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-   -   Why do the RAF still use QFE? (https://www.pprune.org/military-aviation/387724-why-do-raf-still-use-qfe.html)

thing 8th Jul 2014 07:43

TA of course, I stand corrected by your correction sir. Any idea how high it's proposed to be? I've heard mutterings of 6,000 but surely you would run into the same problem in the mountainy bits of Europe? I believe in the US it's 18,000 which seems to make more sense.

Background Noise 8th Jul 2014 09:03

CAA docs here, relating to UK initially, but it is being looked at for Europe.

Consultation - Transition Altitude | Consultations and Responses | About the CAA

Boudreaux Bob 8th Jul 2014 12:00

Clinging to the QFE Altimeter setting is so....well Wellington like. Then add in all this Transition Height, Regional QNH, and the like. You folks should simply join the real World and go to a single Altimeter setting using QNH below the one Altitude such as the US FAA does.

It makes sense.

It makes things far more simpler and SAFER.

But then whenever did KISS hold sway with the CAA or RAF?

HTB 8th Jul 2014 12:25

Or who use metres for vertical measurement, or another reference for altimeter setting, or crossing an area where there is steep pressure gradient and a great range of high ground...

Mister B

AutoBit 9th Jul 2014 00:16

Boudreaux Bob,

Im sure this has already been said but the whole reason why the UK mil use QFE is to keep it simple. High altitude on 1013, then move across to QFE when switched to either Director or Tower and cleared to a 'height'. How is that complicated? What bit of the KISS principle does that infringe?

Mil ac, particularly FJ and Rotary, fly a lot of visual arrivals (via VRPs) and visual ccts as they save fuel and time. In my experience its far easier to have initials at 1500' and fly a cct at 1000', then at say 2265' and 1765'. It also has the advantage of being the same for every airfield you go to. The alternative is to use the radalt, but this has problems when your airfield is surrounded by hills.

Simple.

Boudreaux Bob 9th Jul 2014 00:30

Yet you still have to use QNH in addition to the QFE don't you?

Of course there is the local QNH, Region QNH, along with the Standard Setting of 1013 for Flight Levels.

We have found it easy enough to do the mental gymnastics you describe and at the same time be able to use a common reference for Terrain and Obstacles which are all based upon MSL which is a nice fit when using QNH Altimeter settings. All of our charts show AGL Heights for Obstacles thus doing the math for you.

Our rules have us using the most up to date QNH Settings within a 100 NM's at a Minimum while Enroute although good practice is to use one from close by and when operating to an airfield or location close by, the setting for that particular Airfield.

It is all what One is used too in a lot of ways.

I have done both the UK and American method and very much find the UK procedures far too complicated and subject to finding the wrong setting showing up.

If you recall that wonderful Memo about Altimeter Settings and the manipulations required for an IF Approach with a Go Around with the attendant shift of controls then you can agree it can get tedious at times using UK Rules. (The Memo was a spoof on BA's system if you recall.)

If FJ's have problem doing Maths perhaps bringing back NAV's might be a good idea you think?

An example of why a QFE Setting might have some flaws:


http://i.kinja-img.com/gawker-media/...s15bds6jpg.jpg

AutoBit 9th Jul 2014 00:37

Never used both QNH and QFE. I would agree that it starts to get complicated at that stage. As I mentioned; the decent is flown on 1013 until you are cleared below TL and then you fly a height rather then an altitude. Its still only one altimeter change. Same for the climb.

And the BA spoof was about the monitored approach. Not sure what it had to do with altimeter settings?

Basil 9th Jul 2014 09:59

Boudreaux Bob, Skied past there a few times.
On QBB (Quinine{Gin}, Beer & Brandy) :}

ShotOne 9th Jul 2014 17:31

Autobit, so how do you know your height above terrain? Surely pretty important in the above instance. All QFE tells you is height above threshold

AutoBit 9th Jul 2014 18:12

UK Mil app plates have the step heights based on QFE, so it's no different to flying a QNH app.

Im not really that fussed about QFE or QNH. Ive done both. Both work. Im just a touch surprised by some of the comments on here that flying QFE is this crazy, un-safe procedure.

Bob Viking 9th Jul 2014 21:06

Two points...
 
1. Shotone. QFE is no better or worse than QNH at giving you your height above terrain. One tells you your height above sea level the other above runway threshold. If I have Valley QFE set (for example) it is not going to stop me flying into Snowdon any more than the Holyhead QNH if I am stupid enough to be tooling around at low level with low SA. Since there are no airfields in the UK below sea level the worst that could happen, if I accidentally left QFE set, is that I would be higher than I think I am whilst blundering around in Snowdonia.

2. Boudreaux Bob. I hear your argument but let's use the example of a display pilot flying an aerobatic routine over an airfield. Would you rather know your height above sea level or your height above the runway? Clearly my thoughts are influenced by a well known example at Mountain Home (where QFE would not have been practical) but in the UK it would work very nicely. Landing in poor weather has similar connotations and I like knowing my height above the runway whilst having SA on surrounding terrain.

For the record I currently fly in Canada where QFE is not utilised or practical (the highest airfield I have been to recently was Rocky Mountain Municipal in Boulder and QFE sure as hell wouldn't work there) but I have flown a lot in the UK. I can cope fine with either system and I really don't care one way or another but I really can't work out why some people think QFE is unsafe.

I guess it depends what you've grown up with. Everyone in this country drives on the wrong side of the road but I've managed to adapt. Mostly.
BV:E

ShotOne 9th Jul 2014 21:17

Bob, well I'm not especially fussed if this is what the RAF want to do but I completely disagree with your point 1. In a mountainous area QFE gives no information relative to terrain heights/spot heights in any given place.

You appear to concede this point in your final para. Agreed, it doesn't matter much either way for most UK RAF bases but why rely on a system which "sure as hell wouldn't work" in many places?

Boudreaux Bob 9th Jul 2014 23:47

I am not suggesting it is "Unsafe" per se.

What I am suggesting is that QFE has some built in issues as it pertains to the runway elevation at the approach end. (Unless my memory fails me.) and as in the photo I posted we can see that might not apply to the entire runway as there could be quite some difference in some locales.

Determining a Circuit Height at an airfield would be easier using QFE but then I am used to doing all that higher math(s) required to do the exact same thing using QNH.

The advantage i see is in determining safe Altitudes in the surrounds of the airfield as there are MSA posted on Maps and Approach Plates which are in MSL rather than absolute heights.

If you guys want too use QFE and are happy doing so.....have at it.

I just happen to see it as being less utilitarian than using a QNH setting.

If the RAF were to suddenly have a change of heart I am sure it would tip some Worlds upside down and require lots of changes to Approach Charts, Maps, and SOP's which itself could present a Safety Issue as any major change does.

That very few places in the entire World use QFE should be some hint but then it would defy the Wellington Rule mandate. Other than the UK or RAF Bases....are there any that use QFE as standard procedure?

In the United States, it is impossible to use QFE in a great part of the country as our terrain is just way too high.

By our standards the UK is all flat land with just a few hills. Some are rather steep but none are really very high.

In Death Valley while setting at a Below Sea Level elevation one can look up at a 13,000 plus foot high Mountain which demonstrates the kind of terrain differences we have.

I guess a question is begged. What changes to procedures does the RAF make when using a QFE altimeter setting is impossible?

DITYIWAHP 10th Jul 2014 00:25

I think QFE appeals to the CFS old-school nibber types who like circuits to be flown at a whole number on an analogue altimeter. No ugly 46 ft etc to look at, and rounding up or down by a few feet is.... well.... imprecise! Baaaa!

Just think.... Approach plates with only one set of numbers on them and a training mindset that prepares you to fly into non-UK mil and any civilian airfield in the world. That's crazy talk!

AutoBit 10th Jul 2014 06:40

Not sure how flying a QFE approach fails to train you for flying around the world or into non-mil airfields. Its the same procedures for QFE and QNH, its just the datum that has changed.

thing 10th Jul 2014 07:03


Its the same procedures for QFE and QNH, its just the datum that has changed.
Couldn't agree more so for the purposes of simplicity why not stick to one datum? The argument for making ccts easier because you're flying 'round' numbers is nonsense really, if you can't add a thousand feet or whatever the cct height is to an airfield elevation then maybe it's time to hang up the flying gloves. Apart from which and not really connected to the issue of QFE but any aviator worth their salt should know what a thousand feet looks like without an altimeter. Has the ability to fly a perfectly good circuit anywhere without an altimeter been lost?

Party Animal 10th Jul 2014 07:31

BV,

Minor correction to your previous:

QNH gives you an 'altitude' above sea level.

QFE gives you a 'height' above a datum.

But we all know what you meant......

just another jocky 10th Jul 2014 07:35


Originally Posted by thing
Has the ability to fly a perfectly good circuit anywhere without an altimeter been lost?

Of course not, but when your visual circuit height is a mere few hundred feet below the instrument approach of another airfield, then "gashing it" isn't really an option.

Even at Elementary training, the ASI is covered up to see how well the student copes. Perhaps I'll try the altimeter next time too.

I don't see too many issues with the RAF flying at various places around the world. I've flown my fast jet into many airfields in the US with no issues at all. I've operated my fast jet in the mountains of northern Afghanistan, in the dark, at low level without issue.

So clearly we're doing something right.

Bored now.

Fareastdriver 10th Jul 2014 09:40

Same here.

I would climb into an aircraft with dials reading knots and feet and fly around China .i.a.w metric flight levels and QFE. Then I would step into an aircraft instrumented with kilometres and metres and fly around Hong Kong using conventional flight levels and QNH.

Don't remember ever flying into anything.

Boudreaux Bob 10th Jul 2014 12:50

At your advanced age it is a miracle you even recall flying anything at all;)!


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