Weather is not the only hazard threatening aircraft parked in the open, but it’s a significant one. In the mid-Atlantic climate, the passage of 12 months can see the same set of wings covered in frost on an otherwise beautiful winter morning, sagging under the weight of a two-foot snowfall, and dinged by summer hailstones. Microbursts have been known to rip airplanes from their tiedowns and throw them across the ramp. Torrential rains put a premium on keeping those rubber gaskets under the fuel caps snug and tight.
Atmospheric conditions in the spring and fall are more benign, although there are plenty of gusty days, and thunderstorm season seems to start earlier and last longer every year. But the respite from foul weather shouldn’t be mistaken for an interlude of carefree aircraft ownership. When Nature isn’t slinging air and assorted forms of water at our prized possessions, she makes up for it by enlisting some of her wild creatures—particularly those that apparently resent our having joined them in the sky.
Insects have a legitimate grudge—we do, after all, smash them by the millions without giving them a thought until the time comes to scrub away their remains. They tend to retaliate via stealth, crawling into and blocking narrow but vital passages such as fuel vents, pitot tubes, and even orifices inside carburetors. Birds, on the other hand, seem motivated principally by spite, and because their sabotage rarely involves suicide missions, they can attack the same aircraft again and again.
For the past three weeks, two senior AOPA staffers (both of whom happen to own Cherokee 140s) have had to devote a portion of every day clearing nesting material out from under their cowlings. The stuff reappears by the next day. Cowl plugs don’t keep the culprits out. Neither do improvised barriers around the nose-gear struts: towels, pillows, plastic tarps, whatever. Birds have been seen nonchalantly perching on the plastic snakes and owls strategically placed to frighten them away, and blocking their favorite spots just drives them to scatter the mess around. As we said, they’re spiteful—not to mention persistent. Their perseverance in starting fresh construction in exactly the places where their previous efforts were destroyed reminded at least one owner of the character of the Swamp King in Monty Python and the Holy Grail:
“All the other kings said I was daft to build a castle in the swamp. They said it would sink into the swamp—but I built it. And it sank into the swamp. So I built another, and it sank into the swamp. Then I built a third, and it burned down, fell over, and sank into the swamp. But the fourth one—aye! The fourth one stood!”
(Of course, as another friend pointed out, there’s no knowing whether it’s the same birds every time. One starling looks pretty much like another. It’s always possible that having been evicted from roosting on top of one Lycoming, they flutter on down the ramp, and—“Hey, honey, what do you think? This looks like a nice place—and it’s vacant!”)
At a minimum, accumulations of sticks and straw atop the cylinders’ fins keeps cooling air from going where it’s needed, sharply increasing the risk of the engine overheating in flight. As the stuff dries out, heat transfer from the fins is liable to set it smoldering—not an appealing prospect no matter how confident you feel of the security of your fire-sleeved fuel lines. If things are allowed to progress until the little monsters take up residence, the mess becomes incomparably worse, providing practical instruction in just how corrosive bird droppings really are. And, of course, there’s always the risk that dislodged nesting material—or even hatchlings—could get wedged into the induction system’s air intake, starving the engine of oxygen at what’s likely to be an inconvenient time. The seller of a Beech Musketeer who tried to deliver the airplane after it had sat unattended for seven months learned the hard way that allowing homesteading to progress unimpeded really isn’t an alternative.
At least by the time this appears, April will be over. The nesting season should end within, what? Another couple of months?
David Jack Kenny is manager of safety analysis for the AOPA Air Safety Institute.