de Havilland DHC-3 Otter

Airworthiness Directives; Viking Air Limited (Type Certificate Previously Held by Bombardier Inc. and de Havilland, Inc.) Airplanes

The FAA is superseding Airworthiness Directive (AD) 2022-23- 08, which applied to all Viking Air Limited (Viking) Model DHC-3 airplanes. AD 2022-23-08 required a visual inspection of the stabilizer actuator to confirm that the stabilizer actuator lock ring is present, correctly seated in the groove in the upper housing, and engaged in the clamp nut, applicable corrective actions, application of a torque seal, and sending the inspection results to the FAA. Since the FAA issued AD 2022-23-08, Transport Canada, which is the aviation authority for Canada, issued mandatory continuing airworthiness information (MCAI) to address the unsafe condition identified as a missing stabilizer actuator lock ring. This AD requires repetitively inspecting the stabilizer actuator to confirm that the stabilizer actuator lock ring is present, correctly seated in the groove in the upper housing, and engaged in the clamp nut; taking applicable corrective actions; applying a witness mark (torque seal); and installing a secondary retention feature as terminating action for the repetitive inspections. This AD also prohibits installing any stabilizer actuator unless it is a serviceable part. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited (Type Certificate Previously Held by Bombardier Inc. and de Havilland, Inc.) Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited (type certificate previously held by Bombardier Inc. and de Havilland, Inc.) (Viking) Model DHC-3 airplanes. This AD was prompted by a report of cracking in the left-hand side (LHS) and right- hand side (RHS) lower engine mount pickup fittings. This AD requires a one-time inspection of the affected parts for cracking, deformation, corrosion, fretting or wear, paint or surface coating damage, and loose, missing, or broken fasteners, and applicable corrective actions. This AD also requires reporting the inspection results. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited (Type Certificated Previously Held by Bombardier Inc. and de Havilland, Inc.) Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited (Viking) (type certificate previously held by Bombardier Inc. and de Havilland, Inc.) Model DHC-3 airplanes. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as corrosion, wear, and fatigue-related degradation in aging aircraft. This AD requires incorporating into the existing maintenance records for your airplane the actions and associated thresholds and intervals, including life limits, specified in a supplemental inspection and corrosion control manual for Model DHC-3 airplanes. This AD also requires completing all the initial tasks identified in this manual and reporting corrosion findings to Viking. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited (Type Certificate Previously Held by Bombardier Inc. and de Havilland, Inc.) Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited (type certificate previously held by Bombardier Inc. and de Havilland, Inc.) Model DHC-3 airplanes. This AD was prompted by multiple recent reports of cracks in the left-hand elevator auxiliary spar. This AD requires repetitive detailed visual inspections of the entire left-hand elevator auxiliary spar for cracks, corrosion, and previous repairs, and depending on the findings, replacement of the left-hand elevator auxiliary spar. This AD also requires sending the inspection results to the FAA. The FAA previously sent an emergency AD to all known U.S. owners and operators of these airplanes and is now issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited (Type Certificate Previously Held by Bombardier Inc.) Airplanes

The FAA is adopting a new airworthiness directive (AD) for Viking Air Limited (type certificate previously held by Bombardier Inc.) Model DHC-3 airplanes with a certain wing strut assembly installed. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI identifies the unsafe condition as fatigue damage of the wing struts. This AD requires a bolt hole eddy current inspection of the lug plate holes, a visual and fluorescent dye penetrant inspection of the lug fittings, and a visual and eddy current surface scan inspection of the wing strut assemblies. This unsafe condition could lead to failure of the wing strut, which could result in an in- flight breakup of the wing. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Viking Aircraft Limited Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Viking Air Limited Model DHC-3 airplanes. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI identifies the unsafe condition as fatigue damage of the wing strut lug fitting components and the fuselage to wing strut attachment (tie-bar). This AD requires determining service life limits for the wing strut fitting on the main spar and for the tie-bar and following instructions for removal and replacement of affected parts. The FAA is issuing this AD to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited Airplanes

We are adopting a new airworthiness directive (AD) for Viking Air Limited Model DHC-3 airplanes. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as pitting corrosion on the shank of the wing strut attach bolts. We are issuing this AD to require actions to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited Airplanes

We are adopting a new airworthiness directive (AD) for Viking Air Limited Model DHC-3 airplanes that are modified with the Baron Short Take Off and Landing (STOL) kit (Supplemental Type Certificate SA94-114 or SA 00287NY). This AD results from mandatory continuing airworthiness information (MCAI) issued by the aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as a center of gravity that is too far aft contributing to a stall during takeoff and loss of control during other phases of flight. We are issuing this AD to require actions to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited Airplanes

We are adopting a new airworthiness directive (AD) for Viking Air Limited Model DHC-3 Airplanes. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as corrugation cracking found at various wing stations and on the main spar lower cap. We are issuing this AD to require actions to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited Airplanes

We are adopting a new airworthiness directive (AD) for Viking Air Limited Model DHC-3 airplanes. This AD results from mandatory continuing airworthiness information (MCAI) issued by the aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as looseness of the horizontal stabilizer actuator mounting block in the forward-aft and side-to-side directions. We are issuing this AD to require actions to address the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited (Type Certificate No. A-815 Formerly Held by Bombardier Inc. and de Havilland, Inc.)

We are superseding an existing airworthiness directive (AD) for all Viking Air Limited (type certificate No. A-815 formerly held by Bombardier Inc. and de Havilland, Inc.) Model DHC-3 airplanes. That AD currently requires repetitively inspecting the elevator control tabs for discrepancies, taking necessary corrective actions to bring all discrepancies within acceptable tolerances, and reporting certain inspection results to the FAA. This new AD retains the actions currently required in AD 2011-05-02 and removes the Supplemental Type Certificate (STC) SA01059SE condition in the Applicability section. This AD was prompted by our determination that we inadvertently omitted certain airplanes from the Applicability section. We are issuing this AD to correct the unsafe condition on these products.

Airworthiness Directives; Viking Air Limited Model DHC-3 (Otter) Airplanes

We are adopting a new airworthiness directive (AD) for the products listed above that are equipped with a Honeywell TPE331-10 or - 12JR turboprop engine installed per Supplemental Type Certificate (STC) SA09866SC. This AD requires incorporating revised airspeed limitations and marking the airspeed indicator accordingly. There is also a requirement for the installation of a temporary placard until the airspeed indicator can be modified but not to exceed a certain period of time. This AD was prompted by analysis that showed that airspeed limitations for the affected airplanes are not adjusted for the installation of a turboprop engine as stated in the regulations. We are issuing this AD to prevent the loss of airplane structural integrity due to the affected airplanes being able to operate at speeds that exceed the speeds established in the Federal aviation regulations for safe operation.

Airworthiness Directives; Viking Air Limited Models DHC-2 Mk. I, DHC-2 Mk. II, and DHC-3 Airplanes

We are superseding an existing airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as:

Airworthiness Directives; Bombardier, Inc. Model DHC-3 Airplanes

The FAA adopts a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-3 airplanes modified with A.M. Luton's Supplemental Type Certificate (STC) number SA3777NM. This AD requires you to inspect the wiring for the heating blankets on P<INF>3</INF> and P<INF>Y</INF> pneumatic lines and the push-to-test function lights to ensure that they are wired to the correct schematic; replace the circuit breaker switch as applicable; and replace the flight manual supplement currently in use with Revision G, dated March 28, 2001 (incorporates Revision I of Sheet 1 of Drawing 20075, "Electrical System Schematic," dated October 10, 2000). This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Canada. We are issuing this AD to detect and correct wiring installed in accordance with an incorrect drawing, which shows the pneumatic heating blankets to the P<INF>3</INF> and P<INF>Y</INF> pneumatic lines wired in series with the indicator lights, rather than parallel. This can result in reduced current for the heating blankets and loss of pneumatic line heating, which can lead to loss of engine power or reverse propeller overspeed governing protection and ultimately loss of control of the airplane.

Airworthiness Directives; Bombardier Inc. Model (Otter) DHC-3 Airplanes

The FAA adopts a new airworthiness directive (AD) for all Bombardier Inc. Model (Otter) DHC-3 airplanes that have been modified by 524085 BC, Ltd. Supplemental Type Certificate (STC) Number ST01243NY or SA01243NY. This AD requires you to replace the existing Viking Air Ltd. elevator servo tab assembly with a redesigned Viking Air Ltd. elevator servo tab assembly. This AD results from mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Canada. There has been one failure of the elevator servo tab assembly. We are issuing this AD to prevent the structural failure of the elevator servo tab. This failure could lead to loss of control of the airplane.

Airworthiness Directives; deHavilland Inc. Models DHC-2 Mk. I and DHC-2 Mk. II Airplanes and Bombardier Inc. Model (Otter) DHC-3 Airplanes

The FAA adopts a new airworthiness directive (AD) for all deHavilland Inc. Models DHC-2 Mk. I and DHC-2 Mk. II airplanes and for all Bombardier Inc. Model (Otter) DHC-3 airplanes powered by radial engines. This AD requires you to visually inspect the firewall connector plugs for proper lockwire security and replace or modify as appropriate. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Canada. We are issuing this AD to prevent loss of ignition systems during flight caused by improper lockwire security, which could result in engine failure. This failure could lead to a forced landing of the airplane.

Airworthiness Directives; Bombardier Inc. Model Otter DHC-3 Airplanes

The FAA is revising Airworthiness Directive (AD) 2004-05-01, which applies to certain Bombardier Inc. (formerly deHavilland Inc.) Model Otter DHC-3 airplanes that have turbine engines installed per one of three supplemental type certificates (STC). AD 2004-05-01 currently prohibits you from operating any affected airplane with these engine and propeller configurations unless a new STC for an elevator servo-tab with a redundant control linkage is installed. The FAA has since evaluated concerns, comments, and technical information related to all three STC configurations. Based on that evaluation, we have determined that further evaluation is necessary for the STCs owned by Texas Turbines Conversions, Inc., and Canada Turbine Conversions, Inc. Therefore, we are removing reference to these STCs from the AD, and the AD will only apply to those Bombardier Inc. airplanes that incorporate STC No. SA3777NM (A.M. Luton installation of Pratt and Whitney PT6A-34/ -135 engine). After further evaluation, we may initiate rulemaking action regarding airplanes with the Texas Turbines Conversions, Inc., and Canada Turbine Conversions, Inc., STC configurations.

Airworthiness Directives; Bombardier Inc. Model Otter DHC-3 Airplanes

The FAA adopts a new airworthiness directive (AD) for certain Bombardier Inc. (formerly deHavilland Inc.) Model Otter DHC-3 airplanes that have turbine engines installed per one of three supplemental type certificates (STC). This AD prohibits you from operating any affected airplane with these engine and propeller configurations unless a new STC for an elevator servo-tab with a redundant control linkage is installed. This AD is the result of reports of the control rod to the elevator servo-tab system detaching from the elevator servo-tab, which caused the elevator servo-tab to flutter on airplanes with a turbine engine installed. We are issuing this AD to prevent a single failure of the elevator servo-tab system, which could cause severe tab flutter. This failure could lead to possible loss of control of the airplane.

Airworthiness Directives; Bombardier Inc. Model Otter DHC-3 Airplanes

This amendment adopts a new airworthiness directive (AD) that applies to certain Bombardier Inc. (formerly deHavilland Inc) Model DHC-3 (Otter) airplanes that have been modified in accordance with A.M. Luton Supplemental Type Certificate (STC) No. SA3777NM. This AD requires modifying the airplane's electrical system. The actions specified by this AD are intended to prevent electrical system failure caused by inadequate electrical system design, which could result in the loss of the engine instruments or a possible electrical fire in the airplane's cockpit.

Airworthiness Directives; de Havilland Model DHC-3 Airplanes

This amendment supersedes Airworthiness Directive (AD) 90-12- 08, which currently requires the following on de Havilland Model DHC-3 airplanes: repetitively inspecting (using dye penetrant methods) the tailplane main rib forward flanges and the main rib forward lower flanges at the tailplane front attachment fitting for cracks and repairing any cracked flange. This AD action will retain the repetitive inspections currently required by AD 90-12-08, and will allow a certain modification as terminating action for these repetitive inspections. This action is prompted by the Federal Aviation Administration's determination that installing new angles and plates on the tailplane root ribs on de Havilland Model DHC-3 airplanes provides an equivalent level of safety to the repetitive inspections required by AD 90-12-08. The actions specified by this AD are intended to prevent failure of the tailplane structure caused by cracked tailplane main rib forward flanges or main rib forward lower flanges at the tailplane front attachment fitting, which, if not detected and corrected, could result in loss of control of the airplane.