Specifically for a piston general aviation aircraft, is there a recommended distance from the runway to fly the downwind leg? Does this change based on the speed of the aircraft?
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1$\begingroup$ I usually fly my down wind in the 172 about 1/2 mile from the runway. Really depends on TPA and speed, usually you can figure out based on your base to final turn. If you are turning too hard, increase the distance. $\endgroup$– Ron BeyerFeb 25, 2016 at 22:32
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1$\begingroup$ Related: Why is “dragging it in” considered bad in small aircraft, but fine in larger aircraft? and this one even has an answer which answers your question: What is a two- or three-mile base exactly?. $\endgroup$– LnafzigerFeb 26, 2016 at 1:16
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$\begingroup$ I don't think most people really think in terms of distance from the runway. At least I don't: I just fly where it "looks right", which is something you pick up in training from an instructor who's telling you to fly the downwind where it "looks right". $\endgroup$– jamesqfFeb 26, 2016 at 20:33
4 Answers
Most instructors say that (in a low wing plane) you should see the runway on the tip of the wing or between the tip and 1/4 in the wing. AOPA has a nice over view of non towered airports here. This FAA brief states it should be flown 1/2 to 1 mile out (page 7-4 of FAA Airplane Flying Handbook, FAA-H-8083-3B).
This leg should be approximately 1/2 to 1 mile out from the landing runway, and at the specified traffic pattern altitude.
There are multiple considerations, among them:
- Other aircraft in the pattern (that may be slower or faster than you): you want to maintain your position, not getting too close to planes ahead of you, nor slowing down planes behind you.
- The descent rate of your aircraft: I was taught to descend 25% from TPA on downwind, 25% on base, and 50% on final. (typically from a 1,000 ft TPA, that is 250ft / 250ft / 500ft)
- The turning rate of your aircraft: You want to make rectangular shaped patterns. If you are too close, your patterns will be more oval shaped. If you are too far, you will have a very long base leg.
"Within gliding distance" is one common rule that many instructors teach. It would be embarrassing to have an engine failure in the pattern and not make it to the runway :-) More seriously, you tend to make a lot of configuration changes in the pattern so the risk of something going wrong is higher, therefore within gliding range is usually a good place to be.
That doesn't mean being in a position to glide the remaining downwind, base and final legs to land neatly on the numbers: it means gliding to somewhere on the runway you can safely land (or even to a taxiway if need be). (The FAA's commercial pilot test standards require the applicant to glide to a landing from the downwind leg starting at 1000 AGL.)
Of course, there are lots of variables and you may have to fly a wider (or tighter) pattern at certain times or at certain airports for any number of reasons: traffic, ATC instructions, noise abatement etc.
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1$\begingroup$ I don't quite follow this. On a normal circuit, I can land on the runway threshold only if I lose the engine shortly after turning base (i.e. where I'd close the throttle anyway). If the engine fails any time on downwind, if I want to land on the runway in the correct direction, I'm going to be touching down some distance along it - possibly too far along to make a safe roll-out. Being able to glide to the runway doesn't seem to be a huge advantage in that case. $\endgroup$ Feb 26, 2016 at 14:34
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$\begingroup$ @DanHulme I updated this based on chat comments $\endgroup$– PondlifeFeb 26, 2016 at 15:42
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$\begingroup$ This is an old thread, but I gotta comment on "gliding distance from runway". Depending on aircraft, this might be very close to runway, assuming normal pattern altitude of 1000ft agl. Not that many common GA aircraft have good gliding properties, and considering all the risks involved in 180 turn at low alt + engine out, I personally would be hesitant turn back unless I had a DA40 or some other slippery plane under me... $\endgroup$– Jpe61Dec 24, 2020 at 14:03
If you lose an engine on downwind, you modify the rest of your pattern immediately to keep your aiming point on the windshield at the distance to your landing point. The pattern will no longer be square, but a continuous descending arc that ‘cuts the corners’ and terminates on a very short final to the runway.
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$\begingroup$ This doesn't answer the stated question. $\endgroup$– Ralph J ♦Dec 24, 2020 at 14:44
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$\begingroup$ Welcome to AviationStackExchange. Although your answer describes a power out landing, it does not answer the specific question asked. Once you have enough reputation points, you can post this as a comment, instead. Otherwise, this answer may be deleted. A more appropriate answer would be to fly a standard traffic pattern far enough away to have a sufficient base leg, but close enough to perform a power off landing from your current altitude anywhere along the downwind leg. $\endgroup$– Dean F.Dec 24, 2020 at 17:55