Odd. All over the world, civil and military pilots takeoff and land on QNH. Private as well as professional pilots. In all kinds of weather. So is using QNH dangerous ?

As someone who used to fly very regualrly into RAF bases as a civ flight.

It really doesn't matter a toss.

QFE/QNH all RAF pilots can operate on QNH and all civi pilots can operate on QFE its not a bloody problem.

If it means that the boy's in theater can get even 1 minute extra on the phone or one of the most piddly little bits of kit which makes life more comfy don't change a bloody thing.

The very small amount of ball ache involved is worth it compared to spending a sodding fortune changing everything.

I do wonder how many of the civi pilots with very strong views on the subject have had to operate day in and day out using the system. It really doesn't matter.

Well said. It really isn't that important so why change it...and it works.

I have - like many of you - used both as a military pilot.

In the UK where even the highest airfields are probably less than 600 feet above MSL, you probably won't mind winding the altimeter from 1013 to 993mb (at worst).

However, if you wanted to fly into - say - Black Rock airfield in the States, you might not enjoy the wrist and finger ache you would get changing from 1013 to 798mb.

Then just imagine going into San Rafael Airport in Peru, where you would need to set 532mb. Anybody know an altimeter that goes that low???

Horses for courses methinks.

Why do RAF pilots use QFE?

Well yeh! but no but yeh! because they can!

Simples!

:ugh:

Altimeter Settings
 

Quite right Wholigan.

There is another, easier option for high level airfields, request QNE. QNE is your altimeter reading with 1013.2 set. Thus ATC would give you the number of feet you would see on your altimeter on the ground at the airfield datum with 1013.2 set in your subscale. I had to use that at Entebbe when the QNH was outside the range of my altimeter.

Neppie
:eek:

QFE or QNH both make some sort of sense - either Oft or the airfield elevation on touchdown. QNE gives you reference to neither very well and is a pointless throwback to the era of limited mechanical altimeters.

I suppose it makes sense if you are still operating really antique equipment AND operating out of Bogota. QFE makes more sense for a largely UK based operator but makes little sense to a largely worldwide operator. If the likes of BA and Virgin and the rest of the airline world use QNH it is not for a whim. Terrain awareness and IAS/TAS issues at hot and high airfields tend to push you towards QNH for safety reasons. QFE is fine for a parochial, inwards looking, UK centric operation.

Is this one of those Pprune threads that gets revisited when there's not much else to discuss? Seems to read that way.

At great risk of repeating previous posters, it really is a case of being able to use either, as is appropriate for the situation. I remember a lecture about flexibilty in air ops...................

I always thought that QNH with ApproacH and QFE with TowEr was the best compromise.

I was instructing at a UAS when we changed from QFE to QNH. Not too difficult until one (very good) student was given an EFATO. She called that she was above the turnback min height and started a turnback only to have the QFI take control and climb away. Brought up on QFE she'd reverted to habit - only the aerodrome elevation was nearly 400 ft and she was much lower than she thought.

The QNH experiment didn't last that long - but it wasn't Learning Command who insisted we went back to QFE, it was the fast-jet pointy-heads.

Why does the RAF use QFE? For the same reason mutts lick their nuts - because they can!

Walter, you didn't offer an answer and no one else has.

RAD ALT.

If there is no one there to measure the pressure then you have to set your own.

If the LZ is on high terrain in a plain then again you need visual or rad alt.

Pontious

Well I will!

Picture flying in a helicopter into a LZ at night in the mountains of Norway to an approach aid consisting of five torches for the use of laid by the MAOT. On the approach the Rad Alt is useless as it is reading under the aircraft and wizzing up and down as you pass over the terrain. What would you like to see on your Bar Alt as you approach the T?

I like to see it winding down to zero not some height above sea level that I have to remember. It's hard enough flying the aircraft especially if the wind is up your chuff and bouncy, it's snowing and you are not allowed to use landing lights. Oh - and you are about to get whiteout in the dark!!

Airfields are a totally different ball game for people with less flying ability!:)

Ducking and running now.................:ok:

[B]Tankertrashnav[B]

I started flying in Phantoms in 1970. All of the aircraft that I subsequently flew in (including some of the prototypes) had altimeters calibrated in millibars.

bast0n, fair dink, except you need a guy on the ground with an anemometer. How do the SAR crews operate?

SAR, overwater; set Baralt to Radalt.

Pontious

Very carefully! :ok:

They also have the ability to use their landing and floodlights and nowadays have NVG and probably FLIR for all I know. They also tend to operate in an area that they get to know very well.

In my days in SAR, Whirlwind and Wessex we were even more careful/stupid!:)

PS. I think you meant altimeter?

Doh! too early, too much vin, I meant barometer.

PS, we did the same, set altimeter to rad alt on the Nimrod so effectively we were on local QNH in an area or Force QNH is operating with other forces.

Pontious

I like the idea of a barometer - sitting there in the cold with this big mahogany banjo shaped thing - tapping the glass and watching the needle jerk to Fair!!:ok:

and reading off the arrow pointing to inches. Actually mine say 1007.2 towards Fair.

To be fair it is cool and sunny.

I think we are on the same hill - VFR is best.

And of course rotary radalts have been known to tell you how far above the underslung load you are....:eek:

P3 - there's no explanation for the use of QFE under those circumstances.

We (I'm a controller) should be expected to be able to work out the difference between RPS/SAS and QFE without being so lazy as to stick everything on one pressure. The only thing I can think of at that kind of distance was proximity to the unit's terrain safe level, which is based on QFE. Still no excuse though. Unless it's a local procedure of some kind, I can't speak for every unit of course. If anything it's easier to have non overhead transiting traffic on RPS/SAS because everything out and about would be using that pressure rather than a specific unit's QFE anyway. Circuit traffic and inbound traffic - QFE. Everything else - be flexible, from my point of view.