What this page is: a restatement of what the official Federal Register
and manufacturer records show as of the date listed below each item. It is not
a determination that any specific aircraft or engine is, or is not, in compliance.
Under 14 CFR §91.403 and §91.417, the aircraft owner/operator is responsible
for maintaining airworthiness and required records. Always verify against the official FAA
and manufacturer sources linked below before making a maintenance or airworthiness decision.
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Airworthiness Directives
29 records · 5 superseded records nested above
AD
2026-06-02
FR doc 2026-05549
AD 2026-06-02Published 2026-03-20Effective 2026-04-24
Bell Textron Canada Limited Helicopters
Requires inspecting the installation of the lockwire on the SCAS actuator jam nut and, if the lockwire is incorrectly installed, removing the lockwire and installing a new lockwire correctly.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 429 helicopters. This AD was prompted by reports of incorrectly installed lockwire on the stability and control augmentation system (SCAS) actuator jam nut. This AD requires inspecting the installation of the lockwire on the SCAS actuator jam nut and, if the lockwire is incorrectly installed, removing the lockwire and installing a new lockwire correctly. This AD also prohibits the installation of an affected SCAS actuator assembly unless certain requirements are met. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2026-05549, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2024-07-51Published 2024-05-24Effective 2024-06-10
Bell Textron Canada Limited Helicopters
Requires repetitively inspecting and checking the T/R blade abrasion strip on certain T/R blades and, depending on results, replacing or marking the T/R blade.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 429 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 multiple reports of tail rotor (T/R) blade abrasion strip cracks. This AD requires repetitively inspecting and checking the T/R blade abrasion strip on certain T/R blades and, depending on results, replacing or marking the T/R blade. This AD also prohibits installing affected T/R blades on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2024-11420, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2022-20-11Published 2022-10-24Effective 2022-11-28
Bell Textron Canada Limited Helicopters
Requires visually inspecting the external surface of the TR gearbox support assembly, borescope inspecting or visually inspecting the inside of the tailboom for certain conditions, and performing a tactile inspection.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 429 helicopters. This AD was prompted by reports of failed rivets between the tailboom skin and the tail rotor (TR) gearbox support assembly. This AD requires visually inspecting the external surface of the TR gearbox support assembly, borescope inspecting or visually inspecting the inside of the tailboom for certain conditions, and performing a tactile inspection. Depending on the results of the inspections, this AD requires removing certain rivets from service or repairing gaps in accordance with an approved method. This AD also requires repeating these inspections within certain intervals. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2022-22593, retrieved 2026-08-18 · not yet re-verified against the live record
Requires recurring inspections regardless of hours time-in-service (TIS) accumulated on the helicopter.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
We are superseding emergency airworthiness directive (AD) No. 2015-16-51 (Emergency AD 2015-16-51) for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. Emergency AD 2015-16-51 required inspections of each inboard and outboard tail rotor pitch link assembly for axial or radial bearing play, and if there was axial or radial bearing play, removing the tail rotor pitch link and inspecting for wear. Emergency AD 2015-16-51 was prompted by several reports of worn tail rotor pitch link spherical bearings. We are issuing this supersedure to retain the inspection requirements in Emergency AD 2015- 16-51 while revising the applicability and compliance time to clarify that all Bell Model 429 helicopters require recurring inspections regardless of hours time-in-service (TIS) accumulated on the helicopter. These actions are intended to prevent pitch link failure and subsequent loss of control of the helicopter.
Source: Federal Register document 2015-27137, retrieved 2026-08-18 · not yet re-verified against the live record
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
We are superseding Airworthiness Directive (AD) 2015-22-02 for certain Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. AD 2015-22-02 required inspecting the tail rotor (TR) pitch link assemblies. This AD retains the inspections of AD 2015-22-02 and requires replacing certain pitch link bearings. This AD was prompted by a new design bearing introduced by Bell. We are issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2019-11991, retrieved 2026-08-18 · not yet re-verified against the live record
Airworthiness Directives; Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
The FAA is superseding Airworthiness Directive (AD) 2019-11-05 for certain Bell Helicopter Textron Canada Limited (now Bell Textron Canada Limited) Model 429 helicopters. AD 2019-11-05 required inspecting the tail rotor (TR) pitch link assemblies, and replacing certain pitch link bearings. This AD was prompted by a report of a worn pitch link, and the FAA's determination that all TR pitch link assemblies are affected by the unsafe condition. This AD continues to require the actions specified in AD 2019-11-05, and revises the applicability and requires inspections of certain other TR pitch link assemblies. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2022-08797, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2022-08-11Published 2022-04-22Effective 2022-05-27
Bell Textron Canada Limited Helicopters
Requires revising the existing rotorcraft flight manual supplement (RFMS) for your helicopter and disabling the traffic alert and collision avoidance system (TCAS) POP-UP feature for certain DUs.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 429 helicopters. This AD was prompted by in-service reports of the loss of display and subsequent recovery of certain display units (DUs). This AD requires revising the existing rotorcraft flight manual supplement (RFMS) for your helicopter and disabling the traffic alert and collision avoidance system (TCAS) POP-UP feature for certain DUs. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2022-08563, retrieved 2026-08-18 · not yet re-verified against the live record
Requires repetitive inspections of certain cyclic and collective assembly bearings.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
The FAA is adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (BHTC) Model 429 helicopters. This AD requires repetitive inspections of certain cyclic and collective assembly bearings. This AD was prompted by reports that precipitation can lead to reduced effectiveness of the grease in the bearings. The actions of this AD are intended to address an unsafe condition on these products.
Source: Federal Register document 2020-21127, retrieved 2026-08-18 · not yet re-verified against the live record
Airworthiness Directives; Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
The FAA is superseding Airworthiness Directive (AD) 2020-20- 06, which applied to certain Bell Helicopter Textron Canada Limited (now Bell Textron Canada Limited) Model 429 helicopters. AD 2020-20-06 required repetitive inspections of certain cyclic and collective assembly bearings. This AD was prompted by new bellcrank assemblies, which have been upgraded with corrosion resistant steel bearings. This AD retains certain requirements of AD 2020-20-06, and depending on the inspection results, requires removing certain parts from service and installing the upgraded cyclic and collective bellcrank assemblies. This AD also requires installing the upgraded collective and cyclic bellcrank assemblies on certain helicopters if not already installed, and prohibits installing certain bellcrank assemblies. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2022-05664, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2021-20-11Published 2021-10-18Effective 2021-11-22
Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
Requires a one-time inspection of the lower surface of the spherical bearing in the directional control bellcrank assembly to determine if it is properly staked and, depending on the findings, applicable corrective actions.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (type certificate previously held by Bell Helicopter Textron Canada Limited) Model 429 helicopters. This AD was prompted by reports of incorrectly staked spherical bearings in the directional control bellcrank assembly. This AD requires a one-time inspection of the lower surface of the spherical bearing in the directional control bellcrank assembly to determine if it is properly staked and, depending on the findings, applicable corrective actions. For certain helicopters, this AD also requires repetitive inspections and, depending on the findings, applicable corrective actions. This AD also provides a terminating action for the repetitive inspections. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2021-22469, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2021-18-16Published 2021-09-27Effective 2021-11-01
Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
Requires repetitive torque checks of the tail rotor gearbox attachment hardware, and corrective action if necessary.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (Bell) Model 429 helicopters. This AD was prompted by reports of tail rotor gearbox assemblies found loose on the gearbox support. This AD requires repetitive torque checks of the tail rotor gearbox attachment hardware, and corrective action if necessary. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2021-20829, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2021-19-01Published 2021-09-08Effective 2021-10-13
Bell Textron Canada Limited Helicopters
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.
Full official abstract
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.
Source: Federal Register document 2021-19244, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2021-18-10Published 2021-09-07Effective 2021-10-12
Bell Textron Canada Limited Helicopters
Requires revising the existing Rotorcraft Flight Manual (RFM) for your helicopter.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited Model 429 helicopters. This AD was prompted by three reports of unexpected forces or uncommanded inputs to the directional (yaw) control system. This AD requires revising the existing Rotorcraft Flight Manual (RFM) for your helicopter. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2021-19049, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2021-13-15Published 2021-06-24Effective 2021-07-29
Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
Requires establishing life limits and CMR tasks for various parts.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
The FAA is adopting a new airworthiness directive (AD) for Bell Textron Canada Limited (type certificate previously held by Bell Helicopter Textron Canada Limited) (Bell) Model 429 helicopters. This AD was prompted by the identification of certain parts needing life limits and certification maintenance requirement (CMR) tasks. This AD requires establishing life limits and CMR tasks for various parts. Depending on the results of the CMR tasks, this AD requires corrective action. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2021-13193, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2021-11-13Published 2021-06-10Effective 2021-07-15
Bell Textron Canada Limited Helicopters
Requires inspecting certain serial-numbered Emergency Flotation System (EFS) inflation hoses and depending on the results of those inspections, marking certain parts or removing certain parts from service.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited Helicopters
The FAA is adopting a new airworthiness directive (AD) for Bell Textron Canada Limited (Bell) Model 429 helicopters. This AD requires inspecting certain serial-numbered Emergency Flotation System (EFS) inflation hoses and depending on the results of those inspections, marking certain parts or removing certain parts from service. This AD was prompted by a report that a float compartment on an EFS did not inflate. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2021-12042, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2021-03-13Published 2021-02-25Effective 2021-04-01
Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
Requires determining the accumulated retirement index number (RIN) and removing each affected CFB from service before it accumulates 8,000 total RIN.
Full official abstract
Airworthiness Directives; Bell Textron Canada Limited (Type Certificate Previously Held by Bell Helicopter Textron Canada Limited) Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (type certificate previously held by Bell Helicopter Textron Canada Limited) Model 429 helicopters. This AD was prompted by the introduction of a new life limit for the centrifugal force bearing (CFB). This AD requires determining the accumulated retirement index number (RIN) and removing each affected CFB from service before it accumulates 8,000 total RIN. The FAA is issuing this AD to address the unsafe condition on these products.
Source: Federal Register document 2021-03659, retrieved 2026-08-18 · not yet re-verified against the live record
Prompted by an FAA determination that additional part-numbered T/R pitch link assemblies (links) are affected by the same unsafe condition and that an additional repetitive inspection is necessary to address the unsafe condition.
1 AD superseded by this oneretired · earliest 2016-02-02
AD
2016-02-06
FR doc 2016-01747
AD 2016-02-06Published 2016-02-02Effective 2016-02-02
Requires inspecting each tail rotor (T/R) pitch link (link) bearing bore for corrosion and pitting and either replacing the T/R link or applying sealant.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited
We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. This AD requires inspecting each tail rotor (T/R) pitch link (link) bearing bore for corrosion and pitting and either replacing the T/R link or applying sealant. This AD also requires a recurring inspection of the sealant and repeating the inspections for corrosion and pitting if any sealant is missing. This AD is prompted by an incident in which a helicopter experienced an in-flight failure of a T/R link. These actions are intended to detect corrosion or pitting and to prevent failure of a T/R link and subsequent loss of control of the helicopter.
Source: Federal Register document 2016-01747, retrieved 2026-08-18 · not yet re-verified against the live record
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
The FAA is superseding Airworthiness Directive (AD) 2016-02-06 for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. AD 2016-02-06 required inspecting certain tail rotor (T/R) pitch link bearing bores for corrosion and pitting. AD 2016-02-06 also required a repetitive inspection of the sealant and repeating the inspections for corrosion and pitting if any sealant is missing. This new AD retains the requirements of AD 2016-02-06, expands the applicability, and adds a repetitive inspection. This AD was prompted by an FAA determination that additional part-numbered T/R pitch link assemblies (links) are affected by the same unsafe condition and that an additional repetitive inspection is necessary to address the unsafe condition. The actions of this AD are intended to address an unsafe condition on these products.
Source: Federal Register document 2020-17779, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2020-04-21Published 2020-03-16Effective 2020-03-31
Bell Helicopter Textron Canada Limited Helicopters
Requires inspecting a certain part-numbered curvic coupling for proper engagement and depending on the inspection results, inspecting for play, inspecting the curvic coupling teeth, inspecting the flapping bearing teeth…
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain Bell Helicopter Textron Canada Limited (Bell Canada) Model 429 helicopters. This AD requires inspecting a certain part-numbered curvic coupling for proper engagement and depending on the inspection results, inspecting for play, inspecting the curvic coupling teeth, inspecting the flapping bearing teeth, replacing parts, performing a rigging check, and reporting information. This AD was prompted by a report of disengaged teeth of a curvic coupling due to improper installation. The actions of this AD are intended to address an unsafe condition on these products.
Source: Federal Register document 2020-05244, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2019-06-04Published 2019-04-02Effective 2019-05-07
Bell Helicopter Textron Canada Limited Helicopters
Requires inspecting each main rotor pitch link rod end bearing assembly (bearing) for wear and play.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (BHTC) Model 429 helicopters. This AD requires inspecting each main rotor pitch link rod end bearing assembly (bearing) for wear and play. This AD was prompted by reports of worn bearings. The actions of this AD are intended to prevent an unsafe condition on these products.
Source: Federal Register document 2019-06018, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2019-03-05Published 2019-02-19Effective 2019-03-26
Bell Helicopter Textron Canada Limited Helicopters
Prompted by revised airworthiness limitations determined by Bell.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. This AD revises the life limit for the nose landing gear (NLG) assembly. This AD was prompted by revised airworthiness limitations determined by Bell. The actions of this AD are intended to prevent an unsafe condition on these products.
Source: Federal Register document 2019-02626, retrieved 2026-08-18 · not yet re-verified against the live record
Requires adding an identification number to life-limited rod ends that do not have a serial number (S/N).
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. This AD requires adding an identification number to life-limited rod ends that do not have a serial number (S/N). The actions of this AD are intended to address an unsafe condition on these products.
Source: Federal Register document 2017-12799, retrieved 2026-08-18 · not yet re-verified against the live record
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
We are superseding Airworthiness Directive (AD) 2017-13-03 for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. AD 2017-13-03 required adding an identification number to life-limited rod ends that do not have a serial number (S/N). Since we issued AD 2017- 13-03, an additional life-limited rod end was identified that is affected by the same unsafe condition. This new AD retains the requirements of AD 2017-13-03 and revises the Applicability paragraph by adding that rod end. The actions of this AD are intended to address an unsafe condition on these products.
Source: Federal Register document 2018-23037, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2018-16-51Published 2018-10-22Effective 2018-11-06
Bell Helicopter Textron Canada Limited Helicopters
Requires inspecting the tail rotor (T/R) gearbox installation, inspecting the T/R gearbox retaining hardware and support attachment point areas, and replacing each nut.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
We are publishing a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. This AD was sent previously to all known U.S. owners and operators of these helicopters as Emergency AD 2018-16-51, dated July 26, 2018, which superseded Emergency AD 2018-15-51, dated July 20, 2018. This AD requires inspecting the tail rotor (T/R) gearbox installation, inspecting the T/R gearbox retaining hardware and support attachment point areas, and replacing each nut. This AD is prompted by two reports of T/R gearbox assemblies loosely attached to the gearbox support. The actions of this AD are intended to address an unsafe condition on these products.
Source: Federal Register document 2018-22414, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2018-14-07Published 2018-07-12Effective 2018-08-16
Bell Helicopter Textron Canada Limited Helicopters
Requires marking a serial number on life-limited forward spars and actuator fitting assemblies.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited Helicopters
We are adopting a new airworthiness directive (AD) for certain serial numbered Bell Helicopter Textron Canada Limited (BHTC) Model 429 helicopters. This AD requires marking a serial number on life-limited forward spars and actuator fitting assemblies. The actions of this AD are intended to prevent an unsafe condition on these products.
Source: Federal Register document 2018-14701, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2017-15-13Published 2017-07-27Effective 2017-08-31
Bell Helicopter Textron Canada Limited
Requires reducing the life limit of certain landing gear parts and is prompted by a stress analysis.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited
We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. This AD requires reducing the life limit of certain landing gear parts and is prompted by a stress analysis. The actions of this AD are intended to address an unsafe condition on these products.
Source: Federal Register document 2017-15552, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2017-05-51Published 2017-04-10Effective 2017-04-25
Bell Helicopter Textron Canada Helicopters
Requires inspecting the condenser blower motor (motor) and condenser blower (blower) to determine if the motor is securely attached to the blower support (shroud).
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Helicopters
We are publishing a new airworthiness directive (AD) for Bell Helicopter Textron Canada (Bell) Model 429 helicopters. This AD requires inspecting the condenser blower motor (motor) and condenser blower (blower) to determine if the motor is securely attached to the blower support (shroud). This AD is prompted by a report that the motor detached from the blower. The actions of this AD are intended to prevent an unsafe condition on these products.
Source: Federal Register document 2017-06710, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2016-20-01Published 2016-09-30Effective 2016-10-17
Bell Helicopter Textron Canada Limited (Bell) Helicopters
Requires replacing certain engine and transmission oil check valves.
Full official abstract
Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters
We are adopting a new airworthiness directive (AD) for Bell Model 427 and Model 429 helicopters. This AD requires replacing certain engine and transmission oil check valves. This AD also prohibits installing the affected check valves on any helicopter. This AD is prompted by a report of several cracked or leaking check valves. These actions are intended to detect and prevent a cracked or leaking check valve which could result in loss of lubrication to the engine or transmission, failure of the engine or transmission, and subsequent loss of control of the helicopter.
Source: Federal Register document 2016-23345, retrieved 2026-08-18 · not yet re-verified against the live record
AD 2015-17-02Published 2015-08-20Effective 2015-09-24
Bell Helicopter Textron Canada (Bell) Helicopters
We are superseding Airworthiness Directive (AD) 2001-13-51 for Bell Model 206L-4, 407, and 427 helicopters.
Full official abstract
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.
Source: Federal Register document 2015-20509, retrieved 2026-08-18 · not yet re-verified against the live record