FAA Issues SAIB 2022-20 for Piper wing spar cracks

Scott Sherer

This wing spar SAIB affects the following aircraft models:

• Small Airplane| Piper Aircraft, Inc.| PA-32RT-300T
• Small Airplane| Piper Aircraft, Inc.| PA-28-140
• Small Airplane| Piper Aircraft, Inc.| PA-32-300
• Small Airplane| Piper Aircraft, Inc.| PA-32R-301 (HP)
• Small Airplane| Piper Aircraft, Inc.| PA-32-301FT
• Small Airplane| Piper Aircraft, Inc.| PA-32S-300
• Small Airplane| Piper Aircraft, Inc.| PA-32-301
• Small Airplane| Piper Aircraft, Inc.| PA-28S-160
• Small Airplane| Piper Aircraft, Inc.| PA-32R-301 (SP)
• Small Airplane| Piper Aircraft, Inc.| PA-32-301XTC
• Small Airplane| Piper Aircraft, Inc.| PA-32R-301T
• Small Airplane| Piper Aircraft, Inc.| PA-32-301T
• Small Airplane| Piper Aircraft, Inc.| PA-28R-201
• Small Airplane| Piper Aircraft, Inc.| PA-28-161
• Small Airplane| Piper Aircraft, Inc.| PA-28R-200
• Small Airplane| Piper Aircraft, Inc.| PA-28-201T
• Small Airplane| Piper Aircraft, Inc.| PA-28-180
• Small Airplane| Piper Aircraft, Inc.| PA-28R-180
• Small Airplane| Piper Aircraft, Inc.| PA-28-151
• Small Airplane| Piper Aircraft, Inc.| PA-32RT-300
• Small Airplane| Piper Aircraft, Inc.| PA-28-160
• Small Airplane| Piper Aircraft, Inc.| PA-28-181
• Small Airplane| Piper Aircraft, Inc.| PA-28-150
• Small Airplane| Piper Aircraft, Inc.| PA-28S-180
• Small Airplane| Piper Aircraft, Inc.| PA-28-236
• Small Airplane| Piper Aircraft, Inc.| PA-28RT-201T
• Small Airplane| Piper Aircraft, Inc.| PA-28R-201T
• Small Airplane| Piper Aircraft, Inc.| PA-28-235
• Small Airplane| Piper Aircraft, Inc.| PA-32R-300
• Small Airplane| Piper Aircraft, Inc.| PA-28RT-201
• Small Airplane| Piper Aircraft, Inc.| PA-32-260

2022-20.pdf

jolexa

@Scott Sherer This is a SAIB requesting more information from operators, not an AD.

Rocky Landsverk

Correct on all @jolexa , this is basically saying "we need feedback" though it is likely headed to another AD, as the FAA confirmed when we asked them to approve our story, which is pasted here

https://piperowner.org/faa-issues-service-letter-updating-piper-wing-spar-guidance/

In other words, we said in this story "could be headed to another AD," then the FAA read our story and said "approved."

jolexa

Thanks @Rocky Landsverk , I also made mental note of that from reading the Intro of the SAIB that another AD might be coming. "The FAA is concerned" tells most of the story. It is also interesting to know that there are more incidents in the field after the inspections from the previous AD. I also took away (again, this is my assumption) that the FSH approach will probably stay and the intentions are good despite a confusing process.

My first post was just to clarify because Scott said "This wing spar AD.." and I was confused because there was no Required Actions, and then I saw it was a SAIB :)

Scott Sherer

Thanks for the correction! I've changed it from AD to SAIB. Thanks again.

aparker

I have a 1976 Piper Lance with just over 10,000 hours on it. It's been maintained to Part 135 from day one to three years ago. I bought it last year, passed the eddy test. I put in a new panel and had the entire aircraft inspected - including removing the wings and checking all the spar bolts. I've since put in a new interior and had it painted.

I can't see why we would limit an aircraft life if its passing all of the inspections. I can see increasing the inspections, from what I think is every seven years, to making it part of the annual, if necessary.

I believe there is a similar AD with the Aero Commander, but they haven't life timed it out.

Why should we have to write off an aircraft if it's still perfectly good.

Seneca38173

The short answer is that neither eddy current, not any other type of nondestructive test we currently practice, can guarantee the future health and safety of your airframe.

The longer answer is this: the structural engineers at AFRL run Piper's spar & carry through units through an accelerated fatigue life test rig. Over the course of a few days they can simulate the effect of multiple lifetimes worth of landings and flight loading. Generally they stop the equivalent of every 2500 hours or so to inspect the structure, using florescent dye, high resolution cameras, eddy current, and a number of other techniques. Then they restart the test and go for another 2500 hours. Eventually, the joint between the spar and the carry through fails. In most cases structural failure happens after the first cracks appear. But not always. If enough of the samples fail before cracking then they have no choice but to time limit the aircraft to a fraction of the shortest failure interval they witness in their tests. Typically that fraction is 40%.

I haven't seen the entire set of results from the current analysis. But from what I have seen, I think they're doing a competent job keeping us all safe in a reasonably cost-effective manner. No one wants to total your airplane!

Bob