Federal Aviation Administration February 25, 2021 – Federal Register Recent Federal Regulation Documents

This action amends the using agency listed for Restricted Area R-4305, Lake Superior, MN. Specifically, this action changes the using agency from ``USAF, 55th Wing, Offutt AFB, NE'' (55th Wing), to ``U.S. Air Force, 148th Fighter Wing, Duluth International Airport, MN'' (148th Fighter Wing). There are no changes to the boundaries, designated altitudes, time of designation, or activities conducted within the restricted area.

The FAA is superseding Airworthiness Directive (AD) 2020-13-02 for Leonardo S.p.A. (Leonardo) Model A119 and AW119 MKII helicopters. AD 2020-13-02 required inspecting for movement and the tightening torque of the tail rotor (T/R) plug, the installation of the outboard and inboard faces of the T/R duplex bearing, and the condition of the T/R duplex bearing, T/R plug threads, and nut threads. Depending on the inspection results, AD 2020-13-02 required corrective actions and reporting information. This new AD retains the requirements of AD 2020- 13-02 except the reporting requirement, updates the service information, and requires repeating the inspection. This AD was prompted by Leonardo's update to the service information. The actions of this AD are intended to address an unsafe condition on these products.

The FAA is withdrawing a notice of proposed rulemaking (NPRM) that proposed to supersede Airworthiness Directive (AD) 2011-18-52, which applies to certain Agusta Model AB139 and AW139 helicopters. AD 2011-18-52 requires establishing a revised life limit for each tail rotor blade (blade), updating the existing historical records for your helicopter, repetitively inspecting each blade for a crack, and replacing certain blades. The NPRM was prompted by the manufacturer developing an improved blade using different materials and establishing life limits for those newly-designed blades. The NPRM proposed to require expanding the applicability to include the newly-designed blades and establish their life limits, and proposed to retain the requirement to inspect each blade for a crack and, if there is a crack, replace each blade with an airworthy blade. Since issuance of the NPRM, the FAA has determined that the NPRM does not adequately address the identified unsafe condition. Accordingly, the NPRM is withdrawn.

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.

The FAA is adopting a new airworthiness directive (AD) for Airbus Helicopters Model AS350B3 helicopters. This AD requires modifying the electrical system of the throttle twist grip, inspecting the routing of a microswitch electrical harness, and correcting the electrical harness routing if it is incorrect. This AD was prompted by reports of the engine remaining in idle when the twist grip was turned from the ``forced idle'' position to the ``flight'' position. The actions of this AD are intended to address an unsafe condition on these products.

The FAA proposes to supersede Airworthiness Directive (AD) 2020-12-07, which applies to certain Hamilton Sundstrand Corporation (Hamilton Sundstrand) 54H model propellers. AD 2020-12-07 requires initial and repetitive eddy current inspections (ECI) of certain propeller blades and replacement of the propeller blades that fail the inspection. Since the FAA issued AD 2020-12-07, the manufacturer determined that all propeller blades installed on Hamilton Sundstrand 54H model propellers with a 54H60 model propeller hub are susceptible to intergranular corrosion cracking in the blade taper bore. This proposed AD would require initial and repetitive ECI of all propeller blades installed on Hamilton Sundstrand 54H60 propeller hubs and replacement of any propeller blade that fails inspection. The FAA is proposing this AD to address the unsafe condition on these products.