Flying Approaches on QNH
Joined: Feb 2005
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From: essex
Changing from QNH to QFE on the approach = room for pilot error in mis setting numbers
Missed approach QFE back to QNH = more chance of "finger trouble" and increased workload / distraction
Alternative = Set QNH and fly to the approach plate QNH decision height or DA.
Missed approach QFE back to QNH = more chance of "finger trouble" and increased workload / distraction
Alternative = Set QNH and fly to the approach plate QNH decision height or DA.
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qfe - never used it. like has been said - do the maths off the plate, and add 1000 to airfield elevation - bingo there's the circuit height. as all kiwis know, we can get 'area qnh' from christchurch or auckland control, which is good enough for all those unattended strips. i'd be reluctant to be flying out of somewhere like taupo (elev. 1335), with someone flying south on qfe, me flying in north on qnh. ouch
Joined: Jul 2006
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From: The 51st State
Thoughts on UK OPS
It is not only in the circuit that you are required to alter the subscale setting. If you do a MATZ penetration your clearance will include, for example, 'Fly at 1500 feet on the Waddington QFE' this requires you to reset your altimeter, when you are busy navigating, planning, listening, looking, flying etc etc etc. Anyone who feels they may not be able to do that successfully or have 'finger trouble' maybe shouldnt be up there. Compared to some of the other stuff we need to do correctly, a subscale change is a fairly minor 'procedure'.
In the military they taught us L.O.I. Limitation - Operation - Indication. That means when you operate something, switch, lever, altimeter, whatever - you should do it. Then CHECK its correct!
NB: Incidentally the MATZ/QFE thing is in one of the airlaw exams!
Having said that my personal preference is for QFE. I know there are other procedures in other places but in the UK we have QFE and you can always access the information if you have radio contact with the field. In high places, winding several thousand feet off the altimiter is both a pain and an unnecessary distraction but in the UK its never very much. Furthermore, when you have altered it you can immediately check whether you were correct (LOI) not so easy with mental arithmetic!
Anyway, my two pennys now inserted I'll B
R off and go flying!regards
N/S
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With 150 - odd aerodromes in NZ and only some 15 controlled, and maybe another 10 with AWIB, using QFE would be nothing short of irresponsible down here.
Does any kiwi/aussie use it? And for a UK pilot, how do you set QFE when 5 miles out from an unattended aerodrome?
Does any kiwi/aussie use it? And for a UK pilot, how do you set QFE when 5 miles out from an unattended aerodrome?
Joined: Mar 2000
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From: U.K.
You either just adjust the pressure setting for the field elevation to give a rough QFE, or just use QNH. Since the UK is relatively flat (in comparison to the states for example) there are rarely many problems.
Last edited by Say again s l o w l y; 6th September 2006 at 00:06.
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From: Orlando, Florida
It's an interesting debate from two sides, I think.
I find all my Floridian flying is prety much height above ground and altitude above sea level, at the same time, no matter what setting I have in the window.....it's all so flat and, near as dammit, sea level.
When I wander across to Arizona, however, there are airfields at 1000', 1500' and 2000' amsl - and lumpy ground rising into the 4 or 5 thousands.
It does take some mental gymnastics when operating into the higher level airfields and, even more so when manoeuvring (stalling, I/F flying etc) over the lumpy bits, when 80% of the day to day flying is done in Florida.
Being able to GET a QFE and set it in the second altimeter as a cross check would be a comforting thing - but still operate the number one altimeter on QNH as discussed so many times in this thread.
I trained, and qualified for licence, in the world of set QFE, and did find the transition to operating QNH only, a little bit difficult at first - and fully understand the concerns of those who still favour it......however, now that I'm used to QNH only, and understand it better, it does make sense.
Bit that does scare me, to an extent, is that pilots are still talking (even in this thread) about setting QNH, adding 1,000' to airport elevation and determining circuit (or decision) HEIGHT. It's a ALTITUDE.
Confusion in communications - especially with a controller who does not use the same national first language as the pilot, may result in exactly the same sort of problem that the QNH only pilots are worried about - aircraft on different settings being at the same level.
You have to call it something - so why not get used to calling it the right thing, ALTITUDE.
I find all my Floridian flying is prety much height above ground and altitude above sea level, at the same time, no matter what setting I have in the window.....it's all so flat and, near as dammit, sea level.
When I wander across to Arizona, however, there are airfields at 1000', 1500' and 2000' amsl - and lumpy ground rising into the 4 or 5 thousands.
It does take some mental gymnastics when operating into the higher level airfields and, even more so when manoeuvring (stalling, I/F flying etc) over the lumpy bits, when 80% of the day to day flying is done in Florida.
Being able to GET a QFE and set it in the second altimeter as a cross check would be a comforting thing - but still operate the number one altimeter on QNH as discussed so many times in this thread.
I trained, and qualified for licence, in the world of set QFE, and did find the transition to operating QNH only, a little bit difficult at first - and fully understand the concerns of those who still favour it......however, now that I'm used to QNH only, and understand it better, it does make sense.
Bit that does scare me, to an extent, is that pilots are still talking (even in this thread) about setting QNH, adding 1,000' to airport elevation and determining circuit (or decision) HEIGHT. It's a
ALTITUDE.Confusion in communications - especially with a controller who does not use the same national first language as the pilot, may result in exactly the same sort of problem that the QNH only pilots are worried about - aircraft on different settings being at the same level.
You have to call it something - so why not get used to calling it the right thing, ALTITUDE.
Joined: Aug 2002
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From: United Kingdom
Keygrip - you need to get out of the valley occasionally. Try SEZ at 4830ft or GCN at 6609ft. I'm old enough to remember when the most common cause of failure at the IRT was forgetting to set QNH on the go-around.
Joined: Feb 2005
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From: essex
Needlesplit
Anyone who feels they may not be able to do that successfully or have 'finger trouble' maybe shouldnt be up there. Compared to some of the other stuff we need to do correctly, a subscale change is a fairly minor 'procedure'
I Understand your comment and yes I can set and check a subscale setting but the point I am making is that if you don't need to then why bother ?
Get rid of unnecessary tasks and boil it down to required essentials which will lead to more efficient and safer flying with less room for human error
If you think that humans are infallible have another look at the accident reports. My point is that we do make mistakes occasionally so anything that reduces the likelihood has got to be good
And yes I know that it is possible to screw up the maths but it is maths that a 5 year old could do
Anyone who feels they may not be able to do that successfully or have 'finger trouble' maybe shouldnt be up there. Compared to some of the other stuff we need to do correctly, a subscale change is a fairly minor 'procedure'
I Understand your comment and yes I can set and check a subscale setting but the point I am making is that if you don't need to then why bother ?
Get rid of unnecessary tasks and boil it down to required essentials which will lead to more efficient and safer flying with less room for human error
If you think that humans are infallible have another look at the accident reports. My point is that we do make mistakes occasionally so anything that reduces the likelihood has got to be good
And yes I know that it is possible to screw up the maths but it is maths that a 5 year old could do
Joined: Jun 2002
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From: Europe
Further East
In this whole universe east of the Urals you talk about they also use Meters for expressing altitude and height, Km/hour for speed , Meters per second for wind, and it does not seem to me all this makes the flying any easier or safer, in most cases it can make it more dificult and unsafe as you probably know .
Official PPRuNe Chaplain
Joined: Apr 2001
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From: Witnesham, Suffolk
I was taught QFE, because that is what PPLs did in those days. Then I did the IMC rating, and found that nasty little trap that if you fail to set QNH on the missed approach, you fail (I never did, but came oh so close!).
So I taught myself to fly QNH. Then I did a load of flying in California and Arizona, including Big Bear, Grand Canyon, and Sedona. That convinced me! There's no chance of setting a QFE for those places!
If a MATZ tells me to use QFE, I'll do so - but the other altimeter will be on QNH, so I know where I am versus local terrain.
So I taught myself to fly QNH. Then I did a load of flying in California and Arizona, including Big Bear, Grand Canyon, and Sedona. That convinced me! There's no chance of setting a QFE for those places!
If a MATZ tells me to use QFE, I'll do so - but the other altimeter will be on QNH, so I know where I am versus local terrain.
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From: Buggleskelly
You have just quoted the reason why QNH is now used by most airlines, it reduces ERROR CHAIN.
Its not your setting above the ground that important its the ground below the setting that kills you
Its not your setting above the ground that important its the ground below the setting that kills you
