Go-arounds

[Bluehawk]

You may have experienced this. If ever air crew, you DEFINITELY experienced this.

Source link:
Ask the pilot | Salon Technology
----------------------------------------------------------
Oct. 3, 2008

"There you are, belted in for landing, at a window seat in Row 36. The approach is smooth, the weather clear, the landing gear drops into place. Down, down, down you come. At 500 feet or so, you can make out the writing on billboards; touchdown is only seconds away.

Then, without warning, the engines roar and the aircraft pitches up sharply. For a second or two the plane seems to wallow, uncertain which direction it wants to take, momentum pushing downward against the sudden burst of power and raising of the nose. Hydraulic pumps whine, gear doors clunk open, turbines scream. The plane begins to climb, groaning and shuddering as the landing gear retracts and the flaps are reset. The ground falls away; the plane banks sharply. You grip the armrest. What the heck is happening?

Finally, a long minute later, the plane levels off and the power drops back. Moments later, the P.A. crackles and the captain speaks. "As you're aware," he says, "we were forced to abandon our approach and make another circuit. Seems that air traffic control had us spaced a bit too tightly with an aircraft ahead. We're circling back around for another approach and will be on the ground in about 10 minutes."

If you fly enough, you have experienced this scenario one or more times. The maneuver is called a "go-around," and it is known to scare the daylights out of passengers. Go-arounds have a special place in the pantheon of anxious flier concerns, up there with the likes of turbulence and wind shear. I read about them all the time, luridly described in letters from fliers, novices and seasoned travelers alike, anxious to know what might have gone wrong, wondering if they narrowly escaped a collision.

In fact, go-arounds are fairly common and seldom the result of anything dangerous. In most cases it's a minor spacing issue: Two arriving planes are no longer able to maintain the required separation parameters, and/or the aircraft ahead has not yet vacated the runway. Not an ideal situation, but let's be clear: This is not the same thing as a proverbial near miss. In all likelihood, the reason your plane is going around is to prevent a near miss. Actual instances where a collision is narrowly averted do occur, but they are extremely rare.

Other times, traffic has nothing to do with it. A variant of the go-around, spoken of somewhat interchangeably, is the "missed approach," when a plane pulls off the same basic maneuver for weather-related reasons. If, in the course of an instrument approach, visibility drops below a prescribed value, or the plane has not made visual contact with the runway upon reaching the minimum allowable altitude, the crew must climb away (often followed by a diversion to an alternative airport). A go-around will also be initiated any time an approach becomes unstable. Glide-path deviations, a too-high rate of descent, severe crosswinds, a wind-shear alarm -- any of these can trigger one. You might recall the storm-whipped approach into New York I described here several months ago, which resulted in two aborted landing attempts.

As for the steepness or suddenness of the climb, that is the manner in which any go-around is executed. No need to dillydally around at low altitude. The safest direction is up -- as quickly as is practical. The abrupt transition from a gentle descent to a rapid climb might be noisy and jarring, but it's perfectly natural for an airplane. In some instances, a plane might actually touch down before lifting off again. Unusual and unnerving, perhaps, but well within an airliner's capabilities.

From a pilot's perspective, these maneuvers are not terribly difficult, but the workload is very high. (Either pilot -- captain or first officer -- can be at the controls, but generally it is the captain who makes the "go-around" or "missed-approach" call.) The first step is advancing the power to go-around thrust, retracting flaps and slats to an intermediate position, and rotating to a target pitch -- somewhere around 15 degrees nose up, depending on the aircraft. Once a climb is safely established, the landing gear is raised. Next, flaps and slats are retracted, followed by additional power and pitch adjustments. Some of this happens automatically, the rest is accomplished by hand. The steps are not random or subjective; they are performed at specific speeds and altitudes. Once at level-off, the flight management system may need to be reprogrammed -- the autoflight components appropriately reset, checklists run, the weather double-checked and so on. All of this while taking instructions (turns, climbs, etc.) from air traffic control. There's lots of talking and a rapid succession of tasks.

All in all, there are few busier times in a cockpit. This is one of the reasons you often don't hear from the pilots for several minutes. And when you finally do hear from the cockpit (either the captain or first officer will do the talking, depending), the explanation is liable to be brief and, much as I hate to say it, maybe not as enlightening as it could be. Truth is, pilots and microphones aren't always a good mix. In our attempts to avoid technical jargon and present complicated situations in layperson's terms, we have a tendency to oversimplify, a proclivity for scary-sounding caricature. Passengers do not need a dissertation on the nuances of ILS visibility requirements or air traffic control procedures, it's true, but statements like "We were a little too close to that plane ahead" paint a misleading, if not terrifying, picture. Later that night, passengers are e-mailing their loved ones with a tale of near death, whereas the pilots have forgotten about it. Not because they are daredevils who revel in danger, but because, quite frankly, it wasn't anything serious.

Which is not to downplay or sugarcoat those occasional near misses. Not all go-arounds are the result of traffic conflicts, but many are, and the congested environments at many airports, especially those with crisscrossing runways, have contributed to a marked uptick in potentially dangerous incursions -- something discussed in a column here last spring.

On the one hand this shouldn't be surprising -- after all, there are twice as many flights today as there were 25 years ago. But the trend is a troubling one, and all involved parties -- pilots, controllers and the Federal Aviation Administration -- need to work together to lessen the odds of a tragedy. We have gone nearly seven years in America without a large-scale air disaster, our longest-ever streak. Not to be morbid, or reckless in my capacity as a pundit, but when that streak finally comes to an end -- and it will -- a ground collision might well be the culprit.

Worrisome, yes. But is there a crisis? No. The system is by no means unsafe. There are somewhere on the order of 20,000 commercial departures in the United States daily -- around 7 million per year. In 2007, there were eight incursions deemed "serious" by the FAA. Of those, only two or three were legitimately harrowing. No airplanes collided.

Meanwhile, the vast majority of go-arounds are what they are: routine maneuvers executed to keep you out of trouble, not in response to it. If you need to, think of it this way: By the time the plane is climbing, you've obviously averted whatever hazard, if any, existed in the first place. For what it's worth, I long ago lost count of the number of times I have, as a commercial pilot, been party to a go-around, be it due to traffic, weather or any other reason. Perhaps 20? (I remember once, at the quiet little airport in Hyannis, Mass., having to go-around twice, on consecutive approaches, because of spacing with aircraft ahead.) Of all those occasions, the number of close calls, or anything like one, stands at zero.

Next time the engines rev and the plane shoots upward, impress your seatmate by hardly batting an eye.