We propose to adopt a new airworthiness directive (AD) for certain Piper
Aircraft, Inc. 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 proposed AD was prompted by reports of
corrosion found in an area of the main wing spar not easily accessible for inspection. This
proposed AD would require installing an inspection access panel in the lower wing skin
near the left and the right main wing spars if not already there, inspecting the left and the
right main wing spars for corrosion, and taking all necessary corrective actions. We are
proposing this AD to address the unsafe condition on these products.