34 Airworthiness Directives: 24 airplane, 5 rotorcraft, 4 engine, 1 appliance.
AD 97-18-04 · published Sep 2, 1997, effective Sep 17, 1997
Boeing Model 757 Series Airplanes Equipped With Rolls Royce Engines
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes, that currently requires repetitive inspections to detect fatigue cracking in the midspar fuse pins; replacement with new or refinished fuse pins, if necessary; and repetitive inspections of newly installed fuse pins. This AD requires earlier initial inspections and replacements; more frequent repetitive inspections of certain fuse pins; and replacement with new fuse pins, if necessary. This amendment is prompted by reports of fatigue cracking of the midspar fuse pins and by fatigue test data indicating that current inspection thresholds and intervals for repetitive inspections are inadequate to detect fatigue cracking in a timely manner. The actions specified in this AD are intended to detect and correct such fatigue cracking, which could lead to separation of the strut and engine from the wing of the airplane.
AD 97-18-05 · published Sep 2, 1997, effective Sep 17, 1997
Boeing Model 757 Series Airplanes Equipped With Pratt & Whitney Engines
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 757 series airplanes, that currently requires repetitive inspections to detect cracking in the midspar fuse pins; replacement with new or refinished fuse pins, if necessary; and repetitive inspections of newly installed fuse pins. This AD requires earlier initial inspections and replacements; more frequent repetitive inspections of certain fuse pins; and replacement with new fuse pins, if necessary. This amendment is prompted by reports of fatigue cracking of the midspar fuse pins and by fatigue test data indicating that current inspection thresholds and intervals for repetitive inspections are inadequate to detect fatigue cracking in a timely manner. The actions specified in this AD are intended to detect and correct such fatigue cracking, which could lead to separation of the strut and engine from the wing of the airplane.
AD 97-18-08 · published Sep 2, 1997, effective Sep 17, 1997
British Aerospace (Jetstream) Model 4101 Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to certain British Aerospace (Jetstream) Model 4101 airplanes. This action requires a visual inspection to detect wear damage of the drag brace of the main landing gear (MLG), and replacement of any worn parts with new or serviceable parts. This action also requires an inspection to determine whether there is movement in the spherical bearing of the lower link of the drag brace, certain measurements of the drag brace, and repetitive inspections, if necessary. This amendment is prompted by reports of loose spherical bearings in the links of the drag brace of the MLG. The actions specified in this AD are intended to prevent reduced structural integrity and potential collapse of the MLG due to loose spherical bearings and subsequent wear damage of the links of the drag brace.
AD 97-18-10 · published Sep 9, 1997, effective Oct 14, 1997
Bombardier Model CL-600-2B19 (Regional Jet Series 100) Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 (Regional Jet Series 100) airplanes that requires a one-time inspection of the direct current (DC) power distribution system for reliability, and correction or repair, of any fuse holders and associated electrical wiring, if necessary. This amendment is prompted by a report indicating that a loose fuse holder caused the DC power distribution system to short circuit on one of the affected airplanes, which resulted in a burnt wire between circuit breaker panel CBP-2 and junction box JB7. The actions specified by this AD are intended to prevent such short circuiting, which could result in a burnt wire, smoke entering the cockpit area, and consequent passenger injury due to smoke inhalation.
AD 97-19-02 · published Sep 9, 1997, effective Sep 24, 1997
British Aerospace (Jetstream) Model 4101 Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to all British Aerospace (Jetstream) Model 4101 airplanes. This action requires repetitive functional testing of the main entrance door, cleaning and lubricating of the ``speed'' lock and ``G'' lock systems, and repair, if necessary. This amendment is prompted by reports of flight crews and ground crews being unable to open the main entrance door. The actions specified in this AD are intended to prevent inability of the main entrance door to open, which could delay or impede passengers exiting the airplane, or rescue personnel from entering the airplane during an emergency.
AD 97-19-03 · published Sep 9, 1997, effective Aug 24, 1993
The Boeing Company Airplanes
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 737 series airplanes, that currently requires an inspection to determine whether the bearings of the tracklock bracket assemblies of the pilot and co-pilot seats are secure, modification of loose bearings, and marking of the seat identification labels. This AD requires a visual inspection to determine whether the modification and marking of the crew seats were accomplished; and, if not, accomplishment of these actions, which constitutes terminating action for the requirements of this AD. This amendment is prompted by a report indicating that a first officer's crew seat on an in-service airplane failed to lock horizontally. The actions specified in this AD are intended to prevent the captain and first officer crew seats from sliding freely on the track, which could result in uncommanded movement of the seats and reduced controllability of the airplane.
AD 97-19-04 · published Sep 9, 1997, effective Sep 24, 1997
Empresa Brasileira de Aeronautica S.A. (EMBRAER) Model EMB-145 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to certain EMBRAER Model EMB-145 series airplanes. This action requires repetitive visual inspections to detect cracks in the firewall of the auxiliary power unit (APU), and repair, if necessary. This AD also requires installation of a visco-elastic damper blanket on the firewall, which constitutes terminating action for the repetitive inspection requirements. This amendment is prompted by reports indicating that cracks were found in the firewall of the APU due to vibration of the firewall. The actions specified in this AD are intended to prevent such cracking, which could result in reduced structural integrity of the fuselage and empennage in the event that a fire penetrates through the firewall of the APU.
AD 97-19-01 · published Sep 11, 1997, effective Oct 16, 1997
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 a one-time inspection of the hydraulic tubes and electrical harness wires of the wing rear access door for chafing, leakage, or wear damage; repair of any discrepancy found; and modification of the wing rear access door. This amendment is prompted by reports of interference between the wing rear access door and the hydraulic tubes and electrical harnesses, and chafing damage to the hydraulic tubes. The actions specified by this AD are intended to prevent such interference or chafing damage, which could lead to failure of the number 2 hydraulic system or loss of certain electrical and landing systems, and resultant reduced controllability of the airplane.
AD 97-19-05 · published Sep 12, 1997, effective Oct 17, 1997
Saab Model SAAB 2000 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Saab Model SAAB 2000 series airplanes. This amendment requires replacement of the ignition exciter in the auxiliary power unit (APU) with a part that is designed to operate better in cold weather. This amendment is prompted by two occurrences of the APU failing to start after flight in cold soak conditions. The actions specified by this AD are intended to prevent such APU failure, which could result in the inability of the APU to restart the engines in the event both engines quit operating during flight.
AD 97-19-07 · published Sep 12, 1997, effective Sep 29, 1997
Dassault Model Falcon 2000 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to all Dassault Model Falcon 2000 series airplanes. This action requires installing new placards that stipulate the use of certain types of fuels, and revising the Airplane Flight Manual to specify the appropriate types of fuels for use in the affected airplanes. This amendment is prompted by a report indicating that, due to use of certain fuels, engine flame-out may occur. The actions specified in this AD are intended to ensure that certain fuels are prohibited from use; use of these fuels could cause an engine flame-out during a rapid throttle reduction.
AD 97-19-08 · published Sep 12, 1997, effective Sep 29, 1997
Boeing Model 747 Series Airplanes
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 747 series airplanes, that currently requires ultrasonic inspection of certain engine strut diagonal brace lugs for cracks, and replacement, if necessary. This amendment requires new repetitive inspections to detect discrepancies of the diagonal brace lugs, and rework of the diagonal brace lug, if necessary. In lieu of accomplishing the rework for certain cases, this amendment provides for an option to defer the rework by accomplishing repetitive inspections and resealing the bushing. This amendment also provides for an optional terminating modification for repetitive inspections. This amendment is prompted by additional reports of fatigue cracking in the diagonal brace lug. The actions specified in this AD are intended to prevent such fatigue cracking, which could result in failure of the strut and consequent separation of the engine from the airplane.
AD 97-19-11 · published Sep 16, 1997, effective Oct 21, 1997
Bombardier Model CL-600-2B19 (Regional Jet Series 100) Series Airplanes
This amendment supersedes an existing airworthiness directive (AD), applicable to certain Bombardier Model CL-600-2B19 series airplanes, that currently requires revising the Limitations Section of the Airplane Flight Manual (AFM) to provide the flight crew with procedures to check the travel range of the aileron. That AD also requires inspection for damage of the shear pins of the aileron flutter damper and aileron hinge fittings, and various follow-on actions. This amendment adds a requirement for accomplishment of an installation that eliminates the need for the AFM revision. This amendment also adds airplanes to the applicability of the existing AD. This amendment is prompted by reports of failure of shear pins in the aileron flutter damper. The actions specified by this AD are intended to prevent damage to the aileron hinge fittings due to failed shear pins, and consequent reduced controllability of the airplane.
AD 97-19-15 · published Sep 17, 1997, effective Oct 2, 1997
Boeing Model 767 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to all Boeing Model 767 series airplanes. This action requires revising the Airplane Flight Manual (AFM) to include procedures that will ensure that the center tank fuel pumps are not operated with less than 1,000 pounds of fuel in the center tank. This amendment is prompted by a report indicating that a fuel pump failed due to damage to an impeller unit and pumping unit housing caused by a loose diffuser ring in the fuel pump assembly. The actions specified in this AD are intended to ensure the flight crew is advised of procedures that will ensure that the center tank fuel pumps are not operated with less than 1,000 pounds of fuel, which will prevent ignition of fuel vapors due to the generation of sparks and a potential ignition source inside the fuel tank caused by metal-to-metal contact during dry fuel pump operation.
AD 97-15-13 R1 · published Sep 22, 1997, effective Sep 22, 1997
Raytheon Aircraft Company Models 1900, 1900C, and 1900D Airplanes
This amendment revises Airworthiness Directive (AD) 97-15-13, which currently requires installing lubrication fittings in the airstair door handle and latch housing mechanisms on certain Raytheon Aircraft Company (Raytheon) Models 1900, 1900C, and 1900D airplanes (formerly referred to as Beech Models 1900, 1900C, and 1900D airplanes). Certain Model 1900C serial number airplanes were incorrectly referenced as Model 1900D airplanes in the Applicability section of AD 97-15-13. This AD maintains the requirements of AD 97-15- 13, and corrects the model and serial number reference as described above. The actions specified by this AD are intended to prevent moisture from accumulating and freezing in the airstair door handle and latch housing, which could result in the door freezing shut and passengers not being able to evacuate the airplane in an emergency situation.
AD 97-20-01 · published Sep 22, 1997, effective Oct 7, 1997
Boeing Model 747 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This action requires repetitive inspections to detect cracks, corrosion, or damage of the lower spar fitting body and lug, and corrective actions, if necessary. This AD also provides for optional terminating action for the repetitive inspection requirements. This amendment is prompted by reports that fatigue cracking was found in the lower spar fitting lug on the number 3 pylon and in the lower spar fitting body. The actions specified in this AD are intended to detect and correct such fatigue cracking, which could result in failure of the strut and separation of the engine from the airplane.
AD 97-20-02 · published Sep 22, 1997, effective Oct 27, 1997
Lockheed Model L-188A and L-188C Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to all Lockheed Model L-188A and L-188C series airplanes. This amendment requires revising the Airplane Flight Manual (AFM) to prohibit the positioning of the power levers below the flight idle stop during flight, and to provide a statement of the consequences of positioning the power levers below flight idle stop. This amendment is prompted by incidents and accidents involving airplanes equipped with turboprop engines where the propeller ground beta was used improperly during flight. The actions specified by this AD are intended to prevent loss of airplane controllability, or engine overspeed and consequent loss of engine power caused by the power levers being positioned below the flight idle stop while the airplane is in flight.
AD 97-20-03 · published Sep 22, 1997, effective Oct 27, 1997
de Havilland Model DHC-7 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all de Havilland Model DHC-7 series airplanes, that requires revising the Airplane Flight Manual (AFM) to prohibit positioning of the power levers below the flight idle stop during flight, and to add a statement of the consequences of such positioning of the power levers. This amendment is prompted by incidents and accidents involving airplanes equipped with turboprop engines in which the propeller ground beta range was used improperly during flight. The actions specified by this AD are intended to prevent loss of airplane controllability, or engine overspeed and consequent loss of engine power caused by the power levers being positioned below the flight idle stop when the airplane is in flight.
AD 97-20-06 · published Sep 25, 1997, effective Oct 30, 1997
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 deactivation of certain floormat heaters in the cabin area. In addition, this amendment provides for optional terminating action for that deactivation. This amendment is prompted by a report indicating that a flight attendant's floormat heater became overheated as a result of a short circuit between a floormat heater and a floor panel that was made of conductive material; this condition resulted in smoke in the cabin area. The actions specified by this AD are intended to prevent such short circuiting, which could cause overheating of the floormat heater and lead to smoke or fire in the airplane cabin.
AD 97-20-07 · published Sep 25, 1997, effective Oct 30, 1997
Airbus Model A300-600 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A300-600 series airplanes, that requires repetitive inspections to detect fatigue cracking in the left and right wings in the area where the top skin attaches to the center spar; and repair or modification of this area, if necessary. This amendment is prompted by a report from the manufacturer indicating that, during full-scale fatigue testing of the airframe, fatigue cracking was detected in this area. The actions specified by this AD are intended to detect and correct this cracking, which could reduce the residual strength of the top skin of the wings, and consequently affect the structural integrity of the airframe.
AD 97-20-10 · published Sep 29, 1997, effective Nov 3, 1997
de Havilland Model DHC-8-100, -200, and -300 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to certain de Havilland Model DHC-8-100, -200, and -300 series airplanes, that requires modification of the attitude and heading reference systems (AHRS). This amendment is prompted by a report of loss of power to both AHRS's during flight due to a faulty terminal block to which the signal ground for the AHRS's are connected. The actions specified by this AD are intended to prevent simultaneous power loss to both AHRS's, which could result in reduced controllability of the airplane.
AD 96-12-03 R1 · published Sep 30, 1997, effective Oct 3, 1997
Sky International Inc. Airplanes
This document corrects the airworthiness directive (AD) number of an amendment that was published in the Federal Register on August 22, 1997 (62 FR 44535), and concerns Aviat Aircraft, Inc. Models S-1S, S-1T, S-2, S-2A, S-2S, and S-2B airplanes. The referenced amendment revises AD 96-12-03, but was inadvertently assigned the number of AD 97-17-07 instead of AD 96-12-03 R1. The AD currently requires repetitively inspecting the aft lower fuselage wing attach fitting on both wings for cracks and modifying any cracked aft lower fuselage wing attach fitting. Modifying the aft lower fuselage wing attach fitting on both wings eliminates the repetitive inspection requirement of the AD. This action corrects the amendment to reflect the right AD number throughout the entire document.
AD 97-20-05 · published Sep 30, 1997, effective Oct 15, 1997
British Aerospace Model HS 748 Series Airplanes
This amendment adopts a new airworthiness directive (AD) that is applicable to all British Aerospace Model HS 748 series airplanes. This action requires installation of a modified aileron cable pulley guard and rubbing strips. 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 jamming or restricting of the aileron cable, which could lead to the loss of aircraft roll control.
AD 97-20-08 · published Sep 30, 1997, effective Nov 4, 1997
Airbus Model A300, A300-600, and A310 Series Airplanes
This amendment adopts a new airworthiness directive (AD), applicable to all Airbus Model A300, A300-600, and A310 series airplanes, that requires inspecting the bearings located in the mechanical control linkage of the nose landing gear (NLG) free-fall mechanism for discrepancies, replacing any discrepant bearings with stainless steel bearings, and conducting a test to ensure that the NLG free-fall mechanism extends properly. This amendment is prompted by a report indicating that, during an operational test of the NLG, the landing gear failed to extend. The actions specified by this AD are intended to prevent the bearings from seizing, which could lead to the loss of NLG free-fall extension capability.
AD 97-20-11 · published Sep 30, 1997, effective Nov 13, 1997
SocataGroupe Aerospatiale Model TBM 700 Airplanes
This amendment adopts a new airworthiness directive (AD) that applies to certain Socata--Groupe Aerospatiale (Socata) Model TBM 700 airplanes. This AD requires removing the main landing gear (MLG) inboard doors and the door locking control mechanism (MOD 70-065-32). This AD is the result of an incident on one of the affected airplanes where the MLG inboard door locking hooks (hinges) corroded, caused the doors to jam, and prevented the MLG from extending. The Federal Aviation Administration's analysis reveals that removing the MLG inboard doors will not cause any airplane safety or performance problems. The actions specified by this AD are intended to prevent the MLG from failing to extend because of corroded MLG inboard locking hinges, which could result in loss of control of the airplane during landing operations.
AD 97-19-09 · published Sep 11, 1997, effective Oct 16, 1997
Bell Helicopter Textron, Inc. Model 214ST Helicopters
This amendment adopts a new airworthiness directive (AD), applicable to Bell Helicopter Textron, Inc. (BHTI) Model 214ST helicopters, that requires creation of a component history card or equivalent record using a Retirement Index Number (RIN) system; establishes a system for tracking increases to the accumulated RIN; and establishes a maximum accumulated RIN for the pillow block bearing bolts (bearing bolts). This amendment is prompted by fatigue analyses and tests that show certain bearing bolts fail sooner than originally anticipated because of the unanticipated high number of takeoffs and external load lifts utilizing high-power settings in addition to the time-in-service (TIS) accrued under other operating conditions. The actions specified by this AD are intended to prevent fatigue failure of the bearing bolts, which could result in failure of the main rotor system and subsequent loss of control of the helicopter.
AD 97-19-10 · published Sep 12, 1997, effective Oct 17, 1997
Sikorsky Aircraft-Manufactured Model S- 64E Helicopters
This amendment supersedes an existing airworthiness directive (AD), applicable to Sikorsky Aircraft-manufactured Model S-64E and S- 64F helicopters, that currently requires initial and repetitive inspections of the main gearbox assembly second stage lower planetary plate (plate) for cracks, and removal and replacement of the plate if cracks are found; and daily inspections of certain main transmission oil filter packs for magnesium chips, and removal and replacement of the main transmission if chips are found. The AD also provides for reworking and re-identifying the plate, as well as establishes a retirement life for the plate, including those that have been reworked and re-identified. This amendment requires, for Model S-64E helicopters, inspections and rework of the plate and establishes a new retirement life for the plate. This amendment is prompted by the type certificate holder's reports that four plates were discovered to have cracks, three of which had been reworked in accordance with the existing AD. The actions specified by this AD are intended to add another plate to the applicability of the AD, remove the requirements of AD 77-20-01 for the Model S-64F and prevent failure of the plate on the Model S-64E due to fatigue cracking, which could lead to failure of the main gearbox and subsequent loss of control of the helicopter.
AD 97-20-09 PL · published Sep 17, 1997
California Department of Forestry, AST, Inc, Rotorcraft Development Corporation, San Joaquin Helicopters, International Helicopters, Inc., Robinson Air Crane, Inc., Smith Helicopters, Southern Helicopter, Inc., Southwest Florida Aviation International, Tamarack Helicopters, Inc., US Helicopter, Inc., Richards Heavylift Helo, Inc., Hagglund Helicopters, LLC, Overseas Aircr
AD 97-19-06 · published Sep 19, 1997, effective Oct 6, 1997
Sikorsky Aircraft Corporation Model S- 61A, D, E, L, N, NM, R, and V Helicopters
This amendment supersedes an existing priority letter airworthiness directive (AD), applicable to Sikorsky Aircraft Corporation Model S-61A, D, E, L, N, NM, R, and V helicopters, that currently requires inspecting certain main rotor blade assemblies (blades) to determine if a blade has a blade trailing edge pocket assembly (pocket assembly) that was anodized by Poly-Metal Company during a specified time period, and if so, replacing it with an airworthy blade. This amendment requires the same actions as the existing AD, but corrects two serial numbers in the list of the applicable blades. This amendment is prompted by the manufacturer's issuance of a service bulletin with a revised list of blade serial numbers. The actions specified by this AD are intended to prevent disbonding and separation of portions of the blade, subsequent excessive vibrations, and loss of control of the helicopter.
AD 97-20-04 · published Sep 22, 1997, effective Oct 7, 1997
Enstrom Helicopter Corporation Model F- 28A, F-28C, 280 and 280C Helicopters
This amendment adopts a new airworthiness directive (AD) that is applicable to Enstrom Helicopter Corporation (Enstrom) Model F-28A, 280 and certain serial-numbered F-28C and 280C helicopters. This action requires an inspection of the voltage control system and an owner/ operator (pilot) cockpit check of the amperage of the electrical system. If certain Prestolite-manufactured components are installed, additional tests and actions are required before further flight and at each pre-flight run-up and annual inspection thereafter. A terminating action is provided by replacing the existing voltage control system with a transistorized system. This amendment is prompted by 14 reports of voltage control system problems, including one incident in which smoke emanated from the radio panel during flight, forcing the pilot to make an emergency landing. The actions specified in this AD are intended to prevent an electrical overload and a failure of the voltage regulator and over-voltage relay, that could result in an inflight fire, and subsequent forced landing of the helicopter.
AD 97-19-12 · published Sep 19, 1997, effective Nov 18, 1997
Pratt & Whitney JT8D Series Turbofan Engines
This amendment adopts a new airworthiness directive (AD), applicable to Pratt & Whitney JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -17, and -17R series turbofan engines, that requires initial and repetitive fluorescent penetrant and eddy current inspections of 4th stage low pressure turbine (LPT) hubs for cracks, and, if necessary, replacement with serviceable parts. This amendment is prompted by a report of an uncontained 4th stage LPT blade release. The actions specified by this AD are intended to prevent a 4th stage LPT blade release due to hub cracking, which can result in an uncontained engine failure and damage to the aircraft.
AD 97-19-13 · published Sep 19, 1997, effective Oct 24, 1997
Pratt & Whitney JT8D-200 Series Turbofan Engines
This amendment supersedes an existing airworthiness directive (AD) 94-23-03, applicable to Pratt & Whitney (PW) JT8D-200 series turbofan engines, that currently requires installation and periodic inspection of temperature indicators installed on the No. 4 and 5 bearing compartment scavenge oil tube and performance of any necessary corrective action. This amendment requires the installation and periodic inspection of temperature indicators to all PW JT8D-200 series engines, including those incorporating the containment hardware specified in AD 93-23-10. This amendment is prompted by a report of an uncontained turbine failure due to a high pressure turbine (HPT) shaft fracture on an engine that had the containment hardware installed. The actions specified by this AD are intended to prevent fracture of the HPT shaft, which can result in uncontained release of engine fragments, engine fire, inflight engine shutdown, or possible aircraft damage.
AD 97-19-14 · published Sep 19, 1997, effective Oct 24, 1997
Pratt & Whitney JT8D Series Turbofan Engines
This amendment supersedes an existing airworthiness directive (AD), applicable to Pratt & Whitney JT8D series turbofan engines, that currently requires inspections of low pressure turbine (LPT) blade sets for blade shroud crossnotch wear, and removal, if necessary. In addition, the current AD requires, as a terminating action to the inspections, installation of improved LPT containment hardware, and installation of an improved No. 6 bearing scavenge pump bracket bushing. This amendment keeps the compliance actions of the current AD intact but changes the compliance time for LPT containment hardware installation from the current calendar end-date to December 31, 1998, for engines that contain suspect 4th stage hubs identified by serial number. This amendment is prompted by a report of a fourth stage hub manufacturing defect that led to the failure of the hub and subsequent release of LPT blades. The actions specified by this AD are intended to prevent damage to the aircraft resulting from engine debris following an LPT blade, shaft, or hub failure.
AD 97-19-17 · published Sep 29, 1997, effective Nov 28, 1997
General Electric Company CT58 Series Turboshaft Engines
This amendment adopts a new airworthiness directive (AD), applicable to General Electric Company CT58 series turboshaft engines, that requires removal from service of certain compressor rear shafts, initial and repetitive inspections of specific critical rotating parts, and replacement if found cracked, until those parts are removed from service and replaced with improved design parts. This amendment is prompted by a stage 2 turbine wheel incident in 1993 which resulted in an increased awareness of small features on critical rotating parts which could affect part life. The actions specified by this AD are intended to prevent fatigue cracking on specific critical rotating parts, which could result in failure of the part, causing an uncontained engine failure and damage to the aircraft.
AD 97-19-18 · published Sep 22, 1997, effective Oct 27, 1997
Airbus, AlliedSignal Inc, The Boeing Company Appliances
This amendment supersedes an existing airworthiness directive (AD), applicable to AlliedSignal Inc. (formerly AiResearch and Garrett) TSCP700-4B and -5 Series Auxiliary Power Units (APUs), that currently requires restretching the first stage low pressure compressor (LPC) tie rods, or replacing affected disks at or before 8,000 cycles since new (CSN). This amendment requires removing from service affected disks, replacing them with serviceable parts, and establishing a life limit of 8,000 CSN for affected disks. This amendment is prompted by a report of a first stage LPC disk rim separation due to low cycle fatigue on an APU that had its tie rods restretched in accordance with the current AD. The actions specified by this AD are intended to prevent first stage LPC disk rim separation due to low cycle fatigue, which could result in an uncontained APU failure and damage to the aircraft.
