Short Brothers Model SD3-30 and SD3-SHERPA series airplanes, that requires inspections of the vertical fin-to-tailplane joint to detect any loose bolts; and, if necessary, inspections to detect elongation of bolt holes, and replacement with new bolts, if necessary. Additionally, this amendment requires inspections of the upper shear angle to detect pulled or loose rivets, and replacement of the shear angle using new rivets, if necessary. This amendment is prompted by reports of loose bolts in the vertical fin-to-tailplane joint and pulled or loose rivets in an upper shear angle. The actions specified by this AD are intended to prevent reduced structural integrity of the vertical fin to tailplane joint due to such discrepancies of the bolts or rivets.
AD 96-21-11 · published Oct 24, 1996, effective Dec 16, 1996
Piper Aircraft Inc. Airplanes
This amendment supersedes Airworthiness Directive (AD) 93-25-08, which currently requires replacing the main landing gear (MLG) actuator reinforcement bracket with a part of improved design on certain The New Piper Aircraft, Inc. (Piper) PA31, PA31P, and PA31T series airplanes. This AD action will require the same action as AD 93-25-08. An incorrect designation of Piper Model PA31-310 airplanes made in AD 93-25-08 prompted the proposed AD action. The actions specified by this AD are intended to prevent the MLG from extending, when not selected and while the airplane is in flight, caused by actuator reinforcement bracket failure, which could result in substantial airplane damage or loss of control of the airplane.
AD 96-20-09 · published Oct 25, 1996, effective Oct 25, 1996
BAE Systems (Operations) Limited Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Jetstream Model HS 748 series airplanes. This action requires a one-time inspection to ensure proper operation, positioning, and lubrication of the aileron, rudder, and elevator cable tensioners; gust lock levers; and cable pressure seals. It also requires a revision to the maintenance program to include these inspections on a repetitive basis. This amendment is prompted by reports of seizure and consequent jamming of the flight control cable tension regulators and gust lock mechanisms. The actions specified in this AD are intended to prevent the flight control cable tension regulators from jamming, which could result in the inability to achieve full deflection of the associated flight control surfaces, and lead to reduced controllability of the airplane.
AD 96-22-12 · published Oct 29, 1996, effective Dec 13, 1996
Textron Aviation Inc. Airplanes
This amendment adopts a new airworthiness directive (AD) that applies to certain Raytheon Aircraft Corporation (Raytheon) Models 1900C, 1900D, and 2000 airplanes. This action requires inspecting (one-time) the fuel filter assemblies to detect any bypass valve that is glued shut. If a bypass valve is glued shut, the AD requires replacing the associated fuel filter assembly. Three in-flight occurrences in which the low fuel pressure light illuminated prompted this action. In each of the instances, a bypass valve on the affected airplane engine was glued shut with anaerobic thread lock adhesive and when the fuel filter became clogged, proper fuel flow to the engine was not obtained. The actions specified by this AD are intended to prevent lack of fuel to the engine and eventual engine shutdown caused by a clogged fuel filter and a contaminated fuel filter bypass valve.
AD 96-21-12 PL · published 1996
Bell Helicopter Textron (Canada) Helicopters
AD 96-18-22 · published Oct 10, 1996, effective Oct 25, 1996
Robinson Helicopter Company Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 96-18-22 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (Robinson) Model R44 helicopters by individual letters. This AD requires an inspection of the mating surfaces of the main rotor gearbox (gearbox) components for pitting, elongated bolt holes, or machining grooves, and replacement of the gearbox if elongated bolt holes, machining grooves, or an improper amount of pitting is discovered; and replacement of the 18 bolts and washers that attach the gear to the gear carrier assembly (gear carrier). This amendment is prompted by an inflight failure of the gearbox on a French-registered Model R44 helicopter that resulted in an accident. The actions specified by this AD are intended to prevent loosening of the bolts securing the gear to the gear carrier, which could lead to fatigue failure of the gear carrier within the gearbox, andsubsequent loss of power to the main rotor which could lead to a forced landing.
AD 96-18-16 · published Oct 10, 1996, effective Dec 9, 1996
CFM International, S.A. Engines
This amendment adopts a new airworthiness directive (AD), applicable to CFM International (CFMI) CFM56-2/-2A/-2B/-3/-3B/-3C/-5 series turbofan engines, that requires part number reidentification of certain low pressure turbine rotor (LPTR) stub shafts and conical supports, and reduction of the low cycle fatigue (LCF) retirement lives for these reidentified parts. This amendment is prompted by the results of a refined life analysis performed by the manufacturer which revealed minimum calculated LCF lives significantly lower than published LCF retirement lives. The actions specified by this AD are intended to prevent an LCF failure of the LPTR stub shaft and conical support, which could result in an uncontained engine failure and damage to the aircraft.
AD 96-20-07 · published Oct 2, 1996, effective Nov 14, 1996
JanAero Devices B-Series Combustion Heaters, Models B1500, B2030, B3040, and B4050 (formerly owned by Janitrol, C&D, FL Aerospace, and Midland-Ross Corporation)
This amendment supersedes Airworthiness Directive (AD) 82-07- 03, which currently requires repetitively testing (pressure decay) the combustion tube of JanAero Devices B-Series combustion heaters, Models B1500, B2030, B3040, and B4050, that are installed on aircraft, and overhauling any heater that does not pass one of these pressure decay tests. This action retains the pressure decay test and possible heater overhaul requirements of AD 82-07-03; and requires repetitive operational testing of the combustion air pressure switch, and replacing any combustion pressure switch that does not pass one of these tests. Two occurrences of failure of the affected heaters prompted this action. In one case, an explosion resulted and the baggage compartment door was blown off the airplane. In the other case, a fire occurred in the baggage compartment while the airplane was in flight. The actions specified by this AD are intended to prevent an airplane fire or explosion caused by failure of the heater combustion tube assembly or combustion air pressure switch.
AD 96-18-17 · published Oct 9, 1996, effective Dec 9, 1996
AlliedSignal Inc. TSCP700-4B, -4E, and -5 Auxiliary Power Units
This amendment adopts a new airworthiness directive (AD), applicable to AlliedSignal Inc. (formerly Garrett) TSCP700-4B, -4E, and -5 auxiliary power units (APUs), that requires removal from service of certain high pressure turbine (HPT) disks identified by serial number, and replacement with serviceable parts. This amendment is prompted by the discovery of a material defect in certain HPT disk forgings that may result in HPT disk rupture prior to reaching the disk cyclic life limit. The actions specified by this AD are intended to prevent an HPT disk rupture.
AD 96-21-13 · published Oct 28, 1996, effective Nov 12, 1996
LITEF GmbH Attitude Heading System (AHRS) Unit Model LCR-92, LCR-92S, and LCR-92H
This amendment adopts a new airworthiness directive (AD) that is applicable to LITEF GmbH Attitude and Heading Reference System (AHRS) Unit Model LCR-92, LCR-92S, and LCR-92H installed on but not limited to Sikorsky Aircraft Model S-76 helicopters, McDonnell Douglas Helicopter Systems Model MD-900 helicopters, Bell Helicopter Textron, Inc. Model 412 helicopters, and Pilatus Model PC-12 airplanes. This action requires either installing a placard adjacent to each primary attitude indicator which states that flight is limited to Visual Flight Rules (VFR) operations only, or modifying and inspecting the AHRS wiring cables, requiring a repetitive inspection of the cable shielding, and inserting a statement into the aircraft flight manual. This amendment is prompted by a field report and verified by laboratory tests that shows there is an unusual AHRS reaction to certain radio frequency signals. The actions specified by this AD are intended to prevent reliance on or to correct the cause of misleading roll and pitch information produced by the AHRS when encountering certain radio frequency signals.
