The Mil and their use of QFE
 

Can someone explain what it is with the military and using QFE for everything (in the UK, obviously)? We transitted a Mil zone today (Class D not just MATZ) and were told to fly on QFE. We were below the cloud at 1500ft QNH. This immediately loses all reference to terrain and obstacles (unless you have two altimeters, we did), except for the airfield within the CTR which we were not inbound to. And how do they go on co-ordinating with each other? Must involve much arithmetic gymnastics, and for why? :confused:

On the way back we elected to climb to 3500ft IFR but again were put on the QFE (and an approx 500ft difference.)

I know the mil at one time were all QNH but went back to QFE. Now it seems all QFE rather than what we do in the civil world of QNH for intermediate approach and zone transits, and QFE for final approach and landing (and that's rare now at my unit.)

Seems odd but I am sure there must be an explanation. :D

Was it the higher or the lower of the Class 'D' airfields ;)

Believe me - you want to try taking handovers from them when you're next door! They've got the traffic on their QFE, you want it on QNH - b*****s muddle or what!

And out of interest - what service did they put you under as you transitted? Bet it wasn't what you expected?

Come on boys (and girls) in blue - isn't it time you realised you're in the same universe as the rest of the world and played accordingly?

As I recall they tried to, at least for a while, in the late 1980s. Can't have been much of a success (for them) because they changed back pdq.

The RN at the time remained QFE based, as they are today. I can see some point in this. Not a lot of terain to miss at sea (one of the reasons I actually like flying over it, even single engined;) )

Rgds BEX

We use QFE in and around our patterns at our aircrews request. Yes we did try using QNH in the mid nineties and confusion reigned.

If I was whazzing around at 380kts into radar patterns or visual circuits in my pointy plane the last thing I would want to be doing is messing around swapping pressure settings.

As a puddle jumper it is in your interest to join in the QFE game while transitting the busy Mil airspace and getting mixed up with the fast pointy jets. It makes co-ordination a lot easier if you are on QFE for us. Its always nice to sing from the same hymn sheet as they say. At the end of the day we are giving you a LARS to help you along safely and ensure you don't end up with a fast jet suppository.

"On the way back we elected to climb to 3500ft IFR"

QFE is just as bad (dangerous) as pilots who fly IFR above the transition altitude on a QNH. ;)

Regards,

DFC

Do we know what the transition altitude was that day??...;) 3500ft may have been fine

<<Its always nice to sing from the same hymn sheet as they say.>>

PRECISELY - so why do Mil opt to be different to everyone else??

Well for you guys everything bimbles around on the SAS or the good old QNH. As I said earlier, it's was the RAF pilots who decided to adopt QFE for all pattern flying,positioning into and visual circuit work. We don't really care what pressure you are on till you start getting mixed up with a of a load of fast jets whizzing around with pattern speeds higher than good old concordes.

At the end of the day as long as you get from A to B safely, with the correct separation standards and terrain clearance applied, we have done our job. It's nice to have co-operation as we go about our military task and thank you puddle jumpers for complying with what appears an alien concept. :D

Can't pointy ended pilots add or subtract then ?? :)

Chill guys!!!
The Mil uk use QFE for circuit work and approaches cos it is easy - the altimeter reads zero, followed as by a little bump as you land. Outside of the MATZ / Military Radar Pattern we obey all the same conventions as the rest of the aviation community (QNH / SPS). Why do sums when you don't need to? What is difficult or wrong about the alt reading zero at touchdown? and If you are flying in / near a MATZ why not accept that you are being safely seperated from traffic that may be fast moving, rapidly changing height (forced landing patterns as just one example) flying many and various sized and speed circuits in many and various configurations - and already damned busy. Frequently we bash the pattern / circuit specifically to practicie emergency procedures (train hard - fight easy!!). We tried QNH and didn't find ANY benefit that outweighed the use of QFE. If in / near the MATZ -transit traffic (on QFE) will be told the Sector Safety Altitude if IMC, based on the QFE. As you reset QNH leaving the "service" - it's back to the deal you usually use vs SALT!
Think before using the big stick your carrying. Its a forum - just ask the Q (nicely):cool:

OK, so there you go, the answer from the jockeys lips.

Mil Controllers serve both communties, that's our job. As long as everybody gets what they want, the fast pointy boys/C172 puddle jumpers don't hit each other, and everybody gets home safely, job done. Have a nice weekend and fly on what every pressure keeps you safe!:ok:

Now you can bet some loony will ask how military controllers can use 500 ft vertical inside a civil control zone!!!! Tee hee!!

Well, thanks everybody. Thought I did ask the question nicely . . . . :hmm:

I'm still not convinced though but accept what you say. Just thought it would be good to do what the rest of us do. And how on earth you do inter-unit coordination . . . . . :confused: Still, I don't sit in front of a radar display these days. But if you want to see busy, I'll show you busy . . . . . :ok:

And as for 'puddle jumper' :mad:

VA, having controled within a CTR where some ac were on QNH, others on QFE, ac in the hold were on QFE or SAS and an adjacent US mil airfield with interlocking patterns was on QNH (inches), I can say that the maths gets somewhat interesting.

HD, Is there such a thing as a "civil" CTR? I was under the impression that the majority were anything but civil. :O

<<HD, Is there such a thing as a "civil" CTR? I was under the impression that the majority were anything but civil. >>

Oh shame... must be because I've gone! Seriously, it used to amaze me that if we got two Heathrow inbounds 500 ft apart all the bells and red squares went off and it was off to the boss before our feet touched the floor... Yet, hand over a civil a/c to Northolt and they could gaily pop it 500 ft above or below any of their traffic quite legitimately...

Batty,

The transition altitude does not change day to day and (except where notified differently) is in general 3000ft in the UK including at Lyneham and Brize.

Regards,

DFC

Would it not be easier for pointy ended jockeys to learn about QNH Ops since that is what they will be forced to use when they undergo their IR and/or ATPL training at the taxpayers expense so they can get their job flying A340s for the Wooly Pully ;)

In the waste Russian airspace QFE is used by everyone: you'll never get altitudes from ATC - civil or mil - only heights. Pilots do maths, not us :=

Rather than the mil changing why not the civilians? Having experienced using both, QFE is (as said previously) much simpler. And sat at the runway threshold showing no altitude is (at least to me) logical. Try explaining QNH to the man in the street!

HD "Why do mil opt to be different to everyone else?"

If you look at JSP 552 (JSP 318A for those of us who can remember) and MATS Part 1 you will find few differences when they talk about the same stuff. Unfortunately, mil controllers tend to apply everything as per the book, whereas civil controllers sometimes tend to do otherwise. Specifically, ATSOCAS! (But lets not get into that again) As far as QFE/QNH is concerned, surely it's better to fly on a pressure setting that gives you a zero reading when you're on the runway? As others have said, it eases co-ordination problems when flying through or near to traffic patterns. As far as coordination with adjacent units is concerned, it's easy as long as you're used to doing those kinds of maths. Most controllers worth their salt will also have a guide made up in their head as to what separation is needed between certain altitudes/heights and differing pressures. Plus which, it's what we're trained to do, so it becomes second nature. :ok:

P R
May I refer you back to my origional reply?
Your:
"Would it not be easier for pointy ended jockeys to learn about QNH Ops" comment was covered.
We do!!!!
As for the sarcstic bit that followed, I choose to refrain from comment since I'm in a good mood today. Chill - think gentle thoughts, then blast away at random :cool: :ok:

Harrier 46Shows how much flying you do outside the UK then. Say QFE to any non-UK European, or US pilot, and they'll look at you with a very quizzical expression.

The earth orbits the sun - not the other way round ;)

WhowhenwhyPeople in glass houses shouldn't throw stones ;) (though I'm intrigued by the word 'unfortunately'). We do things by our book, you do it by yours - but who's book is right? And what is this attraction to to military of holding onto traffic until it's almost in someone else's overhead? I'm noticing that more and more these days. (sorry - off topic I know)
See my comment above. In the world of instrument flying you really don't care what the altimeter reads on landing. All you want to to know is:

a) MSA - Last time I looked spot heights were based on amsl, not some arbitrary airfield elevation. QNH is therefore more relevant than QFE when I'm working that out on a route

b) DA/MDA - after that you can see where you're going so you don't actually look at the altimeter. What it reads is therefore of no consequence. As an instrument go around will, in most cases, be based on QNH why would you want to complicate matters by transitioning from QFE to QNH in addition to the rest of the tasks that need to be carried out in a very short space of time in that scenario.

Still think the military is right and the rest of the world is wrong? I've not flown a QFE approach in the last 5-6 years - it's no hardship, believe me.

After all, your MIL boys do manage very well on QNH abroad, it can't be too bad, since they keep coming back! :cool:

"Try explaining QNH to the man in the street"

See that hill over there - the map here says that it is 2500ft above sea level. When the altimeter reads 2500 or less with the sea level pressure set we will hit that hill.

See that airfield over there - the map here says that it is 625ft above sea level. When the altimeter reads 625ft we will hit that runway.

Most common cause of initial IR rating test failure is pilots failing to reset QNH in the missed approach having made an approach using QFE - UK CAA.

It's an altimeter not a heightameter! :D

Regards,

DFC

Doh!
OK Mr man-in-the -street:

See that runway, in fact any runway, anywhere any time? Well with QFE set - when the altimeter reads zero you will be landing on it.
See that hill just over there? The nice man / lady in ATC or the little book of Approach Plates I carry that tells me how to get to the runway also tells me a height not to fly below so that I can be sure to miss that hill.
When we fly away from the airfield but stay quite near the ground I will set the QNH on the altimeter so that I know how high I am in relation to the sea level cos that is the datum height my maps use to show me how high the hills are. But just like the QFE thingy - we'll need to change it every now and then cos the pressure over the country changes you know.
And if we go high, no matter where we are we set SPS so that we can all miss one another.
Easy isn't it? - no matter where I go or how busy I am I know that the runway = zero on the altimeter with the QFE set and there are only the other two thingys to remember when you arn't quite as busy.
Now would you like to be patronised about any thing else?:E

There's always one that falls into the trap ;)
.
Not so hypothetical question. If the QNH was the same as the standard (1013) what would the QFE be at:

a) Las Vegas McCarran (2181 ft amsl)?

b) Big Bear City (6748 ft amsl)?

There are others around the world - they're just two that I have the figures in my head for.

As an addition to the question - can you physically set that QFE on your altimeter?
All the plates I've used show MSA, not MSH, but happy to be corrected if the Mil produce the latter.

<<Not so hypothetical question. If the QNH was the same as the standard (1013) what would the QFE be at:

a) Las Vegas McCarran (2181 ft amsl)?

b) Big Bear City (6748 ft amsl)?>>

Sounds like a QNE question to me..........

If I can't set the QFE (altimeter mb sub-scale limited I presume) I'll set QNH and get on with it! - just like I did in both Big Bear and McCarran. I am both flexible and a realist.:cool: It ain't a pi**ing contest, it's a forum. I can & do work both procedures - I just prefer QFE.
Your right about the MSA thing - for that I take off my shoes and socks and do the difficult sums before the approach (and set QNH on the other altimeter). Its only a trap if you don't know the way out:p Now the Russian thingy was a real bag of metered worms
:yuk:
We could keep this going for weeks!

Ahhhh QNE!

Have actually used it... once. Extremely low pressure up in Aberdeen (942mb?).

A further question. The RAF isn't the only air force to drive fast pointy things around the sky. What do other air arms use? How many use QFE (or would have any idea what you are talking about)?

Rgds BEX

How many of us (in the UK) fly around the visual cct with QNH set?

Similarly, how many of us transit underneath a TMA with the local airfield's QFE set?

How many of us have tried to set the Kabul (6870ft AMSL) QFE?

Why do we have a mixed transition altitude in the UK (mostly 3000ft but 6000ft under a number of TMAs)?

What does it matter as long as everyone knows what datum they are flying relative to and the controllers can do their maths when mixing 2 or more pressure settings?

Personally, I think the mixed use of pressure settings can be a recipe for disaster. However, surely we can just bite the bullet and get on with it.

PS. How many feet equate to one millibar at 35000ft when the temp is ISA -10deg Celcius. Anyone who uses the 30ft rule will be in for a shock.

Whipping Boy's SATCO
Well said that man:cool:

I think you'll find also that SID's use flight levels and altitudes for the initial climbing levels. If there was a high transition altitude then in the initial climb from take off through the TA would involve three changes of pressure settings, which would increase workload.
I assume that the mil use QFE because they like it and the controllers can provide some separation. Don't forget that anyone bashing circuits at a civilian airfield will use QFE.
If the mil want to transit civil CAS then they will be instructed to fly QNH for separation purposes. I find it far easier, with less workload to use QNH, 1013.25 and airfield elevation.

If you are flying at 35000ft then you should be flying at a flight level of 35 with all the other a/c in the area flying on 1013.25. minus 10 degrees is irrelevent. I agree with all using the same datum, however radar cannot determine the datum a/c are flying to. It is easier for the controller to have all the a/c flying on the same pressure setting to ensure separation.
Please keep safety first.

<<I think the mixed use of pressure settings can be a recipe for disaster. However, surely we can just bite the bullet and get on with it.>>

Hopefully not the attitude of professional controllers! If something is that dangerous it needs fixing.

ILS 119.5 wrote: "If you are flying at 35000ft then you should be flying at a flight level of 35"

I think not, but I (think I) know what he means.

ILS 119.5. WB's SATCO is alluding to other airspace users who use a regional pressure setting to maneouvre up to say 45 000'. In this instance, when coordinating with said users, finding that the 30' per millibar assumption is wrong has come as quite a shock and no-one is quite sure exactly what to do about it.

As far as the QFE/QNH issue is concerned, I think people are starting to get a little confused. We use QFE in the instrument and visual circuits and for aircraft flying close to, or through, these patterns. Outside this, ac should be flying on a RPS below the TA and the SAS above.

Chilli, aside from the differences of necessity due to mil vs cvi ops, there aren't that many key differences between "your" book and "ours." They would all have come from the same root document in the dark mists of time. But why would you change from QFE to QNH on a missed approach? Maybe yes if you were flying away from the airfield after the approach, staying below the TA, but certainly not if you were going back around for another go.

My 35000 ft comment was aimed at some elements of the mil who fly at this sort of level on the RPS!!

Regarding my "biting the bullet" statement, maybe it was not the best choice of words. What I meant to say was that there may be perfectly valid reasons for operators to fly on different pressures. We should be able to manage their expectations and deal with the issues.

1) All civil holds (which missed approaches often end up in) are flown on QNH / Standard depending on whether above or below TA.

2) After a missed approach you'll often have briefed the plan that you may be going somewhere else, at MSA - hence QNH required

3) All missed approaches are required to be "terrain safe" (obviously). Approach plates show MSA, not MSH (as stated before) therefore datum required is QNH

DFC's post is quite correct when he points out the single biggest fail on Instrument Rating tests flown on QFE is failing to reset QNH on the missed approach - hence flying the approach QNH takes out that possibility.

Re (1 & 3) above it's worth remembering of course that, unlike the military, not all airfields with IAP's have radar. Therefore an RVA chart is not applicable from which a controller can put you on QFE and keep you 'terrain safe' according to his chart / video map. Terrain clearance is still the responsibility of the pilot fully in that scenario hence the use of QNH as the 'safe' datum

It is nonsense and, in my view dangerously confusing, to use QFE for anything other than final approach. Indeed, most civil operators long since ceased to use it even for that.

HD

Yeah sorry FL350, too used to doing approach. Have not done area since 85.

Also for any a/c to fly up to 45000' why use a regional pressure setting? I think that the rules of the air state that above a certain level all a/c must fly on 1013.25. Please correct me if I am wrong.

Unless under the control of ATC, HM Ships or ASACS!!!!! Say, if they were in the block surface to 45 000'? That's the problem!

Chilli. Good points. Some down to civ/mil differences and of course I am viewing QFE/QNH from a purely mil point of view. I can certainly see the benefits from a human factors point of view, but still like the idea of seeing 0 when I'm on the runway. Maybe I'm just old and resistant to change?? Unlike my NATS brethren who have their destinations and who are all far from being resistant to change (sorry going off thread now!). :ok: