Standard Visual Circuits

[bemused1812]

Hi, I wonder if you experts can help me. I’m an ex-military pilot. I have no GA experience, but recently I went to my local flying club, as I wanted to get checked out on a light aircraft. I have flown with two flying instructors. They have left me totally confused about a couple of things; amongst them the ‘standard’ visual circuit. Each seemed to have a different idea about how it should be flown.

In an attempt to clarify things, I’ve been looking up various references, on and off-line, to see how to fly a ‘standard’ powered visual circuit. The first thing that I have discovered is that there does not seem to be any such thing; something which seems to be borne out in the real world! The references are all delightfully vague and contradictory. But further than that, I can find none that actually ‘work’. By work, I mean that the described geometry actually works out.

Let’s take RD Campbell, author of the AOPA Flying Instructor’s Manual, which I understand is often considered an authority.

Campbell suggests climbing at Vx to a minimum of 500 ft, a climbing turn onto the crosswind leg and then levelling at circuit height (800 or 1000 ft). The turn downwind is made level using 30ºAoB ‘when at a suitable distance out from the runway’. He gives no clues what he considers the downwind spacing should be.

He suggests the turn onto base should similarly be made level at 30ºAoB ‘at a suitable distance from the touchdown area’. Elsewhere he mentions that the ideal point to turn is ‘when the intended touch-down point lies at an angle of approximately 45º behind the wing’. Presumably this is in still air conditions.

He then says that ‘the approach will be prepared at some stage along this [the base] leg’. So, at an unspecified point after rolling out on base leg, one should ‘select required power, select flap and adjust the attitude [for the descent].

There is no indication precisely where the finals turn should commence, other than the height should be 500-600 ft. He has already stated that all turns (other than the climbing turn onto crosswind) should be flown at 30ºAoB. After rolling out on finals the approach is flown straight in.

Now, this is my problem with this description. A normal approach is flown at 3º. This means approximately 320 ft per NM travelled. Let’s use a typical light aircraft base leg speed of 75 KT. The rate of descent required to achieve 3º is approx 400 fpm. At 30ºAoB the aircraft has a turn radius of 1860 ft, circumference of 1.92 NM and will take 23 sec to complete a 90º turn, in which time it will have lost about 150 ft. If it started at 500 ft, it will then roll out at 350 ft which equates to 0.875 NM. If the turn were started at 600 ft, the roll-out would be at 450 ft/1.125 NM. So far, so good (ther than the fact that we now have 2 'standard' circuits).

Between commencing descent and start of turn the aircraft must lose 400 or 500 ft, taking it 1 or 1.25 NM. The turn onto base leg and the finals turn will take the aircraft a further 3720 ft or 0.6 NM, plus the unspecified distance travelled after rolling out on base leg to commencing descent. Let’s say that is brief: in 10 seconds the aircraft would travel 0.2 NM. Add that all together and we get a downwind spacing of 1.8 to 2.05 NM. Does that sound right?

Well how about this. Let’s plot out the start of base leg turn point(s). If X is the distance along the extended centreline and Y is the distance in the direction of the downwind leg, then we know that Y is 1.8 or 2.05 NM. As the 2 turns cancel each other out in direction X, then the start of the base leg turn is the same distance from the touchdown point in direction X: 0.875 or 1.125NM. So the angle from the touchdown point to the start of base turn is either 23º or 32º aft of the wing. But wait a minute, didn’t Mr Campbell tell us that it was 45º?

I’ve tried other references. Some day that the downwind spacing should be 0.5 to 0.75 NM (woah, that’s some difference from what Campbell’s works out at). Many agree on 45º being the cue to start the base turn. Some say do a descending base turn. Most agree on about 500 ft being the turn onto finals height. Several suggest rate one turns (specifically argued against by Campbell). However, none are specific; they are all vague about the detail, and the reason is that none of them actually work, when one plots out where the aircraft would actually travel if their descriptions were followed.

Then another can of worms is opened when it comes to how to space from other traffic. I’ve read extend upwind (most would agree with that one), extend crosswind (so presumably have varying downwind spacing and delay descent on base leg by the same amount) and extend downwind (a total no-no for others).

The fact is that (assuming a 1000 ft circuit height) one must travel 3.14 NM from descent to touchdown (2.5 NM for a 800 ft circuit) unless doing a steeper approach. The final approach will account for 300-450 ft of descent, the 2 x 90º turns another 300-400 ft, so the base leg descent must be between 150 and 400 ft, which equates to 0.5 to 1 NM. Added to the turn radius x 2 (0.6NM at 75 KT and 30ºAoB, more at higher speeds/rate one) and you can see that the downwind spacing is a minimum of 1.225 NM (achieved by doing a descending turn with 30ºAoB and commencing the finals turn at 600 ft). Incidentally, this pattern is the closest to 45º from the touchdown point; but it is still a little less (42.5º). Most are considerably more. The only way to achieve closer spacing is a steeper descent or to extend downwind.

So, after all that waffle, my questions: what do you regard as a ‘standard circuit’? What do you use to judge one? What do you teach, and what are your sources?

And what has the esteemed Mr Campbell been doing all these years: dive bombing the runway or flying bomber circuits?

I have to say I’m totally bemused by this approach to aviation. Both in the military and the airline I now work for, standard procedures have been, well, standard. No grey, just black and white! That’s the point; isn’t it?

[Duchess_Driver]

You are correct that there is no such thing as a standard circuit - as (mostly) the circuit is determined by airspace constraints (vertically and laterally), by noise abatement procedures and by local procedures.

Whilst prepping a student for first solo we fly a standard LH or RH circuit with reference to clock positions (8,4,2 and 10) and back up that with ground tracks. Much of this is confirmed (at home base) by reference to ground features to ensure noise abatement/airspace etc.

The difficulty in GA comes when you start to 'land-away'. What works at your home airfield may not fit in with the procedures at your destination. The generics need to be adjusted to fit what ground tracks and features you can gleen from Pooleys/AFE/AIP information and/or a PPR briefing.

When turning final its a variable feast again. We aim to start the turn at about 500' AGL rolling out about 350' but where the turn begins is obviously a factor of wind with reference to the position of the runway in the side window (vertically as well as laterally). In our SOP's it's a MAX 25degree AOB turn onto final, but thats a minor point. And a 3degree glideslope.... mostly a myth in GA.

I'm sure that you'll appreciate all of that anyhow, but there are far more variables at GA airfields than there are at military - and far more 'standards' being applied. There is, unfortunately, no civilian CFS!

HTH

DD

[S-Works]

And to throw into the pot a standard visual approach fir a light GA aircraft s not 3 degree either. That's a standard instrument approach.

A visual approach angle for GA is whatever is appropriate for the type and the field.....

[Whopity]

A normal approach is flown at 3º. This means approximately 320 ft per NM travelled. Normal in a larger aeroplane, but what if you have an engine failure? Whilst some pilots may fly a 3 degree approach, it is more common to fly a 5 degree approach in light aircraft, commencing at 1nm from touchdown at 500 ft. When I taught MOD flying scholarships, CFS mandated the 5 degree approach. Three degree approaches are probably first taught for the IMC rating.

Ron Campbell brought most of his ideas from the RAF circa 1950s, they have largely been the basis of GA ever since however; with no APs to set things in concrete, there has been a natural drift. Perhaps the largest factor in destroying the Standard Circuit concept has been Noise Abatement, with local circuit patterns that are more concerned with missing some Nimbie's house than flying a safe pattern.

[172_driver]

bemused1812,

I'd say what you need is a good SOP. Most flight schools have this. Normally as a picture of a traffic pattern with comments along side with guidance of what track/speed/configuration to use. Not sure what aircraft you check out on, but I have a traffic pattern profile for C172 if you'd like it sent over. PM me if so. Not sure if it will confuse you even more or point you in the right direction.

The traffic pattern is really easy for someone who knows how to fly, but I agree that without clear instructions HOW TO do it, it can become very confusing. This can be a big problem when a training organisation lack good SOP and standardisation among instructors. There are many ways to skin a cat, none necessarily wrong just different.

[Genghis the Engineer]

Welcome to General Aviation!


I think I could explain this far better with the aid of a whiteboard and a set of coloured markers! However, let's just start with variability...

- Aircraft in a GA airfield circuit may well have downwind speeds from 50-110 knots

- 3 degrees is only an instrument approach. What is normally appropriate depends upon the aircraft, varying from around 5 degrees for something like a PA28, to over 20 degrees for a really slow and draggy microlight like a TST or an XL. The XL and the PA28 may be in the same circuit.

- Circuit height varies also - from 600ft at some microlight airfields, to 1200ft at some places with a lot of irritable neighbours. 800ft or 1000ft is most normal. Some airfields change the circuit height at night.

- Most airfields reference QFE in the circuit, a few reference QNH

- Usually there's a single circuit, sometimes two (higher/faster, lower/slower): for example at Booker or Popham. They are defined geographically (rather than the time defined military circuit).

- As Whopity rightly says, at-least half of all UK GA airfields have a circuit modified for noise abatement.

- Different aircraft types, with different circuit heights, and often different circuit shapes and sizes will inevitably require differences in where you select flap, approach speed, approach power.... And if there are multiple aircraft behind you, select all of them as late as possible to help them keep their spacing. Alternately if you are in a microlight that accelerates for finals, select them as early as possible!


So basically you've correctly put your finger on the fact that there isn't a standard circuit in GA. There is a correct circuit at a given field, modified for your type, modified further to fit in with everybody else.

Strangely, it all makes good sense after a while. I think that some quality time with an FI and a whiteboard will certainly help - on the other hand, some quality time in the right hand seat with some experienced PPLs doing burger runs might help you out in seeing the variations in circuits (and much else, not all of which is quite so healthy :yuk:)

G

[foxmoth]

With what has been said above about there being no such thing as a standard circuit I will tell you what I was taught and teach as standard. Climb out at a suitable speed - this can vary depending on type, but for a normal training aircraft I would probably use Vx. Turn crosswind at 500', level at circuit height (1,000' for a standard field) and turn downwind, call downwind abeam the upwind end of the runway (this may be modified dependant on other r/t traffic, but this IS the correct place to call), then do checks. Tracking for most low wing aircraft should have the wingtip just over the far side of the runway - adjust if you have a particularly long/short wingspan. Turn base with the threshold 45 degrees behind the wing (as said - this is nil wind, so adjust as needed). Immediately after the turn, close the throttle, hold attitude, select initial flap and on reaching your initial approach speed, adjust attitude and power so that you start your turn onto final to roll out on final at 500', this should put you about a mile and 1/2 on final - note - steeper than a 3 degree slope, then take final flap and adjust speed. Each leg should be adjusted for driftto track at 90 degrees/parallel to the runway and power on base/final will need to be adjusted to allow for tail (hopefully only on base)/headwind.
As pointed out, this WILL need to be varied because of local procedures and/or how other pilots are flying their circuit ahead (and behind) of you, but IMHO should form the basis if there is nothing written down or been passed by briefing.:ok:

[bingofuel]

Turn crosswind at 500', level at circuit height

The problem with this is, with the poor climb performance of a typical trainer, probably at max weight, the crosswind climb from 500' to 1000' followed by the protracted levelling out by the student before turning can position you very wide downwind. I would suggest in these circumstances to climb straight ahead to a greater height, possibly 700' or so to keep the downwind leg closer to the runway and avoid the. 'bomber' size circuits which seem to be rather prevelant these days.

[mrmum]

Good point, you do see some very wide downwinds sometimes, outside the ATZ even. I also do tend to climb further upwind myself, say 600', but it does depend which aeroplane I'm flying. You could also continue a climbing turn from crosswind to downwind instead.

All this of course is not really giving the OP what he was looking for, other than the fact that we fly steeper than 3 deg. approaches, which should make his maths work better.

Bemused1812
I think one thing you should do is get one instructor you're comfortable with and stick with them, that'll reduce the variables while you get yourself sorted out. It's a bit disappointing that two FIs at the same school haven't sorted themselves out with some common standards to teach though isn't it.

[foxmoth]

The problem with this is, with the poor climb performance of a typical trainer, probably at max weight, the crosswind climb from 500' to 1000' followed by the protracted levelling out by the student before turning can position you very wide downwind.
Not normally a problem, though you do either need to get the stude to get the level off sorted and double check it after turning downwind - the time it does get tricky is if you have a crosswind blowing you away from the field, then you do need to think about climbing more before the turn.

[bemused1812]

Wow, thanks very much for all the advice. The lack of standardisation is disappointing, mrmum. I am heading towards the opinion that I might have to look elsewhere for a different level of professionalism. But that’s another matter.

I have come across these notes which I believe apply to a PA-28-180. They seem much more like what I was expecting. What do you think?

Climb and Crosswind Turn and Crosswind Leg

Complete the after take-off checks and climb straight ahead (track along the runway centreline) at VY (76 KT) until at least 500 ft (note 1). Lookout to clear the turn as you approach 500 ft. At 500 ft commence climbing turn with 15° AoB. Roll-out to track at 90° to runway (allow drift for wind at circuit height).

Level at 1000 ft. Accelerate to downwind speed (85 KT) and set downwind RPM (2000 RPM).

Downwind Turn and Downwind Leg

Downwind spacing is 1 NM out from the runway. Judge the turn by looking back at the runway and turning when it is relative to part of the aircraft (be aware that the angle looks different when allowing for drift crosswind), and/or by looking for a ground feature on the downwind leg if there is one.

Turn downwind using 20°AoB. Adjust heading to allow for wind at circuit height. Use a ground feature if available to aid accurate downwind spacing. Otherwise use position of the wing relative to the runway, but make sure wings are level when checking, and be aware that the picture is different when drift is applied. Adjust your track if necessary to maintain the correct downwind spacing. When you are abeam the upwind threshold, make the downwind R/T call “[C/S] downwind [intentions]” (note 2). Carry out the pre-landing checks, including selecting 10° flap. Progressively adjust the attitude and trim as the speed reduces towards the base turn speed (75 KT). If it reaches 75 KT before the turn in point be prepared to increase power a little to maintain 75 KT.

Base Turn and Base Leg

If there is a ground feature at 1 NM on the extended centreline, use it to judge when to commence the base turn (turn when abeam); otherwise use the angle to the touchdown point: 45°. If there is a strong headwind, turn early. Turn level using 20°AoB.

Roll-out tracking at 90° to the runways heading; allow drift for wind. As soon as you roll out, select base leg descent RPM (1700 RPM), flap (25°) and lower the nose to achieve 665 fpm rate of descent in still air conditions. The RPM and hence RoD should be adjusted to take account of crosswinds. A tightening crosswind will require a reduced RPM/ increased RoD, and a slackening crosswind will require increased RPM/reduced RoD.

Finals Turn and Short Finals

If there is a ground feature at 1 NM on the extended centreline, use that to judge the finals turn. Otherwise look at the runway and ‘imagine’ the extended centreline. Ideally the turn is commenced at 720 ft, but it is initiated at the right point over the ground rather than height. If you turn over the correct point on the ground and the height differs from 720 ft, you can use that as a check height and adjust the RPM and hence rate of descent to compensate; reduce RPM if high, and increase if low. Use 20°AoB but adjust the AoB as required to roll-out tracking along the extended centreline; use a maximum of 35°AoB. If you need more, consider going around at this point.

In theory, you should roll out at 530 ft and 1 NM from touchdown. This will give you a 5° approach. Adjust the attitude to pick the landing point. Use power as required to maintain 75 KT until you select full flap (40°). The point at which to select full flap depends on the headwind. In still air conditions, it should be at about 300 ft. In any case, you should have stabilised your approach by 300 ft. That means you should be on the centreline, at the correct speed and configuration, and have received clearance; if you have not achieved these criteria, go-around immediately. After selecting flap, allow the aircraft to gradually decelerate towards VAT of 66 KT, trimming as it slows down.

Note 1

Consider extending upwind (beyond 500 ft; even up to, or after levelling at, 1000 ft) if:

• You wish to increase the spacing between you and an aircraft ahead;

• There is a very strong headwind at circuit height which is shortening the time on the downwind leg too much; or

• The aircraft performance is such that it is difficult to achieve circuit height before turning downwind.

If you extend upwind significantly and there are aircraft following you in the circuit, make the information call “[C/S] extending upwind”.

Note 2

If you are unable to make the R/T call in the correct place due to other R/T traffic, do not delay your checks while you wait. If you delay the call for this reason, or forget to make it on time, say “[C/S] late downwind [intentions]” when you make the call.

Spacing

Avoid the temptation to adjust the circuit by widening the downwind leg or extending downwind to adjust your spacing from aircraft ahead; the place to do this is upwind. If you are too close crosswind or downwind, then go around from circuit height and judge the point you re-join the circuit pattern to fit in with other aircraft. Be aware that others will use poor techniques, including flying very wide circuits and extending downwind. Do not compensate by adopting poor techniques yourself, nor get into arguments over the R/T; sort out such problems by discussion on the ground later. One common reason for poor circuit patterns is when pilots attempt to compensate when there there are too many aircraft attempting to fly circuits at the same time. The solution is to fly practice circuits elsewhere or at another time. The two problems arising from widening the pattern are:

• It makes it difficult for other aircraft (and ATC) to spot you if you are not where you should be, and there is a danger of other aircraft turning inside you (deliberately or inadvertently) if you are very wide.

• It makes the judgement of the finals turn and a constant angle approach very difficult if you deviate from standard parameters. The circuit described here will result in a 5° approach path, and the speeds/heights/RPMs are all calculated to help you achieve that without too much thought or judgement. It is far more difficult if you deviate from this standard. Good landings result from good and stabilised approaches.

[Genghis the Engineer]

As a starting point in a PA28 I'd agree with most of that. With practice, you'll get used to adjustments, just as I'm sure you did in your military flying.

One thing I disagree with is the proscription against extending downwind. A great many airfields prefer this as a means of ensuring spacing. I do agree however that widening the circuit is a poor practice. Some airfields also prefer orbits for spacing, but those need treating with care because it can just mess everybody up behind you.

It is very "flying by numbers" mind you, which is perhaps appropriate to military training or airline flying, but light GA does both allow and need a bit more flexibility on speeds / power settings / turning points, particularly if e.g. you find yourself sharing a circuit with a couple of microlights and a helicopter, as well as the usual mix of fixed wing traffic which might have downwind speeds from 50-110 knots, requiring care and flexibility from everybody. The pilot insistent on flying an absolutely standard circuit regardless of what's going on around him will make few friends!

G

[bingofuel]

lower the nose to achieve 665 fpm rate of descent in still air conditions.

Hmmmm, and what if it isn't still air conditions?
I think a slightly more flexible approach is preferable.

I would also add that if incorrectly spaced, orbits on downwind are not a good idea, preferably go around and try again. Of course we all know how to go around from any point in the circuit and not just on final, don't we?

[riverrock83]

Doing my training from a large airport I was/am taught not to turn crosswind until past the end of the runway which is often well after climbing through 500' (especially on a go-around) unless OKed by ATC.

ATC also prefer orbits for spacing where I'm based - but its normally due to longer waits for 737s (or larger) to land. They often have some aircraft on rt hand and some on left hand circuits at the same time so harder to judge. They have also asked me to extend downwind on occasion.

Another reason to not fly too far away from the runway is you should be within gliding distance (in case of engine failure) so a 500' circuit would be closer to the runway than a 1000' circuit.

PAPI is set at 3 or so degrees so can be missleading.
For a PA28 we don't use 10° flaps at all (selecting carb heat pretty much reduces speed enough to select 2 stages of flaps) - find what works for you and follow the advice of an instructor.

[mrmum]

Bemused1812, that set of notes look pretty reasonable to me, nothing really wrong with it at all and some very good points covered.

[bemused1812]

Thanks again for your thoughts guys.

Bingofuel, is your point not covered by:

"The RPM and hence RoD should be adjusted to take account of crosswinds. A tightening crosswind will require a reduced RPM/ increased RoD, and a slackening crosswind will require increased RPM/reduced RoD."

It would be useful to have some rules of thumb for how much to adjust the power, and rate of descent, mind you.

Genghis, I take your point about flying by numbers, but I guess that cuffing it requires judgement and experience, which is lacking in inexperienced pilots, therefore it's good to give them a framework to hang their hats on. I'd put myself in that category, with regard to this type of flying anyway. I've been a trainee and trainer in several different flying disciplines, and have always found that walking before running is best. Maybe I’m too institutionalised, but I don’t feel right now that I have the experience to make it up as I go along, and really want someone to tell me what I should be aiming for; even if achieving it in the real world is a little challenging.

My instructors seem to think that I don’t need any instructing, probably giving too much credit for my experience in other types of flying. But without that experience, I’d be really bemused right now!

I guess what I really want is a student study guide like we gave to ab-initio pilots in the RAF.

[bingofuel]

My comment was a bit tongue in cheek re the exact fpm quoted.

Difficult o give exact power/rod clues but try 100 rpm will change rod by 100 fpm as a starting point.
I dislike concentrating on flying too much by numbers in a visual circuit when you need your eyes outside because unfortunately circuit discipline can be very poor at some airfields. However if you are learning on a PA28 here are some numbers to try , 2100 rpm downwind, turn base , 1500 rpm/ flaps 25, and it should settle about 75 kts with no trim change required, then on final, full flap should give you about 65kts again with negligible trim change so it helps reduce the workload.

[dobbin1]

Of course we all know how to go around from any point in the circuit and not just on final, don't we?

Actually, no. How do you go around from down wind?

[Genghis the Engineer]

I guess what I really want is a student study guide like we gave to ab-initio pilots in the RAF.

Well that book certainly exists here (http://www.afeonline.com/shop/product_info.php?cPath=38_179&products_id=29).

However, can I suggest that what you might want to try - as an experienced aviator who can take material in rather faster (one hopes) than most student pilots, you consider acquiring an instructors guide?

The two I have, both excellent in their own ways are Philips and Cole and the much more recent Newton and Halstead: http://www.ontrackaviation.com/book.htm. For what you want, I think I'd pick the second.

Ultimately however, I still think you'll find sitting next to an experienced PPL doing a few burger runs will go a long way to helping it make a bit more sense. If you've associated yourself with a club, I'm sure they can recommend some of the good guys who wouldn't mind a passenger, particularly if you offer to chip in something for fuel and lunch.

G

[212man]

Am I alone in finding a hint of 'disconnect' in the OP's comments?

[Cows getting bigger]

I wouldn't be encouraging students to set a specific ROD in the cct. On base leg I give them a 'starter for ten' power setting which in a 152/172/PA28 would be in the region of 1600-1700 rpm, set two stages of flap and maintain level flight attitude until approach speed + 5 is met. Only then should they set an attitude to maintain that speed, trimming as necessary. From now on they should be judging their ROD from the runway 'picture', airspeed from the horizon and rarely look inside the cockpit.

Taking a step back, I'm rather wary of being so prescriptive as far as visual ccts are concerned.

[Genghis the Engineer]

Taking a step back, I'm rather wary of being so prescriptive as far as visual ccts are concerned.

Well yes, I think we've all been saying that, 212man perhaps more directly than most.

I do find it a little curious that somebody who implies that they have been a qualified service pilot, and now to be flying for an airline (which implies having passed a CPL skills test) has trouble with this stuff which I'd expect to have been thoroughly dealt with at both stages of training.

IIRC, the UAS and JEFTS syllabi on the Bulldog/Tutor/Firefly all included how to fly circuits at civil airfields. The CPL certainly does. In between doing service flying *may* have been more prescriptive, depending upon the aircraft type, but to quote an old RAF adage: "Flexibility is the key to air power".

G

[212man]

Thanks GTE - I had my 'polite head' on when writing my comments........

[madlandrover]

(which implies having passed a CPL skills test)

Not necessarily - most QSP's are exempt the CPL test if they are in current practice, although they will have to pass an IRT. That can be done in their service type as an observed test for some though. Most do still know how to judge a visual circuit!

[Crankshaft]

In our SOP's it's a MAX 25degree AOB turn onto finalIs it only me finding this sort of imposed restrictions quite dangerous?

I've never heard about someone stalling in the circuit due to overbank. But I know loads of accidents caused by lack of bank.

Solo student: "Oh no, I'm overshooting the rwy centerline and are already having max allowed bank - but hey, that rudder gets me nicely in on the centerl... OOops!"
And so he spins into the ground!

[foxmoth]

Personally always used and taught 30 degrees bank for all turns apart from climbing ones (in the circuit, turning crosswind) when it is 15 degrees.

[bemused1812]

Well sorry to disappoint with my lack of GA experience, but until recently I’d never flown a square circuit. My flying started in the RAF, and all I was ever taught were oval circuits. Madlandrover is right in describing my route to my ATPL; a few hours in a Seneca, and the only circuits we did were oval and seemed quite familiar. Strange as it seems looking back at it, I seem to recall both the instructors I flew with at my IR school taught the same circuit pattern, and were able to tell me what power and attitude to set, to give the required performance at the appropriate stage. And yes of course as a QSP I flew at civilian airports. But the location did not change the way I flew my aircraft, unless the pattern had to change to cope with local restrictions which are as common at military bases as civilian airports.

Sorry, Genghis, if I gave you the impression that I was giving ‘trouble with this stuff’. Actually, the only difficulty I am having is understanding the lack of standardisation between my instructors. Reading back over this thread I’m beginning to understand that lack of standardisation; it sems that everyone does/teaches their own thing.

I don’t believe that this is an RAF/civvy difference of approach; with both of the airlines I have flown with there is only black and white about the SOPs for visual circuits or anything else for that matter. Indeed, the procedures are far more prescriptive that I was used to in the RAF. So I conclude this is just a GA thing; perhaps for good reason Genghis, as you pointed out the other traffic is all over the shop so one just has to cope.

Out of curiosity, if you fly within a student who does things ‘differently’ to the way you like, is she wrong, or merely exercising flexibility and therefore to be encouraged?

[madlandrover]

Out of curiosity, if you fly within a student who does things ‘differently’ to the way you like, is she wrong, or merely exercising flexibility and therefore to be encouraged?

If you are flying within a student, your professionalism is suspect. And her flexibility should be encouraged ;)

[Genghis the Engineer]

No offence meant bemused, just a little bemusement of my own.

(Quick disclaimer, whilst I've a lot of GA hours in the UK and elsewhere, I'm a quite inexperienced instructor, so won't be offended by more experienced instructors who care to disagree.)

With civil flying students there are many right ways, and many wrong ways of flying. The trick is to make sure that they are doing it "a right way", and not to get anally retentive about "not my way".

At most civil airports, the 3D shape of the circuit (apart from the climb and descent angles) is generally not negotiable - apart from some small variations (depending upon local preferences, extending downwind or orbiting). The downwind call position is fixed - apart from variations to suit other radio traffic.

But yes - it's nominally rectangular (with local shape variations), some debate about angle of bank in the turns: I'd personally use about 10-15 degrees in the climb or level, 15-25 degrees descending - speeds and flap settings to fit into other traffic and suit the aeroplane, angle and power on the descent to do the same (and also many of us prefer a low power steep approach if landing over somewhere you can't land - for example over High Wycombe into 24 at Booker). Microlights and homebuilts may often fly idle approaches as a matter of course (a mentality brought on by uncertified engines), creating particularly steep approach angles.

G

[Big_Buddha36]

Hi,

just want to put my 2p's worth

reading a few posts here stating facts & figures of when to do things - 1 particular thing I have seen in experience, is a student grabbing hold with extreme vigor, the idea that you turn base2final at a PARTICULAR height.

whilst in practice this works out ok - it all goes horribly wrong when they are then asked to position for a 2 or 3 mile final - they still aim to turn final at 600ft - completely ignoring that the approach has LOOKED low for some time.

i cant argue on the When to turn, when to call, how wide/close, since this is done with reference to the strip & not the instruments - nor do i advocate learning the local circuit with reference to ground markers - houses/villages etc

I have found that if students learn the "overall circuit 'picture'" they find it easier to transpose that when off visiting different airfields

Less is more, perhaps, in this case & rather than fixate of precise numbers (with the exception of AirSpeed), learn what it should look like and fly it!
..2p spent!

BB

[Genghis the Engineer]

nor do i advocate learning the local circuit with reference to ground markers - houses/villages etc

This is an interesting point - I've seen this approach in quite a few places, but it always seems to me that all instructors are doing is teaching people how to fly one aeroplane at one airfield: rather than to fly properly judged circuits.

G

[Madder]

In my opinion you loose the big picture if you get caught up in all the small details.

Is it really that hard?

Its 4 90degree turns while climbing from 0-1000' and descending from 1000-0'.

Circuit flying is best learned in the circuit.

Procedures and speeds are in the AFM / SOP.

[Pull what]

I don’t believe that this is an RAF/civvy difference of approach; with both of the airlines I have flown with there is only black and white about the SOPs for visual circuits or anything else for that matter. Indeed, the procedures are far more prescriptive that I was used to in the RAF. So I conclude this is just a GA thing; perhaps for good reason Genghis, as you pointed out the other traffic is all over the shop so one just has to cope.

You may have failed to consider that the average standard at the average flying school/ club is quite low, standardisation is rarely in place or enforced. General civillian circuit discipline is very poor too, put 3 different schools in the circuit and you will get three different patterns. Recently on here a PPL examiner stated that a student downwind should be able to reach the runway in the event of an engine failure. Other folk lore widely preached is that 3 degree glide paths are only for airliners. Another examiner I know says every standard approach must be a glide approach! Over the years Ive worked in 10 different flying schools and in only one of them was there an acceptable standard and that school was run by an RAF wing commander!
Ron Campbell by the way was more influenced by US methods than 50s RAF methods as anyone who knew him would tell you.

[BristolScout]

Lots of good stuff here for you, bemused, and I agree with it all! Another very germane factor is that most GA airfields do not have air traffic control, only an A/G service which removes one of the layers of discipline you are used to in military and airline flying. Where I instruct, for example, there's a busy parachuting school which effectively removes the 'dead side' so there's a combination of microlights, SEPs, helos, canopies in the air and the drop aircraft trying to cut in to land for the next uplift. Compared with Heathrow or Leeming, it's anarchy - so next to impossible to standardise. Welcome to general aviation.