Radio calls in the circuit

[old man emu]

I know that a landing aircraft is required to broadcast its intention to turn onto Base Leg, but it it also OK to report turning onto Final?

 

The reason behind my question is this. The flying event I am trying to run involves the contestant making good the ETA claimed in the flight plan for the event. Therefore I have to have a way of noting the time of touchdown.

 

My first idea was to mark out an area on the runway, about 50 metres long, near the threshold, and ask pilots to make that space their landing zone. I was going to station observers adjacent to that area to observe the touchdown and record the time. Then I began to worry about the safety of the observers, although the risk level  of being hit by a landing aircraft would be minimal, but, no doubt, extreme in CASA'a eyes.

 

So I thought that, if I monitored the circuit frequency, I would know which aircraft was turning onto the Base Leg. Then, I was going to ask pilots to make a short broadcast " <call sign> <Turning Finals>". I would record that time. To determine time of touchdown I was going to find the most common airspeed of the contestants when they turned final (book value), and calculate a time to descent from 500 ft based on that airspeed and wind strength and direction and add that to the time the pilot reported turning Finals. The same value would be added to every aircraft.

 

I'm expecting pilots to fly normally on the Final leg, not full STOL, nor C-130 tactical approaches. Gyrocopters will just have to wear fixed-wing values.

 

MY QUESTION IS:

Is it safe, considering workload, for a pilot to make that short broadcast at that point?

 

 

[facthunter]

Why not make the CALL    IDENT."Clear of runway"? Good to know and not a time of pressure   Nev

[old man emu]

6 minutes ago, facthunter said:

Why not make the CALL    IDENT."Clear of runway"? 

Hadn't thought of that. That's a lot easier and has the advantage of telling following aircraft that the runway is clear for landing. I just hope that we don't get the Oshkosh problem and have to have aircraft land long or short due to congestion.

 

Like the majority of rural aerodromes, there are no constructed taxiways. However, the other day I took a run in my car along a suitable path for a taxiway and had no problems at 30 kph in a car with sports suspension. What we are going to do is lay out a path as indicated here by mowing the grass very short. We'll use empty 20 litre herbicide drums secured to the ground to delineate the taxiway. We are also going to make short taxiways about every 100 metres so that aircraft only have to go about 50 metres after slowing sufficiently before they can clear the runway. 

 

 This is a part diagram. The runway goes a lot further in the 22 direction, and there will be a runup bay at the threshold of 04.

[turboplanner]

1 hour ago, old man emu said:

I know that a landing aircraft is required to broadcast its intention to turn onto Base Leg, but it it also OK to report turning onto Final?

 

The reason behind my question is this. The flying event I am trying to run involves the contestant making good the ETA claimed in the flight plan for the event. Therefore I have to have a way of noting the time of touchdown.

 

My first idea was to mark out an area on the runway, about 50 metres long, near the threshold, and ask pilots to make that space their landing zone. I was going to station observers adjacent to that area to observe the touchdown and record the time. Then I began to worry about the safety of the observers, although the risk level  of being hit by a landing aircraft would be minimal, but, no doubt, extreme in CASA'a eyes.

 

So I thought that, if I monitored the circuit frequency, I would know which aircraft was turning onto the Base Leg. Then, I was going to ask pilots to make a short broadcast " <call sign> <Turning Finals>". I would record that time. To determine time of touchdown I was going to find the most common airspeed of the contestants when they turned final (book value), and calculate a time to descent from 500 ft based on that airspeed and wind strength and direction and add that to the time the pilot reported turning Finals. The same value would be added to every aircraft.

 

I'm expecting pilots to fly normally on the Final leg, not full STOL, nor C-130 tactical approaches. Gyrocopters will just have to wear fixed-wing values.

 

MY QUESTION IS:

Is it safe, considering workload, for a pilot to make that short broadcast at that point?

 

 

Given that at one event where contestants were flying around Australia one called "XXX on loooooong final"  when I had just turned downwind and found him heading straight for me, and the liking of a lot of pilots to only do straight in landings on cross country flights, I'd say you probably wouldn't get the accuracy you were looking for.

[pmccarthy]

I thought turning final was a standard call. Last chance to avoid a conflict.

[facthunter]

When you have a lot of arrivals expected having them all do a circuit is not wise. Experience has proven straight ins are not as dangerous as first considered. You  are down and out of the traffic quicker and the circuit is less or not congested.  Pilots have to have a way of safely going around if something happens ahead Have a plan. Nev

[spenaroo]

9 minutes ago, pmccarthy said:

I thought turning final was a standard call. Last chance to avoid a conflict.

....... "standard call"
in my limited experience there is no such thing.

[facthunter]

 For track distance you are committed on turn to base pretty much. The most dangerous place in a circuit is final.  Nev

[aro]

3 hours ago, facthunter said:

When you have a lot of arrivals expected having them all do a circuit is not wise. Experience has proven straight ins are not as dangerous as first considered.

I don't believe that. What do you do if you have someone on a straight-in doing 75 knots behind someone doing 65? And then someone (or more than one) goes around?

 

The circuit gives you a chance to see other aircraft, figure out where you are in the sequence, and adjust spacing. That is all more difficult with straight in approaches. Multiple aircraft in the circuit can manage spacing well enough that runway occupancy becomes the limiting factor for full stop landings.

 

3 hours ago, facthunter said:

The most dangerous place in a circuit is final.

Straight in approaches put multiple aircraft on final, with less ability to manage spacing, for a longer time. It's hard to see how that doesn't increase risk.

[facthunter]

Aro PLEASE don't pick two sentences out of context. I qualify most of my stuff.  Your varying speed will have to be coped with for a longer time if they all fly a circuit. The main way to lose time in a circuit is to extend downwind and others behind you will have to do likewise. People get impatient and cut inside. I referred to go around's and planning. That can happen anytime and you should always be ready for such things Pass on the right. There won't be any gliding or Conta circuits here. Nev

[old man emu]

I'm getting the feeling that getting a whole lot of pilots to think and act for the benefits to the whole group, rather than being self-centred, is worse than trying to herd cats. 

 

Anyway, Facthunter has given me the answer to my problem that will work to achieve the goal I want. It just means that I'll be a nervous wreck until the last contestant is tucked up in bed, because if any hot shot pilot causes an incident, CASA is coming after me, and they won't  approve future events of the same ilk. So once again, some idiot will stuff up something good.

[aro]

I don't see what context I missed.

 

In a circuit you can fly closer in, further out, adjust your base turn... many options. One time I was in a Gazelle sharing the circuit with a C172. They took off as I turned crosswind. I kept the circuit tight because they were much faster. After 3 circuits I was turning base as they turned final. It's much harder to manage e.g. a C172 behind a Gazelle on a straight in approach.

 

Straight in approaches are a bit of a disaster if you have a lot of traffic (without ATC). They still seem to be uncommon so I'm not sure where your experience with significant traffic would have come from. As soon as someone goes around you have an aircraft doing a regular circuit, so you have straight in approaches mixing with circuit traffic which makes it worse. It tends to fall back to a regular circuit.

[old man emu]

4 hours ago, facthunter said:

When you have a lot of arrivals expected having them all do a circuit is not wise.

Due to the fact that the competition route means that the aircraft will be approaching the circuit area at a right angle, straight in approaches would not be an option to contestants. If you look at the diagram I posted, if 22 is the active runway, then they can enter the circuit at crosswind for 22 and join at the start of downwind. If 04 is the active, then they can let down on the dead side and enter the circuit on the crosswind leg of 04.

 

Also, as a result of the starting order - fastest first - aircraft should be returning in groups related to their cruise speed - C172s withC172s/PA-28s and Gazelles with whatever flies as fast as they do.

[facthunter]

I'm not directing you or anyone to do things a certain way.  I'm just throwing in some considerations and potential issues. Are they all arriving from one direction?  IF they come from everywhere then they just apply the rules and will individually join the circuit in the best way they decide to do and you are not obliged to do anything but hope they are competent and careful. That includes overflying and joining midfield and descending most likely to downwind. You should be able to advise wind direction and runway and a local QNH from a couple calibrated altimeters where you set the elevation  on the instruments.  Nev

Edited January 16, 2023 by facthunter
spelling

[old man emu]

2 minutes ago, facthunter said:

You should be able to advise wind direction and a local QNH

I am thinking of installing a weather station permanently to know wind speed and direction, as well as temperature. 

 

Just be careful: aircraft operate on area QNH. What you are suggesting is broadcasting QFE, but doing that would open a bag of worms where the worms were the size of boa constrictors. Also there is a legal limit to the amount of this type of information that can be broadcast. It's all in the CASA airport operators MOS.

7 minutes ago, facthunter said:

I'm not directing you or anyone to do things a certain way. 

As I said, your suggestion for pilots to advise clear of runway meets my needs perfectly. I've already put it in the race rules.

[aro]

No-one is suggesting QFE.

 

Area QNH is probably sufficient, it shouldn't differ from local by much (from memory there is a limit, where they have to split the area and use 2 area QNH values)

[facthunter]

We officially don't use QFE here. Using it would give you a zero alt on the ground. If the 2 TWO calibrated altimeters read aerodrome height that would be a reasonable way of providing  a QNH like an ATIS does. Otherwise they use the area QNH provided when you flight planned. It's not critical anyhow but they would be told that if they were doing a local flight Putting the actual drome height on the ALT is the approved method.  Nev

[facthunter]

The permitted MAX error used to be 200 feet on the ground. I  recon that is too much. AS I said it's not critical as it's not IFR but the more accurate the better the separation you are relying on works.   QFE can be essential for aerobatics where actual height above ground may be vital. Nev

[aro]

I just looked it up... the max difference is 5 hPa. So the maximum altimeter difference between someone on local QNH and someone on area QNH should be about 150 feet.

 

http://www.bom.gov.au/aviation/data/education/awp-area-qnh.pdf

[facthunter]

That isn't what I'm talking about. Thats a forecast requirement. Mine is related to the requirement to check the Planes altimeter before flight  at an aerodrome where you get the ACTUAL QNH and set your Kolsman scale to it and see what altitude you indicate. The difference between  your indicated height and the actual (depending where you are on the aerodrome) is the error and that is what I'm referring to.  Nev

[kgwilson]

Just to be clear, there are no mandatory calls in CTAF other than to avoid a collision. I have been flying  in to events for many years and they range from full ATC to nothing. At warbirds over Wanaka in 2000, 600 light aircraft flew in on the Saturday morning. Even with temporary ATC it was bedlam. At the reporting point I has told I was No15 & saw nothing in front till we started to bunch up & then drama as the twin comanche in front of me forgot to put his gear down. he did at the last minute.

 

It is recommended that you make a 10 mile call with your callsign, location, height inbound intentions and ETA at the circuit. Then you listen as you should have been doing all along. Depending on traffic chatter you can make a 3 mile call and continue. If there is traffic you should now know the runway in use and determine whereabouts to join the circuit (crosswind, downwind, base or straight in) and make that announcement. If there are aircraft in front say No 2 (or whatever position you are)  to the Cessna on downwind. You then make a call on every leg, (turning base, turning final & even short final depending on traffic). This will also inform those following.

 

There is always contention of what the right thing to do is when there is an event on an the main one is aircraft calling straight in when the circuit is already established. Straight in is fine so long as there is no conflict. Straight in is just joining the circuit on final. The problem arises when you are already in the circuit and No 2 to an aircraft that has just turned base & you are downwind & then someone announces they are on 3 mile final straight in. You have right of way as No 2 in the circuit & this upstart is pushing in & you can't see him. This has happened to me several times. The last 2 times were at the last Evans Head Great Eastern Flyin & Airventure at Parkes in 2019. My response has been to immediately announce turning base & tell the straight in aircraft he is No3. If he doesn't acknowledge, tell him to acknowledge.

 

When things get busy stress levels go through the roof especially of you are not used to lots of traffic. 

[Bruce Tuncks]

I reckon it depends on the amount of other aircraft who are using the radio.  If it is none, then calling "turning left onto base for 36" is a good idea.

If there are lots of other planes, then ( anytime)  calling " following   blah" would do the job. The important thing is to not have a collision due to a misunderstanding.

If there are people doing straight-ins, then it is really  important to speak up.

[pmccarthy]

I would ban straight in approaches in busy traffic.

[old man emu]

You know, all this reeks of "I'm alright Jack. bugger you." I've done all I can think of to make coming to Tooraweenah safe by indicating ideal locations to overfly at 10 nautical. I am NOT ALLOWED to provide air traffic control and I can't afford to pay for Airservices to come and do it. It's not my responsibility to fly people's plans for them. If people want to disregard CASA's advice on operating at a non-controlled aerodrome, so be it.

 

But remember, Arthur Butler Aviation Museum Inc is organising this event for the enjoyment of recreational fliers and with the hope that it will become an annual event. If one arsehole does something that gets up CASA's nose and CASA says, "No more", I'll personally beat the living shit out of the arsehole  so that the next set of wings they get issued will be from the Angel Gabriel.  I've worked too hard and for too long on this project to have some FIGJAM ruin it. 

 

And to add to that. The aerodrome is a place which meets the definition of an inclosed land under the NSW INCLOSED LANDS PROTECTION ACT 1901 . As the event organiser I have the authority to direct any person to leave the inclosed lands and may specify how long they are to stay away.  

[aro]

1 hour ago, kgwilson said:

My response has been to immediately announce turning base & tell the straight in aircraft he is No3. If he doesn't acknowledge, tell him to acknowledge.

Bad idea. You are not ATC so you can't tell other aircraft to do anything.

 

All it takes is for the other aircraft to file a report:

"I was on a straight in approach following another aircraft. After I made a broadcast at 3nm an aircraft on downwind announced they were turning base and told me I was number 3. I was forced to go around, and there was a breakdown of separation as a result"

 

You are 100% on the hook for illegally issuing instructions to other aircraft and knowingly creating an unsafe situation.

 

The reality is that even though aircraft on a straight in are supposed to give way, there is very little they can do for separation other than go around. The aircraft on downwind has many more options, so usually they can adjust to let an aircraft in on a straight-in.