Max "safe" number of aircraft in circuit at any one time?
 

Do you feel that there is a maximum "safe" number of aircraft per circuit at any one time, assuming that there are aircraft with different speeds in that particular traffic pattern? If so, what do you think is the maximum "safe" number? Do you feel it makes any difference if it's a GAAP, MBZ or Class C/D?


P.S. I think I'm bored to have come up with this question! :}

1

I've been in the Circuit with 9 at one time. and 7 at night during MBZ hours. No drama's.

as many as you like - just make the circuit bigger. That's common practice! :}

Unless taken to the extreme, it's not really a safety issue. At the end of the day it does the student a dis service. Fewer landings in his/her hour that s/he worked hard for to pay for, so an extra hour required to prefect that x-wind.

Ahem! Trust me to ask a crap question.

I'll add "without extending the downwind leg enough to turn it into a mini cross country" to the question above.

:}

You answered your own question by saying acft with different speeds. A safe number with all C152's and say one twin Baron ie YPJT is going to be different with a tigermoth,grumman,C172 and different twins doing asymetric go rounds.

Always a consistent problem at any major GAAP ad but other facors such as weather, ATC abiltity, adherance to ''common sense cct size'' and how things are going to go if one of th acft has an emergency. An engine failure on D'WIND with a close base and landing with 5 acft in front with inexperienced pilots could really compound the problem.


I must be bored for writing this as well...

I've been in a circuit at night at Ardmore (the C-Cats graveyard) with 12 in the circuit.. well thats what I counted...

I didn't feel comfortable with that.. considering Ardmore is uncontrolled... and decided to land asap.

Moorabbin is (or was a while ago) max 5 in the CCT during MBZ hours.

Probably due to resident's noise concerns...but also probably an element of safety in there as well.

I have been in the circuit with 13. Pretty freaky when you are not that experienced and you know quite a few of the other dudes are just as inexperienced as you.

DirectAnywhere. The five aircraft maximum in the circuit area was a spillover from an Air Traffic Controllers dispute linked with number of ATC on duty. Sorry if I am a little vague on that because it was such a long time ago. . It was not a flight safety issue and there was no measured research done on how many aircraft could operate uncontrolled.

When Moorabbin became uncontrolled (MBZ), it became all too hard for Air Services to go back in time to re-visit old decisions and so the arbitary limit of 5 aircraft in the circuit at night was left in. This is all from memory but I am probably 75% correct.

I remember, when I was learning to fly at Canberra, my instructor whinged that ATC couldn't deal with any more than three aircraft in the circuit.

Don't know if that was true or an exaggeration, but circuit training there was always an interesting experience as the controllers had to work hard at certain times of the day to keep us separated from the RPT traffic.

It was quite common to have to do long downwind legs or orbits on downwind (or even base leg) to ensure separation.

Circuit direction also changed quite frequently during a training session, and often they wouldn't tell you which direction to turn until the last moment.

Thanks for the history lesson Hudson!!;)

Believe it or not, 4 years ago I was number 5 on final at BK for rwy 18. There was 25kts straight on the nose though!

AS

I recall a controlled field in the UK where 1 aircraft in the circuit would sent the ATC into fits of stressed hysteria:ugh:

Yeah! I was one of 6 or 7 at Luton in training - but had to take avoiding action when another got too close. Any more than that and the chance of having to go-around from final gets too likely.

If there are 6 in circuit and it takes a minute to do the touch & go till the next one can be cleared to land, you'd better all be flying 6 - 7 minute circuits. Regardless of speed, timing is what's important when there are several in circuit.

Of course, if you can land 3 at once - as OSH will be doing next week - and all are arriving to land or all are departing, it's a bit easier - but once the first one has to go round he needs to find a slot to fit in for the second attempt: hence few people get a clearance for curcuits if there is a busy arrivals sequence.

Incidentally, the finish of a glider race with 10+ in circuit together can get a bit fun when nobody can go around!!! Helps to clear the strip quickly after landing! :D

I must say the Clevedon Valley looks quite pretty with the strobes of 11 C172R's bashing night circuits overhead.

The problem is with that many in the circuit (aka Ardmore) it only takes one pilot to stuff it all up by extending downwind too far.

I have seen it Ardmore with that many in the circuit and aircraft extending out to nearly 3-4nm downwind, with no thought as to what they are going to do when the engine fails. That in its self should be the deciding factor as to how many aircraft should be in the circuit at any one time.

splat

:ok:

I guess the idea is that if you have an engine failure down the bottom of the circuit, you just land at NZRV.

How many do you think were there when parallel ops, skydiving and gliding all went on at the same time?