Post-Paint Preflights: Flight Controls, Landing Gear, Antennas

True story. A guy fetches his big Twin Cessna from the paint shop and the next day loads in his family for a trip, flies the airplane into mountain turbulence and part of the tail section comes off. Thanks to skilled flying (and a boatload of good luck), it was a favorable outcome, and the owner sued the paint shop for negligence and won.

The drama is enough to make the hair on the back of the neck stand up—and contemplate bringing your mechanic along to inspect the bird before flying it away from a teardown paint project. But that’s usually not necessary, because I’d estimate that the majority of paint shops are skilled enough to reassemble the aircraft the right way before handing it back to an owner. But in the world of aircraft maintenance, stuff happens—and in the world of aircraft painting, a lot can go wrong. Approach the flyaway with extreme caution and vigilance. Start by understanding how much of the aircraft was disassembled (the Grumman Tiger in the lead image, thanks to Bob Reed, is proof) and put a hawk’s eye on how it was put back together.

Teardown—Lots of It

Part of the reason for the high cost of paint work is the amount of disassembly that’s required to do the job right. It goes without saying that you want to avoid the proverbial Earl Scheib spray-and-go low-budget project. You want quality work that’s going to last as long as possible. But it’s more than that. Choose a paint shop not only on its paint prepping and application skills, but for its ability and experience working with your airframe model. It’s even more critical with larger complex machines. That’s because when the aircraft hits the shop floor, nearly every major component on the airframe might be removed, stripped and masked off. Once it’s cleaned and prepped, it’s shot with layers of primer and paint (with inevitable overspray in areas that should be avoided). When it’s dry, all of the pieces and parts are reassembled. Retracs deserve an even closer look.

For that reason, I believe that every paint shop that works on retracs should accomplish a gear swing before handing it back to the owner. At the very least, you’ll want to be sure the landing gear doors were not only put back on properly, but that they’re properly rigged. A friend with a Piper Comanche couldn’t understand why the plane lost a few knots of speed in cruise flight—and had a slight buzzing vibration—after a paint project. Turns out one of the main gear doors wasn’t properly rigged, keeping it from completely closing. It also explained why the turn coordinator showed uncoordinated flight no matter how well he trimmed it.

But rigging aside, closely inspect the components inside the gear wells. Were the grease fittings painted over? Good shops will mask them and the best shops might actually replace them, especially part of a high-end refurb project. It’s a good idea to completely lube the landing gear and all of the wheel bearings after a strip-and-paint project. Think about all of the moisture that gets into critical areas during the stripping, etching, alodining, and rinsing stages preparation. While in the wheel wells, look for stuff left behind that shouldn’t be there.

Speaking of stripping, if you haven’t had paint work done since the Reagan era, the dominant method now is chemical stripping, not bead blasting. When it was first introduced, bead blasting was blamed for damaging metal surfaces and even instruments and radios if the media found its way into the cabin.

Stripping and prepping are harsh. I recently read a good tech report by Dick Pederson (a technical consultant at the American Bonanza Society), who worked on a Bonanza that was recently turned loose by a paint shop, and not only found the nosewheel bearing making a racket when spinning the wheel, but also that the nosewheel wouldn’t even come off the axle shaft. It seems the bearing was weld-rusted to the axle shaft, probably from the stripping process done during the recent painting. The reason the wheel would not slide off the axle was because the bearing and race being so badly rusted that during the first takeoff or landing after the paint job, the bearing had been binding on the inner bearing race, causing it to spin on the axle shaft instead of remaining stationary on the axle as it’s supposed to. Pederson also made good points that it’s not uncommon to find masking tape and paper accidentally left on items including control cables, flap actuator shafts, flap limit switches and squat switches.

Paint Doesn’t Belong There

During your preflight walkaround, pay close attention to fresh paint that might be in areas it doesn’t belong, including on the aircraft’s static ports. If they aren’t masked, it’s easy for overspray to plug the small holes. This includes aftermarket static ports that are part of autopilot systems. If you don’t know if the airplane has them, hit the autopilot’s flight manual supplement and learn where and how many there are. S-TEC is one aftermarket system that uses static ports for the altitude hold system. Paint that clogs the ports will induce all kinds of autopilot pitch-axis problems. And it isn’t only paint that can cause problems … so does masking tape that didn’t get removed. Put a good eye on it.

The same goes for fuel vents, which are there to allow air to displace into the tank as fuel is burned off. If they are painted closed, there can be enough vacuum to cut off fuel flowing to the engine. Verify that the vents are unobstructed—no tape or paint covering the hole.

Beyond Free and Correct

It goes without saying that any preflight after paint work should focus sharply on the aircraft’s flight controls, which were removed and hopefully properly balanced before reinstallation. There have been ugly wrecks after maintenance where control surfaces were hooked up in reverse. Simply moving the controls in the usual box pattern and feeling for binding isn’t enough. Before you even strap into the aircraft, move the ailerons, rudder and elevator to verify that they deflect properly. Run the flaps up and down and inspect the rollers and attachment hardware. If the aircraft has electric pitch trim (or even manually activated trim), run it to the stops in both directions, making sure there’s no binding and that it runs at the correct speed and in the proper direction.

Painting control surfaces requires rebalancing for good reasons. While the balance of a flight control doesn’t change appreciably in the life of the machine, any time repairs are made to a balanced flight control or it gets repainted, its balance must be verified—and documented in the aircraft logbooks with a proper sign-off. And of course, there should be an update to the aircraft’s weight and balance report to reflect the paint work. It changes the weight of the aircraft more than many think. Moreover, you generally won’t know if a control surface is out of balance until you get it in the air.

While you’re doing your walkaround, operate all of the aircraft’s doors—cabin, baggage, and even wing lockers on twins. Are there any gaps? Do the doors close and lock properly? More than one door latch pin was improperly reinstalled after paint work and we know what can happen when pilots become distracted by a door opening on takeoff.

Look carefully at cowl fasteners. Are they all there, and if so, are they tight? The same goes for inspection plates on the underside of the wings and fuselage. And what about static wicks, are there any missing? Aircraft data plate? Sometimes it’s forgotten, and it’s required. Consider having cam fasteners and other surface hardware replaced during the paint job—new hardware just looks good. Old ones don’t.

Bad Work is Easy To Spot

We all know a crappy paint job when we see it, but it also takes a sharp eye to spot some red flags. Take your time during the delivery. Look closely for indications that the control surfaces weren’t removed for stripping and painting, and look for globs of stripper that was left in hard-to-reach places and sometimes even painted over. Other red flags include stripper that wasn’t rinsed from the skin laps, inspection panels that are glued in place because there weren’t removed before spraying, wheel bearings shot through with stripper crud because the wheels weren’t properly masked, paint oversprayed on the windows, the poor masking of stripes and trim, plus overspray in the door jambs, engine spaces and other places that aren’t supposed to have paint.

In the end, paint shops that perform poorly don’t stay in business for long. We’re putting together a paint shop satisfaction survey to see which ones are standouts and we’ll report back with the findings. Got a paint shop that’s done well—or poorly—for you? We want to hear about it.