Robinson R44

Airworthiness Directives; Robinson Helicopter Company Helicopters

The FAA is superseding Airworthiness Directive (AD) 2024-19-11 for all Robinson Helicopter Company Model R44 and R44 II helicopters. AD 2024-19-11 required visually inspecting a certain flex plate assembly (flex plate) and certain clutch shaft forward yokes (yokes), including each flex plate bolt, and depending on the results, taking corrective actions. AD 2024-19-11 also required removing certain yokes from service within a specified threshold, or as an alternative, performing in-depth inspections. Since the FAA issued AD 2024-19-11, it has been determined that clarifications regarding the alternative inspections are necessary. This AD requires the actions of AD 2024-19- 11 and clarifies that the alternative inspections are repetitive and adds a particular paint remover option to use when performing those alternative inspections. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company

The FAA is adopting a new airworthiness directive (AD) for certain Robinson Helicopter Company Model R44 and R44 II helicopters. This AD was prompted by several reports of failed clutch actuators and failed rivets attaching the belt tension clutch actuator brackets (bracket) to the fan scroll housing. This AD requires inspecting each bracket and, depending on the results, accomplishing additional inspections or taking any necessary corrective actions. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company Helicopters

The FAA is adopting a new airworthiness directive (AD) for Robinson Helicopter Company (Robinson Helicopter) Model R22 Beta, R22 Mariner, R44, and R44 II helicopters with a certain governor controller installed. This AD was prompted by reports of engine governor failure, which was a result of water intrusion inside of the governor controller. This AD requires replacing certain governor controllers and prohibits installing those governor controllers on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company Helicopters

The FAA is adopting a new airworthiness directive (AD) for certain Robinson Helicopter Company Model R22, R22 Alpha, R22 Beta, R22 Mariner, R44, R44 II, and R66 helicopters. This AD was prompted by reports of helicopters losing a tail rotor blade (TRB) tip cap. This AD requires visually checking and inspecting certain part-numbered and serial-numbered TRB tip caps for evidence of corrosion and, depending on the results, removing the corrosion. This AD also requires removing all affected TRBs from service and prohibits installing them on any helicopter. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company Helicopters

The FAA is superseding Airworthiness Directive (AD) 2021-19- 08, which applied to certain Robinson Helicopter Company (Robinson) Model R44 and R44 II helicopters. AD 2021-19-08 required checking each tail rotor blade (blade) for any crack and removing any cracked blade from service. AD 2021-19-08 also required removing all affected blades from service and prohibited installing any affected blade on any helicopter. Since the FAA issued AD 2021-19-08, it was determined that an additional model helicopter and additional blades are affected by the unsafe condition. This AD requires the same actions as AD 2021-19- 08 and adds certain Robinson Model R66 helicopters to the applicability and adds additional part-numbered and serial-numbered blades to the applicability. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company Helicopters

The FAA is adopting a new airworthiness directive (AD) for certain Robinson Helicopter Company Model R22 BETA, R44, and R44 II helicopters. This AD was prompted by reports of intermittent or abnormal operation of the engine revolutions per minute (RPM) governor (governor). This AD requires inspecting the engine RPM sensor wiring and installing a wiring kit. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company

The FAA is superseding Airworthiness Directive (AD) 2019-12-18 for Robinson Helicopter Company (Robinson) Model R44 II helicopters. AD 2019-12-18 required inspecting certain engine air induction hoses (hoses) and replacing any hose that was not airworthy. AD 2019-12-18 also prohibited the installation of certain hoses. This AD continues to require inspecting those previously affected hoses and amends the applicability, clarifies an inspection requirement, adds a requirement to repeat the inspection, and expands the installation prohibition. This AD was prompted by an additional report of separation between the outer and inner hose layers. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company Helicopters

The FAA is adopting a new airworthiness directive (AD) for Robinson Helicopter Company (Robinson) Model R44 and R44 II helicopters. This AD was prompted by reports of cracking in certain tail rotor blades. This AD requires visually checking each tail rotor blade for a crack. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company Helicopters

The FAA is adopting a new airworthiness directive (AD) for Robinson Helicopter Company Model R44 and R44 II helicopters with an agricultural spray system installed by Supplemental Type Certificate (STC) SR00286BO (spray system). This spray system is also known as a Simplex Manufacturing Company (Simplex) Model 244 spray system. This AD was prompted by a report of an in-flight failure of the spray system elbow pump fitting (pump fitting). This AD requires repetitive inspections of the spray system pump fitting, corrective action if necessary, replacement of the spray system pump fitting, and installation of hose supports and a pump outlet cover. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company Helicopters

We are adopting a new airworthiness directive (AD) for Robinson Helicopter Company (Robinson) Model R44, R44 II, and R66 helicopters. This AD requires inspecting the main rotor blade (MRB). This AD was prompted by a determination that some MRBs may have reduced blade thickness due to blending out corrosion. The actions are intended to prevent the unsafe condition on these products.

Airworthiness Directives; Robinson Helicopter Company Helicopters

We are superseding Airworthiness Directive (AD) 2011-12-10 for Robinson Helicopter Company (Robinson) Model R22, R22 Alpha, R22 Beta, R22 Mariner, R44, and R44 II helicopters with certain main rotor blades (blade) installed. AD 2011-12-10 required inspecting each blade at the skin-to-spar line for debonding, corrosion, a separation, a gap, or a dent and replacing any damaged blade with an airworthy blade. This new AD also requires a terminating action for those inspection requirements. These actions are intended to detect debonding of the blade skin, which could result in blade failure and subsequent loss of control of the helicopter, and to correct the unsafe condition by replacing the main rotor blades with new blades that do not require the AD inspection.

Airworthiness Directives; Robinson Helicopter Company Helicopters

We are adopting a new airworthiness directive (AD) for Robinson Helicopter Company (Robinson) Model R44 and R44 II helicopters equipped with emergency floats. This AD requires replacing the inflation valve assembly. This AD was prompted by the failure of the emergency floats to deploy during a factory test because a needle was binding within the inflation valve assembly. The actions are intended to prevent the failure of the floats to inflate during an emergency landing.

Airworthiness Directives; Robinson Helicopter Company Model (Robinson) R22, R22 Alpha, R22 Beta, R22 Mariner, R44, and R44 II Helicopters

This amendment supersedes an existing airworthiness directive (AD) for the specified Robinson model helicopters that currently requires a visual inspection for skin separation along the leading edge of blade skin aft of the skin-to-spar bond line on the lower surface of each main rotor blade (blade) and in the tip cap area. The existing AD also requires a "tap test" for detecting a separation or void in both bonded areas and repainting any exposed area of the blades. If any separation or void is detected, the AD requires, before further flight, replacing the blade. Thereafter, before each flight, the existing AD also requires checking for any exposed (bare) metal along the skin-to- spar bond line on the lower surface of each blade near the tip. If any bare metal is found, that AD requires an inspection by a qualified mechanic. This amendment contains the same requirements but expands the applicability to include all serial-numbered model helicopters and limits the applicability to specific blade part numbers. This amendment also requires a repetitive inspection of the blade and any necessary rework. This amendment is prompted by a fatal accident in Israel. We have also included responses to comments objecting to the recording requirements in the current AD relating to the pilot checks before each flight and to comments that the burden of the before-each-flight pilot check exceeds the benefit. We have concluded that a check before the first flight of each day is sufficient for aviation safety. The actions specified by this AD are intended to provide more specific AD actions, to relieve the burdens associated with the before-each-flight check by changing it to a daily check, to detect blade skin debond, and to prevent blade failure and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company (Robinson) Model R22, R22 Alpha, R22 Beta, and R22 Mariner Helicopters, and Model R44, and R44 II Helicopters

This amendment adopts a new airworthiness directive (AD) for Robinson Model R22, R22 Alpha, R22 Beta, and R22 Mariner helicopters, and Model R44 and R44 II helicopters. This AD requires visually inspecting each tail rotor (T/R) control pedal bearing block support (support) for a crack, measuring the thickness of each support, installing support safety tabs on certain supports, and replacing supports of a certain thickness during the next 2,200 hour overhaul. This amendment is prompted by two reports of Model R22 helicopters experiencing broken supports during flight, which resulted in the T/R control pedals becoming jammed. The actions specified by this AD are intended to prevent the supports from breaking, which can bind the T/R control pedals, resulting in a reduction of yaw control and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Models R22, R22 Alpha, R22 Beta, R22 Mariner, R44 and R44 II Helicopters

This amendment adopts a new airworthiness directive (AD) for the specified Robinson Helicopter Company (Robinson) helicopters. This action requires a one-time visual inspection for skin separation along the leading edge of blade skin aft of the skin-to-spar bond line on the lower surface of each blade and in the tip cap area. This action also requires a "tap test" for detecting a separation or void in both bonded areas. This action also requires repainting any exposed area of the blades. If any separation or void is detected, replacing the blade before further flight is required. Thereafter, before each flight, this AD also requires checking for any exposed (bare metal) along the skin-to-spar bond line on the lower surface of each blade near the tip. If any bare metal is found, a mechanic must inspect the area. This amendment is prompted by 11 reports of blade debond, some occurring in flight causing the pilot to feel excessive vibrations and land, and some found during routine maintenance. The actions specified in this AD are intended to detect blade skin debond and to prevent blade failure and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 and R44 II Helicopters

This amendment adopts a new airworthiness directive (AD) for Robinson Helicopter Company (Robinson) Model R44 and R44 II helicopters that have a certain seat belt buckle (buckle) assembly installed, that requires removing the buckle assembly and the buckle assembly spacer, and replacing them with airworthy parts. This amendment is prompted by an accident in which a seat belt failed, and also by reports of cracking in the buckle assembly stainless support strap (support strap). The actions specified by this AD are intended to prevent cracking in the support strap and failure of a seat belt.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment rescinds an existing Airworthiness Directive (AD) for Robinson Helicopter Company (Robinson) Model R44 helicopters, which currently requires revisions to the R44 Rotorcraft Flight Manual (RFM). The RFM revisions limit operations in high winds and turbulence. The RFM revisions also provide information about main rotor stall and mast bumping with recommendations for avoiding these situations and additional emergency procedures for use in certain conditions. This amendment is prompted by the FAA's determination that the limitations and the procedures required by that AD are no longer necessary to correct an unsafe condition. The actions specified by this AD rescind all the requirements of AD 95-26-05, Amendment 39-9463, Docket 95-SW- 30-AD.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD) for Robinson Helicopter Company (RHC) Model R44 helicopters that requires inspecting the tail rotor pitch control assembly for roughness or binding of the pitch control bearings (bearings) by hand-rotating the pitch control bearing housing (housing). If the housing does not rotate freely, the AD requires replacing the unairworthy pitch control assembly with an airworthy unit. This amendment is prompted by reports of failure of the tail rotor pitch control assembly due to improperly lubricated bearings on the RHC Model R22 helicopters. Although there have been no reported failures on the RHC Model R44 helicopters, the design of the tail rotor pitch control assembly makes it susceptible to the same failures as have occurred on the Model R22 helicopters. The actions specified by this AD are intended to detect corrosion of the bearings and to prevent bearing failure and subsequent loss of directional control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD) for Robinson Helicopter Company (RHC) Model R44 helicopters that requires establishing a life limit of 2200 hours time-in-service (TIS) for affected horizontal stabilizers. This amendment is prompted by engineering analysis which indicates that certain vertical-to- horizontal stabilizer attach channels (channels) will crack sooner than the original life limit of the horizontal stabilizer. The actions specified by this AD are intended to prevent a crack through a channel, separation of the stabilizers, and subsequent loss of directional control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to Robinson Helicopter Company (RHC) Model R44 helicopters. This action requires replacing certain serial number (S/N) sprag clutches with an airworthy sprag clutch as specified in this AD. This amendment is prompted by several reports of sprag clutch failures. The actions specified by this AD are intended to prevent a sprag clutch failure, loss of main rotor RPM during autorotation, and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to Robinson Helicopter Company (Robinson) Model R44 helicopters, that requires inspecting the wire harness for contact with the fuel line assembly, removing and replacing the fuel line assembly if chafing has occurred, and installing spiral wrap tubing on the fuel line assembly. This amendment is prompted by four incidents of contact between the wire harness and the fuel line assembly. The actions specified by this AD are intended to prevent contact between the wire harness and the fuel line, which could result in chafing of the wire harness and a potential fire hazard.

Airworthiness Directives; Robinson Helicopter Company (Robinson) Model R44 Helicopters

This amendment supersedes an existing airworthiness directive (AD), applicable to Robinson Model R44 helicopters, that currently requires removing and replacing the pilot's cyclic control grip assembly (grip assembly) with an airworthy grip assembly. This amendment requires the same actions as the current AD but would change a part number (P/N) referenced in the current AD. This amendment is prompted by the discovery of an error in the P/N of the current AD. The actions specified by this AD are intended to prevent use of a grip assembly that may crack, resulting in failure of the grip assembly and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-17-17 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (RHC) Model R44 helicopters by individual letters. This AD requires, prior to further flight, replacing certain yoke assemblies with airworthy yoke assemblies. This amendment is prompted by an incident in which, during cruise flight, the pilot heard a loud bang and no tail rotor effectiveness due to a cracked yoke assembly. RHC has identified the manufacturing lots associated with the failed yoke assembly. The actions specified by this AD are intended to prevent failure of the yoke assembly, which could result in loss of main and tail rotor drive and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company (Robinson) Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to Robinson Model R44 helicopters, that requires installing a shutoff clamp on the auxiliary fuel tank sump drain tube (drain tube) and a placard decal to alert operators as to the proper use of the auxiliary fuel tank drain. This amendment is prompted by a report of fuel leaking from a drain tube opening in the area of the horizontal and vertical firewalls. The actions specified by this AD are intended to prevent fuel leaks from the drain tube that could cause a fire and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-07-18 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (RHC) Model R44 helicopters by individual letters. This AD requires, before further flight, inserting a Special Pilot Caution into the Normal Procedures section of the Rotorcraft Flight Manual (RFM). This amendment is prompted by several reports of sprag clutch assemblies with cracked or fractured sprag ends. The sprag clutch failures, determined to be due to a change in the manufacturing process, could result in loss of main rotor revolutions-per-minute (RPM) during autorotations. The intent of this AD is to alert pilots of the potential for the sprag clutch failing to overrun during autorotation, loss of main rotor RPM, and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company (RHC) Model R44 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 98-22-16 which was sent previously to all known U.S. owners and operators of RHC Model R44 helicopters by individual letters. This amendment supersedes AD 98-12- 19, issued August 5, 1998, applicable to RHC Model R44 helicopters, that currently requires main rotor blade inspections and replacement if a crack is found. This amendment requires the same inspections as AD 98-12-19, but mandates replacement of all the affected main rotor blades prior to further flight after November 15, 1998. This amendment is prompted by an incident in which a crack was discovered in a main rotor blade. The actions specified by this AD are intended to prevent failure of a main rotor blade and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to Robinson Helicopter Company (Robinson) Model R44 helicopters, that requires removing and replacing the cyclic control pilot's grip assembly (grip assembly) with an airworthy grip assembly. This amendment is prompted by a report of a crack in the welded corner of a grip assembly. The actions specified by this AD are intended to prevent use of a grip assembly that may crack, resulting in failure of the grip assembly and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 98-04-12 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (RHC) Model R44 helicopters by individual letters. This AD requires an initial and repetitive measurement of the lateral cyclic trim spring shaft (shaft) diameter and replacement of the shaft spring assembly (spring assembly) if the shaft diameter is excessively worn. Replacement of the spring assembly with a modified spring assembly is considered terminating action for this AD. This amendment is prompted by an incident in which a pilot felt binding in the cyclic control when attempting to move it to the left. A precautionary landing was made using only right-hand turns. Subsequent inspection revealed that a notch was worn in the shaft, which caused the shaft and spring to move from the lower mount and interfere with the lateral control. Inspection of a second RHC Model 44 helicopter revealed similar wear. Excessive wear can create a notch on the shaft, which can cause the spring assembly to move out of its lower mount. This condition, if not corrected, could lead to the shaft interfering with lateral cyclic control, which could result in loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD) that is applicable to Robinson Helicopter Company (Robinson) Model R44 helicopters. This action requires replacing the aluminum elbows that connect the oil cooler lines to the engine accessory case with steel elbows. This amendment is prompted by two reports of cracks that were discovered in aluminum elbows. The actions specified in this AD are intended to prevent failure of either the 45 deg. or 90 deg. aluminum elbows that connect the oil lines from the oil cooler to the engine accessory case, which would cause loss of engine oil, resulting in an engine failure and a subsequent forced landing.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD) that is applicable to Robinson Helicopter Company (Robinson) Model R44 helicopters. This action requires inspections of the belt tension actuator switches (up-limit switches) for proper operation, and replacement if necessary; and replacement of a certain part-numbered clutch assembly. This amendment is prompted by six occurrences of prematurely worn sprag clutches. The actions specified in this AD are intended to prevent failure of the sprag clutch to lock in the driving direction, which would result in loss of power to the main rotor system and a subsequent forced landing; or failure of the sprag clutch to unlock in the overrunning direction, which, if combined with engine failure, would result in an inability to autorotate and a subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment supersedes an existing airworthiness directive (AD), applicable to Robinson Helicopter Company (Robinson) Model R44 helicopters, that currently requires an adjustment to the low RPM warning unit threshold to increase the revolutions-per-minute (RPM) at which the warning horn and caution light activate, and revisions to the R44 Rotorcraft Flight Manual that prohibit flight with the throttle governor (governor) selected off, except in certain situations. This amendment requires the same compliance actions required by the existing AD, and corrects the applicability section of the existing AD. This amendment is prompted by the need to expand the applicability statement of this AD to include all Robinson Model R44 helicopters. The actions specified by the proposed AD are intended to minimize the possibility of pilot mismanagement of the main rotor (M/R) RPM, which could result in unrecoverable M/R stall and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 96-18-22 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (Robinson) Model R44 helicopters by individual letters. This AD requires an inspection of the mating surfaces of the main rotor gearbox (gearbox) components for pitting, elongated bolt holes, or machining grooves, and replacement of the gearbox if elongated bolt holes, machining grooves, or an improper amount of pitting is discovered; and replacement of the 18 bolts and washers that attach the gear to the gear carrier assembly (gear carrier). This amendment is prompted by an inflight failure of the gearbox on a French-registered Model R44 helicopter that resulted in an accident. The actions specified by this AD are intended to prevent loosening of the bolts securing the gear to the gear carrier, which could lead to fatigue failure of the gear carrier within the gearbox, and subsequent loss of power to the main rotor which could lead to a forced landing.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD), applicable to Robinson Helicopter Company (Robinson) Model R44 helicopters, that requires an adjustment to the low-RPM warning unit threshold to increase the revolutions-per-minute (RPM) at which the warning horn and caution light activate, and revisions to the R44 Rotorcraft Flight Manual that prohibit flight with the throttle governor (governor) selected off, except in certain situations. This amendment is prompted by an FAA Technical Panel Review of Robinson accident history data which revealed that main rotor (M/R) blade stall at abnormally low M/R RPM resulted in accidents. The actions specified by this AD are intended to minimize the possibility of pilot mismanagement of the M/R RPM, which could result in unrecoverable M/R stall and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment supersedes an existing airworthiness directive (AD), applicable to Robinson Helicopter Company (RHC) Model R44 helicopters, that currently requires revisions to the Limitations section, the Normal Procedures section, and the Emergency Procedures section of the R44 Rotorcraft Flight Manual, revised September 6, 1994. These revisions limit operations in high winds and turbulence; provide information about main rotor (M/R) stall and mast bumping; and provide recommendations for avoiding these situations. Additionally, emergency procedures are provided for use should certain conditions be encountered. This action would require similar revisions to the Limitations, Normal Procedures and Emergency Procedures sections required by the existing AD, but the revision to the Limitations section would prohibit only pilots without a certain level of experience and training from operating in the flight conditions specified. This action is prompted by data that indicates pilots who possess a certain level of experience and training are more able to recognize and react to the adverse meteorological conditions specified in the AD. The actions specified by this AD are intended to prevent M/R stall or mast bumping, which could result in the M/R blades contacting the fuselage causing failure of the M/R system and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 95-11-10 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (Robinson) Model R44 helicopters by individual letters. This AD requires installation of a placard in the helicopter, and insertion of a prohibition against low-gravity (G) cyclic pushover maneuvers into the LIMITATIONS section of the Rotorcraft Flight Manual. This amendment is prompted by a recent Federal Aviation Administration (FAA) analysis of the manufacturer's data that indicates a low-G cyclic pushover maneuver may result in mast-bumping on the Robinson Model R44 helicopters. The actions specified by this AD are intended to prevent in-flight main rotor separation or contact between the main rotor blades and the airframe of the helicopter, and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment adopts a new airworthiness directive (AD) that is applicable to Robinson Helicopter Company Model R44 helicopters. This action requires removal of the push-pull tube sleeve guide assembly (sleeve guide) and replacement with a push-pull tube roller guide assembly (roller guide); and, inspections of the push-pull tube sleeves for signs of wear and replacement as necessary. This amendment is prompted by a report of an operator experiencing binding in the cyclic control system caused by torn heat-shrink material (material) on the cyclic push-pull tubes binding in the sleeve guide. The actions specified in this AD are intended to prevent binding in the cyclic control system and subsequent loss of control of the helicopter.

Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment supersedes an existing airworthiness directive (AD), applicable to Robinson Helicopter Company Model R44 helicopters, that currently requires revisions to the Limitations section, the Normal Procedures section, and the Emergency Procedures section of the R44 Rotorcraft Flight Manual, revised September 6, 1994. These revisions limit operations in high winds and turbulence; provide information about main rotor (M/R) stalls and mast bumping; and provide recommendations for avoiding these situations. Additionally, emergency procedures are provided for use should certain conditions be encountered. This amendment requires the same revisions required by the existing Priority Letter AD, but revises certain words and phrases to further clarify the revised Limitations and Normal Procedures sections, deletes the paragraph that referenced recording compliance with the AD, and adds another paragraph that states that no special flight permits will be issued prior to compliance with this AD. This amendment is prompted by two Model R44 accidents since April 1994 involving M/R blades contacting the helicopters' fuselage; and, 26 accidents involving M/R blades contacting the fuselage on the Model R22 helicopter since 1981. The Model R22 helicopter M/R system design is similar to the Model R44 helicopter M/R system design. The actions specified by this AD are intended to prevent M/R stall or mast bumping, which could result in the M/R blades contacting the fuselage causing failure of the M/R system and subsequent loss of control of the helicopter.