Circuit Procedures
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Jumbo Driver, how do you arrive at a "45 degree turn against the circuit direction in the midfield downwind position?" being the norm in the US of A?
If I remember correctly, you arrive at CIRCUIT (PATTERN) height after announcing your plan on unicom: for example, "Puddletown traffic, Cessna 152 joining downwind for 09". And you simply slot in after having a jolly good look, and follow the other guys around. How does that compute to being a 45 degree turn AGAINST the circuit (PATTERN) direction? Seems to me you have joined downwind, in the same direction of flight as everybody else. And then two left turns, unless the local rules call for RH PATTERNS in the airfield information, which of course you have checked ahead of going there. Simple.
But that overhead join at Wellesborne gets me completely confused. And even on a murky day the local numpties don't turn on their landing lights or indeed nav lights which could help everybody else see them. Saving money perhaps?
If I remember correctly, you arrive at CIRCUIT (PATTERN) height after announcing your plan on unicom: for example, "Puddletown traffic, Cessna 152 joining downwind for 09". And you simply slot in after having a jolly good look, and follow the other guys around. How does that compute to being a 45 degree turn AGAINST the circuit (PATTERN) direction? Seems to me you have joined downwind, in the same direction of flight as everybody else. And then two left turns, unless the local rules call for RH PATTERNS in the airfield information, which of course you have checked ahead of going there. Simple.
But that overhead join at Wellesborne gets me completely confused. And even on a murky day the local numpties don't turn on their landing lights or indeed nav lights which could help everybody else see them. Saving money perhaps?
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I think that the point being made may be that in a left-hand circuit, the turn from the 45deg leg to establish on the downwind track is a right turn, thus going against one of the UK rules of the air.
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Joining straight in I'm a fan of the military Initials join, though I appreciate that's an even more esoteric option and can't be done at a civilian airfield. It certainly avoids a 270 degree turn in the overhead before the deadside descent.
Again the OH should be at 2000 in the OH not 1900 1800 1700 or lower which is often the case with cloud base restrictions and again often with aircraft scud running the base of those clouds and should you question the advisability of having everyone approach the same point at exactly 2000 feet?
Pilot Information - West London Aero ClubWest London Aero Club
I am beginning to wonder if the bias for or against the OH join is simply a matter of your normal a/c type - high or low wing.
For me the descending, dead-side, continuous turn gives me maximum visibility for a leisurely assessment of the total airfield environment. That is why I like it, and I do not recognise Pace's "unnecessary 90 degree blind turns".
My very limited hours in a high wing have probably never included an OH join but I am all too aware of how horrendously the dropped wing blocks ones view in a typical Cessna. So I can see how such a joining technique may not seem nearly so nice for high wing types.
I remember, when being taught the OH join, my instructor explained the 1500ft minimum at final runway crossing ensured you were still above the departing traffic "..unless its a departing 757 in which case it may be 1500ft above you by that point!" 
However, commercial jets aside, I think it is beholden on departing aircraft at a GA airfield to be aware that the OH join is an accepted procedure and behave accordingly.
For me the descending, dead-side, continuous turn gives me maximum visibility for a leisurely assessment of the total airfield environment. That is why I like it, and I do not recognise Pace's "unnecessary 90 degree blind turns".
My very limited hours in a high wing have probably never included an OH join but I am all too aware of how horrendously the dropped wing blocks ones view in a typical Cessna. So I can see how such a joining technique may not seem nearly so nice for high wing types.
I've had ATC hold an airliner on the runway until I (making an OHJ) was clear of his take-off path. Would it be reasonable to hope/expect ATC to be aware of the performance of a "super-performing sports job" and take similar precautions?
However, commercial jets aside, I think it is beholden on departing aircraft at a GA airfield to be aware that the OH join is an accepted procedure and behave accordingly.
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http://www.caa.co.uk/docs/33/ga_srgw...osterJan09.pdf
This gives a good picture of the standard OH join in this case a join which could have involved one turn from base to final involves 5 turns.
Every extra turn involves increased collision especially unlike the picture where you might be mixing several aircraft or more some high wing, some low wing some fast some slow.
Also consider the VFR rules vertically clear of cloud unlike many who scud run the bases to the overhead or where the bases do not meet the published procedure and it has to be a very nice day for the OH to work as published something which is rare in the UK.
So while I appreciate its place in joins in good weather I do not like the STANDARD part and pilots attempts to fly it in less than perfect which happens all the time.Even from ATC telling aircraft to Join OH when bases do not meet the VFR requirements vertically clear of cloud or OH join heights
Pace
This gives a good picture of the standard OH join in this case a join which could have involved one turn from base to final involves 5 turns.
Every extra turn involves increased collision especially unlike the picture where you might be mixing several aircraft or more some high wing, some low wing some fast some slow.
Also consider the VFR rules vertically clear of cloud unlike many who scud run the bases to the overhead or where the bases do not meet the published procedure and it has to be a very nice day for the OH to work as published something which is rare in the UK.
So while I appreciate its place in joins in good weather I do not like the STANDARD part and pilots attempts to fly it in less than perfect which happens all the time.Even from ATC telling aircraft to Join OH when bases do not meet the VFR requirements vertically clear of cloud or OH join heights
Pace
Its a nice picture but of course gives one example. Of course one might have approached the field on the dead side and traffic willing merely "decended dead side and turned down wind... What is wrong with that?
I am surprised that this CAA guidance would have us crossing the depart-threshold at 1000ft. Not what I was taught and seems to risk unnecessarily coming into conflict with a high performance departure. Surely the key thing is to be flying level at 1000ft before joining late downwind? With all but the tightest circuit I think a 1500ft crossing will work, and adds a significant safety margin.
With all but the tightest circuit I think a 1500ft crossing will work, and adds a significant safety margin.
For me a fundamental point is that whether you're doing an OHJ or some sort of direct join you must be established at the circuit height before entering the live part of the circuit.
Whichever method one uses to join the circuit there is never going to be a "one type fits all". Traffic and situational awareness are vital to conducting a safe join. My observation is that circuit joining (and departure) is sometimes poorly taught.
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Pace, that is a lovely ideal picture of the overhead join,CAVOK conditions, published by an optimist. Why not simply approach the airfield at 1,000, I used to do this all the time going to Enstone for fuel; call them up abeam Hook Norton, and then slot in downwind. What is this prohibition against a right turn? that's news to me. I had a fright climbing out of Wellesborne when the overhead joiner skated across too close for comfort, that danger shows up clearly in the lovely ideal picture. That situation simply would not arise with the American join downwind at circuit height.
And don't be shy about turning on your lights. Come on, chaps, see and be seen.
And don't be shy about turning on your lights. Come on, chaps, see and be seen.
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Mary
I am in total agreement with you I consider the OH join to be a relic from the past and fraught with extra risk.
like you under a low overcast base had an aircraft cut across the down wind leg proclaiming he was joining overhead and starting his descent towards the deadside early the cloud base was up and down between 1400 and 1500 feet where the FIS at the airfield cleared him for a standard OH join. He came straight through the down wind leg.
This brings another unthought of problem that many of these uncontrolled airfields other than pilot reports do not have accurate cloud base determining ability and will clear such aircraft to join in a fashion which isn't workable
Pace
I am in total agreement with you I consider the OH join to be a relic from the past and fraught with extra risk.
like you under a low overcast base had an aircraft cut across the down wind leg proclaiming he was joining overhead and starting his descent towards the deadside early the cloud base was up and down between 1400 and 1500 feet where the FIS at the airfield cleared him for a standard OH join. He came straight through the down wind leg.
This brings another unthought of problem that many of these uncontrolled airfields other than pilot reports do not have accurate cloud base determining ability and will clear such aircraft to join in a fashion which isn't workable
Pace
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Ahem! It is my understanding that an UNCONTROLLED airfield is not qualified to CLEAR anybody to do anything! Even using the supposed magic words "At your discretion!" That goes for a Flight Information Service, or a Base station, unless they've changed the rules since I looked at them.
All any uncontrolled radio ground station is entitled to do is to give information. Not CLEARANCES.
All any uncontrolled radio ground station is entitled to do is to give information. Not CLEARANCES.
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Mary
You have caught me out this time 😎yes of course you are right but I still know such airfields where little hitlers will still tell you to join OH )))
Pace
You have caught me out this time 😎yes of course you are right but I still know such airfields where little hitlers will still tell you to join OH )))
Pace
Airfields like Denham, White Waltham and Fairoaks are embedded in the Heathrow Class D CTR and hence altitude limited, so a 2,000ft OHJ is impossible. Go above 1,000ft QNH at Denham and you might be 'collected' by a '146 bound for Northolt!
I must have led a sheltered life - I've never encountered any of these problems when executing an OHP but I have had to Go Around on several occasions when aircraft have barged into a busy circuit by flying a straight in etc at a non controlled airfield.
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If aircraft are on final they should have priority to aircraft flying down wind it takes nothing to extend down wind and create a decent spacing so an aircraft can clear ahead.
If an aircraft turns base then chops in front that aircraft should not do that.
on final with one ahead create the space with speed control and important in todays age of GPS is to give final distances and communicate with other aircraft.
Part of the problem is aircraft flying circuits and cutting in on aircraft on final approach thinking they have priority which they do not only turn onto base and final when you are clear to do so
FFB Why would you have to go around unless you were on final and hence how could someone barge in on final unless they overtook you? A go around is a final procedure usually on very short final or when unable to land not a base or downwind procedure! I think I know what you mean
Pace
If an aircraft turns base then chops in front that aircraft should not do that.
on final with one ahead create the space with speed control and important in todays age of GPS is to give final distances and communicate with other aircraft.
Part of the problem is aircraft flying circuits and cutting in on aircraft on final approach thinking they have priority which they do not only turn onto base and final when you are clear to do so
FFB Why would you have to go around unless you were on final and hence how could someone barge in on final unless they overtook you? A go around is a final procedure usually on very short final or when unable to land not a base or downwind procedure! I think I know what you mean
Pace
Last edited by Pace; 5th Jun 2015 at 19:25.
Avoid imitations
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The problem with extending downwind is that subsequent aircraft are forced to do the same, or risk a conflict at the normal base leg to final point.
When the circuit is busy, once someone extends downwind the circuit pattern becomes longer and longer until aircraft can end up outside the ATZ. Pilots lose situational awareness because more than one aircraft can be on final, but spaced downwind of the threshold. This effectively results in the same situation as someone just calling "long final" and joining straight in.
Better to extend upwind to gain extra spacing.
Btw, if you try extending downwind at a military airfield you may be told to break off your approach, go to the dead side, and rejoin the circuit from there.
When the circuit is busy, once someone extends downwind the circuit pattern becomes longer and longer until aircraft can end up outside the ATZ. Pilots lose situational awareness because more than one aircraft can be on final, but spaced downwind of the threshold. This effectively results in the same situation as someone just calling "long final" and joining straight in.
Better to extend upwind to gain extra spacing.
Btw, if you try extending downwind at a military airfield you may be told to break off your approach, go to the dead side, and rejoin the circuit from there.
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ShyTorque
i am half stirring things but there still is a point that aircraft on base do not have a priority over aircraft established on final and to only establish on final when its clear to do so.
Even in the OH join and conventional pattern pilots may have different base points. One ahead may turn later meaning the aircraft behind is turning ahead of him ( that happens a lot especially mixing less experienced and experienced pilots. The pilot behind should still extend to slot in behind the aircraft he is following and not chop him up by turning inside him. As stated I have seen that on numerous occasions.
Final is the right of aircraft already established and those aircraft have to be configured and stabilised. You may have faster aircraft which are adding drag to get stabilised to land and and back to VREF there is nothing worse than Billie Bob doing multiple circuits chopping across in a Cessna 150
The secret is communicate
Pace
i am half stirring things
but there still is a point that aircraft on base do not have a priority over aircraft established on final and to only establish on final when its clear to do so. Even in the OH join and conventional pattern pilots may have different base points. One ahead may turn later meaning the aircraft behind is turning ahead of him ( that happens a lot especially mixing less experienced and experienced pilots. The pilot behind should still extend to slot in behind the aircraft he is following and not chop him up by turning inside him. As stated I have seen that on numerous occasions.
Final is the right of aircraft already established and those aircraft have to be configured and stabilised. You may have faster aircraft which are adding drag to get stabilised to land and and back to VREF there is nothing worse than Billie Bob doing multiple circuits chopping across in a Cessna 150
The secret is communicate Pace
Last edited by Pace; 5th Jun 2015 at 20:18.