What hight to turn final?

[ChiSau]

As a relatively low-hour PPL contemplating flying to a number of different airfields this weekend, can I check how everyone flies a standard circuit?

I'm used to my homefield, where we fly a 750' aal circuit with a relatively short final approach. For that I aim to be turning final at about 500' aal.

For airfields with a 1000' aal circuit, are you guys doing the same thing, but therefore losing 500' on base leg? Does that mean you fly a larger circuit pattern as a result?

Grateful for your input as always and here's to CAVOK, no haze and gentle breazes! :cool:

[Hersham Boy]

Really depends on the individual field and runway... at my home field we have one runway that you can comfortably turn final at 1000' on QFE and one that you need to be closer to 400'.

Personally, I try and have a height benchmark closer to the threshhold and start looking for that on base leg. That way I have an idea about when to start descending before I get that 'never-going-to-get-it-down-better-go-around' feeling :D

Hersh

[QDMQDMQDM]

For airfields with a 1000' aal circuit, are you guys doing the same thing, but therefore losing 500' on base leg? Does that mean you fly a larger circuit pattern as a result?

We've discussed it on here before, but personally I think learning to fly would be a lot easier if all circuits were close in, racetrack pattern at 500 feet max. These 1000 foot square circuits are actually really difficult to fly, at least partly because they're taught by the numbers -- turn final at 'x' height etc. It just complicates things.

QDM

[FlyingForFun]

Depends on everything from the field and runway, to the traffic in the circuit, to the aircraft and the pilot's preferences.

In the Super Cub, my prefered approach, noise-abatement permitting, was a very tight circuit, cutting the power completely and putting in full flaps when, or before, abeam the numbers on downwind for a 1000' circuit, or later for a lower circuit. Then I'd turn final fairly close at just a couple of hundred feet.

Compare this to the Europa, which is not a particularly good aircraft for side-slipping. Beacuse of this, I prefer to approach slightly flatter with just a bit of power, which gives me the option of reducing power if I find myself too high (as opposed to slipping which I would do in the Cub). This is particularly important on a short field, but I might approach power-off instead if the approach is over a built-up area to ensure I can make the field if the engine quits. I also prefer to turn final slightly further out (and therefore higher) because I have a couple of checks to do on final (prop pitch set for go-around, gear down and locked).

Then there's the Aztec, an aircraft which I never really got to grips with in the 5 hours I spent flying it. But one thing I did learn is that if I turned final too early or too high I was screwed - its weight and momentum meant I needed a much more stable approach than I'm used to in the aircraft I usually fly.

Very often a published noise-abatement circuit will ruin all the best plans. There's no way you can do a Cub-style short final approach if there's a noise-sensitive village just inside base leg that you have to fly around.

As for traffic, well, all bets are off. Hopefully you can judge your circuit speed early on in the circuit to be able to turn final where you want to. At ATC fields, though, with some traffic joining straight-in, you probably won't be able to plan until ATC tell you whether you're in front of or behind the straight-in traffic. The chances are you'll be behind them, but if you plan for that and are then cleared number 1, you might have to lose height in a hurry!

There are no rules for this kind of thing - at least not unless you're going to fly airliners. Do whatever seems right at the time - and don't be afraid to admit you got it wrong and go around for another try if necessary!

Good luck, and have fun! :D

FFF
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[knobbygb]

I like to fly the circuit as tight as possible - nice to be able to glide in if you lose power. I'm only low-hours but I admit to getting frustrated at these 'bl00dy learners' who fly huge circuits - I then remember that I was in that position not long ago and remember just how high the workload seems at first and chill out.

To be honest, I've never considered what height I should be turning final - it sort of comes by instinct - whatever seems right on the day. If you try to do it by the numbers it just wont seem 'natural'. You ought to proctice both scenarios with an instructor - coming in low on the wrong side of the drag curve and being way too high and slipping-in for the numbers. That way you'll cope whatever happens and wont let it worry you.

Chill out - if you're at a new field and there's somebody local in the circuit - follow their lead. If there's nobody else there, do it your way and nobody'll be affected if you get it a bit wrong. Once you've been to a couple of strange fields you'll wonder what you worried about.

[matspart3]

My home airfield (where I think you did your QXC) has a 1000' circuit but I honestly don't think I've ever looked at altimeter after the end of the downwind leg. I've flown short and long approaches, to fit in with other traffic and never really thought about my height at a particular point of the approach, unless it all starts looking wrong.

I think there are too many variables, e.g aircraft performance, configuration, surface wind etc. to plan the circuit 'by numbers'. As long as you fly the right approach speed, you'll always be able to get the height off by S turns or sideslipping. There are plenty of visual cues to tell you if things are working out or not and never be afraid to go-around...it doesn't mean you've cocked it up, it's a good decision!

Have a good weekend...hopefully you're coming back to one of your QXC haunts!!...Buy some fuel & you'll get a cheap landing fee!

BTW, I'm not an instructor, and with 170 or so hours, by no means an expert!...in fact, maybe I'm just gash!!

[topcat450]

For what it's worth I learnt at a field with 1000ft circuit....my approach was aways turn base at 1000ft...pull off power...slow down...1 stage flap and start decent. Aiming to be around 700ft when turning final and adding a second stage of flap (that was in a C150 at a longish runway so rarely used full flap).

At the end of the day, on your first attempt you'll learn pretty quickly whats looking good, and remember a go-around is great practise...its just like a landing but without the fee. :)

[Whirlybird]

I learned to fly at Welshpool (f/w that is, not rotary). 1500 ft circuits, because of the hills!!! And you still turn final at 500 ft. I thought it was normal to bring back the power in the turn on to base, and to find it very difficult to lose the height before turning final. It isn't so bad in tomahawks, which I learned on, but in Cessnas! :eek: Now I descend a little on late downwind, while still being careful of the hills. But I wouldn't teach a student to do that, not at Welshpool; you just don't have enough margin for error. So I suppose what I'm saying is that there are lots of different ways of doing it, and it doesn't have to be done by numbers. But initially, that's probably the esiest way to learn.

[singaporegirl]

I was taught similar to topcat, at an airfield with a 1000ft circuit, viz:

In an ideal world the downwind leg should result in the inside wingtip appearing to run along the middle of the runway. When the runway threshold is at 4 o'clock (or 8 o'clock, depending on direction of circuit), turn base, still at 1000ft. Reduce power when threshold is at 45°, two stages of flap when speed is in white arc. Aim to be at 600ft by the time you've turned onto final and straightened up.

But that was in a PA28/AA5 Cheetah. In faster aircraft I'm having to reduce power earlier. And of course it's rarely an ideal world, thanks to wind, other people in the circuit, etc ;)

[High Wing Drifter]

With reference to the alty I am with matspart3. I was taught swap my view between the runway and my ASI continually throughout the approach. Really, I seldom feel the need to look at the alty once I have turned onto base.

[tacpot]

Most circuits as taught by instructors seem to end up with the aircraft established on finals at 400'. Beginning a turn at 500-600' would therefore seems a sensible height to begin the turn onto finals at.

With the exception of circuits that are widended for noise abatement, we will be flying circuits exactly the same shape (in plan) as your own, and as you say, we just start descending earlier to end up as the same place for finals.

[Evil J]

Perhaps I'm just gash as well, but if I got the circuit to myself I don't really care what sort of circuit I fly, if I haven't then I fit in and in both cases as long as I'm stable and set (in the slot I believe is the trendy phrase from the CAA safety evening!!) by 200 ft I'm happy.

That is not to say I fly sloppy circuits just that I may fly a military oval circuit (to remind me how I used to do it!!!) or even a run and break if I can (doesn't look all that punchy in a PA38!!) to a bad wx circuit and possibly flapless too. For that matter I cant remember the last time I did a normal circuit....(when the circuit was clear anyway!!)

[Flyin'Dutch']

ChiSau,

The easiest way to tackle this one is to get an instructor or experienced safety pilot to come with you in the RHS and cover up the altimeter after going onto the downwind leg,

That way you will learn (and you will be surprised how quick you will master this art) to judge the perspective. If it looks good it will be good.

Trust me........

Have fun

FD

[The Cook]

I agree with QDM

As a mil type most ccts are based on 'gates'. A 300 ft gate with wings level and a sensible G/S means a gate at 90 deg to go at a height of your start height, minus 300 ft, divide by 2 then add to 300ft..adjust at 90 deg if not in the right place. Of course if someone has extended downwind.....

Oval ccts are certainly easier to fly, they ensure you remain visual with the runway at all times and therefore all other players. It also means that a route plan is not required for a ccts bash. Mind you, we fly downwind at 220 kts.

Good luck and keep looking out.:ok:

[Canadian Luscombe]

Due to my natural sloppiness, I don't worry about turning final at any particular altitude; I just keep looking out of the cockpit and visually judging when/where I need to turn.

I often tend to come in slightly high on final, but a slip always takes care of that. If low (rarely happens), I add a touch of power.

In any case, it's best not to get in the habit of relying too much upon the altimetre for circuit decisions ... won't do you much good if you have to make a forced approach some day. The only instrument that I check once having turned base is the ASI (and VSI, if flying a glider).

[Perfect PFL]

Having learnt to fly in bulldogs on a UAS my preference is also to fly oval circuits like a few others have said.

I was taught to fly the part of the circuit from the end of downwind to landing visually, all on the angle to the runway being correct.

The way this works out in practice (for an 800' circuit) is to fly downwind until the threshold is at an angle of 45degrees behind you, then reduce power and begin your turn. One continuous turn onto finals, aiming to be halfway round at 600', and rolling level on finals at 400'.

I personally think this is the best way to fly a circuit, much better than the square circuits people seem to be taught to fly in civil flying clubs.

I would always fly an oval circuit for a glide circuit, as if I ever had an engine failure I'd fly an oval circuit, as the "sight-line angle" is the best way to achieve the correct landing position during a forced landing, imo. When being taught during PPL instruction, how are you taught to fly a circuit for a PFL / glide circuit / real forced landing? I did my PPL at a military airfield, so am not sure how it is taught by a purely civil club.

[phnuff]

I was always taught 500' QFE however I really think that it varies airfield to airfield. There was (still is ?) an southerly runway at Fowlmere which demanded a late final (150-200ft) because of a bird reserve (Pooleys not to hand, is it still there ?) . The one I always find a bit unsettling is Luton 08 if you get asked to orbit left base. Going around and around at 500ft above Luton town centre is alarming in case something goes wrong. I generally orbit somewhat higher and praise the fact that Luton has a good long runway and that ATC there are as good a bunch of guys as infest control towers anywhere in the universe (grovel)

[foghorn]

Ideally aim to start the turn after 600'QFE to be straight in by 400-500'QFE. On a 3 degree descent that should give you 1.5nm to touchdown, nicely inside the ATZ.

Of course 'ideally' here is based upon lots of assumptions to do with other traffic, ATC requests, noise sensitive areas, local controlled airspace, bad weather, etc. etc. etc.

I agree with HWD the most, though, once you are in the descent and on base leg on a visual approach, runway-airspeed-runway-airspeed is more important than watching the altimeter. It's best to learn early to judge how you're doing from the aspect rather than 'standard' circuits.

[Monocock]

Correct me if i'm wrong but surely this whole subject is a "moveable feast". There is no ideal height for turning finals and it surely must never be beleived that there is.

If you are flying in "calm" condotions your height loss will be slower per "minute" than if you have a 5 kt wind or a 15 kt wind.

Is your final a 2 mile one or a half mile one?

Is you AUW near the limit or are you alone with quarter full tanks?

What a/c are you flying, a high wing "floater" or a low wing "rock"?!

Whats your HASL at your airfield, sea level or 2000ft?

Surely there can be no hard and fast rule for all these variations?

Speak to your instructor, he will explain all.