Primarily for general aviation discussion, but other aviation topics are also welcome.
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When doing circuits, what height setting do you use on your altimeter?

QFE
130
65%
QNH
67
33%
RPS
No votes
0%
I don't look at the altimeter anyway
4
2%
By riverrock
#1518146
It has been mentioned on a different topic that QFE may be being got rid of, as the main user of this (military) are changing to use QNH.

Would removal of QFE be a loss to you? Would it cause less consistent height holding in a circuit? How do those in the USA survive without it?
#1518151
I'm pretty happy using either qfe or qnh be honest. In fact I deliberately use both from time to time.
RPS makes no sense in the circuit, it's not telling you anything useful then.
After the turn onto base I don't look at the altimeter.
On balance I think it's easier to use QNH. It avoids the "hmmm those houses look a bit big" moment when you've descended to circuit height and forgotten to change the setting. We've all done it...
#1518153
The question refers to 'when doing circuits'. Not, 'when descending to circuit height'. If staying in the circuit, I set my altimeter to zero on the ground. I then fly accurate circuits. Anyone who thinks it's clever to do otherwise needs their nuts crushing.

I'll ignore the USA remark. For obvious reasons. :(
Nick, Rob P, Maxthelion and 3 others liked this
User avatar
By Dave W
#1518156
RPS?! What's wrong with GPS Height? :twisted:

It's not whether RPS (or GPS Height! ;) ) is telling you anything useful, it's that it is inherently telling you (and therefore other circuit users) something that is NOT useful - in fact, quite probably telling you something hazardous.

Either QNH or QFE are fine, since all circuit flyers are using the same pressure datum (with/without an elevation correction of course). The important thing is to fly the correctly chosen height/altitude accurately, as Joe says.
User avatar
By Rob P
#1518158
Regional Pressure Setting

Discussed in the 'High-Low Pressure' thread at length
#1518159
If I'm departing the circuit, I use QNH, as I don't care about circuit height.
When joining, I tend to set QFE when entering the ATZ if its supplied. Saves me calculating what altitude to descend to within the circuit.

(I mentioned the USA as they don't use QFE over there, and I added RPS to remind us not to use it, but also as a prompt about what people do when they don't have a FISO handy to tell you the QNH at your grass strip).
#1518160
RPS = Regional Pressure Setting i.e. "...a forecast of the lowest QNH value within an altimeter setting region" (my bold) i.e. quite possibly not the pressure at the time i.e. not the one that everybody else is using.

I fear this thread is based on a misconception, from the other thread where somebody said (paraphrasing) "I seem to remember that QFE (and RPS) will be done away with..."

RPS to go, maybe yes - there is a consultation, I believe.

QFE to go? An incorrect recollection, not something currently under consultation.
Maxthelion liked this
#1518164
RPS also has a buffer - I don't think its published what that buffer is, but a quick glance suggests its around 10hPa (so 300 feet). It is useful when you are below transition altitude (so can't use a flight level) but not near an airport to use their QFE for terrain clearance (due to that buffer) but if you tried to use it in the circuit you are likely to be at least 300 feet higher than you think you are, and perhaps a lot more (when I looked yesterday, it was 420 feet different than QNH at some airports). The other danger is because of that 300 - 500 foot buffer you can inadvertently climb into / bust controlled airspace.
So it certainly shouldn't be used in a circuit.
#1518166
I do wonder why people get all excited about QFE. Choose to ask for and use it, or don't, it's irrelevant to other people and as ever up to you to use your chosen datum correctly.

RPS is a different matter.
#1518167
If QFE were to go, then the circuit height would become the circuit altitude and would be published as that, so no mental gymnastics required. Popham, say, would then have a circuit altitude of 1400 feet (800+550). That should be accurately flyable!
It would be safer to use QNH all the time below Transition as it would involve much less chance of miss-setting! (Done that by 10mb , houses look awfully big!!)
T67M liked this
#1518168
PPL training in the UK for me has always been to use QFE in the circuit.
When I did my IMCR, QFE was never used.

What I use depends whether I am doing a VFR circuit or an IAP. As my IR(R) is long lapsed, I use QFE. It would not bother me if QFE was scrapped.
#1518174
Warning:
Following is my own opinion...student pilots look away now!!

To me, QFE is just another bit of unnecessary fiddling about with eyes in (and squinted to read that tiny little hectopascal scale in the glare!) during the most likely stage of the flight to have a midair...joining the circuit!

Not smart having everyone at exactly the same height in the circuit either really, when 20 feet could mean the difference between an "Oh shyte!" moment and a series of funerals. A little bit of natural separation goes a long way.

I'm biased because I learnt to fly at around 5000' field elevations, and QFE was an alien and totally unnecessary term to me when I started flying in the UK.
malcolmfrost, johnm, FrankS and 6 others liked this
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