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Thread: Lazy pattern is forward thinking.

  1. #1

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    Lazy pattern is forward thinking.

    I once got kidded that my rectangular pattern is more like a race track.

    Turns out my curved out corners (which is mostly due to flying closer in patterns) may actually be a safer way to do things.

    https://www.aopa.org/News-and-Media/...lized-approach

    The hypothesis to be studied is that in contrast with a rectangular pattern, a continuous turn from downwind to final may provide for increased stability, reduced pilot workload, and a constant bank angle throughout the maneuver, helping pilots better manage angle-of-attack variances. Additionally, the use of a continuous turning approach has the potential to reduce the likelihood of overshooting a runway during base-to-final turns, a scenario that has resulted in multiple stall/spin accidents due to aggressive corrective maneuvering. Depending on the results of the study, this procedure may serve as a mitigating technique to reduce the likelihood of loss-of-control accidents during the landing phase of flight.
    I think they're going to hit into some problems with the study, owing to the difference in aircraft out there.

    For little LSA aircraft like mine, I'm in the "continuous turn" camp (but still call base and final - let's not deviate too far from things), as low speeds make a closer half mile from the runway pattern better for a host of reasons. It also means less distance for turns, so the corners get chopped off.

    Now, then, my friend's newly built KR2 is a hot little aircraft (on final he's exceeding my Vne), and if he flew my pattern he'd be dead. Naturally his pattern is much larger than mine, and so the standard rectangle is just fine, and has some advantages. With more than just a throttle, stick, and rudder to worry about, he has to do stuff with levers, wheels and pushy-pully things attached to his dash board and other parts of the cockpit, and that time is invaluable to him and the "corners" are mental cues that develop into muscle memory.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

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  3. #3

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    Quote Originally Posted by Frank Giger View Post
    Turns out my curved out corners (which is mostly due to flying closer in patterns) may actually be a safer way to do things.
    I have no doubt that it is safer, and have been flying my patterns with much larger radii turns and a minimal level base leg for a long time.
    Quote Originally Posted by Frank Giger View Post
    For little LSA aircraft like mine, I'm in the "continuous turn" camp ... Now, then, my friend's newly built KR2 is a hot little aircraft (on final he's exceeding my Vne), and if he flew my pattern he'd be dead.
    If he (or I, in my COZY MKIV, in which I fly my pattern between 90 KIAS and 80 - 75 KIAS on short final) flew at TIGHT a pattern as you're flying, we'd need some pretty steep turns, for sure and that would be dangerous. But no matter how large the pattern is, a rounded downwind-base-final turn, rather than two turns with a level period between them, will provide a lower bank angle, less probability of overshooting and skidding around the base/final turn, and a more stabilized approach, since you're not changing bank angle four times, but only twice. So I'd argue that this type of pattern will benefit high speed aircraft with larger patterns as well as slower aircraft with smaller patterns - in either case, the radius of the turn is larger than a "standard" pattern and hence the bank angle lower, and the approach more stabilized.
    Quote Originally Posted by Frank Giger View Post
    With more than just a throttle, stick, and rudder to worry about, he has to do stuff with levers, wheels and pushy-pully things attached to his dash board and other parts of the cockpit, and that time is invaluable to him and the "corners" are mental cues that develop into muscle memory.
    I'd say that having do do less with stick, throttle and rudder gives more time and mental energy to the other pushy-pully things. It's still fairly obvious where you are in the pattern, since you're always looking at the runway to see your relationship in any case.

    Personally, I think that recommending this type of pattern and teaching it to everyone WILL be a step forward and upward in safety for all types of aircraft.

  4. #4
    Mayhemxpc's Avatar
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    Quote Originally Posted by Marc Zeitlin View Post
    I have no doubt that it is safer, and have been flying my patterns with much larger radii turns and a minimal level base leg for a long time.
    If he (or I, in my COZY MKIV, in which I fly my pattern between 90 KIAS and 80 - 75 KIAS on short final) flew at TIGHT a pattern as you're flying, we'd need some pretty steep turns, for sure and that would be dangerous. But no matter how large the pattern is, a rounded downwind-base-final turn, rather than two turns with a level period between them, will provide a lower bank angle, less probability of overshooting and skidding around the base/final turn, and a more stabilized approach, since you're not changing bank angle four times, but only twice. So I'd argue that this type of pattern will benefit high speed aircraft with larger patterns as well as slower aircraft with smaller patterns - in either case, the radius of the turn is larger than a "standard" pattern and hence the bank angle lower, and the approach more stabilized.
    I'd say that having do do less with stick, throttle and rudder gives more time and mental energy to the other pushy-pully things. It's still fairly obvious where you are in the pattern, since you're always looking at the runway to see your relationship in any case.

    Personally, I think that recommending this type of pattern and teaching it to everyone WILL be a step forward and upward in safety for all types of aircraft.
    This is mostly the way I have been flying (and teaching) for as long as I can remember. There is some math behind this. If an airplane is flying downwind one mile from the runway at 90 kts, then a standard rate turn will bring the airplane around 180 degrees one mile to the side of the turn, or lined up with the runway. (Calm wind.) A 30 degree bank would get you spun around in a half mile. 30 degrees, level off, then another 30 degrees gives you about 10 seconds of wing level flight, including the time it takes to get from 30 to 0 and back to 30. Not that I would ever recommend 30 degrees base to final. (With the admission that what I would recommend and what I have been known to do may not be the same thing.) From this, and imagining the effects of wind coming from different relative aspects to the plane, we can begin to see one reason why patterns can get to be much wider out that 1 mile (which is still pretty wide.) One turn, with runway in sight and continually assessing (what should be an ever decreasing) angle of bank required for completing the turn seems to be safer.

    Slower airplanes, of course, have tighter turning radii, but I think we are looking at a common pattern suitable for all likely users of the patter.

    On the other side of the argument, the level off theoretically allows for one more check to see if someone isn't coming in on a long or straight in final. You would do that during the somewhat less than ten seconds while lowering the flaps some more, doing another GUMPS check, assessing where your airplane is in relation to the airport, and managing your rate of descent and airspeed while changing angles of bank -- with associated G loads and vertical components of lift.

    Curiously, the USAF flying manual (Dash 1) for my airplane -- an O-2A -- shows a continuous turn from downwind to final as the normal approach path for both the "overhead" and "square" approaches in the normal procedures portion of the manual. The emergency landing procedure also uses the oval, continuous turn procedure. (I don't know, but I am guessing that the USAF thought it less confusing if flying around an airport or in preparation for landing was as standardized as possible.) In any case, this is not something new and there should be plenty of data already out there.

    I suppose that is a long way to say that I am supportive of the initiative.
    Chris Mayer
    N424AF
    www.o2cricket.com

  5. #5

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    I'm against the continuous turn for a few reasons, the main one being that you eliminate one last look to see conflicting traffic, which only takes 5 seconds. That 5 seconds only adds one tenth to two tenths of a mile wider pattern for 95% of the planes out there.

    And, you can still stall/spin in a continuous turn.

    If one just pays attention to basics they should not have a problem, regardless. Trim for the speed you want for the whole approach, do not change configuration after you put the gear down to go down, or start to make your descent by reducing power (if you don't have a retract), and if you need flaps, add them after the gear. Do not change the configuration until short final, when the field is make, and you're wings level, add flaps, reduce power, pitch to slow, flare and land.

    There's MUCH more risk if you change speed or add flaps during the approach. If you keep the speed constant, your trim will remain constant, JUST DON'T EVER PULL in the pattern until you're ready to land. As you turn, the descent will increase some but speed and trim remains constant. If you're going to undershoot, add power if you're going to overshoot, decrease power.

    If you overshoot, you can tighten the turn, BUT DO NOT PULL, if beyond your comfort zone, go around.

    And 95% of the planes out there, can stay within a mile of the runway with this technique. And if wind is a factor, we all adjust for it. Works.

  6. #6

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    Military overhead circle to land approaches are intended to get airplanes on the ground as quickly as practical, especially when there are unfriendly folks outside the airport fence taking shots at the traffic. Works really well when the tower and the rest of the aircraft in the pattern expect that.

    But now we get to the typical continental US towered airport where the pattern stretches for miles and the tower wants to "continue downwind and I will call your base", or on downwind says "make a 360 for spacing". All of that AOPA proposal goes out the window.

    The advice above to set up power and trim, stay on your trim speed, fly smoothly, stably, and keep the ball in the middle is best. Works for everything from Cubs to Gulfstreams.

    Best of luck,

    Wes
    N78PS

  7. #7
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    Flying into Copperstate in the SuperCub a few weeks ago Falcon tower had me flying 360s because I had traffic faster overtaking me. Like some how I was going to somehow run down that Velocity XLRG that went screaming past me at 200+ kts once we got into the pattern.

    FWIW, I do find the continuous turn to be useful in slower planes like my SuperCub where I typically fly very tight patterns. In my other plane, I often times come screaming into the downwind at 150 - 170 kts. I use the turn to base to scrub off excess speed and the turn to final to scrub off the last of the energy, drop the flaps, and hit my approach speed after I roll out of the turn. So I like two turns in the faster plane. If the tower wants me to keep it in tight in the fast plane, it gets very busy. In the SuperCub, the tower (at a near-by airport) usually tries to clear me to land while I'm on downwind just so they can watch me make the turn abeam the numbers and make the first exit from the runway. As a practical matter, I use both types of patterns at uncontrolled fields depending on which plane I'm flying, and have done so for many years.

    One thing to remember is that turns in the pattern are designed to allow pilots to see other traffic that may be above, below, or crossing in front of them. My home airport has a very unusual approach since it's one way in and one way out (opposing traffic) with restricted airspace next to the airport. So they want traffic to fly a straight in 6 mile final. With no turns, it's easy to have planes stacked vertically that don't see each other, especially if one of them plugs the wrong freq into the radio. Remember the stacked Bonanzas landing a few years ago? Yeah, that was our airport. Those guys proved the point about turns for visibility in the pattern.

    -Cub Builder

  8. #8

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    Quote Originally Posted by cub builder View Post
    Flying into Copperstate in the SuperCub a few weeks ago Falcon tower had me flying 360s because I had traffic faster overtaking me. Like some how I was going to somehow run down that Velocity XLRG that went screaming past me at 200+ kts once we got into the pattern.

    FWIW, I do find the continuous turn to be useful in slower planes like my SuperCub where I typically fly very tight patterns. In my other plane, I often times come screaming into the downwind at 150 - 170 kts. I use the turn to base to scrub off excess speed and the turn to final to scrub off the last of the energy, drop the flaps, and hit my approach speed after I roll out of the turn. So I like two turns in the faster plane. If the tower wants me to keep it in tight in the fast plane, it gets very busy. In the SuperCub, the tower (at a near-by airport) usually tries to clear me to land while I'm on downwind just so they can watch me make the turn abeam the numbers and make the first exit from the runway. As a practical matter, I use both types of patterns at uncontrolled fields depending on which plane I'm flying, and have done so for many years.

    One thing to remember is that turns in the pattern are designed to allow pilots to see other traffic that may be above, below, or crossing in front of them. My home airport has a very unusual approach since it's one way in and one way out (opposing traffic) with restricted airspace next to the airport. So they want traffic to fly a straight in 6 mile final. With no turns, it's easy to have planes stacked vertically that don't see each other, especially if one of them plugs the wrong freq into the radio. Remember the stacked Bonanzas landing a few years ago? Yeah, that was our airport. Those guys proved the point about turns for visibility in the pattern.

    -Cub Builder
    Cub,

    Interesting, but there is no need that the tower made you do multiple turns. It's a first come, first served policy. Who ever will get to the runway first, should be the one that the tower clears to land first. This is a bit of a judgment call on the towers part, but it should be fair. If you're doing 60 knots on a 2 mile final and a jet is going 250 knots over the marker, the tower should have the intelligence to realize that you will get there first and slow the jet, or have HIM do a 360 or S turns. At 250, that jet (to be anywhere a stabilized approach, by jet definitions) would have to be slowed to target speed about a mile out, which would take him a minute to touch down plus the minute and a half or more from the marker to slow to ~500 feet.

    If that happens to, a polite call to the tower with an explanation of speeds is appropriate. I've done that a few times. Often you can see it coming and offer a solution early like I can slow, speed up or take another runway.

    For a non towered airport, there's just no reason that anyone would come blasting into the pattern over 150 knots, and more likely 120 knots. There's very few civilian planes that need over 150 knots. Just shows bad form, sloppiness and inefficient flying.

  9. #9

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    Flying into Copperstate in the SuperCub a few weeks ago Falcon tower had me flying 360s because I had traffic faster overtaking me.
    Silly me, I thought slower aircraft had the right-of-way.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  10. #10

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    Like many others, I was initially trained in a Pt141 school. Then trained the Navy way at Saufley Field. "Rectangular" patterns, racetrack patterns. Gosh, what do you know, ordinary people trained that way can do either safely. Probably because nobody can actually fly a rectangular pattern in an ASEL. The corners are rounded. Not 90deg.

    Where is the reg spelling out the downwind leg distance from the runway for piston ASEL less than 6000 lbs? The traffic pattern altitude? The base leg, crosswind, length of final? The reg, not the best practices. With no other airfield traffic some folks fly close in on downwind, turn abeam the touchdown point, level the wings on base leg to check for NORDO traffic, roll final, and land - including a stabilized approach below 500AGL as the Friendly Aviation Advisors recommend for light piston-engine aircraft. Racetrack? Rectangular? A distinction without a difference. But certainly not a "lazy pattern". Be safe, be legal, be decisive and expeditious. Impossible to have a midair after you've landed. Your mileage may vary.
    Last edited by Mike M; 11-22-2016 at 10:09 AM.

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