Airworthiness Directive · Amendment 39-21335 · Wing spar
Piper Aircraft, Inc. Airplanes
This AD applies to the following Piper Aircraft, Inc. model airplanes that are certificated in any category:
The FAA is adopting a new airworthiness directive (AD) for certain Piper Aircraft, Inc. (Piper) Models PA-28-140, PA-28-150, PA- 28-160, PA-28-180, PA-28-235, PA-32-260, and PA-32-300 airplanes. This AD was prompted by reports of corrosion found in an area of the main wing spar not easily accessible for inspection. This AD requires inspecting the left and right main wing spars for corrosion, and, if corrosion is found, taking all necessary corrective actions. The FAA is issuing this AD to address the unsafe condition on these products.
Within the next 100 hours time-in-service (TIS) after the effective date of this AD or within the next 12 months after the effective date of this AD, whichever occurs first, and thereafter at intervals not to exceed 7 years, inspect the forward and aft surfaces of the left and right main wing spars between wing station (WS) 24.24 and WS 49.25 for corrosion as follows.
(1) Gain visual access to the inspection area by complying with either paragraph (g)(1)(i), (ii), (iii), or (iv) of this AD.
Note 1 to paragraph (g)(1) of this AD: Step 1 and figure 1 in Part I Wing Spar Inspection of Piper Aircraft, Inc. Service Bulletin No. 1304A, August 14, 2018 (Piper SB No. 1304A), contain instructions you may use for identifying the inspection area and determining if wing access panels have been installed.
(i) Remove existing wing inspection access panels and fairings.
(ii) Install Inspection Access Hole Kit part number 765-106V, and then remove the wing inspection access panels and fairings.
(iii) Access the inspection area during concurrent maintenance such as a wing tank removal, wing removal, or wing skin repair.
(iv) Use a lighted borescope capable of 10X or higher power magnification display through existing access points (e.g., wing root fairing, landing gear panels, internal lightening holes, or other access points depending on model).
(2) Identify the wing spar configuration for your airplane in accordance with table 1 and figure 2 (sheets 1 and 2) in Part I Wing Spar Inspection of Piper SB No. 1304A. Visually inspect each spar component for evidence of corrosion, including irregularities such as blisters, flakes, chips, lumps, bulging skin, and missing rivets.
Note 2 to paragraph (g)(2) of this AD: Paint coatings may mask the initial stages of corrosion, and faying surfaces, such as riveted lap joints, may hide corrosion.
(1) If any evidence of corrosion is found during any inspection required by paragraph (g) of this AD, before further flight, remove the corrosion and determine whether the thickness of the component meets or exceeds the minimum thickness at all locations in accordance with table 2 and step 5 in Part I Wing Spar Inspection of Piper SB No. 1304A. If the thickness of the component at any location is less than the minimum thickness specified in table 2 of Part I Wing Spar Inspection of Piper SB No. 1304A, before further flight, repair the structure in accordance with a method approved by the Manager, Atlanta ACO Branch, FAA. For a repair method to be approved by the Manager, Atlanta ACO Branch, as required by this paragraph, the Manager's approval letter must specifically refer to this AD.
(2) If corrosion preventative compound was removed as part of any inspection required by paragraph (g) of this AD, before further flight, apply corrosion preventative compound by following step 1 in Part III Return to Service of Piper SB No. 1304A.
This paragraph provides credit for the initial inspection and application of corrosion preventative compound required by paragraphs (g) and (h)(2) of this AD if you performed the inspection before the effective date of this AD using Piper Aircraft, Inc. Service Bulletin No. 1304, dated August 23, 2017, and no evidence of corrosion was found.
