FAA Issues Airworthiness Directive For Certain Piper Aircraft Models

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The Federal Aviation Administration (FAA) issued a new Airworthiness Directive (AD) for specific Piper aircraft models after an unscheduled inspection, prompted by a ground collision with an automobile, revealed a double-drilled bolt hole in the rear wing spar attachment fitting.

The FAA says the AD will affect some 500 U.S.-registered aircraft—including certain serial-numbered Piper models PA-28-181, PA-28R-201, PA-34-220T and PA-44-180. It requires inspection of the rear wing spar attachment fitting and, if discrepancies are found, inspecting the forward wing spar attachment fitting as well. The directive mandates performing necessary corrective actions and notifying the FAA once these actions have been completed.

While ADs are typically issued after a Notice of Proposed Rulemaking (NPRM) is published, the FAA has determined an unsafe condition exists in this case—prompting the agency to bypass the usual public comment period.

The findings suggest that the double-drilled bolt hole in the rear wing spar attachment fitting significantly reduces the strength of the fitting below its limit load. If left unaddressed, this could lead to the separation of the wing and loss of control of the aircraft. Given that these aircraft are frequently used in training and quickly accumulate flight hours, inspecting for this condition before further flight is critical, according to the FAA.

The AD is effective June 6, 2024.  

Amelia Walsh
Amelia Walsh is a private pilot who enjoys flying her family’s Columbia 350. She is based in Colorado and loves all things outdoors including skiing, hiking, and camping.

28 COMMENTS

  1. I think there was a corrosion inspection AD on the spar by the retract gear some years ago as well. They are robust and fun flying machines from what I recall. I found the Cherokee 180 to be the nicest balance between airframe and power, but I’m sure more power in the Arrow was a nicer machine.

  2. Tom I couldn’t agree more, specially the semi-tapered wing variants (ones with a “1” at the end of the horsepower designation). I recall taking students up in my full time CFI days and performing the “falling leaf” maneuver where you stall the aircraft and maintain back pressure on the yoke to keep it in the stall then utilize the rudder to pick up a dropping wing. That plane would just bob it’s nose up and down, give you plenty of “feel” with nary a vice. Very gentle.

    • Thanks. I’ve enjoyed the Cherokees in good or bad wx and never had a concern with their reliability. With the wide track gear crosswinds were no big issue and the ?laminar flow wing? seemed to hang on for longer than expected in the flare. really a good, decent design.

  3. This AD is for the P28-181 “Archer III (3)” not the older Archers… yet!
    Serial numbers are listed in Service Bulletin 1413.

      • Double drilled means that two holes were drilled where there should only be one. The two hole centerlines are typically parallel but separated by less than the diameter of the hole. In an extreme case, the “hole” has a figure 8 shape, but more typically it appears as a slightly elongated hole.

  4. Have about 850 hours, in a ’65 PA-28- 180, and 250 hours in a ’69 PA -28-140 and one must remember the Cherokee series was drsign

    • Have about 850 hours, in a ’65 PA-28- 180, and 250 hours in a ’69 PA -28-140 and one must remember the Cherokee series was designed in part by Fred Weick , designer of the Ercoupe.
      Unfortunately, it seems the wing spars and attachment fittings have been subject to AD’s and wing pull inspections for decades for varying reasons on select models and serial numbers.

  5. I hate to be the skunk at this garden party, but unless I don’t fully understand the way airplanes are put together and maintained, a double-drilled bolt hole is a serious mistake that was done either by human hands or by an automated process, both of which would had one or more sets of human eyes on it before buttoning up the aircraft. In other words, someone almost certainly saw this flaw and said, “Eh…good enough” (or words to that effect) and slapped the thing together or signed it off—which amounts to the same thing. That person was willing to put another person’s life at risk because it was too much trouble, too expensive, or too embarrassing to stop the error chain right there and then, and insist that the thing be put right. This is the attitude that lies at the heart of things as small as an badly-torqued bolt somewhere inside an engine case all the way up to something as large as a window blowing out on a Boeing, or a bunch of improperly packaged oxygen generators tossed in with a load of tires in a forward baggage compartment. Of course the AD is necessary. How else to track down and fix the sloppiness in the mind of a person who handled not only that airplane, but perhaps many, many others?

    As it happens, I just finished re-reading Round the Bend, by Nevil Shute, in which one of the main characters creates a sort of quasi-religious cult of aircraft maintenance, preaching to his fellow “engineers” (Shute was British) that every act of maintenance is a prayer lifted up to an all-seeing god. I admit to being an agnostic myself, but I do believe that a little more religious fervor needs to be brought to the shop room floor—maybe a lot more. And, by the way, if you haven’t read Round the Bend, you should. It’s a great story—available in both print and audiobook (which is excellent).

    • I heartily second the recommendation of “Round the Bend” by Neville Shute! There are numerous other great aviation oriented books by this great author!

      • As a Naval Flight Officer aboard EC130G/Q TACAMO birds, I often thought of Shute’s “On the Beach.” I highly recommend it as well. This from his Wikipedia page: “Sales of his books grew slowly with each novel, but he became much better known after the publication of his third to last book, On the Beach, in 1957.”

    • Thank you EJborg for assuming the skunk’s role at this party. Your literary and very readable comment is refreshing. Neville Schute’s Round The Bend is in my library.

    • You’re right, but don’t become a Cultist. I bought a set of cutlery some time ago and a few handles began separating from the blades. Perhaps I bought bladeless knives without handles but I glued them and life has returned to normal. Even if you buy top quality stuff online it seems everyone makes mistrakes. It’ll get sorted before Cherokees fall from the sky like a locust plague.

  6. I would be interested to hear from an A&P familiar with Piper singles as to how this inspection might be accomplished. How much of the plane needs to be removed to gain access, and how long might all this may take? The FAA tends to “shotgun” these types of ADs, which means a lot of owners spend a lot of time and money to find nothing of consequence. But, I guess if they keep one plane from failing in flight, that will save some poor soul’s life.

    • A double drilled hole is when someone attempts to drill out a rivet and doesn’t drill it correctly . It is drilled offset making the drilled hole not in tolerance to correctly drive a new rivet. It also can be from manufacturing predicting of holes not to line up with the other sheetmetals prefilled hole.

      • Please clarify what you mean by “manufacturing predicting of holes not to line up with the other sheetmetals prefilled hole.” Manufacturing doesn’t do predicting of holes not lining up, engineering (design) does, and depending on the application the solution can vary from drilling the mating hole only on-assembly, drilling the mating hole larger, machining a slot, etc. but none of those would be called a double drilled hole.

  7. I have expressed my concern about factory new aircraft previously. This post amplifies that plus casting a look at some Maintenace Shops.
    As an A&P I agreed to maintain this 172 in exchange for flying time. The owner cautioned me that the right fuel tank leaked if full. From the looks of the stain it had been leaking for some time. Removing the cover revealed that the filler neck was welded to the tank top only 3/4 of the way around. Also, in addition to many other Squawks (including hangar rash) the left flap push/pull rod was bent. Inspection showed that the flap was bottoming in the track and starting back up. The left bell crank was not in “parallel” with the right one. The adjustment for this is a couple of turnbuckles in the overhead. Removing the head liner showed that these turnbuckles still had the unbroken QA marks on them.
    Was Cessna guilty of turning out such an aircraft. YES! Unquestionably so. However, this aircraft had previously been through many _________Annual Inspections??

  8. I would say that Piper is extremely fortunate that the “double drilled bolt hole” was found repairing non flight related damage, rather than found by the NTSB after examining the wreckage of the airplane that lost its wing in flight.

    Still it is not a good look for Piper, especially for such an important part. I wonder if they have any X Boeing managers on the production line…..

  9. John Mc; detailed instruction are in the Service Bulletin 1413. Illustrations are on pages 6 & 7.

  10. I still don’t understand what a “double drilled” hole is. I drilled about 15K rivet holes in home-builts, and never to my knowledge had to double drill one.

  11. “I still don’t understand what a “double drilled” ”

    Double Drilled is basically 2 holes drilled side by side and looks like a Figure 8, Kind of looks sort of like a Figure 8 in the fact you literally have 2 holes very close together and many times they are connected.

    And David G, you can count on that the NTSB will be in the middle of this one overseeing what is going on and what is really found.

  12. So I guess what you are reporting here is that Boeing isn’t the only aircraft manufacturer with QC issues?

  13. ER’s Arrow had a wing come off a few years ago while giving a commercial check ride. Did they decide what caused that?

  14. No word as to who has to pay for this inspection and/or repair. From information I’ve seen, this AD only applies to late model Piper Aircraft. Although I’m sure that the 499 aircraft affected are past the warranty period.

    If this is a factory defect, Piper should be responsible for correcting this condition. It would be a lot cheaper than a liability claim based on a wing failure accident lawsuit.

  15. Strange that the AD requires inspection of the forward spar fitting only if discrepancies are found on the rear spar fitting. Maybe I’m missing something, but given that a double drilled hole is not caused by wear, if 500 airplanes are to be inspected according to serial number the implication is that the defect occurred at manufacture, not by in-service maintenance procedures. Since a double drilled hole is usually created by improper manufacturing process and only on situational necessity, the location of a double drilled hole is likely to be random and there is no reason to believe that a double drilled hole will be present on the forward spar fitting only if the same also exists on the rear spar fitting. If my analysis is correct then the AD is ineffective in its purported aim to uncover and remedy an unsafe condition caused by double drilling holes. Often, improper or inefficient logic in a proposed AD is caught by at least one out of the thousands of “second set of eyes” enabled by the NPRM process. The FAA’s criteria for deciding when to dispense with the NPRM process needs review. Also, the duration of the drafting-publishing-commenting-considering-revising-publishing sequence needs to be streamlined and optimized so the delay burden is reduced and less likely to nudge the FAA towards eliminating the valuable external preview of any AD.

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