Thrush S2R

Airworthiness Directives; Thrush Aircraft, Inc. Model 600 S2D and S2R Series Airplanes

We are adopting a new airworthiness directive (AD) to supersede AD (AD) 2006-07-15, which applies to Thrush Aircraft, Inc. Model 600 S2D and S2R (S-2R) series airplanes (type certificate previously held by Quality Aerospace, Inc. and Ayres Corporation). AD 2006-07-15 currently requires repetitive inspections of the 1/4-inch and 5/16-inch bolt hole areas on the wing front lower spar caps for fatigue cracking; replacement or repair of any wing front lower spar cap where fatigue cracks are found; and reporting of any fatigue cracks found to the FAA. AD 2006-07-15 also puts the affected airplanes into groups for compliance time and applicability purposes. Since we issued AD 2006-07-15, FAA analysis reveals that inspections are not detecting all existing cracks and shows the incidences of undetected cracks will increase as the airplanes age. Consequently, this AD retains the actions of AD 2006-07-15 and imposes a life limit on the wing front lower spar caps that requires replacement of the wing front lower spar caps when the life limit is reached. This AD also changes the requirements and applicability of the groups discussed above and removes the ultrasonic inspection method. We are issuing this AD to prevent wing front lower spar cap failure caused by undetected fatigue cracks. Such failure could result in loss of a wing in flight.

Airworthiness Directives; Thrush Aircraft, Inc. Model S2R Series Airplanes

We are adopting a new airworthiness directive (AD) for certain Thrush Aircraft, Inc. (Thrush) Model S2R series airplanes. This AD requires you to do repetitive visual inspections of the vertical and horizontal stabilizer attach fitting, attach fitting bolts, and the vertical fin aft spar for cracks or corrosion. This AD also requires immediate replacement of the vertical and horizontal stabilizer attach fittings and attach fitting bolts if cracked or corroded parts are found, and the inspection of the vertical fin aft spar with repair or replacement if cracks or corrosion are found. This AD requires the eventual replacement of the vertical and horizontal stabilizer attach fittings and attach fitting bolts if no corrosion or cracks are found as terminating action for the repetitive inspections. This AD results from reports of cracks in the empennage of Thrush S2R series airplanes. We are issuing this AD to detect and correct these cracks, which could cause the vertical stabilizer to lose structural integrity. This failure could lead to loss of control.

Airworthiness Directives; McCauley Propeller Model 4HFR34C653/L106FA-0

This amendment adopts a new airworthiness directive (AD) that is applicable to McCauley Propeller Systems 4HFR34C653/L106FA-0 model propellers that are installed on Jetstream Series 3200 airplanes. This action is also applicable to 4HFR34C653/L106FA-0 model propellers that are installed on Ayres S2R-G5 and S2R-G10 airplanes if the propeller was previously installed on Jetstream Series 3200 airplanes or if installation history of the propeller is unknown. This action requires one-time and repetitive eddy current inspections of the camber side of the blade surface. This amendment is prompted by a report of a crack on the camber side of the blade surface. The crack was found during a dye penetrant inspection as part of a normal overhaul process. The actions specified in this AD are intended to detect cracks that could cause failure of the propeller blade, which can result in loss of control of the airplane.

Airworthiness Directives; Ayres Corporation S2R Series Airplanes

This amendment adopts a new airworthiness directive (AD) that applies to all Ayres Corporation (Ayres) S2R series airplanes that are equipped with at least one main landing gear fuselage attach bolt with a grease fitting installed through the shank. This AD requires replacing the main landing gear fuselage attach bolts that are drilled with a grease fitting with undrilled (no grease access) attach bolts. This AD is the result of a report of cracks found in all four main landing gear fuselage attach bolts on one of the affected airplanes. The actions specified by this AD are intended to prevent collapse of the main landing gear caused by cracked main landing gear fuselage attach bolts, which could result in main landing gear collapse with possible wing fuel tank rupture and consequent fire.

Airworthiness Directives; Ayres Corporation S2R Series Airplanes

This amendment supersedes Airworthiness Directive (AD) 97-13- 11, which currently requires inspecting the \1/4\-inch and \5/16\-inch bolt hole areas on the lower spar caps for fatigue cracking on Ayres S2R series airplanes, and replacing any lower spar cap if fatigue cracking is found. That AD resulted from an accident on an Ayres S2R series airplane where the wing separated from the airplane in flight. AD 97-13-11 incorrectly references the Ayres Model S2R-R1340 airplanes as Model S2R-1340R. This AD requires the same actions as AD 97-13-11, but corrects the designation of the Model S2R-R1340 airplanes. The actions specified by this AD are intended to detect fatigue cracking of the lower spar caps, which, if not corrected, could result in the wing separating from the airplane with consequent loss of control of the airplane.