Close encounters in the circuit: Was the other guy in the wrong, and what can I learn?

It’s been nearly two weeks since I last flew, and in that time I’ve returned to full time work. The balance of my PPL – perhaps another 15 hours – will now have to be done on a part-time basis, maybe once a week. Factoring weather variability in, I anticipate it will take another 2 to 3 months.

Back in late April I made my maiden cross-country solo flight, a 2-hour return trip down the Hume Highway nearly to Marulan, then east direct to Wollongong, land, then direct north back to Bankstown. It was a fantastic trip on which I learned a lot.

But there’s one thing that stands out particularly, and the more I think about it, the more it’s got me reflecting on the question of safety in the circuit.

Standard circuit legs

To set the scene, for any non-flying readers, there are standard “legs” that you fly when flying in the circuit around a landing strip. As described in the diagram below, these legs are always relative to the “active” runway in use. This in turn depends on the prevailing weather conditions, in particular the direction from which the wind is blowing.

For illustrative purposes: in the below diagram, the runway runs in the 11 (110 degrees magnetic) direction (from top to bottom of page) and in the 29 (290 degrees magnetic) direction (from bottom to top of page). Let’s assume the wind is currently blowing from 110 degrees magnetic. In this situation, the runway in use would be runway 11 – that is, takeoffs and landings take place in the 11 direction, “into the wind”. The standard circuit legs are sketched accordingly, assuming a standard left-hand circuit.

The situation at YWOL

When I landed at Wollongong (YWOL) back in April, this was the standard circuit in operation that day. (YWOL’s north/south runway has different headings to the example I’ve sketched in the diagram, but the principles and circuit legs are the same).

I approached YWOL from the west and made the standard 10-mile inbound call on the YWOL CTAF (Common Traffic Advisory Frequency). I then descended to circuit height by doing a couple of orbits on the “dead” side of the YWOL circuit (on the left hand side of the runway with reference to the above diagram).

At circuit height, I made the mandatory CTAF call indicating my intentions and joined the circuit “mid-crosswind”. That is to say, I flew at circuit height across the runway, from left to right as you view this diagram, more or less right across the middle of the runway between the north and south ends.

Once across the runway and on the “live” side (on the right hand side of the runway with reference to the above diagram), I then turned onto the downwind leg of the circuit, making the mandatory CTAF call as I was doing so.

Now, here’s where things got interesting. The following amended diagram hopefully illustrates the situation.

As I flew downwind, and (as I recall it) not long before I was due to make my base turn, I heard a call over the CTAF, “Traffic Wollongong, Diamond XXX [I don’t remember his call-sign] joining base for 11”. (Actually it was for runway 16, but I’m trying to stay consistent with my diagram). I glanced ahead of me and to my right, and a second or two later, there he was, joining the base leg from my right – and it was the first time I’d seen him! I was not a little surprised. Here I’d been happily tooling along, alone in the YWOL circuit, and all of a sudden I had traffic joining the circuit ahead of me and flying directly across my flight path from right to left.

(The diagram may be a bit misleading insofar as the scale is off. The Diamond was not as close to me as the diagram suggests. But having said that, I felt the separation between our two aircraft was more than a tad too close for comfort).

A split second’s assessment and I decided on two things:

  1. That I was not at risk of colliding with the Diamond – he flew right across my flight path from right to left, and was quickly clear of my flight path. I did not need to take any sort of evasive action. Having said that, if he was any slower, or if he’d been much closer to me when he joined base, I do feel that I would have had to take evasive action.
  2. To maintain adequate separation between the Diamond and me, I would have to fly an extended downwind leg and then turn base later than I usually would, in order to give the Diamond time to land and clear the runway before I came down behind him. (I would have course had the option to go around had I approached the runway and felt that landing was still not safe, but this did not eventuate).

So that was that. The Diamond landed. I flew a slightly longer downwind leg, then turned base and final and landed uneventfully.

My take-outs

The more I’ve thought about this since, the more I think it’s one of those classic learning situations in aviation in which, regardless of who’s “in the right” and who’s “in the wrong”, the critical importance of maintaining situational awareness and practising alerted see-and-avoid techniques is highlighted.

Was I in the wrong, or was the Diamond?

It’s difficult to say. I definitely felt that the Diamond’s entrance to the circuit was too sudden, that he did not give enough notice of his intentions, that he was too close to me, and that he was unaware of my presence in the circuit.

Checking the current AIP (Aeronautical Information Publication), I note that para 47.7.1 in AIP ENR 1.1 notes the following (the italics are mine):

Joining on Base

Joining in base leg, whilst not prohibited, is not a recommended standard procedure. CASA recommends pilots join the circuit on either the crosswind or downwind leg. However, pilots who choose to join on base leg should only do so if they:

  1. have determined the wind direction and speed;
  2. have determined the runway in use;
  3. give way to other circuit traffic and ensure the aircraft can safely (no traffic conflict likely) join the base leg applicable to the circuit direction in use at the standard height; and
  4. broadcast their intentions.

I am aware, from some introductory Googling, that there is a wide variety of opinion around the practice of joining circuits on the base leg (and even more so around joining on final). Some are for it, some against it. And CASA does not make things easier by not recommending, but then failing to forbid, joining on base. Based on the above, it must be acknowledged that the Diamond was not breaking any rules simply by virtue of joining the circuit on base. However, I certainly believe that the Diamond contravened provision (c) in that he did not give way to me, and in that he did not ensure adequate separation between his aircraft and mine. I also feel that he contravened provision (d) insofar at it was literally only a second or two between his radio call for joining base and his proceeding to do so.

On balance, I’ve arrived at the view that – strictly speaking – the Diamond was in the wrong.

So what? What about my situational awareness?

With all that said, I have to acknowledge the fact that I was completely unaware of the Diamond’s presence until his base call and joining base. I did not see him until alerted to his presence by his radio call. And I can’t say for sure whether he did, or didn’t, make his inbound call at 10 miles or closer. If he had made an inbound call, you could certainly make the case that good airmanship on my part – had I been listening out carefully on the YWOL CTAF – would at least have put the Diamond somewhere in my “mental picture” of the YWOL traffic situation and made me at least aware that he was out there somewhere and inbound. Had this been the case, I could perhaps have been more vigilant when joining and in the circuit, perhaps been slightly more ready to respond to his arrival, and perhaps have seen him earlier through more active scanning.

What did I learn?

  1. Be super-vigilant in the circuit, especially at non-towered aerodromes. Just because you haven’t heard radio calls from other aircraft doesn’t mean they aren’t out there – somewhere – perhaps quite close to you.
  2. Don’t assume you’re alone. Even if you can’t see any other traffic – if you’re not hearing any – expect the unexpected. Keep scanning during all legs of the circuit, including directions from which you may not normally expect traffic to appear.
  3. It doesn’t matter who’s “right” and who’s “wrong” – you’ve still got to stay safe. This was not a particularly close call, but it could have been, and in the heat of the moment, no-one cares who was the good guy and who was the baddie. It’s still my responsibility to remain alert and to see-and-avoid, to keep myself and my aircraft safe, even if the other guy’s not doing the right thing.
  4. I did the right thing and handled the situation well. I heard the Diamond’s call; I immediately spotted him; and I took positive steps to avoid him and to ensure adequate traffic separation.

As a result of this experience, hopefully I am now a safer pilot. But I’d be really curious to hear the views of any other pilots reading this.

14 responses to “Close encounters in the circuit: Was the other guy in the wrong, and what can I learn?

  1. Pingback: Close encounters in the circuit: Was the other guy in the wrong, and what can I learn? (via MidLifePilot’s Flying Blog) « Calgary Recreational and Ultralight Flying Club (CRUFC)

  2. Pingback: Close Calls, Near Misses, and Collisions |

  3. Dave,

    Good discussion. It served as a springboard for my blog today. Check it out…


  4. Hi Joe

    Many thanks, glad it helped and thanks for your kind comments. I enjoyed your post on this!


  5. Wow, I’ve always been afraid about stuff like that would come up but never had to deal with it first hand. Great observations on the whole situation.

    • Thanks Jeanne. Maybe it’s a reflection of the busy nature of most of the airspace in which I fly … I kind of expected to deal with this sooner or later, but didn’t expect something like this so early in my flying.

      There’ve been 1 or 2 other occasions around my home aerodrome (Bankstown, Australia), when flying dual with my instructor, that other aircraft have come uncomfortably close to us. Not sure whether this is just a reflection of Bankstown traffic(2nd busiest GA airport in Australia and a major training airport) or also of the quality of air traffic control in our Class D airspace … It’s always been me (or my instructor) to spot the risk first and take immediate and positive steps to avoid. Though none of these events have been as “close” as my landing at Wollongong.

  6. Dave,

    That’s an uncomfortable situation to be in, but having said that, you picked up the Diamnond’s position early enough to know what you might have had to do if the situation demanded it. That’s a good thing, sort of.

    Did the Diamond make their 10-mile and 5-mile calls on approach? They really shold have let down on the dead side and then entered circuit on midfield crosswind, slipping in behind you… by which time you’d well and truly be on short final.

    I enjoy flying more in untowered airfields these days, but in situations like that, I can also appreciate the circuit procedures in places like Jandakot where there’s ATC.

    You’re going to be a better pilot for this experience.

  7. Patrick, I can’t *swear* that the Diamond didn’t make 10-mile and/or 5-mile calls. I’m pretty sure he didn’t, I just can’t be 100% sure. I was – as you can imagine for a first solo approach to a non-towered aerodrome – absolutely on the edge of my seat trying to listen out for traffic. And I don’t recall any radio traffic. So – 98% sure, just not 100%.

    Definitely learned from the whole experience, however.

  8. Pingback: Joining circuit on base/final legs - Good or bad? - PPRuNe Forums

  9. Just to offer a slightly different approach, the issue here, as I see it, is radio calls not where he joined.

    Imagine the same scenario, you doing exactly the same and the other aircraft joining the downwind leg earlier. You make all the calls you said you did, he makes one saying that he is joining downwind moments later and now he is right behind you. He should be making the call to say what his intentions are before he enters the circuit. Make your 10 mile call, then when you work out how you plan on joining the circuit make a call, then make another as you join.

    If he had have done that then you would have expected him to be coming in on the base leg and then you could have called him and told him (again) where you are. You both know what is going on and can plan accordingly.

    You think it is bad about CASA allowing a base or final join. I think it is worse that you can make a call at 10 miles saying you intend to join the circuit and then there are no other mandatory calls (unless joining final). From memory the AIP’s say something like make broadcasts to allow for separation and safety. Peoples views on safety are wildly different!

    Even more crazy is that at some CTAF aerodromes carriage of a radio is not mandatory……

  10. Blake, I entirely agree. The CTAF radio call regime should surely be mandatory, including inbound at 10 miles, inbound at 3 miles (straight in approaches), and the calls for joining and proceeding through the circuit at whatever position including mid-crosswind, downwind, base, final. If it’s worth “suggesting” for safety reasons, surely it’s worth mandating so at least the discipline is taught consistently in our flying schools?

    Some of the considerable amount of feedback I’ve had on this blog post – from older/more experienced pilots if I can hazard a generalisation – offers the view that we “used” to be expected to maintain appropriate separation and traffic flow in and around the circuit based on visual look-out and we’ve perhaps grown over-reliant on radio calls as a proxy for good see-and-avoid techniques?

    I think there’s some truth in that view, at least to the extent that your primary means of safety and avoidance should always be your eyes by maintaining an active scan at all stages of your flight. “You fly the aircraft, not your radio”. Having said that, we’ve got the radio in the aircraft with us, why not use it to our advantage? Even after a few short nav flghts I’ve not found it a hard discipline to pick up …

  11. Pingback: Nav 6: 2nd solo nav flight Bankstown-Cowra-Orange-Bankstown « MidLifePilot's Flying Blog

  12. I had an instructor recently that had asked me to replicate his commands like a “symphony” on downwind, to power back, trim, carb heat, flaps & turn base leg on his command. Without sight of the traffic on mile and 1/2 final, which we were informed of by ATC, I turned on his ‘turn base’ command, and soon closed in on an aircraft on final. We were likely 500 feet vertically and horizontally away from the aircraft but nonetheless I have always been instructed to turn base once your traffic is passed your wingtip to allow separation. I understand that we all make mistakes, but when he insisted on rambling about how correct he was and couldn’t own up for a premature base leg call, I fired him the same day. A few weeks later, another student had released him from duty as well, and so the school followed en suite. Pilots like him are out there; not that your article is the same situation but I figured I’d share my awareness and caution of the air. A quick heads up, maybe misunderstood this part of your article, but if the winds are blowing from 29 I would think you’re better off departing / arriving on 29 rather than along with the wind on 11. In Canada where I’m born, raised & currently training, the winds are measured from the magnetic angle they would hit you at, and you would depart on a runway with the same magnetic heading.

  13. Interesting experience with your instructor! During my GFPT (General Flying Proficiency Test) I actually had our flying school’s CFI in my ear for not turning base early enough – he felt I was getting too close to controlled (Sydney) airspace to the east of the aerodrome. Like yourself, I was waiting for some preceding traffic on base/early final to pass my wingtip before I turned base. I explained my rationale to him and he was satisfied with that.

    Regarding wind direction and runway selection: thanks! You picked up a major editorial flaw in my article, don’t know what I was thinking when I wrote it or whether I didn’t adequately proofread. I will amend immediately. 🙂 *facepalm*

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