Dead Bug Landings
Most fields of endeavor have tricks of the trade or rules of thumb that help practitioners take care of business more easily. For example, one trick to parallel-parking a normal car in countries where we drive on the right side of the road is to wait to turn the steering wheel hard right until you, the driver, is aligned with the other car’s steering wheel, then whip it hard left once you’re aligned with that car’s rear bumper. Aviation also has lots of these tricks and rules, and one of the best is Dead Bug Landings.
Why? Because landing an airplane demands the most finesse from the pilot. Also, pretty much everyone tends to judge the worth of a pilot by the quality of his or her landings.
Is that fair? No. Landings in an airplane is not just skill-based; it is an interplay between skill and the vicissitudes of weather. A perfectly-competent pilot can appear to screw up a landing like a first-week student who didn’t sleep last night if, for example, there’s a gust of wind that catches the wing shortly before touchdown.
This article will consider private planes flying and landing in visual flight conditions. Technically, we are talking about “VFR Flight,” where “VFR” stands for Visual Flight Rules. Landings under a different set of rules called, “IFR,” are different.
Bear this in mind: If driving a car were analogous to landing an airplane, the road would be moving up, down, left, and right randomly, and – get this – the road would be invisible.
Pilots are at the whims of weather when they land, although there are some things the knowledgeable captain knows that can help minimize wild landings. Much of this knowledge depends on knowing a little aviation secret: The wind interacts with the ground and buildings and mountains and such very much like water would interact with them. If a landing is to take place when there’s a right crosswind (meaning that the wind is blowing from the right of the airplane rather than, for example, directly down the runway), the pilot can adjust his or her flight path to counter being blown toward the left.
Now let’s add in a building a hundred feet or so to the right of the runway. The knowledgeable pilot will visualize the wind coming from the right, hitting the building, and burbling over the building toward the runway. This effect will cause some bumpiness that wouldn’t otherwise take place.
One of the rules of thumb in aviation is, if the landing is expected to be very gusty or bumpy, one may add a certain amount of speed and perhaps use less flap extension to make the gusts less of an issue. How much speed? How much less flap extension? Learn to fly and you’ll find out!
Let’s get back to Dead Bugs.
The Standard 3° Glidepath
The angle the airplane flies to the ground as it descends toward the runway varies somewhat, but the most standard angle is 3°. Most airports that don’t use 3° use something close, like 3.5° or 4°. It’s the very-unusual airport that uses more than 4°.
We’ll use the standard 3° angle for this article. Pilots are trained from the first day they are shown how to land to visualize that 3° glide path as they come in to land.
Student pilots find this descend-at-3° almost impossible to do initially, but it really is a learned skill. Most pilots pretty much “get it” after several learning sessions.
The thing is, the closer to the runway one gets during the descent, the harder it is to continue to visualize that glide path. The better the pilot is, the more accurately he or she will descend at 3° as if the airplane were on rails.
But there’s a cheat here. A trick of the trade, so to speak.
Dead Bug Landings
All airplanes have windscreens. “Windscreen” is the aviation term for what, in the car, would be called a windshield.
Although the windscreens start out pretty clean, it is almost inevitable that, during flight, one will run into a bug in the air, and, if the bug is small enough(!), the bug will experience its last moments watching the airplane approach. When the insect splats on the windscreen, it tends to leave a little trace – often a black dot or some such indicator
Even if the flight is bug-smash free, tiny bits of dirt tend to get onto the windscreen.
Dead bugs and bits of dirt are visible to the pilot if he or she looks for them.
Okay, fasten your seatbelt for landing now.
When the airplane is on “final approach,” which is sometimes just called, “final,” that means that it is aligned with the runway, heading for it, and in a position and orientation to land if the airplane has descended all the way to the ground. (“If” rather than “when” because sometimes, usually for practice, the pilot will “go around” without actually touching down: The airplane will then rise back up to the traffic pattern and work on landing again.)
On final, the pilot will establish the 3° glide path from some miles away from the runway and, as you know, will attempt to maintain that 3° all the way to the ground. One way to help do this well is to find a Dead Bug on the windscreen and look past it to the runway. That Dead Bug will appear to cover a particular spot on the runway (or maybe a spot just off to the side of the runway).
If the pilot can keep that Dead Bug covering that exact spot all the way down, then the pilot will follow the already-established 3° glidepath pretty easily! This requires arguable a little less skill from the pilot, and that means that he or she can put more effort into other aspects of making a good landing. Coincidentally, these landings are impressive to passengers, other pilots, and ground-based onlookers, too.
More importantly, a well-executed landing is a safer landing, and it even can reduce wear and tear on the airplane itself.
At least that poor bug gave its life for an admirable cause.