The Rituals of Spring

Ah, yes, spring has arrived in all of its beauty and glory — the bugs are flying, the birds are back in the northern parts of our country… and that’s bad news for pilots. A lot of pilots are just beginning to really shake the winter out of their aircraft and they know their skills may be rusty, but are they really aware of all the surprises that might be waiting for them in their aircraft? More importantly, have you really checked out that plane for the problems that spring brings?

Like it or not, birds are driven by their instincts, and right now, that instinct is telling them to BUILD A NEST! Not just any nest mind you, but one big enough to hold their brood, which they will be looking to lay as soon as they can. While these nests will delight your children should the birds happen to build one within your eyesight, they will give you headaches if they build one or more in your airplane.

Really, anyone with an airplane is at risk — especially if your airplane is stored outside. Even if your plane is inside, if your hangar has any gaps or holes, you need to look for the danger signs that birds may have taken up residence somewhere in your airplane, and if you find them, remove their nesting materials before you fly.

There are several signs that birds have taken a liking to your airframe and have decided to set up house.

  • The first is the most obvious — nesting materials protruding from your cowl or control surfaces. Note: This material, which is usually comprised of dry grasses, but can include just about anything that a bird can carry, will burn readily if heated.
  • Another sign of problems are those nasty white stains that most birds leave as droppings. If you happen to see a lot of white stains inside your cowling inlets, the chances are good that a couple of birds may have set up housekeeping inside your cowling.
  • Pay attention to your surroundings as you preflight your aircraft. If there seems to be a lot of chirping coming from a tree or bush near the aircraft or flustered-bird activity, that’s a tell-tale sign that a bird thinks you’re too close to its home — and that home is probably somewhere in your airplane.

The worst place for birds to nest is inside your engine cowling. Here, you have several spots between the cylinders that are almost the perfect size and shape for birds to nest in. If you use an engine heater, the birds will like it even more, since that keeps the nesting area nice and toasty-warm.

Fires can and will erupt from these nests if they are built in the engine compartment. When the fire burns, it will usually damage the cowling at a minimum. In some cases, the fire will damage the baffles and, in the worst case, the fire can even damage the engine! Needless to say, if the fire happens to burn through a fuel line while you are in flight or on the ground, the results can be disastrous!

Worst Case: At the very least, fires in the engine compartment will create smoke, which any pilot will recognize as a serious problem. Depending on how much smoke is generated, you may elect to make a forced landing. With Murphy already on board (who do you think suggested your cowling to the birds for nesting in the first place), you will have a good chance of making a forced landing faux pas, and picking the wrong place to land. The resulting damage to your aircraft could be substantial, several orders of magnitude beyond what the bird nest that started the whole thing would have cost to remove.

There are still other locations where birds love to nest. The first applies to the retractable gear crowd, since birds love to nest in open gear wells. These locations are dark and sheltered, generally quiet (until the doors open), and make a perfect location to build a nest. Look for bird droppings around the gear well, and use a light to see into the gear well to see if any nesting materials are present.

Another favorite location for birds is the lightening holes in the back of the wings and vertical stabilizer. These holes look just like a birdhouse hole to the birds, and they are more than happy to try to fill your wing structure with nesting materials. The problem with these nesting materials is simple: they absorb moisture, and cause corrosion of your airframe. That corrosion could result in your having to replace the skin on that section of the wing or stabilizer, which is expensive proposition.

Caution: A bird will make a home anywhere that a bird can fit — and they can fit just about anywhere!


  • If you see nesting materials, or signs of bird occupation such as droppings, •THOROUGHLY INSPECT THE AIRCRAFT.
  • Look into EVERY OPEN HOLE in the airframe with a good light.
  • If you see any nesting materials, REMOVE THEM.

Important Note: Without the engine, most planes become an expensive and inefficient glider.

BOTTOM LINE: Birds will go anywhere there is a hole and a cavity to build a nest in. With spring here, you need to keep your preflight skills focused to find bird nests before they show themselves off to you. By being proactive, you will be able to avoid running afoul of our feathered friends, and keep your flights safe and uneventful. …and if you do find a nest, just be glad it wasn’t the beginnings of a bee-hive.