Pa-28 wing strut AD
Answered By AOPA
Good afternoon

i’m contemplating purchasing a 1968 Piper Arrow and wish to inquire about the PA-28 AD covering the lower wing strut electric current inspection.

what is the recent development on this AD?
how much could it cost to inspect?
How much could it cost to correct?

thank in advance

E from Laval Qc
5 Replies
AOPA Staff Answer
Hi Emile,

The most recent development for this AD is a Supplemental Notice of Proposed Rulemaking (SNPRM) that was published on June 3rd. Comments on this SNPRM were open until July 20th. The SNPRM can be found here. The AOPA article covering this can be found here. This is not an AD yet, the FAA is still working on it.

Here are the FAA estimates costs:

Good afternoon Emile,

As of 18 August 2020, the FAA has not issued an Airworthiness Directive (AD) for this issue.  As such, you, as a private operator, are not required by law to do any thing yet.  However, Piper issued a Service Bulletin (SB345, I believe) to address this issue.  You can print out a copy of this SB from the Piper website ( and look for technical information by the SB number).  The SB gives approximate costs and materials information.  Keep in mind that the actual cost may differ due to who and where the inspections will be conducted.  It costs money to certify and calibrate the Eddy Current Non Destructive Inspection (NDI) equipment.  The cost of the NDI inspection will not be excessive, but if a crack is found, replacing the wing may be very costly.

The FAA Notice of Proposed Rulemaking (NPRM) included a "factored flight hours" calculation based upon 100 hour inspections.  If this Arrow has been flown for private use only or has had only a few 100 hour inspections (ie-commercial operations, such as a flight school), the factors are not very restrictive.  If however, this Arrow was used extensively in a flight school (lots of 100 hour inspections), the factors build up quickly, and this airplane will be required to be inspected earlier.  Flight school operations tend to have large flight hour accumulations with a large build up of aircraft takeoff/landing cycles, leading to lots of wear & stress on the airframe.

As an Arrow owner, I performed a visual borescope inspection on my wing spar attach points as soon as the SAIB (Special Airworthiness Information Bulletin) came out, which is an FAA publication for owner information only.  The SAIB is not mandatory, but its detail is very useful.  When the NPRM came out, I calculated the factored flight hours and determined that my Arrow was not in the highest risk group.  I am considering doing SB345, but am not ready to do it just yet because I am waiting on the AD to be issued, which may differ significantly from the SB or the NPRM, which might lead to additional costs for which I have not taken into account.

I hope this helps for your decision.

Hello again Emile,

Just a separate Arrow question for your consideration.

The 68 Arrow should have the Hartzell HC-C2YK series propeller.  There is an Airworthiness Directive (AD 2009-22-03) on this prop hub.  Actually, there are 2 different prop hubs in use, the "A" hub, which the prop was built with, and the "B" hub, which is beefed up structurally.  The A hubs have an AD that requires Eddy Current  Non Destructive Inspection every 100 hours, but the B hub does not.  You will need to verify, through the aircraft/propeller maintenance records, which hub is installed.  (Installation of a B hub terminates the AD, but is costly for the part.)

I hope this helps.

Hoss and Jim

thank you both for your precious and knowledgefull  replies.

thanks for the headsup concerning the prop hub AD, Jim

regards to both.

Québec Canada

Correction:  The wing spar Service Bulletin number is Piper SB 1345.