1500ft circuits
 

I'm curious to know what people think of the recently introduced changes(relatively) to circuit heights for "high performance" aircraft.

Generally, I have found that most have not adopted to the 1500' cct ht and continue to fly 1000' ccts. I personally fly a 1500' cct, but prefer the shorter and quicker 1000' cct when I'm flying at about 140kt.

I reckon the new laws were introduced to provide better conflict resolution between faster and slower aircraft in the circuit area, but I have not once overflown and overtaken another aircraft in a circuit.

How do you fly your circuits? Do you extend your downwind to drop the extra 500'? Do you accept a larger rate of descent within the same downwind leg of the 1000' circuit? Do you slow down to 120kt? Have your companies SOP changed to reflect the new legislation? How do the military teach it?

The legislation from the AIP enroute (25may08) is shown below

57.3 Circuit Height
57.3.1 When operating at non−towered aerodromes, the following circuit
heights are recommended:
a. jets/turbo props/high performance aircraft, 1500FT AGL;
b. typically single engine piston, 1000FT AGL;
c. ultralights with a maximum speed of 55KTS and
helicopters, 500FT AGL.
NOTE: High performance aircraft are those that have a normal
downwind speed of greater than 120 knots.

I hate them but for selfish reasons, I can't stand making circuits any bigger than they need to be and they just feel to me too high/large to be practical.

Newly adopted ??????????? how so, 1500 has been thus as long as I can remember for high performance aircraft.

Forkair SOPs call for tight circuits. For what its worth, I extend the downwind leg to allow for the additional 500'.

Dr :8

Yep, been around a long time.
As to how sensible it is; not very, in my view - having aircraft doing circuits at different heights just increases the chance of someone descending on top of someone else, I reckon.
Probably why nobody does it.
In reality, most of your so-called high performance aircraft would be coming off instrument approaches, or visual approaches under tower instructions, so the 1500 ft rectangular circuit thing isn't going to be relevant anyhow.
OCTA, I can't imagine the 1500 ft circuit gets much of a look-in.

T28D - Perhaps I didn't realise the clause earlier when I was flying slower aircraft, or CASA defined high performance aircraft as aircraft that fly >120kt ccts.

I also fly tight ccts but instead of extending downwind, I drop full flap and accept a larger RoD. Although the flaps in the piston acft that i fly most allows for this since they are hydraulically actuated and if both engines fail (read: hydraulic pumps fail) they will retract with the airflow provided I pull the electrical hyd pump ccb. People on the ground always make comments on "how high were you on downwind?" etc But i dont like extending the cct to more than it needs to be.

The result for me is that I cant get a good short cct that im comfortable with. Are today's instructors teaching larger ccts in these " high performance " acft? Does anybody expect a light twin to be at 1500' on downwind? How many people have changed their flying technique to suit 1500' rule? I have but I dont like it.

The 737s in Broome fly 1500' circuits, but its never a problem for traffic.

I'd consider that to be a relatively high performance aircraft, but do light twins really count?

I am holding my breath for the first "airprox" that occurs when an a/c does a 1500' circuit at Camden whilst another a/c reports inbound at 2RN at 1500'....


if it ain't broke... don't fix it (or f*ck with it)

Can anyone point me to the reference for circuit height at a towered aerodrome please.

As long as I have been involved in aviation it has always been 1500 ft CCTS for high performance A/C?? To my knowledge not many regional airlines adopt the 1500ft ccts at CTAFs . Try following a metro at night into YSBK, The tower asks for speed reduction for both A/C at prospect. I can never seem to keep up:sad: They dump the gear and flap and fly a tight base and final. No need for 1500 Ft ccts maybe just for the jets, even the smaller citations and Learjet’s seem to manage fine with 1000ft ccts.:ok:

Maybe a few Light jet and turbo prop drivers can shed some light???

No way Jose!

I'll stick with extending downwind rather than descend on the downwind leg.

Dr :8

"The legislation from the AIP enroute (25may08) is shown below

57.3 Circuit Height
57.3.1 When operating at non−towered aerodromes, the following circuit
heights are recommended:
a. jets/turbo props/high performance aircraft, 1500FT AGL;
b. typically single engine piston, 1000FT AGL;
c. ultralights with a maximum speed of 55KTS and
helicopters, 500FT AGL.
NOTE: High performance aircraft are those that have a normal
downwind speed of greater than 120 knots."


Theres the critical word in that paragraph. "recommended"!!!!

So if the pilots that are not flying at the 'recommended' circuit altitudes have in fact read this chapter in AIP/Jepp then they are obviously taking the word recommended quite literally. Or they just havent read this and are just flying at 1000' as per the old days.

I brought this exact subject up last year & am happy to see it's back on the agender.
'Pas' yes what you say would be a simple way of dealing with the extra height, start down on say late downwind, abeam the ldg thresshold drop gear & head on down (typical), that's exactly what I/we do to avoid high ROD's.

'airman1' yr right there mate 1500' cts have been in place since Noah took up flying, well for jet types anyway. I believe they brought them in for high perfomance 'anything' because most slippery types fly downwind at say 130-150 kts anyway, LR35 for Eg.

'htb' also correct the whole procedures are 'recomended' as you have highlighted I think mainly because 1500' may not be possible wx wise but still legal visually for ldg.

Like I said once before healthy debate is good:ok:


CW

Young Wally...... Was just about to page you I could smell the debate brewing at post 3. So in the lovely king air you always fly a 1000ft cct and just extent the downwind?? Good thing you have two engines wouldn’t want to go extending the downwind too much in a single (lets say a PC12) you mighten make the keys in an engine failure!!! :ok:

Hirethebetter, your dead right recommended is the key word there!!!

I just wonder how many drivers get lazy and let down on downwind earlier?? (None that would ever admit to it anyway):ugh:

Oh Brother! Not that crock of sh*t again!

The L35's a bit of a slug in the circuit, huh Wally? I used to fly the FTDK downwind at 140 kts until dropping the gear out opposite the threshold.

Dr :8

PS: Why doesn't someone do a bit of research and post a few crash reports on SE aircraft that have suffered engine failures on the base or final approach leg of the circuit - due to other than fuel starvation!

FTDK - don't get all wound up - airman has probably never flown a PC12 or Bo

Desert Duck/Forkt don’t get your knickers in a knot, just stirring the pot!! And yes have over 50 Hrs in the PC 12 logged in the book. Lovely piece of gear but it definitely has its place in the industry like capt Wally has always said. :ok:

Sorry for the thread drift continue.......

It all makes sense when you fly a Category C machine in a cct in VFR/IFR situations.
When in VFR a 1500' cct is perfect. And you are following the local VFR rules..ie left or right hand ccts. In total, cct times are similar for all categories as a result.
In a circling approach (following an IFR instrument approach)(in a cct) max speed is 180kts and then you know that you are the only one doing the cct, so therefore do either left or right hand cct, whatever suits-you-sir. You just need to maintain obstacle clearance (400' for cat C) till on approach path/angle for the runway which could be as early as on an oblique downwind. These ccts are usually done at about 1000' and are limit by visibility.
Sorry to be so tech but it all works nicely.

:)

Day or night as the PIC you have to guarantee obstacle clearance.
Its in the regs my friend.

TTT,

I can understand the rules' application to a faster CAT C acft but how about a fast CAT B? Without descending on downwind, which i thinks contradicts the reason for the implamentation of the 1500' >120kt cct, the question becomes do you allow for a greater rate of decent and keep the cct tight, extend the downwind, or don't apply the recommended procedure altogether?

Bad Boy
 

Can’t remember when I last flew strait and level in a circuit

S & L or adding throttle during a decent and landing means I have stuffed up the decent profile and wasting fuel :E.

Just for comparison a military fast jet will fly 1500' on downwind. Spacing about 9000' from the runway centreline. Descent is commenced at the base turn point. In nil wind the BTP is abeam where the finals glide slope will intercept 500'. Speed on downwind anywhere from 160-250kts. This varies subtly with from type to type but is basically as I've outlined. Circuits take about 4-6 minutes each which is the same as oval circuits in CT4's, and PC-9's which fly a closer circuit spacing. Much more efficient than a square circuit. Extending base is a no no at military training airfields as is stuffs up the spacing of all following traffic.

Not saying that any previous posters are wrong just giving some info on how military circuits are flown.

Cheers

Watch out below
 

Well for my two cents worth, As a Captain of a regional turboprop i thank God that there is a 500' buffer between me and a smaller craft be it fast or slow, i say this as all too common i have seen aircraft enter the curcuit at regional airports beneath me with no radio calls ,this after i have called at 25 nm and 10nm and when joining the curcuit.I tell you this that one day mark my words there will be a midair at a regional aerodrome between rpt and private aircraft,not only do you have aircraft not calling to avoid charges but unfortunately a great many pilots lack situational awareness when it comes to other traffic , especially when the target is travelling at 4 nm a minute on descent.

I am not going to assume what you are saying but in all instances, VFR/IFR day/night, you must be aware of your minimum height above terrain at all stages of flight as PIC.
It can never be a guessing/assuming game. The consequences can be catastrophic.
Whether pre-flight or in-flight situational awareness you must be in no doubt about your height above terrain, it is the basis of flight training.
But I'm sure you know that...

:)

Would be interested how NOT following a "RECOMMENDATION" will stand up in court:{
Most ops manuals for Jets/TP will have a "practise inst approach company min(usually 800ft agl), so you can get down if you want to.
Never had a prob with 1500ft circuits, dont really know what the prob is:rolleyes:,circling approaches,however,are a totally different story:=

NOSIG

I can understand the rules' application to a faster CAT C acft but how about a fast CAT B? Without descending on downwind, which i thinks contradicts the reason for the implamentation of the 1500' >120kt cct, the question becomes do you allow for a greater rate of decent and keep the cct tight, extend the downwind, or don't apply the recommended procedure altogether?

quote.....


A bit different in that one is a VFR cct (1000' or 1500') and the other refers to a IFR cct (max circling speeds..Cat A=100, Cat B=135, Cat C=180 Cat D=205) to keep you within the cicling areas of the aerodrome for the Cat.
Generally don't have a rate of descent greater than 1000fpm (plus other limits) for final.
A good RoD is 3 x G/S for a 3 degree slope, or thereabouts, and that can begin on downwind.
Based on having a stabilized approach for a landing.
Remember the old saying 'can't have a good landing from a bad approach'.

:)

I fly a cat B aircraft and use a 1,500' circuit but the aircraft has been on a descent from TOD and that continues throughout the circuit so no extending downwind or other such games are necessary.

From TOD to 10 miles from TOUCHDOWN the aircraft (non-pressurised) has been at 500 FPM ROD (although lately with the tailwinds up my clacker I have been using 600'). At the 10 mile point I should be 3,000' AGL and I take approach flap and the ROD then goes to whatever equals 3 degrees. Gear is taken at 5 miles to touchdown and second stage of flap usually on base which is taken at 1,000 AGL and within the cat B circling area. Final stage of flap at 1 mile to touchdown with everything stable.

Please note that the ROD after the first stage of flap will vary according to the speed of the aircraft but once the gear is out the ROD is quite benign and back around what it was on the early descent.

I use this approach everywhere (except during instrument approaches and even then it depends on what sort of approach I am doing and what has to happen on getting visual) for visual approaches, controlled 'dromes (unless they want something different), CTAFs, night approaches into remote communities and it works for me. It has become an SOP for me so that when life is difficult (coming into my home base at night with marginal visibility even in the circuit and a black hole away from the field) I don't have to work out something new when all I want to do is fly the aircraft.

Yes I make the required radio calls (even at 0400 in the bleedin' morning) and because there are a number of gyrocoptors around where I am based I am very cautious during the day. They are equipped with VHF but I am not impressed with some of the flying I have observed. I have found the whole concept of a constant descent easier than having to manage a descent then level off then descend again and it is easier on the passengers.

5nm final bro! Downwind descent get my two thumbs up :ok:

Speaking of circuits, heard the funniest thing the other day; QF requesting radar vectors for every leg of the circuit - pathetic.

On a more serious note than my previous post, as a glider pilot and tug pilot I do have problems with set altitude circuits, to date to my knowledge circuit altitudes apart from Secondary Control Zones (or what ever they are called these days) have been recommendations only – I will check the docs when I get to the office tomorrow

As a glider pilot – try flying a level circuit, and before some of you go off on tangents, while many gliding operations are from gliding paddocks, there are also many gliding operations conducted from licensed airfields (CTAF) and in rare cases CTAF (R).

As a Tug Pilot – having towed to 2000ft agl which what is considered a standard release height for gliders, and still being in the “circuit” most tug pilots I know make a continuous decent using a miliary style circuit, and even with a mix of traffic I have never experienced any conflicts that could not be sorted out with a bit of common sense and consideration for other airport users.

I'm scared.

Whats your point Hempy, he can fly a plane but he can't spell.. want to make a big deal out of it? :*

I suppose you've never made a spelling mistake in your entire life?

During line training circuits were at 1000'. . (fast Cat B). . . As I was finishing this was modified to 1500' for CFIT purposes. . .

Circuit join is at 1500' then abeam the threshold, wheels down to go down. . .There was no change to the circuit size or typical RoDs.. Once rolled out on base you were @1000 as per the training!! The bonus now was that you were all set up for a landing without the need to make configuration changes (u/c, pitch or power) - keeping more focussed attention outside for other aircraft and on the runway - especially useful at night when getting into those poorly/dimly lit runways :ooh:

It's much less stressful, giving a more stabilised approach (configured from a safe downwind height to the "committed-to-land" height for full flaps selection), more looking out the window time and so I guess safer!?! . . . .

I've not come into conflict or had any hassles with the piston singles at 1000' - they tend to be closer on the downwind leg - depending on their Instructor :oh:

Looking back, I would have used this 1500' circuit in the piston twins as well.

The bit that concerns me, especially in light of flyby's comments, is that when one wishes to overfly the circuit, have a gander at the windsock, and then choose a runway for landing, this is supposed to be at 1500' - to keep a 500 foot buffer between you, and traffic already in the circuit.

So what happens if a 1000' circuit aircraft trundles in, after having broadcast intentions to overfly, and having copied down the inbound regional turboprop joining downwind, yet assuming that their downwind is the same altitude as its downwind, both aware of the presence of the other, but unaware they are at the same height?

Don't you trust the regional turboprop captain to be using the into wind runway :E

With broadcast AWIS and/or the agents on the ground they already know what the wind is so they can plan a downwind join, which should be keep them away from the windsock gander airspace. Or even better, a straight in approach that keeps them out of (most of, anyway) the circuit.

Situational awareness must come into play - no one wants an AirProx - the paperwork :eek: You heard the Regional. They heard you. You're both in the circuit so the "See and Avoid" surely would work since you know where each other roughly are - don't have to look at ALL the sky just a wee bit of it.

..... what to do now with those ultralights when I want to do a practice day visual circling approach at 300' .... :p

Hempy thanks for your correction, i reckon 14 years flying experience allows me a grammatical error occasionally .Any how come fly with me and ill teach you a couple of new words and sentences, like multiple missed approaches at the missed approach point at the minima in imc and icing followed by a diversion to alternate followed by another approach at the alternate getting visual 50' above bingo height then having to co-ordinate with company , passengers , crew ,refuellers, atc,and wife,all the while knowing todays flight is just another day at work.
P.S - My FO was two weeks checked to line ,with less than 1000 hrs total time no atpl and very limited ifr experience.He commented after the second approach that this was the first time he had conducted an approach to the minima in imc.
Such is the life of a regional driver.

In theory if you do a 1500' circuit, then you would be slightly wider on downwind, but the centreline would be in the same position relative to your wing as it would be at 1000'.

So because of that, the 45deg pt for turning base would also be further out than at 1000', so noone should be descending on anyone, as you are further out than the 1000' guys.

Does mean you don't end up behind a 152 or a Sportstar at 150kts though:ok:

BTW Lasior, perhaps if the aircraft on 1500' calls "High Downwind" instead of just downwind? Also, I was taught to overfly at 2000AGL, although my current school teaches 1500AGL overhead. I just make sure to brief my students that at busy regional CTAFs, if they hear Eastern/Sunstate/Rex anything, or something of a similar size, expect it to be at 1500' on downwind.:ok:

I second FLYBY's comments.
My 2 cents worth; Situational awareness + F'n common sense - there's also an apparatus in your aircraft, usually you'll have 2, they're called radio's - don't be afraid to use, if necessary take controll of the situation i.e. I'll be at 1000', confirm your intentions!
Re IF exposure, Flyby, simular experience just the other day - R/H seat first real approach. If pax new, they'd be mortified.

Cap'n Arrrr,
Leave your theory books behind pal, I know plenty of lads who'll safely throw a regional turboprop around well within/inside the circuit spacing of a piston aircraft.

ah don't let the speeling nazi's faze you 'Cypher' they often opo up 'cause they have little else to contribute.

'flyby' sadly I have to agree with you, there will come a day where 2 shall meet & it won't be in a bar afterwards either!:bored:

now now 'airman1' I was wondering when you would mention that CW was thinking of 'adding' words here:) And I fly 1500' curcuits(:E) not 1000', too scarey down there:)

hey 'forky' if I see you trying to pass me on down wind & i'm driving a LR35 I'll soon fix that mate, how fast can that funny tailed beast go?:ok:

This whole debate about curcuit (:E)height is predicated on good airmanship & the use of proper R/T, the latter almost no existant at times & not just from the 'farmer browns' out there . Radios ought to be mandatory for ALL airports over a certain rwy length, say 600 mtrs, less than that there are only toy planes that can land on that & it's unlikely you will find traffic at varying Alt's anyway.:)
Decent at abeam the thresshold works well at 130 kts without having to point the nose down too much. The only trouble with diff curcuit(:E) heights is that we all have to come down some time to meet up!:bored:


CW

If you operate a turbo prop to the same airport as single engine training aircraft most schools teach their students to overfly at circuit + 500, so thats smack in to the turbo prop circuit pattern.

Its not fun trying to convince the student that they are not clear of you just because they are overflying at 1500 AGL.

So why dont we give up with the 1500 circuit and drop to a 1000, its safer that way.

I would love to know who dreampt up the change and why?:D