QNH/QFE/QNE

In this lesson, we shall cover the difference between QNH and QFE. The images below were taken at the same time one with the QNH set and the other with QFE you can see the difference.

QNH

Is the atmospheric pressure at mean sea level (MSL) To ensure all aircraft have the same altitude you set the local QNH so if you read 3000ft all other pilots will also have 3000ft, if one of those pilots is on a different QNH they may believe they are at 3000ft when in fact they could be at 4000ft without even realising.

You obtain the QNH from a controller’s ATIS, if not controller is online you can get metar from inside the pilot software altitude by typing.wx EGPH for example. You can also use the met office aviation briefing or other sites, check out the resources link on the main menu.

QFE

Where QNH is the height above mean sea level, QFE is the height above the ground.  To get the QFE you take the airport elevation so in this example 136 divide that by 30 equals 4.53 recurring and then round up to the fullest number so 5  then minus that from the QNH so QNH is 1027 – 5 = 1022.

 QNE

QNE is simply the standard pressure setting you should set once above the transition altitude of 1013.25. The transition level in the UK unless stated is 3000ft if flying above this you should use standard pressure, then when you pass back below set the regional or Metar QNH.

Finding the QNH.

You can find the QNH in the following locations.

  • The airport Metar.
  • The regional pressure via the met office briefing service.
  • Via ATC/AFIS/AGCS.

Finding the QFE

To calculate the QFE you need to know the airport’s elevation and the QNH.

Shurburn Elevation = 36ft. 36 / 30 = 1.2 Next we round that to up so 2, then delete 2 from the QNH and this will give you the QFE.

Regional Pressure Settings.

To make up for any lack of stations reporting actual QNH, the UK has been divided into several ASRs for each. The National Meteorological Office calculates the lowest forecast QNH (Regional Pressure Setting) for each hour.

Click here for the image of the regions.