Royal Air Force - DA or DH?
Dumb Colonial but:
” Is not DA used for non-precision approaches and DH for precision ( ILS) approaches. You may not descend below a DA until you have “The Runway Environment” in sight but you decide at the DH whether to land or overshoot and you will descend slightly below the DH due to your downward momentum and inertia while initiating a missed approach.
In both cases referenced to QNH.”
” Is not DA used for non-precision approaches and DH for precision ( ILS) approaches. You may not descend below a DA until you have “The Runway Environment” in sight but you decide at the DH whether to land or overshoot and you will descend slightly below the DH due to your downward momentum and inertia while initiating a missed approach.
In both cases referenced to QNH.”
albatross-No-DA QNH, DH QFE
HP- I wonder what the reds did on the USA tour. Come to think about it what to the TBirds and Blue Angels do?
As for circuit work students at say KRND seem to manage. Virtually the all of the world uses QNH so why not move with the times (albeit belatedly). Even BZN has done so (a major challenge in itself).
ID beat me to the typing.
HP- I wonder what the reds did on the USA tour. Come to think about it what to the TBirds and Blue Angels do?
As for circuit work students at say KRND seem to manage. Virtually the all of the world uses QNH so why not move with the times (albeit belatedly). Even BZN has done so (a major challenge in itself).
ID beat me to the typing.
Last edited by vascodegama; 17th Oct 2022 at 19:17. Reason: Addition
In over 45+ years i of aviating I have not even once been asked to use or even been given the QFE.
I do remember it being briefly talked about on various courses but only as an interesting historical aside.
Probably a good thing as I am so easily confused by new concepts and procedures. A problem often commented upon, sometimes in official writing and at great length, by various bemused instructors and examiners.
.
I do remember it being briefly talked about on various courses but only as an interesting historical aside.
Probably a good thing as I am so easily confused by new concepts and procedures. A problem often commented upon, sometimes in official writing and at great length, by various bemused instructors and examiners.
.
albatross-No-DA QNH, DH QFE
HP- I wonder what the reds did on the USA tour. Come to think about it what to the TBirds and Blue Angels do?
As for circuit work students at say KRND seem to manage. Virtually the all of the world uses QNH so why not move with the times (albeit belatedly). Even BZN has done so (a major challenge in itself).
ID beat me to the typing.
HP- I wonder what the reds did on the USA tour. Come to think about it what to the TBirds and Blue Angels do?
As for circuit work students at say KRND seem to manage. Virtually the all of the world uses QNH so why not move with the times (albeit belatedly). Even BZN has done so (a major challenge in itself).
ID beat me to the typing.
Some airfields use 800ft QFE, some use 1000ft, some use 1200ft, some use a combination depending on whether single or multi engined.
OH LORD...NO!
Please let this die a quick death and spare us what is coming.
We have hashed this to death several times in the past.
Can we just accept the UK goes it alone on this as they do lots of interesting things in aviation.
That is their choice.....leave them to it.
Please let this die a quick death and spare us what is coming.
We have hashed this to death several times in the past.
Can we just accept the UK goes it alone on this as they do lots of interesting things in aviation.
That is their choice.....leave them to it.
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Brize uses QNH, everywhere else in the UK Mil appears to use QFE. AIDU plates have both (M)DA and (M)DH printed on them, though the altitude rather than the height is the primary.
When flying IF some quaint ATC chat remains at military airfields such as confirming the minima over the radio and “cockpit checks, report complete” whereas civvies just expect you to know what you’re doing and be ready (or say if you aren’t) and there aren’t differing instrument rating limits so just one minimum. Always confuses the exchange pilots.
When flying IF some quaint ATC chat remains at military airfields such as confirming the minima over the radio and “cockpit checks, report complete” whereas civvies just expect you to know what you’re doing and be ready (or say if you aren’t) and there aren’t differing instrument rating limits so just one minimum. Always confuses the exchange pilots.
There are many reasons why a controller needs to know what your DH, DA, MDH or MDA is, as well as knowing when your checks are complete. Time, space on this thread and my reluctance to explain prevent me from going into detail.
Re-attack
Part of my logic for suggesting it is time for the UKMIL to make the switch comes from flying fast jets in many different countries. None of which use QFE routinely.
I will additionally admit that, on my first overseas tour (in Canada), my SOP ‘British Officer’ approach to IFR operations did not adequately prepare me for the rigours of operating a Hawk into large, international airports (San Fran Int, Chicago, Seattle and Calgary to name a few). In fact I would go so far as to say the ease and freedom with which we operate in the UK is pretty much unique for military operators worldwide. It is also worth noting that there are many airports where QFE just isn’t possible unless your altimeter can wind down a very long way (Rocky Mountain Municipal outside Denver was my highest at 5673’ AMSL).
I firmly believe we would serve our pilots better by introducing them to QNH from day one. After all, if you really need to know your height above ground most of our military aircraft are now Radalt equipped anyway.
The difference between DH/MDH and DA/MDA operations is minimal in practice. You have to remember a number and make a decision whichever you use. Your actual height above the ground at that point is no different so your ability to manoeuvre to make a successful touchdown is unchanged.
BV
I will additionally admit that, on my first overseas tour (in Canada), my SOP ‘British Officer’ approach to IFR operations did not adequately prepare me for the rigours of operating a Hawk into large, international airports (San Fran Int, Chicago, Seattle and Calgary to name a few). In fact I would go so far as to say the ease and freedom with which we operate in the UK is pretty much unique for military operators worldwide. It is also worth noting that there are many airports where QFE just isn’t possible unless your altimeter can wind down a very long way (Rocky Mountain Municipal outside Denver was my highest at 5673’ AMSL).
I firmly believe we would serve our pilots better by introducing them to QNH from day one. After all, if you really need to know your height above ground most of our military aircraft are now Radalt equipped anyway.
The difference between DH/MDH and DA/MDA operations is minimal in practice. You have to remember a number and make a decision whichever you use. Your actual height above the ground at that point is no different so your ability to manoeuvre to make a successful touchdown is unchanged.
BV
With QFE being an anachronism in the most countries, the term Decision Height is now usually associated with Low Visibility Operations where the vertical element of the approach minima is derived from radio altimeters. ILS Cat II DH is circa 100 ft, Cat IIIA 50ft and Cat IIIB usually NO DH.
Brize uses QNH, everywhere else in the UK Mil appears to use QFE. AIDU plates have both (M)DA and (M)DH printed on them, though the altitude rather than the height is the primary.
When flying IF some quaint ATC chat remains at military airfields such as confirming the minima over the radio and “cockpit checks, report complete” whereas civvies just expect you to know what you’re doing and be ready (or say if you aren’t) and there aren’t differing instrument rating limits so just one minimum. Always confuses the exchange pilots.
When flying IF some quaint ATC chat remains at military airfields such as confirming the minima over the radio and “cockpit checks, report complete” whereas civvies just expect you to know what you’re doing and be ready (or say if you aren’t) and there aren’t differing instrument rating limits so just one minimum. Always confuses the exchange pilots.
No such requirment at civil airfields; pilots are expected to pre brief their minima and to carry out checks when convenient.
Last edited by chevvron; 18th Oct 2022 at 08:13.
If you are wearing an RAF pilot's brevet in the cockpit you should be able to use either without any problem.
I taught a number of AAC pilots procedural IF and we used QFE at mil airfields (except Brize) and QNH at civ fields - and they all managed it very well.
I taught a number of AAC pilots procedural IF and we used QFE at mil airfields (except Brize) and QNH at civ fields - and they all managed it very well.
Brize uses QNH, everywhere else in the UK Mil appears to use QFE. AIDU plates have both (M)DA and (M)DH printed on them, though the altitude rather than the height is the primary.
When flying IF some quaint ATC chat remains at military airfields such as confirming the minima over the radio and “cockpit checks, report complete” whereas civvies just expect you to know what you’re doing and be ready (or say if you aren’t) and there aren’t differing instrument rating limits so just one minimum. Always confuses the exchange pilots.
When flying IF some quaint ATC chat remains at military airfields such as confirming the minima over the radio and “cockpit checks, report complete” whereas civvies just expect you to know what you’re doing and be ready (or say if you aren’t) and there aren’t differing instrument rating limits so just one minimum. Always confuses the exchange pilots.
It strikes me that pilots who habitually depart from and arrive back at the same airfield prefer QFE. Those that don't, prefer QNH possibly because it provides better awareness of terrain around the airfield and the effects of pressure altitude.
Northolt and Odiham's use of QNH will be because they are under the London TMA and it will avoid potential level busts changing late from QFE to QNH on the go around/departure.
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Thank you for all the replies. I had no intention to re-open (again) the QNH v QFE debate.
All I was after was that a demi-god from Central Fun School would jump in with chapter and verse from the METS syllabus.
Given that QFE is still generally used in the RAF, in the multi-crew environment, what is the phraseology in use? 'One Hundred Above'.........'Decide' (like wot i learnt) or a mongrolised version of the continental version 'Approaching Minimums'........'Minimums' followed by that ultimate in buck-passing - 'continue'.
All I was after was that a demi-god from Central Fun School would jump in with chapter and verse from the METS syllabus.
Given that QFE is still generally used in the RAF, in the multi-crew environment, what is the phraseology in use? 'One Hundred Above'.........'Decide' (like wot i learnt) or a mongrolised version of the continental version 'Approaching Minimums'........'Minimums' followed by that ultimate in buck-passing - 'continue'.
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As an aside - Mil ATCOs are not allowed, or taught, to use speed control as a tool when establishing an arrival sequence. Therefore, the 'cockpit checks - report complete" is frequently used as a very coarse technique to get arrivals towards some sort of commonality in approach speeds to maintain a sequence.