PC-12Pilatus

Certain Pilatus PC-12/47E airplanes have inward vent valves installed without proper chromate conversion coating on bonding surfaces, creating a corrosion risk. This AD requires modifying the inward vent valves and prohibits installation of unmodified valves.

Strake attachment brackets and fuselage frames have failed at the upper bracket attachment location on certain Pilatus PC-12 airplanes equipped with the Spectre Lift Platform System. This AD requires inspecting the strake, attachment brackets, surrounding structure, bolts, and replacing or repairing any damaged components.

Inboard flap fairings may have incorrect shape causing chafing that could lead to failure of the inboard flap drive arm and asymmetric flap extension. Inspect inboard flap fairings for correct shape and chafing, with corrective action as necessary.

Main landing gear spring pack assemblies on certain PC-12/47E airplanes can seize, creating a landing gear safety hazard. This AD requires replacement of affected spring pack assemblies and prohibits reinstallation of the affected parts.

Certain horizontal stabilizer rear attachment bolts were improperly manufactured and could fail in fatigue, leading to loss of airplane control. This AD requires identification and replacement of the affected bolts.

The Primus APEX flight management system software builds 10 and 10.9 contain an error that can cause incorrect barometric vertical navigation glide path calculations. This AD requires replacing the affected software with corrected versions.

Engine mounting frame assemblies may experience longitudinal material separation on internal surfaces, potentially leading to partial or complete structural joint failure and in-flight engine detachment. Owners must inspect affected engine mounting frames and replace any with identified serial numbers.

Incorrect installation instructions for torlon plates in the forward wing-to-fuselage attachment may result in improper installation. This AD requires corrective actions to ensure proper installation of these plates.

A malfunction of the universal joint has been identified on certain Pilatus PC-12 series airplanes. This AD requires actions to address the unsafe condition of the universal joint.

The aileron trim tab can disconnect above 10,000 feet altitude on certain PC-12/47 and PC-12/47E airplanes. This AD requires actions to address the unsafe condition and prevent aileron trim tab disconnection.

This AD is being withdrawn. It previously required inspections or removal of certain Honeywell air data pressure transducers installed in various aircraft because inaccurate pressure sensors could cause altitude and airspeed computation errors.

A common ground connection between the pilot primary flight display and Electronic Standby Instrument System could fail, causing both navigation systems to fail simultaneously and resulting in loss of control. This AD requires corrective actions to address the unsafe grounding condition.

This AD is being rescinded because the unsafe condition regarding pitch trim actuator life limits is now addressed in another AD. No further action is required by aircraft owners under this directive.

This AD addresses an unsafe condition identified on Pilatus PC-12/47E airplanes through mandatory continuing airworthiness information. The AD requires operators to take corrective actions to correct the unsafe condition.

This AD supersedes an earlier directive addressing an unsafe condition on Pilatus PC-12/47E airplanes identified through mandatory continuing airworthiness information. Operators must comply with the corrective actions specified in the AD to ensure continued airworthiness.

An unsafe condition has been identified on Pilatus PC-12 and PC-12/45 airplanes that requires corrective action. This AD requires operators to comply with the mandatory continuing airworthiness information issued by another aviation authority.

This AD addresses an unsafe condition identified on Pilatus PC-12 series airplanes. The AD requires compliance with corrective actions to restore airworthiness.

An unsafe condition has been identified on certain Pilatus Aircraft Limited models requiring corrective action. The FAA is adopting this airworthiness directive based on mandatory continuing airworthiness information from another country's aviation authority.

This airworthiness directive addresses an unsafe condition identified on Pilatus PC-12 series airplanes through mandatory continuing airworthiness information from an international aviation authority. The directive supersedes a previous AD and requires corrective action to ensure continued airworthiness.

Executive seats on certain Pilatus airplanes were manufactured with material that deviates from approved design specifications, creating a potential safety issue. Operators must take corrective action on affected seats.

An unsafe condition has been identified on Pilatus PC-12 and PC-12/45 airplanes. This AD requires actions to correct the unsafe condition.

Cracks in backrest tubes of certain crew seat bucket assemblies could fail, reducing pilot control ability and seat restraint function. This AD requires replacement of backrest tubes at a specified time and establishes a life limit for these components.

Certain main landing gear bolts may corrode and fail, risking landing gear collapse during takeoff or landing. Inspect main landing gear assemblies for bolts without white primed and painted heads and replace them with new approved bolts.

Certain nose and main landing gear assemblies on these airplanes are affected by hydrogen embrittlement that could cause landing gear failure and collapse. The AD requires checking maintenance records and/or inspecting to identify affected gear with serial numbers beginning with AM and replacing them with unaffected units.

An out-of-trim condition can occur when flaps are at 40 degrees and the autopilot is disconnected, potentially reducing control ability. This AD requires a temporary POH revision and replacement of the pitch actuator with an improved design, including associated wiring and circuit breaker changes.

Windshield de-ice wiring may be damaged or incorrectly sized, creating a fire hazard in the overhead panel. Inspect the windshield de-ice wiring system for heat damage and incorrect wire sizes, and replace any defective wires.

Some main landing gear actuators were incorrectly heat-treated and may fail, preventing the landing gear from extending or retracting. Replace any installed actuator with the affected serial numbers with a properly heat-treated unit.

Certain inboard and outboard flap flexshafts may rupture due to corrosion, causing the flap system to become inoperable. Operators must check the airplane logbook to verify that improved-design flap flexshafts are installed and replace them if necessary.

Certain main landing gear shock absorber attachment bolts may be subject to hydrogen embrittlement, which could cause main landing gear failure and collapse. This AD requires replacement of shock absorber attachment bolts on affected aircraft.

Gasket material can extrude from engine-driven pump housings and relief valve attachment screws may lack adequate torque, potentially causing fuel leakage and engine compartment fires. Owners must inspect the pump joints for leakage and gasket extrusion, replace affected pumps, verify relief valve screw torque, and eventually replace the pump with an improved design.

Certain Pilatus PC-12 and PC-12/45 airplanes have fuel booster pumps that may have defective electrical leads prone to arcing in the fuel tank, creating fire or explosion risk. The AD requires inspection and replacement of affected fuel booster pumps, or installation of lead protection wrap if defects are found.

The pressure dome on certain Pilatus PC-12 airplanes may have developed cracks or damage that could lead to rapid decompression. This AD requires inspection of the pressure dome's front and rear surfaces and repair of any damage found.

Passenger seat pedestal leg assemblies on aft-facing seats may be incorrectly configured, which could result in passenger injury during an emergency. Inspect the pedestal leg assembly on aft-facing passenger seats for correct configuration and modify any that are incorrect.

Certain push switch caps on the electrical power management overhead panel can fail, preventing operation of related systems. This AD requires replacement of these caps with improved parts.

Main landing gear assembly bolts with serial numbers beginning with 'AT' and 299 or lower may have improper cadmium plating causing hydrogen embrittlement and potential bolt failure, which could lead to landing gear collapse. This AD requires inspection of left and right main landing gear assemblies and replacement of any defective bolts with properly plated bolts.

Some Pilatus PC-12 and PC-12/45 airplanes with rear bench seats may have insufficient oxygen available to rear seat occupants in emergency conditions. This AD requires replacing the metered connector, oxygen tubing, and related components in the rear seat bench.

Current surges in the flap control system can damage the flap power drive-unit motor and prevent the flight control unit from detecting a worn actuator, risking flap system failure. This AD requires modifying the flap control wiring and installing a new flap power drive-unit field control panel to allow the circuit breaker to close during flight.

Cargo door end frames with plain lightening holes are susceptible to cracking, which could cause major structural damage and loss of control. This AD requires inspection of cargo doors and installation of reinforcing plates on any frame found with plain lightening holes.

The A250 voltage spike suppression filter in a previous modification can cause circuit breaker 235 to trip and potentially overheat wiring if generator 2 is not switched off before engine shutdown. This AD requires installing an improved suppression filter and new 5-amp circuit breaker to prevent loss of electrical power to critical airplane components.

Operation of the windshield heating system in LIGHT mode can disable the windshield deicing system, risking windshield icing and loss of control. The AD requires incorporating POH restrictions on LIGHT mode operation and modifying the windshield deicing system wiring and circuit breakers.

Some aircraft with pneumatic deicing boots have not had them activated in icing conditions, leading to controllability issues from ice accumulation. This AD requires revising the Airplane Flight Manual to mandate activation of pneumatic wing and tail deicing boots at the first signs of ice.

The stick pusher system on certain Pilatus PC-12 airplanes may operate improperly due to design defects, potentially causing loss of control during a stall. This AD requires replacing the stick pusher capstan and servo with improved-design components.

The flap inboard attachment fittings on certain Pilatus PC-12 aircraft may buckle during full-flap operation with full power in a head-wind gust, risking loss of control. This AD requires installing a reinforcement angle bracket on the inside of the center web of both flap inner attachment fittings.

Flap drive shafts can corrode and rupture, potentially rendering the flap system inoperable. This AD requires replacing all flap drive shafts with improved versions, installing additional gaskets on the power drive unit, and modifying attachment hardware.

Incorrectly connected cables or broken wires can cause excessive voltage to the second generator, resulting in loss of electrical power during flight. This AD requires installing a support bracket and cut-out relay for the second generator control unit, along with all necessary wiring additions and adjustments.

The Alternate Flap System on certain Pilatus PC-12 airplanes can cause flap asymmetry, potentially resulting in loss of aircraft control. This AD requires removing the Alternate Flap System from the flight controls and updating the Pilot's Operating Handbook to reflect this change.

Passenger seat configuration on certain Pilatus airplanes does not fully meet head injury criteria regulations. This AD requires modifying the passenger seats and seat rail covers.

Flight crews operating Pilatus PC-12 and PC-12/45 airplanes may lack adequate procedures and awareness for severe icing conditions, creating a safety hazard. This AD requires revising the Airplane Flight Manual to prohibit flight in severe icing conditions, limit use of flight control devices in icing, and provide recognition cues and procedures for exiting severe icing.

Moisture can enter fuel tank vent valves and freeze at altitude, potentially causing wing damage and handling problems. This AD clarifies procedures for replacing fuel tank vent valves, drilling fuel filler caps, and optionally installing modified vent valves, along with POH revisions for checking fuel cap ventilation.

Electrical current overload in the airplane structure can cause directional deviation on the standby magnetic compass, risking flight-path deviation during critical phases in icing and instrument conditions. This AD requires replacing and re-routing power return cables on the starter generator and generator 2, inserting a temporary POH revision, and installing a placard near the standby magnetic compass.

The lavatory wall and passenger seat configuration in certain PC-12 aircraft do not meet head injury protection criteria. The AD requires modifying the lavatory wall and passenger seat configuration to prevent head injuries during crashes.

Elevator rivets on certain Pilatus PC-12 airplanes may have incorrect lengths or excessive gaps in the rivet shanks, which could cause fatigue damage and structural failure. Inspect the elevator for incorrect rivets and excessive gaps, replace rivets as needed, and install shims to fill gaps exceeding 0.004 inches.

Fuel tank access panels on certain Pilatus PC-12 airplanes are insufficiently electrically bonded to the airframe, which could allow electrical arcing and detonation of fuel-air mixture, creating a fire hazard. The AD requires installing aluminum bonding bushings over certain screws in the fuel tank underwing access panels.

Certain propeller de-icing controllers are susceptible to electromagnetic interference, which could cause ice build-up on the propeller and controllability problems. This AD requires replacing those controllers with ones that are not susceptible to EMI.

Aileron tie-rod jam nuts on certain Pilatus PC-12 aircraft can loosen, causing unequal aileron control between pilot and co-pilot sides. The AD requires inspecting and tightening these jam nuts and installing locking sleeves on both ends of the aileron tie-rod.

Improper use of propeller beta during flight has caused loss of airplane control and engine overspeed. This AD requires amending the airplane flight manual or pilot's operating handbook to prohibit positioning the power levers below the flight idle stop while in flight.

Certain PT6 series turboprop engines may have defective compressor bleed-off valves due to improper cotter pins or guide shaft pins, which could cause inflight engine power reduction and a forced landing. This AD requires a one-time visual inspection of the bleed valve cover, and if an affected supplier code is found, removal and inspection of the valve assembly with modification or replacement if defects are discovered.

LITEF AHRS units may produce misleading roll and pitch information when exposed to certain radio frequency signals. Either install a VFR-only placard or modify the AHRS wiring cables with repetitive shielding inspections and update the aircraft flight manual.