We perform takeoffs and landings all the time. I’ve done more than a little reading in aviation textbooks and periodicals, and aside from the statistically greater number of incidents and accidents during these phases of flight that are attributable primarily to human error, I don’t recall either one getting much bad press by itself as being somehow inherently dangerous. But when you begin one landing, break off the attempt for whatever reason, and then proceed to attempt another one well, suddenly, it gets hard. I’m being a tad facetious of course; competence in executing go-arounds (or wave-offs, or whatever colloquial name you may prefer) is something that all pilots should possess…and not just after their primary flight training is complete. The problem is that—well, there are two of them. The first one implies motor skills, memory, procedures, and awareness; rejecting a landing involves a rapid transition from one configuration and mind-set, to another one that is significantly different. From a purely procedural standpoint, performing a specific set of control manipulations in a specific sequence, in a short (and limited) span of time, when you’re close to the ground, does kind of emphasize the point that cleaning up the airplane isn’t at all arbitrary. Secondly, there are psychological reasons; we don’t like wasting time and money repeating an approach that up until a moment earlier was going along just fine until something else came along to screw it up, and we don’t like having to admit that something got the better of us for fear that someone else might question our flying skills.
That said, there are quite a few situations where the wisdom of doing a go-around is self-evident. Seeing half the runway going by before you’re able to touch down would be one of them. (Actually, a better metric would be to call it off if you’re not on the ground within the first third of the runway.) The sudden appearance of a deer bounding across the numbers when you’re on short final (or the proboscis of an inattentive pilot’s airplane promenading onto the runway) is another.
There is also another even more common type of down-and-up-again event in aviation, and that is the touch-and-go landing, which is like an intentional go-around that is always initiated after the aircraft has contacted the runway (although usually, gently). Unlike the go-around however, in which it has sometimes proven in retrospect that a pilot should not have continued his landing but cut his losses and gone around for another try, the touch-and-go has sometimes proven in retrospect, but in an opposite way, that unless one is well prepared for it, it may be safer simply to follow through with a full stop landing!
Having its origins in the pilot training programs during World War II, during which it was critically important to train as many pilots as possible within the shortest time, the advantage of saving time and money hasn’t been lost on the civilian sector, either. The problem, as with the go-around, is that…well, things can get pretty busy in a very short time. In fact, some people in the flight training community aren’t exactly sold on the ostensible financial and scheduling advantages of the go-around. They say that it denies flight training students the gestalt of the full experience of landing an aircraft. (I might agree with them when it comes to tailwheel airplanes, but that’s about it.) But they also point out something else; it is actually a kind of “negative transfer” against the inculcation of regularly performing a pre-takeoff checklist. During any touch and go landing, how often do you think pilots are quickly peeking down at a checklist? I’d imagine that unless it was yoke-mounted or plastered onto a panel-mounted placard, that it wouldn’t be very often. Then there’s the ubiquitous issue regarding retractable-gear aircraft during go-arounds: it must be rather embarrassing to grab for the wrong handle during such a transition and inadvertently raise the gear instead of the flaps. Finally, the go-around doesn’t provide a situation free from distractions, during which a CFI can critique the previous approach and landing. This is a situation where a student is likely to be bandwidth-saturated, and any advice or admonishments can easily go in one ear and out the other. Believe me, I know; I’ve been the sieve in the left seat (and in learning to fly helicopters, on the right) enough times to know that task-saturated feeling.
But back to the go-around: the first type of problem with the go-around that I alluded to above exists independently of the best of intentions; it is simply procedural rather than perceptual. You’re approaching the runway, trimmed to land (not take off), and as such, any application of power usually causes the nose of the aircraft to pitch upward. You will most likely have to maintain significant forward elevator pressure to keep the airplane from approaching a stall. The more powerful the airplane, the worse it can be. (They don’t call one of the maneuvers in the practical test standards the “takeoff and departure stall” for nothing.) Power must be applied quickly, but smoothly. Doing otherwise could result in some heart-stopping hesitation. Power—and that’s full power, not just “more” power—is the first thing you suddenly need again. And it’s not the only thing; the sequence is much the same for most airplanes. Coincident with power and pitch control, is directional control in general (because of left turning tendencies).
Then come the flaps; many airplanes don’t climb much with full flaps, so you need to get rid of some—but not too soon, because the stalling speed with no flaps is significantly higher than when you have them extended, so you have to be mindful of that, or you might get that sinking feeling. In some airplanes the stall speed increase isn’t insignificant; it can be a double-digit difference. Typically you would milk them out 10 degrees at a time, generally to 20 degrees of flaps, and at that point maintain your best climb airspeed (angle or rate, as appropriate for the particular situation). The manufacturer’s recommended procedure takes precedence over any generalization, naturally. Generally, your “pitch up” angle with flaps is going to be noticeably more tame (less pronounced) than it would be without flaps, simply because the partial flaps themselves are giving you an effectively higher angle of attack. After you’ve taken care of the power, pitch attitude, and flap setting, then you can re-trim to relieve your aching arm muscles.
Finally there’s the landing gear if you’re flying a retractable gear aircraft, and other things like carburetor heat (or cowl flaps). One general rule says the gear can go up when you have a positive rate of climb. (The logic there is that if you were not ascending as planned, you’ll still have something that rolls underneath you, instead of something that just slides, if you catch my subtle inference…) Then again, there’s another point regarding obstacles, and runway remaining; there wouldn’t be much advantage to retraction during a successful climb-out if something else happened and then you couldn’t land on the remaining runway because your wheels couldn’t get back down fast enough.
I hasten to add the inevitable qualifying caution that you don’t always want to wait until the last minute to initiate a go-around (or for that matter, a touch-and-go). Some reasons for this probably seem subjective, such as discretion being the better part of valor, while others are simply logistical, like having enough runway remaining (or in the case of a go-around, avoiding a departure path that is at too low an altitude over the departure end of the runway, thus worsening the noise footprint). The earlier they’re started, the easier they are to do, and the more likely they are to have an uneventful conclusion.