The Squawk Sheet

✦   Preflight Brief

The good ones don’t tell you what’s wrong. They show you.

Welcome back to The Squawk Sheet. Issue One landed in nearly every Texas hangar that subscribes to anything — thank you for the responses, the forwards, and the questions. We read all of them. A few even made it into this issue.

This month: a heads-up for every Piper PA-28, PA-32, PA-34, and PA-44 owner about a fresh FAA airworthiness concern that could become an AD if owners don’t get ahead of it. Plus the truth about what summer heat is actually doing to your powerplant (it’s not what most pilots think), and an honest look at the maintenance crisis the industry is finally admitting it has.

Plus a hangar joke at the end. Some traditions earn their keep.

On April 2, 2026, the FAA quietly issued an Airworthiness Concern Sheet (ACS) that more Piper owners need to know about than currently do. It does not have the legal force of an AD — not yet — but it is the FAA’s formal way of saying: we’re watching this, we’ve seen enough cases to be concerned, and if owners don’t address it voluntarily, an AD is the next step.

The concern: severe corrosion on the forward wing spar-to-fuselage attach fittings of Piper PA-28, PA-32, PA-34, and PA-44 airplanes. The trigger was a single airplane found with the forward spar attachment so badly corroded that — quite literally — it should not have been flying. A subsequent fleet inspection found four more airplanes in the same fleet with corrosion, less severe but present. That is what caught the FAA’s attention. The Cherokee family is the most-produced general aviation airframe in history. If five airplanes from one fleet have it, the question is no longer “is this a real problem?” — it is “how many other airplanes are flying with it right now?”

What This Actually Means For You

First, the technical part. The forward wing spar attaches to the fuselage through steel fittings bolted to an aluminum spar. Steel and aluminum, in the presence of moisture, generate galvanic corrosion — an electrochemical reaction that eats the aluminum from the inside, often invisibly, until structural integrity is compromised. This is different from the aft spar corrosion most owners already know about. The aft issue is water intrusion. The forward issue is the metals themselves quietly corroding each other any time humidity is present. Florida airplanes were the first to show severe damage. Coastal airplanes are most at risk. But every PA-28, PA-32, PA-34, and PA-44 in the fleet has the same dissimilar-metal joint — including airplanes that have lived in Texas their entire lives.

Second, the inspection part. The FAA already issued SAIB AIR-21-10 back in 2021 recommending owners check this area — and pilots largely didn’t, because the area is brutal to access. The new ACS exists precisely because the SAIB inspection is so difficult that even shops doing it correctly were missing severe corrosion. Piper’s response is Service Bulletin 1400A, dated March 13, 2026 — a more thorough procedure that walks through the inspection, and where necessary, the disassembly required to actually see what’s back there. Some owners are now installing borescope inspection ports to make this easier on every future annual.

Third, the warning sign part. Before you ever schedule an inspection, look at the rivets in your forward wing-to-fuselage attach area. “Powdery” rivets — that white, chalky residue around the rivet head — are the visible tell of galvanic corrosion underneath. If you see it, you almost certainly have it. If you don’t see it, you might still have it — but you’ve eliminated the most obvious red flag.

Fourth, the timing part. This is not an AD — today. The FAA explicitly issued an ACS rather than an AD because they want field data first. But the path from ACS to AD is well-traveled, and the trigger here (severe corrosion in five fleet airplanes) is exactly the pattern that often results in AD action within twelve to twenty-four months. The owners who get ahead of it now do the inspection on their schedule, at their cost, with a familiar shop. The owners who wait do it under deadline pressure, at AD-emergency pricing, and with whatever shop is available. If you fly any Piper PA-28, PA-32, PA-34, or PA-44 — any of the 36 affected models — we strongly recommend including this inspection in your next annual. We’ve already added it to ours.

Pilots talk about density altitude in terms of takeoff roll and climb performance. Mechanics talk about it in terms of cylinder head temperature, oil temperature, and detonation margin — because that is what actually breaks engines in the summer. A 95°F day at KCPT puts the density altitude well above 2,500 feet before the wheels leave the ground. Your engine is breathing thinner air, working harder for less power, and shedding heat into ambient temperatures that are already most of the way to its operating limits.

Most pilots think hot-weather flying is a takeoff-performance problem. It is. But it is also a maintenance problem the engine remembers long after the flight is over. Detonation events leave fingerprints. Repeated high-CHT operations age cylinders. The damage is silent until it isn’t. Here is the checklist we ask every owner to walk through before the heat really sets in.

In February, AOPA published one of the bluntest pieces ever written about the state of personal aviation maintenance. The author was Mike Busch — arguably the best-known A&P/IA in general aviation. His verdict: “What we are facing today is not just another cyclical downturn. It is a systemic failure of the infrastructure that keeps personal aviation flying.”

A month later, an industry survey from TBX confirmed it with numbers. Three findings stood out: