Md helicopters airworthiness directives
52 ADs in the reference matching Md helicopters — from the Federal Register, checked every weekday. Applicability may depend on serial and effectivity: verify against the official AD before any maintenance action.
Reference last synced: 10/22/2026 16:00 UTC · 10,462 ADs indexed
Airworthiness Directives; MD Helicopters, LLC Helicopters
The FAA is correcting an airworthiness directive (AD) that was published in the Federal Register. That AD applies to all MD Helicopters, LLC Model 369, 369A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. As published, the header of the regulatory text is missing the AD number and the amendment number. This document corrects those errors. In all other respects, the original document…
Airworthiness Directives; MD Helicopters, LLC
The FAA is adopting a new airworthiness directive (AD) for certain MD Helicopters, LLC, Model 369 (Army YOH-6A), 369A (Army OH- 6A), 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. This AD was prompted by multiple reports of cracked tail rotor (T/R) pedal support brackets. This AD requires repetitively inspecting certain part-numbered T/R pedal support brackets and depending on the re…
Airworthiness Directives; MD Helicopters, LLC, Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain MD Helicopters, LLC (MDHI), Model 369, 369A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. This AD was prompted by a report of a seized and damaged roller bearing in the pilot interconnecting cyclic torque tube (torque tube) assembly. This AD requires repetitively inspecting the torque tube assembly and roller bearin…
Airworthiness Directives; MD Helicopters Inc. (MDHI) Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain MD Helicopters Inc. (MDHI), Model 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. This AD was prompted by a report of a spiral crack in the pilot-to-copilot tail rotor torque tube (torque tube). This AD requires a one-time visual and recurring borescope inspections of the torque tube and depending on the results, remov…
Airworthiness Directives; MD Helicopters Inc. (MDHI), Helicopters
The FAA is adopting a new airworthiness directive (AD) for certain MD Helicopters Inc. (MDHI) Model 369A, 369D, 369E, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. This AD was prompted by reports of abrasion strips departing the main rotor (MR) blade in- flight. This AD requires tap inspecting each MR blade leading edge abrasion strip. The FAA is issuing this AD to address the unsafe condition on the…
Airworthiness Directives; MD Helicopters Inc. Helicopters
The FAA is adopting a new airworthiness directive (AD) for MD Helicopters Inc. (MDHI) Model 600N helicopters. This AD requires establishing a life limit for the main rotor (M/R) blade upper control collective/longitudinal link assembly (link assembly). This AD was prompted by the discovery that the life limit was omitted from the maintenance manual. The actions of this AD are intended to prevent an unsafe condition…
Airworthiness Directives; MD Helicopters, Inc. (MDHI), Helicopters
We are adopting a new airworthiness directive (AD) for MDHI Model 369A, 369D, 369E, 369FF, 369H, 369HE, 369HM, 369HS, 500N, and 600N helicopters. This AD requires inspecting each main rotor blade (MRB) for a crack. This AD was prompted by reports of cracked MRBs. The actions of this AD are intended to address an unsafe condition on these helicopters.
Airworthiness Directives; MD Helicopters Inc., Helicopters
We are adopting a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI), Model 369A, 369D, 369E, 369FF, 369HE, 369HM, 369HS, 500N, and 600N helicopters with a certain part-numbered main rotor blade attach pin (pin) installed. This AD requires ensuring the life limit of the pin as listed in the Airworthiness Limitations section of aircraft maintenance records and Instructions for Continued Airworthiness (I…
Airworthiness Directives; MD Helicopters Inc.
We are adopting a new airworthiness directive (AD) for MD Helicopters Inc. (MDHI) Model 500N and 600N helicopters with certain rotating cone assemblies installed. This AD requires establishing a life limit of 10,000 hours time-in-service (TIS) on these rotating cone assemblies. This AD was prompted by the determination that MDHI created rotating cone assemblies with new dash numbers but incorrectly failed to identif…
Airworthiness Directives; MD Helicopters, Inc., Helicopters
We are adopting a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI), Model MD900 helicopters. This AD requires an eddy current inspection of the main rotor upper hub assembly (upper hub) for a crack and replacing the upper hub with an airworthy upper hub before further flight if there is a crack. This AD is prompted by a report of cracks on an upper hub at the blade attach holes. The actions specified…
Airworthiness Directives; MD Helicopters, Inc. (MDHI) Helicopters
We are adopting a new airworthiness directive (AD) for MDHI Model MD900 helicopters with certain main rotor blade (MRB) retention bolts (bolts) installed. This AD requires a daily check of the position of each bolt, a daily check and a repetitive inspection for a gap in each bolt, and, if necessary, removing and inspecting the bolt for a crack and replacing any cracked bolt with an airworthy bolt. This AD was prompt…
Airworthiness Directives; MD Helicopters, Inc., Helicopters
We are superseding Airworthiness Directive (AD) 2003-08-51 for MD Helicopters, Inc. (MDHI), Model 369A, 369D, 369E, 369H, 369HE, 369HM, 369HS, 369F and 369FF helicopters with certain MDHI or Helicopter Technology Company (HTC) tail rotor blades installed. AD 2003-08-51 required reducing the retirement life of each tail rotor blade (blade), performing a one-time visual inspection of each blade's pitch horn (pitch hor…
Airworthiness Directives; MD Helicopters, Inc., Helicopters
We are adopting a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model 500N, 600N and MD900 helicopters to require determining the cure date for each NOTAR fan blade tension- torsion strap (T-T strap), establishing a calendar-time retirement life for certain T-T straps, reducing the retirement life of certain T-T straps, marking each T-T strap with the expiration date, creating a component record c…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This amendment supersedes an existing airworthiness directive (AD) that applies to MD Helicopters, Inc. (MDHI) Model MD900 helicopters. That AD currently requires turning ON both Vertical Stabilizer Control System (VSCS) switches and turning OFF the autopilot (AP/SAS) switch; pulling certain AP/SAS circuit breakers; installing a placard near the AP/SAS master switch; installing an airspeed limitation placard on the…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This amendment supersedes an existing airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model MD900 helicopters. That AD currently requires visually inspecting the main rotor lower hub assembly (lower hub) for a crack, and if you find a crack, before further flight, replacing the unairworthy lower hub with an airworthy lower hub. Additionally, within 10 days of finding a cracked lower hub, the existing AD…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This document publishes in the Federal Register an amendment adopting Emergency Airworthiness Directive (AD) 2010-18-52 which was sent previously to all known owners and operators of MD Helicopters, Inc. (MDHI) Model MD900 helicopters by individual letters. This AD requires visually inspecting the main rotor hub (hub) for a crack. If a crack is found, this AD requires, before further flight, replacing the unairworth…
Airworthiness Directives; MD Helicopters, Inc. Model MD-900 Helicopters
This amendment supersedes an existing airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) model MD-900 helicopters that currently requires applying serial numbers to certain parts, increasing the life limit for various parts, maintaining a previously established life limit for a certain vertical stabilizer control system (VSCS) bellcrank assembly and bellcrank arm, and correcting the part number for the VSC…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 (including the MD902 Configuration) Helicopters
This amendment adopts a new airworthiness directive (AD) for the specified MD Helicopters, Inc. (MDHI) model helicopters that requires, within 30 days, reducing the current gross weight limit to a maximum gross weight limit of 5,400 pounds and inserting a copy of this AD into the Limitations section of the Rotorcraft Flight Manual (RFM) or making certain optional modifications that constitute terminating actions. Th…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This document supersedes AD 2008-18-52 and publishes in the Federal Register an amendment adopting Emergency Airworthiness Directive (AD) 2008-22-53 which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model MD900 helicopters by individual letters. This AD requires turning ON both Vertical Stabilizer Control System (VSCS) switches and turning OFF the autopilot (AP/SAS) swit…
Airworthiness Directives; MD Helicopters, Inc. Model 500N and 600N Helicopters
This document supersedes AD 2008-18-52 and publishes in the Federal Register an amendment adopting Emergency Airworthiness Directive (AD) 2008-22-52 which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model 500N and 600N helicopters by individual letters. This AD requires turning OFF the Yaw Stability Augmentation System (YSAS); installing a placard that limits airspeed to…
Airworthiness Directives; MD Helicopters, Inc. Model 600N Helicopters
This amendment supersedes an existing airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model 600N helicopters. The AD currently requires modifying the fuselage aft section within the next 24 months to strengthen the tailboom attachment fittings and upper longerons. This amendment retains the current required modification and adds the following requirements: Repetitively inspecting the tailboom attachment…
Airworthiness Directives; MD Helicopters, Inc. Model 369A, OH-6A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, and 369HS Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model 369A, OH-6A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HM, and 369HS helicopters that requires repetitive tap inspections of each tail rotor (T/R) blade abrasion strip. This amendment is prompted by an incident in which an abrasion strip separated from a T/R blade. The actions specified by this AD are intended to prevent di…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2008-17-51, which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model MD900 helicopters by individual letters. This AD requires, before further flight, fluorescent magnetic particle inspecting the aft threads of the forward directional control cable (control cable) for a crac…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Series Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model MD900 series helicopters that requires modifying the pilot and co-pilot dual-control directional pedal assemblies, or the pilot single-control directional pedal assembly (directional control pedal assembly). This amendment is prompted by an accident which has been attributed to loss of directional control due to failure of…
Airworthiness Directives; MD Helicopters, Inc. Model 600N Helicopters
This document supersedes an existing airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model 600N helicopters. That AD currently requires interim initial and repetitive inspections of tailboom parts, installing six inspection holes in the aft fuselage skin panels, installing tailboom attachment bolt washers, modifying both access covers, and replacing broken attachment bolts. The current AD also provides…
Airworthiness Directives; MD Helicopters, Inc. Model 369A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HS, 369HM, 500N, and OH-6A Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model 369A, 369D, 369E, 369F, 369FF, 369H, 369HE, 369HS, 369HM, 500N, and OH-6A helicopters that requires inspecting each landing gear fairing support assembly (support assembly), replacing or reworking certain forward and aft landing gear assemblies, and creating an access hole to facilitate inspections and a recurring inspecti…
Airworthiness Directives; MD Helicopters, Inc., Model 369, YOH-6A, 369A, OH-6A, 369H, 369HM, 369HS, 369HE, 369D, 369E, 369F, and 369FF Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2007-09-51, sent previously to all known U.S. owners and operators of the specified MD Helicopters, Inc. (MDHI), model helicopters by individual letters. This AD requires, before further flight, removing each affected tail rotor blade assembly and inspecting the bore of the tail rotor blade root fitting. If the blade a…
Airworthiness Directives; MD Helicopters Inc. (MDHI) Model MD600N Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2007-05-51, which was sent previously to all known U.S. owners and operators of MDHI Model MD600N helicopters by individual letters. This AD requires, before further flight, a visual and eddy current inspection of each lateral mixer output link assembly (mixer link) and replacing any cracked mixer link. This AD also re…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This amendment supersedes an existing airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model MD900 helicopters, that currently requires reducing the life limit of certain Notar fan system tension-torsion (TT) straps. That existing AD also requires, at a specified time interval, removing each affected TT strap from the helicopter, doing a visual and X-ray inspection, and replacing any unairworthy part bef…
Airworthiness Directives; MD Helicopters, Inc. Model 600N Helicopters
This amendment supersedes an existing airworthiness directive (AD) for the MD Helicopters, Inc. (MDHI) Model 600N helicopters, that currently requires inspecting both upper tailboom attachment fittings, nut plates and both angles for a crack or thread damage, and repairing or replacing any cracked or damaged part. That AD also requires replacing the upper right tailboom attachment bolt with a new attachment bolt, an…
Airworthiness Directives; MD Helicopters, Inc. Model 369D, 369E, 369F, 369FF, 500N, and 600N Helicopters
This amendment supersedes an existing airworthiness directive (AD) for the MD Helicopters, Inc. (MDHI) Model 369A, H, HE, HM, HS, D, and E helicopters with a certain part-numbered main rotor blade (blade) and modified with a Helicopter Technology Company, LLC (HTC), Supplemental Type Certificate (STC) No. SR09172RC, SR09074RC, or SR09184RC. That AD currently requires recording on the component history card or equiva…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This amendment adopts a new airworthiness directive (AD) for the MD Helicopters, Inc. (MDHI) Model MD900 helicopters. This action requires reducing the life limit of certain Notar fan system tension- torsion (TT) straps. This action also requires, at a specified time interval, removing each affected TT strap from the helicopter, doing a visual and x-ray inspection, and replacing any unairworthy part before further f…
Airworthiness Directives; MD Helicopters, Inc. Model 600N Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. Model 600N helicopters that requires replacing the fuselage Station 75 control support bracket assembly (control support bracket), reducing the life limit, and revising the Limitations section of the applicable maintenance manual to state the reduced life limits on certain serial-numbered helicopters. This amendment is prompted by info…
Airworthiness Directives; MD Helicopters, Inc. (MDHI) Model 500N and 600N Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model 500N and 600N helicopters. This action requires using a bright light and a 10x or higher magnifying glass to inspect each forward and center thruster control cable assembly connector (connector) for corrosion pitting or cracking. If you find corrosion pitting or cracking, this AD also requires replacing the cable assembly…
Airworthiness Directives; MD Helicopters Inc. Model MD900 Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. Model MD900 helicopters. This action requires installing a fan input force limiting control rod assembly fail-safe device (fail-safe device). This AD also requires, after installing a fail-safe device, before the first flight of each day, checking the fail-safe device for bent clips, taut lanyards, and piston rod movement. If any of th…
Airworthiness Directives; MD Helicopters, Inc. Model 369A, H, HE, HM, HS, D, and E Helicopters
This amendment adopts a new airworthiness directive (AD) for the specified model helicopters modified with a Helicopter Technology Company, LLC, Supplemental Type Certificate (STC) No. SR09172RC, SR09074RC, or SR09184RC. This action requires recording on the component history card or equivalent record the number of torque events (TEs) on each main rotor blade (blade). When a blade accumulates 13,720 TEs and 750 hour…
Airworthiness Directives; MD Helicopters, Inc., Model 600N Helicopters
This amendment adopts a new airworthiness directive (AD) for the specified MD Helicopters, Inc. (MDHI) model helicopters that requires reducing the life limit of the main rotor drive shaft (drive shaft) and changing the life limit on the component history card or equivalent record. This amendment is prompted by the review of final fatigue test data, which indicates that the life limit of the drive shaft should be re…
Airworthiness Directives; MD Helicopters, Inc., Model MD900 Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2003-14-51, which was sent previously to all known U.S. owners and operators of the specified MD Helicopters, Inc. (MDHI) helicopters by individual letters. This AD requires checking and inspecting each main rotor blade retention bolt (bolt) and replacing the bolt with an airworthy bolt if necessary. The actions specif…
Airworthiness Directives; MD Helicopters, Inc. Model 369A, D, E, H, HE, HM, HS, F, and FF Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2003-08-51, which was sent previously to all known U.S. owners and operators of the specified model MD Helicopters, Inc. helicopters by individual letters. This AD requires reducing the retirement life of certain tail rotor blades, performing a one-time visual inspection of each tail rotor blade pitch horn (pitch horn)…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model MD900 helicopters that requires inspecting and, if necessary, repairing the longitudinal drive link (drive link) and modifying certain nonrotating swashplate (swashplate) assemblies. This AD also requires recording compliance with the AD on a component history card or equivalent record. This amendment is prompted by report…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2002-22-51, which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model MD900 helicopters by individual letters. This AD requires, before further flight, certain procedures and inspections of the main rotor support static mast (mast) and the mast threads for any crack or pittin…
Airworthiness Directives; MD Helicopters, Inc., Model MD900 Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc., Model MD900 helicopters that requires, for the lateral-mixer bellcrank assembly (bellcrank), establishing a life limit, creating a component history card or equivalent record, determining the hours time-in-service (TIS), and applying a serial number (S/N). This amendment is prompted by additional testing that revealed that the origina…
Airworthiness Directives; MD Helicopters, Inc. Model 369D, 369E, 369F, and 369FF Helicopters
This amendment adopts a new airworthiness directive (AD) for specified MD Helicopters, Inc. (MDHI) helicopters with a tailboom modified according to Aerometals Supplemental Type Certificate (STC) SH5055NM or SH4801NM. This AD requires an inspection to identify the part number (P/N) of the bolts that attach the tail rotor gearbox to the tailboom and replacing any bolt of inadequate grip length with an airworthy bolt.…
Airworthiness Directives; MD Helicopters Inc. Model MD-900 Helicopters
This amendment supersedes an existing airworthiness directive (AD), applicable to MD Helicopters Inc. Model MD-900 helicopters, that currently requires inspecting the main rotor upper hub (hub) assembly drive plate attachment flange (flange), determining the torque of each flange nut (nut), and if a crack is found, before further flight, replacing the hub assembly. In addition to the current requirements, this actio…
Airworthiness Directives; MD Helicopters, Inc. Model 600N Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2001-24-51, which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model 600N helicopters by individual letters. This AD requires, within 5 hours time-in-service (TIS), inspecting both upper tailboom attachments, nutplates and both angles for a crack or thread damage and repairi…
Airworthiness Directives; MD Helicopters, Inc. Model MD900 Helicopters
This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 2001-25-51, which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model MD900 helicopters by individual letters. This AD requires performing a dual power confirmation test on the Integrated Instrument Display System (IIDS) and inserting a revision to the Rotorcraft Flight Manua…
Airworthiness Directives; MD Helicopters Inc. Model MD-900 Helicopters
This amendment supersedes an existing emergency airworthiness directive (AD) that applies to MD Helicopters Inc. (MDHI) Model MD-900 helicopters. That emergency AD requires, within 6 hours time-in-service (TIS), or before further flight after January 31, 2000, whichever occurs first, inspecting the main rotor upper hub assembly drive plate attachment flange (flange) and determining the torque of each flange nut (nut…
Airworthiness Directives; MD Helicopters, Inc. Model 369A, H, HE, HM, HS, D, E, FF, and 500N Helicopters
This document publishes in the Federal Register an amendment adopting Emergency Airworthiness Directive (AD) 2000-25-52 which was sent previously to all known U.S. owners and operators of MD Helicopters, Inc. (MDHI) Model 369A, H, HE, HM, HS, D, E, FF, and 500N helicopters. This amendment supersedes an existing emergency AD that requires, before further flight, performing a tap inspection on both the upper and lower…
Airworthiness Directives; MD Helicopters, Inc. Model MD-900 Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters, Inc. (MDHI) Model MD-900 helicopters that requires modifying the non-rotating swashplate assembly and re- identifying it and the swashplate assembly with new part numbers. This AD also requires creating a component history card or equivalent record to track the life of the newly identified non-rotating swashplate assembly and establishing a…
Airworthiness Directives; MD Helicopters Inc. Model MD900 Helicopters
This amendment adopts a new airworthiness directive (AD) for MD Helicopters Inc. (MDHI) Model MD900 helicopters. This action requires visually inspecting the drive shaft to determine the assembly part number (P/N) and marking the drive shaft assembly P/N and serial number (S/N) on any unmarked drive shaft. This AD also requires creating a component history card or equivalent record for certain drive shaft assemblies…
Airworthiness Directives; MD Helicopters Inc. Model 369D, 369E, 500N, and 600N Helicopters
This amendment adopts a new airworthiness directive (AD) applicable to MD Helicopters Inc. (MDHI) Model 369D, 369E, 500N, and 600N helicopters with certain analog/digital turbine outlet temperature (TOT) indicators installed. This action requires repetitive calibration testing of the TOT indicating system and corrective actions if necessary. This amendment is prompted by seven reports of erroneous TOT readings and t…
Airworthiness Directives; MD Helicopters Inc. Model MD600N Helicopters
This amendment adopts a new airworthiness directive (AD), applicable to MD Helicopters Inc. (MDHI) Model MD600N helicopters, that requires inspecting each internal fuel hose connection to verify proper installation. This amendment is prompted by the discovery that certain fuel hose connections between the fuel cells and the engine can be incorrectly installed. The actions specified by this AD are intended to prevent…