PPRuNe Forums

PPRuNe Forums (https://www.pprune.org/)
-   Private Flying (https://www.pprune.org/private-flying-63/)
-   -   About the altimeter setting (https://www.pprune.org/private-flying/577011-about-altimeter-setting.html)

Silvaire1 3rd April 2016 15:58

Hinhin, your main lesson from the thread should be that if you ever fly in the UK, you will be facing entrenched irrationality, regulatory stupidity, and impractical complexity on a level that most American pilots would find inconceivable. Be glad that you don't need to remember 19th century Q-codes and good luck with your (one) written exam!

charliegolf 3rd April 2016 16:30

Do pilots in America have to file a flight plan to go for 'a fly around'?

CG

Talkdownman 3rd April 2016 17:28

Do you mean a completely un-planned Class G so-called 'bimble'...?

charliegolf 3rd April 2016 17:35

Yes, that kind of bimble.

Genghis the Engineer 3rd April 2016 17:54

Have you actually done much flying in the UK Silvaire?

G

Tinstaafl 3rd April 2016 22:53

Above the Clouds, 'A' is correct. Temperature correction for True Altitude only applies to the *air* column, and not any Terra Firma between the bottom of the column and sea level.

Charliegolf, you can fly across the US without submitting any form of flightplan and not talk to anyone provided you avoid D, C, B & A airspace. If within 30nm of certain designated airports then you must have a transmitting Mode C transponder (but still needn't talk to the controller if you stay outside the controlled airspace.

Most of the country is Class G or E. To a VFR pilot Class E is transparent unless you avail yourself of radar advisory services. If, while VFR in Class E, you choose to communicate with a controller then you must obey the controller's instructions, no different to other airspace.

charliegolf 4th April 2016 08:46

Tinstaafl:

:ok:

CG

kghjfg 4th April 2016 21:48

Interesting.......

I set QNH before taking off, as it's easiest to do it then, and I can confirm it's right as I know the field elevation above mean sea level.

QNH = Newlyn Harbour = Sea level !

On returning to an airfield, you know those pre landing checks, where you say "instruments", that reminds me to set QFE for that airfield.

All very simple really.

EXCEPT

came unstuck the other day, "cleared to transit the overhead not below height 2500' "

and I was on QNH and I selected 2800, and the airfield was >300' amsl. Oops.

The Ancient Geek 5th April 2016 00:37

<Rant>

When are we finally going to consign this QFE nonsense to the dustbin of obscure aviation history where it belongs.
It serves no usefull purpose, causes confusion and incorrct altimeter settings are a major cause of accidents.
Move transition altitude to a sensible consistent standard of 19000 feet and we would have a simple and safer system of QNH for everthing below 19000 where we have plenty of time to twiddle knobs and 1013 above.

</rant>

On Track 5th April 2016 01:41

What the Ancient Geek said.

FullWings 5th April 2016 08:16

This might happen sooner rather than later: HETA.

Above The Clouds 5th April 2016 08:20


The Ancient Geek
When are we finally going to consign this QFE nonsense to the dustbin of obscure aviation history where it belongs.
It serves no usefull purpose, causes confusion and incorrct altimeter settings are a major cause of accidents.
Move transition altitude to a sensible consistent standard of 19000 feet and we would have a simple and safer system of QNH for everthing below 19000 where we have plenty of time to twiddle knobs and 1013 above.
Just as well you don't fly in Russia then, or China and quite a few other countries around the world that still use QFE, its called adapting to the situation :rolleyes:

FullWings 5th April 2016 10:09

Although the whole thing might be overtaken by geometric altitude - no messing around with pressure setting at all...

Fly4Business 5th April 2016 10:16


Although the whole thing might be overtaken by geometric altitude - no messing around with pressure setting at all...
Exchange for the mess of defining "geometric altitude" ... ? No, that won't cure anything.

FullWings 5th April 2016 10:33

Why, what’s the problem with everyone working off the same datum?

It’s a bit like magnetic vs. true navigation. I’m not the slightest bit interested in what the Earth’s magnetic field is doing in various places - I just want to get from A to B in the most expeditious manner.

Geometric altitude gets rid of many of the errors that plague pressure altimetry, like temperature, lapse rate, variability and not least, transcription. No need to know the surface pressure. What’s not to like?

Fly4Business 5th April 2016 11:02


Why, what’s the problem with everyone working off the same datum?
They don't and even if, we use different reference frame over the globe.

Geometric altitude gets rid of many of the errors that plague pressure altimetry, like temperature, lapse rate, variability and not least, transcription. No need to know the surface pressure. What’s not to like?
My plane flies on pressure and air flow, not strict mathematical geometry. I prefer an altitude with a relationship to the physics of flying, not artificial rulers and dividers. If I get a QNH is does not only tell me about heights, it does tell me more on the things I have to expect when piloting - it connects to your guts feeling. I prefer an intuitional connection to the air outside.

Discorde 5th April 2016 11:03

The problem is political inertia. It takes the authorities ages to respond to technical advances. In an ideal world a decree would be issued by all aviation regulators:

On and after 01 January 2018 all altimetry and navigation will be GPS based.

No more TAs and magnetic navigation! Pressure altimeters (automatically set to local sea level air pressure via data link) and compasses (with local variation data available on EFIS displays) only for back-up.

ShyTorque 5th April 2016 12:19


Originally Posted by The Ancient Geek (Post 9333744)
<Rant>

When are we finally going to consign this QFE nonsense to the dustbin of obscure aviation history where it belongs.
It serves no usefull purpose, causes confusion and incorrct altimeter settings are a major cause of accidents.
Move transition altitude to a sensible consistent standard of 19000 feet and we would have a simple and safer system of QNH for everthing below 19000 where we have plenty of time to twiddle knobs and 1013 above.

</rant>

There's nothing to prevent you as an individual flying on QNH rather than QFE.

FullWings 5th April 2016 13:13


My plane flies on pressure and air flow, not strict mathematical geometry. I prefer an altitude with a relationship to the physics of flying, not artificial rulers and dividers. If I get a QNH is does not only tell me about heights, it does tell me more on the things I have to expect when piloting - it connects to your guts feeling. I prefer an intuitional connection to the air outside.
I think you get to keep your ASI for a while longer... ;)

There’s nothing wrong with knowing the surface pressure as well but for vertical navigation, accuracy and commonality are important for separating aircraft from each other and from the ground. CAT III GBAS is due in a year or two which is amazing progress for aviation. Ever since GPS was invented it has been accurate enough for en-route navigation.

Better not mention FBW!

fireflybob 5th April 2016 16:35


There's nothing to prevent you as an individual flying on QNH rather than QFE.
True bit it can get a bit more complex when flying through a MATZ and they give you QFE to fly on. Granted to an experienced pilot this is no big deal but I agree with the original poster than QNH only operation for all would be simpler but there again the QFE/QNH debate is as old as aviation almost so I'm not holding my breath. Trouble is in UK we don't really have any "high" elevation airfields. Try setting the QFE in Nairobi or Mexico City....


All times are GMT. The time now is 02:51.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.