Bell 407

Airworthiness Directives; Bell Textron Canada Limited Helicopters

The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (Bell) Model 407 helicopters. This AD was prompted by a report of a fractured pilot cyclic stick tube and subsequent findings of other pilot cyclic stick tubes with fatigue cracking. This AD requires repetitively inspecting the pilot cyclic stick tube assembly for a crack and, depending on the results, repairing or replacing the pilot cyclic stick tube assembly. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Bell Textron Canada Limited Helicopters

The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (BTCL) Model 407 helicopters. This AD was prompted by a determination that chafing can occur at various locations on the electrical harnesses located in the aircraft instrument panel area. This AD requires a one-time detailed visual inspection of the electrical harnesses for chafing and corrective actions if necessary. This AD also requires rotation of the backshell cast housing of connectors of the lower engine airframe unit and installation of a wire harness bracket and support, and for certain helicopters, installation of a wire bundle sleeve. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Bell Textron Canada Limited Helicopters

The FAA is adopting a new airworthiness directive (AD) for all Bell Textron Canada Limited (BTCL) Model 407 and 427 helicopters. This AD was prompted by a report that certain expandable blade bolts installed on the main rotor blade may not have received the correct heat treatment, which could result in stress corrosion cracking of the expandable blade bolts. This AD requires removing the expandable blade bolts from service and replacing them with a part eligible for installation. This AD also prohibits the installation of an affected expandable blade bolt on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Bell Textron Canada Limited Helicopters

The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 407 helicopters. This AD was prompted by a report that a certain part-numbered fuel system standpipe assembly (standpipe) may have sharp edges at the interval weld joints due to a quality escape during the manufacturing process. This AD requires inspecting certain fuel system parts and, depending on the inspection results, taking corrective actions and performing a fuel quantity gauging system calibration. Depending on the results of the fuel quantity gauging system calibration, this AD requires performing additional corrective actions and repeating the fuel quantity gauging system calibration. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Bell Textron Canada Limited Helicopters

The FAA is adopting a new airworthiness directive (AD) for all Bell Textron Canada Limited Model 407 helicopters. The FAA previously sent this AD as an emergency AD to all known U.S. owners and operators of these helicopters. This AD was prompted by a report of a disbonded area in a tail rotor (T/R) blade. This AD requires determining if an affected T/R blade is installed, inspecting each of those T/R blades and, depending on the results, replacing the T/R blade as specified in a Transport Canada emergency AD, which is incorporated by reference. This AD also limits the installation of T/R blades to certain T/R blades. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Bell Textron Canada Limited Helicopters

The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 407 helicopters. This AD was prompted by an accident. This AD requires inspecting the tailboom attachment structure, as specified in a Transport Canada AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters

The FAA is superseding Airworthiness Directive (AD) 99-23-18, AD 2005-03-07, AD 2013-12-07, and AD 2014-04-07, which applied to certain Bell Helicopter Textron Canada (now Bell Textron Canada Limited) Model 407 helicopters. AD 99-23-18 required revising the life limits for certain parts, replacing each part that had exceeded its life limit, and revising the Airworthiness Limitation Section (ALS) of the existing maintenance manual. AD 2005-03-07 required establishing a maximum accumulated Retirement Index Number (RIN) count for certain crosstube assemblies and revising the ALS of the existing maintenance manual. AD 2013-12-07 required inspecting the tailboom assembly for a crack, loose rivet, or other damage and depending on the inspection results, replacing certain parts. AD 2014-04-07 required preflight checking, repetitively inspecting for a crack in certain tailbooms, modifying and re-identifying certain tailbooms, installing an improved horizontal stabilizer assembly, and revising the ALS of the existing maintenance manual. Since the FAA issued those ADs, a report was received of a crack on the tailboom lower skin due to fatigue damage and new and more restrictive airworthiness limitations have been issued. This AD was prompted by a report of a crack on the tailboom lower skin due to fatigue damage and the issuance of new and more restrictive airworthiness limitations. This AD requires incorporating into existing maintenance records requirements (airworthiness limitations) as specified in the ALS service information. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Bell Textron Canada Limited Helicopters

The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 206, 206A, 206A-1 (OH-58A), 206B, 206B-1, 206L, 206L-1, 206L-3, 206L-4, 222, 222B, 222U, 230, 407, 427, 429, and 430 helicopters. This AD was prompted by a report of a shoulder harness seat belt comfort clip (comfort clip) interfering with the seat belt inertia reel. This AD requires removing each comfort clip from service, inspecting the shoulder harness seat belt for any rip and abrasion, and removing any shoulder harness seat belt from service that has a rip or abrasion. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters

We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 206A, 206B, 206L, 206L- 1, 206L-3, 206L-4, and 407 helicopters. This AD requires inspecting and cleaning the oil supply restrictor (restrictor) to the freewheel assembly. This AD was prompted by reports of a blocked oil line restrictor in the freewheel lubrication system. The actions of this AD are intended to address an unsafe condition on these products.

Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

We are adopting a new airworthiness directive (AD) for Bell Model 407 helicopters. This AD requires repetitive inspections of the tail rotor (TR) driveshaft segment assemblies and a torque check of the TR adapter retention nuts. This AD was prompted by a report of an in- flight failure of the TR drive system. The actions of this AD are intended to detect and correct an unsafe condition on these products.

Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Helicopters

We are superseding Airworthiness Directive (AD) 2001-13-51 for Bell Model 206L-4, 407, and 427 helicopters. AD 2001-13-51 required inspecting certain driveshafts for a crack, a loose bolt or nut, or red powder residue and replacing a driveshaft if there is a crack, a loose bolt or nut, or red powder residue. AD 2001-13-51 also required notifying the FAA within 10 days if a crack is found in the driveshaft. This new AD retains the inspection requirement of AD 2001-13-51, expands the applicability to include the Model 429 helicopter, and removes the reporting requirement. This AD is intended to prevent failure of a driveshaft, loss of drive to the main rotor system, and a subsequent emergency landing.

Airworthiness Directives; Bell Helicopter Textron Canada Helicopters

We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters. This AD requires inspecting the aft fuselage upper skin (upper skin) for a crack and the upper left longeron assembly (longeron assembly) for a crack, corrosion, or defect. This AD requires replacing or repairing a part or section, depending on the inspection's outcome. This AD was prompted by reports of cracks in the upper left-hand longeron. This AD's actions are intended to prevent failure of the longeron assembly or the upper skin, which could lead to a structural failure and loss of helicopter control.

Airworthiness Directives; Bell Helicopter Textron, Inc., Helicopters

We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron, Inc. (Bell), Model 206A, 206B, 206L, 206L-1, 206L- 3, 206L-4, and 407 helicopters with an Apical Industries, Inc. (Apical) emergency float kit installed under Supplemental Type Certificate (STC) Number SR01535LA. This AD was prompted by an incident in which the floats installed on a helicopter failed to deploy. This AD requires inspecting, labeling, and replacing the float inflation hoses. We are issuing this AD to prevent failure of the emergency floatation gear to deploy during an emergency event.

Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

We are adopting a new airworthiness directive (AD) for certain Bell Model 407 helicopters. This AD requires installing a placard beneath the NR/NP dual tachometer and revising the limitations section of the rotorcraft flight manual (RFM). This AD was prompted by several incidents of third stage engine turbine wheel failures, which were caused by excessive vibrations at certain engine speeds during steady- state operations. These actions are intended to alert pilots to avoid certain engine speeds during steady-state operations, prevent failure of the third stage engine turbine, engine power loss, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Helicopters

We are adopting a new airworthiness directive (AD) for Bell Model 206L-4 and 407 helicopters. This AD requires replacing or reworking certain aft bearing caps. This AD was prompted by the manufacture of certain freewheel aft bearing caps without a lubrication channel to allow oil flow into the aft bearing support assembly. The actions of this AD are intended to prevent failure of the freewheel unit and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

We are adopting a new airworthiness directive (AD) for Bell Model 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, 222, 222B, 222U, 230, 407, 427, and 430 helicopters. This AD requires inspecting each bearing to determine if it has been properly staked and replacing the bearing or assembly if it has not been properly staked. This AD was prompted by bearings not being properly staked and migrating out of their proper position, which may limit the functionality of the affected part. The actions of this AD are intended to prevent failure of a bearing and the assembly in which it is installed and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Helicopters

We are adopting a new airworthiness directive (AD) for the Bell Helicopter Textron Canada Limited (BHTC) Model 407 helicopters. This AD requires you to replace tailboom-attachment hardware (attachment hardware), and perform initial and recurring determinations of the torque on the nuts of the tailboom-attachment bolts (bolts) at all four attachment locations. This AD was prompted by a review of the tailboom-attachment installation, which revealed that the torque value of the bolts specified in the BHTC Model 407 Maintenance Manual and applied during manufacturing was incorrect and exceeded the torque range recommended for the bolts. The actions required by this AD are intended to prevent an over-torque of a bolt, bolt failure, loss of the tailboom, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Helicopters

We are adopting an airworthiness directive (AD) superseding an existing airworthiness directive for Bell Helicopter Textron Canada (Bell) Model 407 and 427 helicopters. The existing AD requires inspecting certain hydraulic servo actuators (servo) to determine whether the shaft turns independently of the nut or the clevis assembly, and additional actions based upon the inspection's outcome. The AD also requires reidentifying the servo. Since we issued that AD, Bell has learned that additional servos may need repair or removal. This AD expands the scope of the current AD to include inspections for all servos, and requires that servos meeting inspection requirements be marked with the letter "V" after the part number on the data plate. The actions are intended to detect any loose or misaligned parts in the servo that could lead to failure of the servo and subsequent loss of helicopter control.

Airworthiness Directives; Bell Helicopter Textron Canada (Bell) Model 407 and 427 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2011-15-51, which was sent previously to all known U.S. owners and operators of the specified Bell Model 407 and 427 helicopters by individual letters. This AD requires inspecting certain hydraulic servo actuators to determine whether the shaft turns independently of the nut or the clevis assembly. If the shaft turns independently, this AD requires replacing the servo with an airworthy servo. If the shaft does not turn independently, the AD requires inspecting to determine the condition of the lock washers. Based on the condition of the lock washers, the AD requires either replacing the servo with an airworthy servo, or if any tab of the lock washer is not flush against a flat surface of the nut or clevis assembly, bending it flush against a flat surface. The AD also requires reidentifying the servo by metal-impression stamping or by vibro- etching "67.01" onto the modification plate. Also, the AD requires before installing a servo with a part number or serial number identified in this AD, not identified by "67-01" on the modification plate, inspecting it by following the requirements of this AD. This AD is prompted by a report that a quality escape by a supplier has occurred and certain servos may have a loose nut, shaft, and clevis assembly due to improper lock-washer installation. An investigation after an accident revealed the clevis nut on the servo was loose. The actions specified by this AD are intended to prevent a malfunction of a servo in the flight control system and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Limited (BHTC) Model 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, 222, 222B, 222U, 230, 407, 427, and 430 Helicopters

This document publishes in the Federal Register an amendment adopting Emergency Airworthiness Directive (AD) 2010-26-51, which was sent previously to all known U.S. owners and operators of the specified model helicopters by individual letters. This AD also supersedes existing AD 2009-08-03. This AD is prompted by another incident in which the tail rotor blade (blade) tip weight separated from a blade during flight causing vibration. This unsafe condition led to the determination that additional blades could be affected and should be added to the applicability. The actions specified by this AD are intended to prevent loss of the blade tip weight, loss of a blade, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada (BHTC) Model 407 and Model 427 Helicopters

We are adopting a new airworthiness directive (AD) for the BHTC Model 407 and Model 427 helicopters. This AD results from mandatory continuing airworthiness information (MCAI) ADs issued by the aviation authority of Canada. The MCAI ADs state that some hydraulic pump driveshaft assemblies may have been delivered with a missing internal plug or fastening rivet. This condition, if not corrected, could result in a loss of hydraulic pressure and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 and 427 Helicopters

We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada (Bell) Model 407 and 427 helicopters. This AD results from a mandatory continuing airworthiness information (MCAI) AD issued by the aviation authority of Canada. The MCAI AD states that, during a preflight check, it was observed that the swashplate link assembly bearing had moved in the lever race, making contact with the swashplate support. The MCAI also states that further investigation revealed that the bearing had not been staked correctly during manufacture. That condition, if not detected, could result in failure of a bearing, failure of the swashplate link assembly, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Limited Model 206A Series, 206B Series, 206L Series, 407, and 427 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2009-07-52 and supersedes Emergency AD 2009-07-51, issued March 17, 2009, which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada Limited (Bell) Model 206A series, 206B series, 206L series, 407, and 427 helicopters by individual letters. This AD requires, before further flight, inspecting each cyclic control lever assembly (lever assembly) that has less than 50 hours time-in-service (TIS) to determine if it is correctly installed and properly staked in the lever assembly. This amendment is prompted by a Transport Canada AD report of a bearing incorrectly installed in the copilot lever assembly. The actions specified by this AD are intended to prevent failure of a bearing, failure of the lever assembly, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 206L, L-1, L-3, L-4, and 407 Helicopters

We are adopting a new airworthiness directive (AD) for the specified Bell Helicopter Textron Canada (BHTC) helicopters. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority to identify and correct an unsafe condition on an aviation product. The Aviation Authority of Canada with whom we have a bilateral agreement states in the MCAI: "Horizontal stabilizers part numbers 206-023-119-167 and 407-023-801-109 may have manufacturing flaws on the inside surface of the upper and/or lower skin at the tailboom attachment inserts. These flaws may result in cracking of the skin and failure of the horizontal stabilizer." The manufacturer's service information states that in addition to cracks, the horizontal stabilizer may have deformation or debonding around and between the inserts. We are issuing this AD to require actions to correct the unsafe condition on these products.

Airworthiness Directives; Bell Helicopter Textron Canada Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 Helicopters

We are adopting a new airworthiness directive (AD) for the specified Bell Helicopter Textron Canada (BHTC) Model 206A, 206B, 206L, 206L-1, 206L-3, and 206L-4 helicopters. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority to identify and correct an unsafe condition on an aviation product. The aviation authority of Canada, with which we have a bilateral agreement, states in the MCAI: "It has been determined that some helicopters have been fitted with a CRES steel fitting, part number (P/N) 407-030-750-103, and the installation of the tailboom attachment bolt does not meet the design criteria." We are issuing this AD to require actions that are intended to address the unsafe condition that results from an improper installation of the tailboom attachment bolt in the upper left-hand tailboom attachment CRES steel fitting.

Airworthiness Directives; Bell Helicopter Textron Canada Limited Model 206A, 206B, 206L, 206L-1, 206L-3, 206L-4, 222, 222B, 222U, 230, 407, 427, and 430 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2007-19-52, which was sent previously to all known U.S. owners and operators of the specified Bell Helicopter Textron Canada Limited (BHTC) model helicopters by individual letters. This AD requires replacing each affected tail rotor blade (blade) with an airworthy blade with a serial number not listed in the Rotor Blades, Inc. (RBI), attachment to the BHTC Alert Service Bulletin (ASB), listed in the applicability section of this AD. This amendment is prompted by three incidents in which blade tip weights were slung from blades during flight causing significant vibration. The actions specified are intended to prevent loss of a blade tip weight, loss of a blade, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment supersedes an existing airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters which requires a one-time replacement of certain oil cooler blower bearings. Also, the existing AD requires adding a limitation and caution to the rotorcraft flight manual (RFM) and inspecting, replacing, and lubricating certain bearings at specified intervals. This amendment adds certain segmented drive shaft bearings to the applicability and requires modifying the oil cooler blower inlet ducts and airflow shields and replacing certain bearings. Thereafter, this amendment requires removing the current temporary limitations and inserting revised limitations into the RFM. This amendment also requires revising the inspection and lubrication requirements. This amendment is prompted by several cases of bearing failure. The addition of certain segmented drive shaft bearings is due to two recent failures. The actions specified by this AD are intended to prevent failure of a bearing, loss of tail rotor drive, and a subsequent loss of directional control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment supersedes an existing emergency airworthiness directive (EAD), which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (Bell) helicopters by individual letters. That EAD requires a visual check to ensure that the two swashplate drive link cup washers (cup washers) are installed correctly. If a cup washer is installed incorrectly, removing and replacing the swashplate outer ring, each cup washer, bearing and liner, and drive link where the cup washer was installed incorrectly are also required. This amendment requires the same actions as the existing EAD, but clarifies that only the visual check may be performed by the owner/operator. This amendment is prompted by two reported failures of the stud portion of the swashplate drive link. The actions specified by this AD are intended to detect an incorrectly installed cup washer, which could limit the travel of the swashplate outer ring and lead to failure of the stud portion of the swashplate drive link, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Limited Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 407 helicopters. This action requires visually inspecting certain tailboom gearbox support castings (castings) for cracks and replacing the tailboom assembly if a crack is found. This amendment is prompted by an incident in which a crack was discovered on the casting that holds the tail rotor gearbox and vertical fin. The actions specified in this AD are intended to detect a crack in the casting and prevent failure of the casting, loss of the vertical fin and tail rotor, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Limited Model 407 Helicopters

This amendment supersedes an existing airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (BHTCL) Model 407 helicopters that requires visually inspecting the brackets that attach the horizontal stabilizer slat (slat) to the stabilizer for a crack. If a crack is found, that AD also requires replacing the slat assembly before further flight. Also, that AD requires installing airworthy, segmented slat assemblies by a specified date. Installing segmented slat assemblies was considered terminating action for the requirements of that AD. This amendment requires, initially and at certain time intervals, checking each slat assembly for a cracked bracket and, if a crack is found, replacing any unairworthy slat assembly with an improved, airworthy slat assembly. This amendment also requires replacing, modifying, and installing identification plates on slats on certain helicopters at specified time intervals. This amendment is prompted by two additional reports of cracked brackets. The actions specified by this AD are intended to prevent a slat from separating, contacting a rotor blade, and resulting in subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron, a Division of Textron Canada, Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron, A Division of Textron Canada (BHT), Model 407 helicopters. This action requires a fuel filler cap assembly shimming and electrical bonding procedure. This amendment is prompted by the FAA's determination, based on information from the manufacturer, that electrical bonding may be inadequate. The actions specified in this AD are intended to prevent a lack of electrical bonding that could result in an electrical arc, ignition of fuel vapors, and an onboard fire.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters that requires visually inspecting the forward hanger bearing bracket (bracket) for a crack. This amendment is prompted by reports of cracks in the bracket. The actions specified by this AD are intended to detect a crack in the bracket, to prevent loss of tail rotor drive or control and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2002-06-52, which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (BHTC) Model 407 helicopters by individual letters. This AD requires a one-time replacement of certain bearings and, before further flight, adding a limitation and caution to the rotorcraft flight manual (RFM) and at specified intervals, inspecting, replacing, and lubricating certain oil cooler blower bearings. This AD is prompted by several occurrences of failure of an oil cooler blower bearing. The actions specified by this AD are intended to prevent failure of an oil cooler blower bearing, loss of tail rotor drive, and a subsequent forced landing.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters that requires replacing certain cockpit warning horns. This amendment is prompted by reports that pilots have had difficulty in distinguishing between the FADEC Fail horn, the Engine Out horn, and the Low Rotor RPM horn. The actions specified by this AD are intended to assist the pilot in properly identifying a specific cockpit warning horn (horn) and prevent an inappropriate pilot response to a horn, which could cause an engine overspeed and subsequent uncommanded reduction to flight-idle engine power.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment rescinds an existing airworthiness directive (AD) that applies to Bell Helicopter Textron Canada (BHTC) Model 407 helicopters and currently requires, before further flight, imposing never exceed velocity (Vne) restrictions on the helicopter. The requirements of that AD were intended to prevent tail rotor blades from striking the tailboom, separation of the aft section of the tailboom with the tail rotor gearbox and vertical fin, and subsequent loss of control of the helicopter. That AD was prompted by an accident suspected of being the result of a tail rotor strike caused by high airspeed. Since the issuance of that AD, accident investigation findings have not substantiated that a tail rotor strike caused by high airspeed was the cause of the accident. This amendment rescinds that AD. This amendment is prompted by the FAA's determination that the Vne restrictions and accompanying actions imposed by that AD do not correct an unsafe condition.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2001-01-52, which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (BHTC) Model 407 helicopters by individual letters. This AD requires, before further flight, reducing the maximum approved never exceed velocity (Vne); inserting a copy of this AD into the Rotorcraft Flight Manual (RFM); installing a temporary placard on the flight instrument panel to indicate the reduced Vne limit; and installing a new redline Vne limit on all airspeed indicators. This amendment is prompted by an accident resulting from a suspected tail rotor strike to the tailboom. The actions specified by this AD are intended to prevent tail rotor blades from striking the tailboom, separation of the aft section of the tailboom with the tail rotor gearbox and vertical fin, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters. This AD requires inspecting the brackets that attach each horizontal stabilizer slat (slat) to the stabilizer for a crack and replacing the slat assembly if a crack is found. Installing airworthy segmented slat assemblies would be required prior to flight after December 31, 2000 and would constitute terminating action for the requirements of this AD. This amendment is prompted by an incident in which a slat separated from a helicopter. The actions specified by this AD are intended to prevent a slat from separating, impact with a main or tail rotor blade, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This amendment supersedes an existing airworthiness directive (AD) for Bell Helicopter Textron Canada (BHTC) Model 407 helicopters. That AD requires installing a tail rotor pitch-limiting left-pedal stop (pedal stop), installing an airspeed limitation placard, marking a never-exceed velocity (Vne) placard on all airspeed indicators, and revising the Limitations section of the Rotorcraft Flight Manual (RFM). This AD requires installing a redesigned tail rotor system and modifying the vertical fin and horizontal stabilizer to allow restoring the Vne to 140 knots indicated airspeed (IAS). This AD is prompted by design changes to the tail rotor system and modification of the pedal stop for airspeed actuation to eliminate a tail rotor strike to the tailboom. The actions specified by this AD are intended to prevent the tail rotor blades from striking the tailboom, separation of the aft section of the tailboom with the tail rotor gearbox and vertical fin, and subsequent loss of control of the helicopter.

Airworthiness Directives; 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 preflight checking and repetitively inspecting the tail boom for a crack and replacing the tail boom if a crack is found. This amendment is prompted by four reports of cracks on the tail boom in the area of the horizontal stabilizer. The actions specified in this AD are intended to prevent separation of the tail boom and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada (BHTC) Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to BHTC Model 407 helicopters, that requires modifying the door latch assemblies on all four crew and passenger doors. This amendment is prompted by an incident that occurred during a manufacturer's flight test, in which a door latch assembly broke, preventing occupants in the helicopter from opening the door. The actions specified by this AD are intended to prevent a door latch rod assembly from disengaging from the door handle and preventing helicopter occupants from opening the door.

Airworthiness Directives; 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, that requires replacing a certain hydraulic relief valve (valve) with a different valve. This amendment is prompted by the discovery of a manufacturing defect in a valve. The actions specified by this AD are intended to prevent intermittent loss of hydraulic pressure to the flight controls and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2000-02-12, which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (BHTC) Model 407 helicopters by individual letters. This AD requires inspecting engine oil cooler blower shaft bearings (bearings) for roughness at specified time intervals and replacing any rough bearings before further flight. This amendment is prompted by several bearing failures. The actions specified by this AD are intended to prevent bearing failure, loss of tail rotor drive, and a subsequent forced landing.

Airworthiness Directives; Bell Helicopter Textron Canada (BHTC) Model 407 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to BHTC Model 407 helicopters, that requires visually inspecting the vertical fin (fin) for reduced skin thickness; repairing or replacing the fin, if necessary; and identifying fins that have been inspected or repaired. This amendment is prompted by a report of an inboard skin damaged during production. The actions specified by this AD are intended to detect fin assemblies with reduced skin thickness which, if not corrected, reduce the strength of the skin and could lead to failure of the fin and loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-06-15 which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (BHTC) Model 407 helicopters by individual letters. This AD requires installing a tail rotor pitch-limiting left-pedal stop, installing an airspeed limitation placard, marking a never-exceed velocity (Vne) placard on all airspeed indicators, and revising the Limitations section of the Rotorcraft Flight Manual (RFM). This amendment is prompted by three accidents involving inflight tail rotor blade strikes against the tailboom. The actions specified by this AD are intended to prevent the tail rotor blades from striking the tailboom, which could result in separation of the aft section of the tailboom with the tail rotor gearbox and vertical fin, and subsequent loss of control of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada (BHTC) Model 407 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 98-19-13, which was sent previously to all known U.S. owners and operators of BHTC Model 407 helicopters by individual letters. This AD requires, on or before the accumulation of 50 hours total time-in-service (TIS) on the engine-to- transmission driveshaft (driveshaft), replacing the driveshaft with an airworthy driveshaft. This amendment is prompted by analysis and test data which revealed that the life limit of the driveshaft is less than that which is stated in the applicable maintenance manual. The actions specified by this AD are intended to prevent failure of the driveshaft, loss of engine drive to the rotor system, damage to critical structural components, and subsequent loss of control of the helicopter.

Airworthiness Directives; 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 that requires shimming the tail rotor drive system bearing supports (bearing supports). This amendment is prompted by reports of cracked bearing hangar support arms in the area of the fillet radius. The actions specified by this AD are intended to prevent failure of the bearing supports, which could result in excessive tail rotor drive system vibration, loss of tail rotor drive, and subsequent loss of control of the helicopter.

Airworthiness Directives; Allison Engine Company Model 250-C47B Turboshaft Engines

This amendment supersedes an existing airworthiness directive (AD) 97-21-09, applicable to Allison Engine Company Model 250-C47B turboshaft engines, that currently requires replacing the engine main electrical harness assembly with an improved assembly, installing a new hydromechanical unit (HMU) and electronic control unit (ECU), removing the placard notifying the pilot that the overspeed protection system is disabled, and revising the Bell Helicopter Textron, A Division of Textron Canada Ltd. (BHTC), Model 407 Rotorcraft Flight Manual (RFM). This amendment continues the requirements of the current AD, but adds the requirement to install ECUs with improved resistance to corrosion. This amendment is prompted by reports of ECUs with annunciated hard faults due to corrosion on internal connectors. The actions specified by this AD are intended to prevent uncommanded inflight engine shutdowns, which can result in autorotation, forced landing, and possible loss of the helicopter.

Airworthiness Directives; Bell Helicopter Textron Canada Model 407 Helicopters

This document publishes in the Federal Register an amendment adopting priority letter airworthiness directive (AD) 97-24-17, which was sent previously to all known U.S. owners and operators of Bell Helicopter Textron Canada (BHTC) Model 407 helicopters by individual letters. This AD requires inspections of components in the tail rotor drive system for scratches, cracks, fretting, corrosion, and proper torquing, lubrications of the oil cooler blower shaft hanger bearings and oil cooler hanger bearings (hanger bearings), and removal of corrosion inhibitive adhesive barrier tape (barrier tape) from the tail rotor gearbox and the tail rotor gearbox support assembly faying surfaces. This amendment is prompted by numerous reports of three problems, all of which are related to the tail rotor drive system. The actions specified by this AD are intended to: detect scratches, cracks, fretting, and corrosion in the disc pack couplings; prevent inadequate lubrication of the hanger bearings and oil cooler blower shaft; and prevent loss of mounting torque on the tail rotor gearbox. Failure of any of these components could result in loss of power to the tail rotor and subsequent loss of control of the helicopter.

Airworthiness Directives; Allison Engine Company Model 250-C47B Turboshaft Engines

This amendment adopts a new airworthiness directive (AD) that is applicable to Allison Engine Company Model 250-C47B turboshaft engines. This action supersedes priority letter AD 96-21-12, applicable to Bell Helicopter Textron, A Division of Textron Canada Ltd. (BHTC) Model 407 helicopters, that currently prohibits further flight, due to uncommanded inflight engine shutdowns. This action requires replacing the engine main electrical harness assembly with an improved assembly, disabling the overspeed solenoid, inspecting the engine control unit (ECU) internal PW10 voltage to determine electrical noise characteristics, and replacing units not considered serviceable. In addition, this AD requires adding a placard to the helicopter instrument panel notifying the pilot that the overspeed protection system is disabled and removes a placard which was required by priority letter AD 96-21-12; revises the BHTC Model 407 Rotorcraft Flight Manual (RFM); and requires maintenance actions to clear the engine electronic control unit (ECU) of faults prior to each flight. Accomplishment of these actions will enable operators to resume flight operations. This amendment is prompted by investigation into the causes of the inflight engine shutdowns. The actions specified by this AD are intended to prevent uncommanded inflight engine shutdowns, which can result in autorotation, forced landing, and possible loss of the helicopter.