Square Patterns?

Who needs em? The overhead or modified overhead offers some relief from boredom, but also sharpens emergency landing skills


by Paul Bertorelli

With few exceptions, the last thing you want to hear in a cockpit is this: Hey, watch this. Yet sometimes theres a thing or two to learn when someone says it.

Five years ago, a Mooney sales person was giving me a demo ride in an oddball airplane called the Predator. It was a prototype built as a military trainer and had side-by-side seating, center sticks and a sliding canopy; very high testosterone.

After an hour of stooging around doing stalls, amateur aerobatics and landings, the salesman was obviously bored with my stodgy square patterns. On the downwind, he said, lemme take it for a minute. He then wrapped the thing into a graceful, tight carving turn toward the runway with a three-second wings-level segment and a squeaker on the numbers. A light bulb went off in my noggin.

When I learned to fly in the late 1960s, I had been taught this method of flying an approach as one option-but not the only option. In the intervening years, along with everyone else, Id fallen into the habit of flying only square patterns, although never the three-mile finals some instructors seem to insist upon. In my view, there are several reasons why ridiculously large square patterns have become the norm.

One, were good at teaching pilots that its always bad to do tight turns close to the ground. Most are too terrified to even think about it. Second, we spend so much training effort on stall avoidance that pilots tend to pad airspeed to the point that a 65-knot approach is viewed as suicidal. Last, anything with the slightest whiff of non-standard tends to excite the Aunt Janes on the airport couch to the edge of apoplexy and this sometimes spills onto the Unicom frequency. And who needs that?

Turn? I Dont Wanna…
This lapse in the training curriculum was driven home for me recently when I was giving an experienced and otherwise proficient pilot some flight review exercises. As an engine-out drill, we crossed the airport perpendicular to the landing runway at 1000 AGL and dropped the power to idle, positioning us perfectly to turn into a modified downwind for a play at the numbers. But thats not what happened. Even with no power, we dawdled across the runway and floated into what turned out to be a normal downwind. Game over. Although it would be close, it was clear we wouldnt make the end of the runway without adding power which was, theoretically, not available.

We flew a low approach and a go around, then set up the exercise again with the same results. Again, we burned off airspeed and altitude until the runway remained elusively beyond reach without adding power. Whats the problem here? Mainly comfort level. With an over-the-runway set-up like this, the only workable response was a decisive steep turn into an abbreviated downwind followed by a more-or-less continuous turn at low-altitude toward the numbers, with a brief roll-to-level and a touchdown.

But like so many of us – myself included – the pilot had been hammered not to make low-altitude steep turns. Further, he had been schooled to avoid stalls by padding the airspeed generously, especially during turns. Thats all good advice, of course, but its also too much of a good thing.

CFIs are right to warn students about low turns but once their charges have graduated to private pilot status, they somehow forget to add that once a pilot has gained some experience, steep turns at almost any altitude are safely doable, provided certain limitations are kept in mind.

As for stalls, so much of modern training concentrates on avoiding them – again, a good thing – that we forget where the stall speed/angle of attack actually is so we tend to add generous margins to avoid even the hint of buffet. The downside of that is that if you cross the numbers with 10 more knots of airspeed than you really need, youll float and use up more runway than necessary. But on a long runway, who cares?

Actually, you should care. Faster-than-normal approaches and landings out of a float tend to encourage ugly touchdowns, leading to porpoising, overruns and other loss of control incidents. On a sphincter-tightening short runway, a too-fast approach may put you into a ditch. This is a common accident scenario.

Training For It
So, if you buy into the notion that low-altitude steep turns arent always a bad thing, how do you train to do them safely so youll have the skills in an emergency situation? One way is to set aside some periodic practice or training to re-enforce the idea that (a) not every pattern has to be square with a two-mile final leg and (b) remind yourself that the time may come when your engine really will quit and you wont have the luxury of a power-on approach.

My method of keeping these skills sharp is to fly every approach I can just like the one the Mooney salesman demonstrated for me, which is essentially the tail end of a military style overhead approach, but without the overhead break.

Overhead approaches are a rarely used maneuver by most GA pilots and are sometimes maligned as showboating when they are used. Pattern Nazis who like things done in a certain way – always their way, of course – may fume with indignity when a pilot tries an overhead. Ignore them. Just make sure you fly your overheads when theres no conflicting traffic; standard common courtesy applies,

According to the AIM (5-4-24), an overhead is supposed to be used in conjunction with an IFR approach, although it is clearly a visual maneuver. In the real world, overheads generally arent connected to IFR operations.

At a towered airport, just ask for the overhead and, since most controllers are familiar with it, theyll approve it, traffic permitting. The tower might even specify a break point. At a non-towered airport, to avoid shouting matches on the Unicom frequency, fly an overhead only when you have the airport to yourself or you can otherwise fit into the flow without causing some kind of hairball in the pattern.

For the typical overhead, you enter the pattern on an upwind leg, aligned with the landing runway. At the appropriate point, you break left or right, depending on the pattern direction, and fly a continuous descending turn into the downwind leg. The AIM shows the break just past the arrival end of the landing runway but thats not the only way to fly the maneuver. The break point should be adjusted to suit the airplane youre flying and whatever other operational considerations apply, such as wind, traffic or runway length.

The AIM version of the overhead seems to suggest a straight-and-level downwind leg but, again, thats only one way to do it. If the overhead is flown as a means of sharpening power-off approach skills, the downwind can be straight and descending or curved and descending.

After the break, as you roll out of that turn parallel to the landing runway but flying in the opposite direction of your landing, you transition into what might best be described as continuous judgment mode. You have to decide how long you want your wings-level final segment to be and then continuously judge your descent on the downwind to set your 180-degree turn point to deliver the final segment you want.

Personally, Im comfortable with low-altitude turns and I like a short, close-in final segment. That means Im rolling level at perhaps 100 feet AGL or less with a wings-level segment of under 10 seconds.

Depending on where the break was flown, some overheads may amount to a nearly continuous turn from the upwind to the final segment, with bank angle varying constantly to play the distance from the runway and the angle to the threshold. The bank angles dont have to be steep, either; 45 degrees may be all youll need. Try this a couple of times and youll discover that its far easier to fly to a consistent touchdown from an overhead approach than it is from a traditional squared-corner approach.

In situations where the overhead with break isnt practical – say, traffic doesnt permit or youre approaching the airport from a direction where a traditional 45-degree entry will work better – you can fly a modified overhead. Simply start your turning maneuver as you roll out on the downwind leg, then vary your bank and descent rate to deliver the final segment youre comfortable with. If you do this correctly, youll fly a continuously curving approach without a squared off downwind-to-base-to-final leg.

Bank Angle, Airspeed
No matter how its flown, theres a lot going on during an overhead approach maneuver. Think of it as dynamic exercise in bank angle, airspeed and wing loading control with all of the variables constantly in motion.

This brings to mind the question of bank angle and airspeed. What are the ideal numbers? There arent any. But there are limitations that are a function of comfort level and actual stall speed. The two are inextricably intertwined.

During the BFR exercise described here, my friend confessed a reluctance to bank steeply for fear of stalling. We were flying these patterns at 80 knots, gear down but flaps up. I wondered to myself what the worry is about stalling at 80 knots. Then it occurred to me that although I knew we were comfortably above the stall speed at 80 knots and a 30-degree bank angle, I knew that by intuition, not by POH reference.

After we landed, I dug up the stall speeds at various angles of bank. At 30 degrees bank, the clean stall speed in the Mooney 231 we were flying is 66 knots; at 45 degrees, its 74 knots. I would guess the bank angles we were actually using were 20 to 30 degrees so, worst case, we had a 14-knot margin above the stall or a little more, since the airplane was light.

Is that enough? Comfort level again. For me, thats a generous margin and Im more than willing to trade a little of it for a steeper bank angle to hurry the turn briefly. At a 40-degree bank angle, for instance, the stall speed is about 70 knots or a 10-knot margin at the speeds we were using. The other side of the stall-speed coin is that excess airspeed can be traded for altitude, although in a power off situation, pitching up to 80 knots from 85 knots wont buy much altitude. But it might buy enough to avoid scraping the landing gear through the trees as you glide toward an obstructed runway.

This is one of the many splendors of the continuously curving overhead approach. Without much practice and with eyeballs entirely out of the cockpit, you can teach yourself to adjust the bank angle, pitch and descent rate to nail the right airspeed with minimal reference to the airspeed indicator. You can, for instance, fly into the upwind leg of the overhead with your hair on fire and well above the gear extension speed. (Yes, I know Aunt Jane, we promise to be prudent when we do this.)

When you reduce the power and roll into the break, youll load the wings sharply and that will tank the airspeed within seconds so you can easily extend the gear and continue the approach. Want less airspeed decay? Unload the wings with reduced pitch and/or roll out some bank.

If theres some ideal bank angle to make all this work perfectly, I dont pretend to know what it is. The better way to look at is to consider limitations on bank angle that depend on your comfort level and the segment of the approach youre flying. At the initial break, 45 or 50 degrees of bank isnt unreasonable because you probably have more airspeed than you want and loading the wings will get rid of it. If you have less airspeed than you want, you have the choice of less bank angle or just letting the nose drop through a little to lessen the load on the wings.

The critical part of this maneuver is the 180-degree turn onto the final approach segment. If youre too close in and low, the temptation will be a steep bank without much pitch down because the ground is, well, right there.

But this is trouble. If youre already in, say a 40-degree bank at 80 knots, and it looks like it isnt going to work, dont crank in more bank angle unless you have enough altitude to unload the wings a little. It will probably be better to accept a bit of overshoot in the turn and correct that with a modest turn back to final for the last-second line-up.

To avoid painting yourself into this corner in the first place, adjust the break and the downwind to allow plenty of turn room when you need to roll back toward final. It may take some practice to get this right. But it doesnt take much practice because yet another advantage of the overhead approach is that you have ongoing opportunities to fix what doesnt look right with the choice of an earlier or later turn, a steeper or shallower bank and a range of airspeed.

In any case, keep the turns coordinated and dont try to cheat with top or bottom rudder combined with opposite aileron. At slow airspeeds, this can be an invitation to a classic over-the-top stall spin.

Remember, too, that turn radius is a function of airspeed. For equivalent wing load factor as determined here by bank angle, doubling the airspeed quadruples the turn radius. What this means in practical terms is that you dont have to fly an overhead at the speed of heat. You can poke around one at 65 knots, with flaps down, adjusting turn points and bank angles accordingly. (At the slower speed, the required bank angles will be shallower to achieve the desired turn radii.)

Practice It
In my view, even if you cant fly one for every landing, there is no better way to get an airplane on a runway then an overhead approach. The military favors these approaches because they are efficient. An entire four-ship formation can recover in a fraction of the time it would take if they flew four-mile straight-ins or conventional rectangular approaches. (When youre in a F-14 with 20 minutes of fuel remaining, this sort of thing matters.)

If you fly the occasional overhead or make the modified overhead described above as your standard approach, what youre really doing is constantly sharpening your ability to put the airplane on the ground where you want it, without power and without under or over shooting. This yields better landings in general but it also maintains the critical emergency landing skill you might need some day.

Last, theres always this: an overhead is a hell of a lot more fun than a stodgy squared off approach. And isnt that why we spend so much time, money and effort doing this stuff?

Also With This Article
Click here to view “Eyes Outside the Cockpit.”
Click here to view “Putting the Unconventional to Work.”
Click here to view “Tricks and Traps.”

-Paul Bertorelli is an ATP, CFII and editor of The Aviation Consumer.


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