Advice - Tight Circuits

[junction34]

Hi All,
I'm looking for some advice/tips on making my circuits better - I've had the PPL since the start of the year, and would like to try and make my circuits a bit tigher.

The procedure as taught (PA38) is a 70 knot climb, at 500' 15deg AOB turn onto crosswind. Continue climbing to circuit height, then accelerate slightly and make a 30deg AOB turn onto downwind. Turn base (30deg AOB) when the landing spot is in the 8 o'clock position, slow to approach speed and first stage of flaps, then no more than a 15deg AOB turn onto final, established above 500', full flaps and continue down to landing.

Obviously, when there's traffic about it's a different matter and I don't have a problem fitting in, but left on my own the above procedure is what I'm aiming for.

However, I downloaded a GPS trace into Google Earth, and my downwind is almost 1 NM from the runway - rather too far IMHO. My final started about 1nm from the threshold at 500' aal. This means at the downwind/base turn I'm almost 2 nm from the centre of the field.

The direct cause of the downwind spacing is climbing to circuit height on crosswind - is it acceptable to turn earlier on crosswind and continue climbing downwind? Also, how about reducing power and starting the descent before base turn? (With both of the above I'd be limiting the AOB to 15deg as I'd be at 70kts rather than approx 85)

What would you consider "best practice" in the circuit?

Thanks for any advice and sorry for the long post.
-j34-

[Mark1234]

I'm no expert - freshly minted PPL, however, flying a 172 I've been taught similar, with the exception that there was no 'ciruit height before downwind' mandate - turn downwind was made when it seemed appropriate.

Normally that started a bit under circuit height, and had me levelling off around the turn completion. Never looked at a GPS trace to see what the numbers are, but with a closer base, your 8 o clock (I'm generally about 45degrees) may need to change - cramping the base too much will make it more difficult to stabilise the final.

[18greens]

In a low powered ac you can turn down wind before hitting circuit height to keep it tight. Make sure its a 15 - 20deg climbing turn.

As for landing don't throw height away early, you may need it if the eng fails. You can do a glide approach from the base turn. That is as tight as it needs to be. The theory with the circuit is you should be able to glide to the field from downwind if the engine fails...

Other options are to negotiate a lower circuit height (microlights use 500, why can't aeroplanes?)

Of course you need to follow everyone else so if they are flying big ones then so do you. A sneaky option is to ask for an orbit on downwind if it looks like the final approach will be at 3 miles (providing no-one is behind you). I also knew someone who used to climb on downwind if it looked like it was going to be a long final due to ac ahead doing long finals in order to keep in gliding range of the field.

Ideally everyone would fly super tight RAF circuits but they don't. Welcome to civil aviation.

[TotalBeginner]

I struggle to make my circuits tighter just because of the aircraft type that I fly. I trained for my PPL on a C-152 but am now flying a PA28 Archer III.

The C-152 has barn-door sized flaps and can make quite a steep approach. The PA 28's flaps are a little more modest however and I find it very difficult to slow down and make a reasonable descent in this A/C. Does anyone else have this problem, or any tips?

[Life's a Beech]

Actually what you describe is almost a perfect circuit as I once calculated, as a junior instructor wanting to know exactly what I was teaching. 1 nm downwind to almost 2 nm away sounds distant, but that is a nice tight circuit compared with many I have seen, and almost precisely what is taught.

I suspect you have realised that there is a lot of circuit where an engine failure would result in a land-away on agricultural property. Always keep an eye on the fields around the climbout, up to the downwind turn, and then near the turn onto base. There is no way to stay within gliding range of the airfield and fly a sensible square circuit. Alternatively take the far more sane military view and fly oval circuits. They're much easier.

[flybymike]

In my opinion there is a little too much veneration of "tight" circuits. The justification for a tight circuit is allegedly to allow a glide approach to the runway in the event of engine failure in the circuit. The reality is that one is no more likely to suffer engine failure in the circuit than anywhere else, and yet we do not afford ouselves the luxury of a runway constantly nearby when travelling from A to B. For those of us flying turbo charged aircraft (especially) the risk of engine failure due to shock cooling caused by full power climbs followed by power off glides , greatly increases the risk of engine failure. There is no point in taking precautionary action against engine failure, if in doing so one is encouraging it!

[n5296s]

I can't see why you would want to climb to circuit height before turning downwind. The only rationale I can think of is so that you will not be climbing into traffic that is already established on downwind. However if the effect is that you are flying a wider downwind than the traffic in question, you can still be climbing into it anyway (as your crosswind intersects their downwind). It's not something I've ever heard of before. If you're flying something low powered (152, Citabria, etc) then you'll end up flying downwind in the next county!

Similarly it makes perfect sense to start decsending abeam the threshold, if there is no other traffic to fit in with. That's the way it's normally taught in the US at least.

The other day I was flying patterns in a Citabria, mainly to remind myself I can still fly a "normal" taildragger since the weather was too poor for acro. A lot of fun, but I ended up flying 500' patterns because otherwise it took forever to get to 1000', then it was time to start down because otherwise you end up flying a maximum slip all the way down final!

15 degree AOB sounds awfully shallow. I can see why people might teach it that way, so they NEVER get to watch their students stall and spin into the ground, but it's EXTREMELY conservative and imo it isn't good practice. I was taught to fly 30 deg banks in the pattern. I'd strongly recommend getting some stall/spin training so you feel confident about recovering if you ever DO get close to a stall. At 30 deg, stall speed is less than 5 knots higher than level so you still have a huge margin. I don't know the exact stall speed for a PA38 - I've only ever flown one once and I certainly don't plan to repeat the experience - but assuming it's below 50 knots, at 70 knots you won't stall until you reach 60 degrees of bank. Get an instructor and go try it, at altitude of course. Accelerated stalls are a bit of an eye-opener but once you've done a few you'll feel a lot more confident.

n5296s

[foxmoth]

15 degree AOB sounds awfully shallow. This is normaly taught as a restriction in the climb - but this is not because you might stall but because in most aircraft more bank kills the climb rate, more should be fine turning base and final.:rolleyes:

[IFMU]

I was taught to fly about 1/2 mile from the runway on downwind. I learned to fly in a PA12 and I used to line up the jury strut with the runway as a sight aid. I've never held a particular angle of bank, rather with eyes out the window I've used the bank angle I need to get to where I'm going. As you get the pattern tighter, the bank angles get steeper. You should fly within your comfort level, else any benefit from the tight pattern goes away if it causes an accident.

The speed of the airplane is a major factor in flying a tight pattern. What is easy in a C140, PA12, PA18, PA25 is pretty sporty with a PA28R. It's a lot easier to stay tight with something slow. I've never flown a PA38.

-- IFMU

[A and C]

How I wish that I could find a civil airfield that would let me fly a tight circuit, I am sure that the local NIMBYS and the flying club owners are working together to make sure that a circuit takes in at lease three counties.

The result of this is that most PPL holders are unable to fly any thing tighter than a three mile final approach in the landing configeration, I don't blame the PPL holders it is the training system that has been unable to teach them to do anything else.

It is a pleasure to teach in an enviroment that has an oval 800ft circuit, this enables the student to get 12 or 13 landings per hour with a turning final approach. It requires a lot of co-ordination from the student but as they don't know any different they rise to the chalenge.

Flying time to solo is lower that average but I suspect landings to solo is about the same.

The aircraft used are C152 & PA28 flown at POH speeds with + 5kt for the turning part of the approach.

[robin]

>>>>>In my opinion there is a little too much veneration of "tight" circuits. The justification for a tight circuit is allegedly to allow a glide approach to the runway in the event of engine failure in the circuit. The reality is that one is no more likely to suffer engine failure in the circuit than anywhere else, and yet we do not afford ouselves the luxury of a runway constantly nearby when travelling from A to B.<<<<

Not sure I'd agree with you totally here.

In the cruise we do have a bit of time to plan our landing spot, but flying behind a VW or an 0-200 on an icing day concentrates the mind a lot.

On bad days I have had the engine show signs of stopping almost the moment the power comes off for the descent, and the prop has stopped on finals before now - so I do keep my circuits tight and prepare for glide approaches

[flybymike]

So why fly circuits? Because downwind joins are the norm and overhead full circuit joins very frequent, and sometimes circuit practice or currency requirements makes 'em unavoidable. Just be kind to your engine when doing them though!

As for an aeroplane that ices up the carb as soon as power is reduced. I think I would swop it for something less scary but I can certainly see why one would want to hug the airfield in those circumstances.
Mike

[tmmorris]

Aha! Now I am sure who A & C is :-)

Quite agree that it has been a revelation for me flying the same 800ft/military circuit pattern. I now get frustrated when I go elsewhere (e.g. Stapleford) and have a little cross-country in the circuit.

FWIW I was taught 15 deg AOB in the climb but definitely 30 for nice sharp turns downwind/base/final. At Welshpool where I trained the circuit was high - 1500ft QFE - because of mountains. We extended our upwind leg and didn't start the crosswind turn until around 800ft, allowing for us to be at 1500ft as we turned downwind (mostly, though with a heavy instructor not always quite ;) ) At Kidlington the circuit is 1200ft QFE and sometimes there we wouldn't quite make circuit height until after the downwind turn, depending on ac performance.

Tim

[FullyFlapped]

So why fly circuits?
I don't, unless I'm forced to either as part of the landing process or being tested/revalidated/etc. I share Flybymike's complete lack of desire to boogle up the engine unnecessarily.

All I'd say to the OP is not to beat yourself up about exact angles of bank, distance from the runway etc (although we all do in the early days). The fact is that away from the home circuit, you're going to meet all kinds of different environments, and the only thing you really need to worry about is flying safely. That often means being able to adapt to a wide range of circumstances rather than doing it "by the book".

Nothing wrong with practice in order to improve, of course : how are your bad weather/someone's cut you up/b*gger me there's a deer on the runway/idiot pilot lining up when you're on short finals/"ATC: can you turn base immediate?"/"sudden silence" circuits ? ;)

FF :ok:

[waldopepper42]

How far from the downwind leg are you at your desired (i.e. closer in) turning point from crosswind to downwind?

I assume that in the climb to 500' you will be a couple of miles upwind of the threshold when you turn crosswind, so you still will be when you turn towards downwind (ignoring drift errors). That means you've still got a couple of miles to go before calling downwind to get that last little bit of altitude, and when you do call downwind you'll be exactly at the height people will expect you to be!

As long as you keep a good lookout for other joining aircraft as you climb crosswind (and if you don't, don't ever ask to take any of my family for a flight!) I can't see there being any problem, and you can experiment to find the turing point that suits you.

I wouldn't worry overly much in the early stages of post PPL by the way if your circuits are a little wide - it all comes together with lots of practice!

WP

[DFC]

Two ponts.

First the CAA policy is for aircraft not to extend downwind because the one in front has. If the one in front has extended downwind beyond the normal point for turning base and remaining within the ATZ then as far as the CAA are concerned they have left the circuit.

All aircraft should fly the standard circuit and if necessary go arround should an aircraft that has "left the circuit" rejoin on a striaght in and become a conflict.

Secondly, I get a lot of "my aircraft is fast so I have to fly bigger circuits". Not true in most SEPs and many Twin pistons unless you insist on flying the circuit at cruise speed. The arrow is very comfortable clean at 90mph or 80Kt (whichever you use on your ASI) which is only 2 knots faster than most C150s downwind.

As for tight circuits - the usual issue is to be in a position to glide back onto the aerodrome not necessarily the runway during the early to late downwind leg. By definition if not doing a glide approach, the aerodrome is mostly beyond gliding distance late downwind, base and final. Similarly don't turn back in an EFATO puts the field out of possible options until one is almost into the crosswind to downwind turn.

Having a reference point on the wing or the strut where one puts the centerline provides automatic adjustment of distance from the runway regardless of height when downwind.

Keeping everything within 2nm is not bad for the average SEP or light twin. Doing less is type and experience dependent and one must not get so engrosed in keeping the procedure so tight that the checks are rushed and lookout less than required.

Far better to have turn from crosswind to downwind based on circuit position (ground location) than some height that will happen in random positions depending on wind, performance etc etc This helps contain noise and keep the neighbours happy. Same for base leg when doing powered approach.

I would not be so hard on using a figure of must be 500ft or above turning final as this is totally dependent on distance to run, wind and type of approach.


Regards,

DFC

[DX Wombat]

How I wish that I could find a civil airfield that would let me fly a tight circuit,Try Halfpenny Green (EGBO) :ok:
First the CAA policy is for aircraft not to extend downwind because the one in front has. If the one in front has extended downwind beyond the normal point for turning base and remaining within the ATZ then as far as the CAA are concerned they have left the circuit.
This happened to me as a student. Another 152 ahead of me downwind extended a long way beyond the circuit and out of the ATZ so I turned onto base at the usual point and then onto Final and made my call. Shortly after turning onto final the FISO asked which one of us was first (you can't read the registration mark from that distance and were were both mainly white in colour.) The other had turned onto final and hadn't made a call. I said I could see nothing ahead of me so thought I was first and that I thought the other aircraft had flown on elsewhere as it was so far outside the ATZ. It turned out to be another student on a QXC from a different airfield and she decided to go around. I gathered later that the FTO at her airfield teaches them to do enormous circuits - NOT a good idea when visiting an airfield where more normal sized ones are flown. :\ As it happened, she was so far behind me that I was well clear of the runway and almost back at the parking area when she went around. :hmm:

[Contacttower]

Secondly, I get a lot of "my aircraft is fast so I have to fly bigger circuits". Not true in most SEPs and many Twin pistons unless you insist on flying the circuit at cruise speed. The arrow is very comfortable clean at 90mph or 80Kt (whichever you use on your ASI) which is only 2 knots faster than most C150s downwind.



I do find this slightly irritating...I was behind a Baron 58 in the circuit today and he flew way downwind. But there is very little one can do except follow them.

[junction34]

Thanks all, some good discussion so far.

I think turning downwind before reaching circuit height is probably the best place to start to keep the downwind closer in.

I had never considered the 15deg limit could be related to climb performance rather than stall margin. The PA38 stalls at 52kts clean, the stall speed at 30deg should be 56kts so 70kts should still give a good margin. However, I'll stick with 15deg base/final turn.

I see both sides of the "within gliding range" argument, my method so far is to keep a little bit of power on and use the flaps from the start of the base leg with full flap on final. Still much steeper than the PAPIs though - not dragging it in with loads of power.

TotalBeginner - I've not flown a PA28, but when getting back in the Tomahawk from a 172 the flap difference is noticeable. Hopefully someone will have some advice for you regarding the Archer - good luck!

-j34-

[C-dog]

Having a reference point on the wing or the strut where one puts the centerline provides automatic adjustment of distance from the runway regardless of height when downwind
DFC is absolutely correct. I did my PPL on Tomahawks at a field with an 800ft circuit height. For LH circuits the filler cap on the left wing in line with the runway on the downwind leg meant you were where you should be.
Threshold 45 degrees over your shoulder was the turn on to base.
I was also taught (and it was in the States) to bung on the first stage of flaps downwind abeam of the threshold and trim out the control forces accordingly, rather than on base when the workload is starting to get a wee bit higher. Subsequent use of flaps was dependant on the conditions during approach, full flaps not necessarily being needed, but the trim change needed was and still is not nearly as much as that inital one.
Of course at 800' circuit height approaches tended to be powered as much as glide, but even now 20-odd years later I rarely use my Cessna barn door full flaps untill I'm over the fence and committed to landing.
If you are trying to tighten circuits at your local airfield then use ground features to mark the corners of the circuit. Certainly works if you don't have other aircraft ahead of you to worry about.
C-dog

[Chuck Ellsworth]

A tight circuit in a small trainer such as a Cessna or Piper is about one minute from touch and go to touch and go...but you have to have the airport all to yourself.

[flybymike]

And no buildings or obstructions above 50 feet...;)

[beeped]

I was taught to make a climbing (10-15AOB) turn after reaching 500' on the upwind leg. If all goes well I'd end up reaching downwind at or nearly at 1000'. T/O flaps would come down once established downwind and turn base when the trailing edge of my wing is about 3 wing chords from the threshold. Full flaps would normally come down just after passing 400' on finals.

Then again it's all pretty leisurely as I have an 11000' runway (RWY21/03 WMKL) to practice on - the traffic's no fun though. There can be 4 a/c holding in the circuit to allow a scheduled arrival to land (normally an a320/a330/b737) plus 2 more aircraft holding in the training areas and 1 more somewhere west of the airfield. Add the controller telling you to maintain the upwind leg for 2 minutes due to traffic - when there are mountains right at the end of RWY03.

:}

[IFMU]

A tight circuit in a small trainer such as a Cessna or Piper is about one minute from touch and go to touch and go...but you have to have the airport all to yourself.
The tightest circuit's I've done is in the pawnee on a ridge soaring day. When the gliders cut loose before the end of the runway, I'll do a chandelle once I hit the ridge lift, I'm at 800' in a blink. During the turn I start reeling in the rope. The wind, 20 kts or more on the ridge makes the downwind go fast. Then once you survive the washing-machine final it's all over. I don't know how long that takes, I've always been too busy flying to notice.

Gliders fly tight patterns too, even though there is no worries about engine failure. Another interesting bit of trivia is that gliders at our club have been known to do T&G's on ridge days. I've never personally witnessed it, or tried it, but have heard of it. I have seen low passes on ridge days before.

-- IFMU

[Chuck Ellsworth]

Circuit height and size is usually determined by location.

Airports, especially controlled ones will almost always require a circuit size to fit the traffic using it.

Sea plane training on the other hand lends its self to making your circuit fit the training desired, I find a 300 foot above the water and three minute circuit to be optimum for training.

[SoundBarrier]

Circuit height is also dependent on airfield elevation...I did my initial training on an airfield 5000ft above sea level in a cessna 150, and many a time we rarely got to circuit height given the hot and high conditions.

If I were to try and make my circuits smaller I would just ensure, as other posters have eluded, that all your turns are not too tight and that you're well away from the stall. Which incidentally doesn't mean that you must fly the whole thing at 50'! :)

What I can say is . . . practice and the more comfortable you feel the better you'll become and of course never be overconfident. I was once, luckily it was on my BMX when I was a kid.:}

[D120A]

Just to lighten the mood a bit, and please don't try this at home...

The late Air Marshal Sir Kenneth Hayr wrote that when he joined his first Hunter squadron, the lads were having a competition to see who could fly the shortest circuit. He said "Someone got it down to 22 seconds, before the Boss put a stop to it."

Happy days! :)