Final Wing Spar AD Affects 11,476 Pipers


The FAA’s Piper PA-28 and PA-32 wing spar inspection AD takes effect Dec. 28 and it involves 11,476 aircraft. The FAA issued the notice on Nov. 23 and requires operators of the affected aircraft to have a look at the hard-to-reach section of spar within 100 hours or 12 months of that date. Extensive input from aviation groups has resulted in a rule that, for the inspection at least, should be a minor issue for most operators. It’s anticipated that most of those inspections will be done with borescopes fished in through existing openings in the wings and cost about $170 in labor. 

The first iteration of the AD called for cutting inspection panels in the wings and that’s still an option for those who want to spend the $730. Those doing major work that requires removal of the wings can do it as part of that process. Whichever method is chosen, assuming there’s no corrosion found, it has to be done again every seven years afterward. If there is corrosion, it has to be looked after immediately.

Russ Niles
Russ Niles is Editor-in-Chief of AVweb. He has been a pilot for 30 years and joined AVweb 22 years ago. He and his wife Marni live in southern British Columbia where they also operate a small winery.

Other AVwebflash Articles


  1. “If there is corrosion, it has to be looked after immediately.”

    Would someone please explain the term “looked after”? Seems, no, it is a very unprofessional way to present written information.

  2. The aging aircraft fleet will set a new old-age record today, and again every day after today. As the fleet ages expect more old-aged related AD’s for all types of “old” birds. Additionally, much of the fleet has been neglected, mechanically, for a long time. In July I tried to buy a lower time PA-28-181 in MO. During pre-buy I noticed a Form 337 for a new wing inspection cover. The seller advised there had been a mouse nest on the spar and corrosion had to be removed and repaired (hmmmm). There was no log entry, or 337, for the spar repair.

  3. To add to Jeff W… The original US manufactured aircraft, of the 1950’s thru 1990’s era. Were seldom treated on the interiors, with anti corrosion paint (zinc chromite/green stuff) because of the limited design life, est. 10-15 years. Metal to metal.. In most cases, the wings steel spar in contact with the aluminum skin, are being exposed to moisture.. Just like in the picture of accompanied article.. A development of dissimilar corrosion becomes extensive, and the cost of replacing the wing spars can be astronomical. During the pre buy, ask where is the aircraft based, stored, and used..!!

  4. Both Jeff and Tom are unfortunately correct that such occurrences will become more common in our aging fleet, that mostly lacks any kind of interior corrosion protection. Years ago I had a 1963 model Beech Musketeer/Sundowner. It developed a serious exfoliation corrosion similar to the type shown in the above photo. The corrosion developed in the outer main wing spar at the lower flange of the spar. The Musketeer’s spar was a two-piece affair with a forged “beam” for the inner section and a heavy gauge aluminum “C” channel for the outer section. The corrosion developed near the junction between the two parts and would have required opening up the wing and replacing the outer spar. I ended up scrapping out the plane. Unfortunately, at the time, the modern CorrosionX or ACF 50 treatments did not exist. It would be interesting to see if those treatments could have prevented the corrosion.

  5. Thanks for the well written article Russ. If I owned one of these aircraft I too would think that it needs “to be looked after immediately”, and I majored in English. Now if you ended all your sentences with prepositions I’d be comin’ at you right were you’re at.

  6. I think this whole AD was triggered by the wing separation of an Embry Riddle training aircraft. Yet the AD doesn’t even cover the accident aircraft. Yes, maybe that plane suffered metal fatigue and this AD is all about corrosion. But what AD addresses future metal fatigue issues then?

  7. Amazing how many cheap Cherks have suddenly appeared on TAP. It’s almost like notoriously tight-fisted pilots don’t want to deal with this AD and would rather pawn it off on some other sucker.

  8. The AD refers to Piper SB 1304A as far as procedures etc but I cannot find the text of this Service Bulletin on the Piper web site nor the ATP web site, where I was directed by the Piper site. When I search for the SB# I get a “nothing found” notice. Anyone know where this info may be found?