Circuit height on Ev4 plates
Circuit height as currently shown I feel could be misleading and is, I believe, wrong.
Circuit height should be either shown at what it actually is i.e. 1000ft, 800ft or whatever or alternatively it needs to be qualified to what is actually being shown i.e. airfield elevation + circuit height( QNH). A lot of pilots, at least in the UK fly as I do on QFE when in the circuit and showing as it currently is has the potential for confusion.
All the guides I know of, (Pooleys,AFE etc) just show the circuit height and then the individual pilot decides himself whichever he wishes to fly it either QNH (+ airfeld elevation)or QFE ( actual height above the threshold)
Either way some sort of clarification is needed on the plate.
please check the attached German DFS plate as an example.
It shows EDRY elev on the top (312 ft), circuit height is 1200 MSL (hence 900 AGL).
Please also note that there are 2 other fields very close to us of which you see their traffic circuits partially in the top right corner.
I don't know if this is the best way of describing where you should be in the air but I agree there definitely is the need for a standard
Yes there needs to be a standard and if you have a published airfield plate then as you say it is normally shown.
However I was actually referring to the Ev4 small airfield layout plates, not published plates. The circuit height is currently being shown as airfield elevation + 1000ft which could be misleading to some.
See attached...Sorry I don't know how to add a screenshot directly.
I see Alan’s point. I never learned flying using QFE, so I never realised the possible confusion. Whenever an altitude in EV is shown without amsl/agl/fl postfix, it is also to be read as amsl. So that can be considered EV’s standard 😉
But I see when used to flying QFE, the circuit alts in AMSL are a pain. Maybe we should do like the French, they display circuit altitudes in AMSL, but the altitude in AGL is displayed between (). So
1200(700) would mean 1200ft amsl, 700ft agl. What do you think?
All UK guides ( Pooleys, AFE etc) normally show circuit height to be flown at AGL, QFE. ( Height above threshold.
Having said that I suppose it doesn't really matter as long as after the circuit height in Ev4 it states what it is you are actually saying. Just state if it QNH or QFE after it is all that is needed was my point to avoid any confusion.
Personally I think the circuit height should always be shown at what is ...AGL
Keep remembering, the ancient pocketfms desktop, ev3 and ev4 always assume AMSL when no reference is given for an altitude. We’ll implement that French system, I think its obvious the lowest value is AGL so something like 1700(1000) says it all I think? No need to do 1700amsl(1000agl) I think?
but just purely for my own interest: how do you know QFE for an airfield? I’ve never learned to use QFE, always AMSL simply because the QNH is always obtainable from a regional FIS (or LARS in the UK?) so approaching an uncontrolled airfield and entering the circuit at the correct altitude is pretty obvious this way. But how do you know what to set the altimeter setting to to land at exactly 0ft (that is what qfe is isn’t it?) when approaching an uncontrolled airfield? Even when controlled, AFIK you always get QNH reported, I don’t recall ever having heard a QFE. Again, just trying to learn something here 🙂
There are quite a few airfields that are now not using QFE unless you specifically ask for it. Redhill only use QNH unless you ask for it. Sherburn in Elmet only use QNH. Perth only uses QNH. So it can be a confusing picture. Yes agreed you can sort it out on arrival/departure by knob twiddling the altimeter either way but it has the potential for confusion if it is not stated on the plate exactly what is being shown.
The easiest way is to just show on the plate the airfield height in feet amsl and the circuit height in feet agl.
I agree about dispensing completely with the bent arrows showing circuit heights/direction on the runway approach plates which could cause confusion at Sywell, Gloucester, Haverfordwest, Wolverhampton,Perth etc and many more who have multiple runways.
The bent arrows though are currently denoting a circuit direction which at some airfields can change as required daily.
No arrows at all would be my view.