What is the difference between qnh and qfe

Settings Altimetry. Eddie sez:. Easy enough you say? Not so fast. Make sure you also take a look at: Altimeter Temperature Compensation if you are flying where it is very cold, and Altimetry, Metric if you are flying where it isn't so westernized. Last revision: Note 1. Altimeter Setting Procedures. Inches in of mercury Most of us in the United States are accustomed to using inches for that scale.

Millimeters mm of mercury A competing system that has pretty much died out in all but a few countries is millimeters of mercury, or mm. See Also:. Learning never stops. Copyright QFE is very good for new pilots who are remaining in the circuit around an airfield and keeps things simple for that task. Sat on the tarmac at your airfield the altimeter will display the airfields elevation above mean sea level.

This is the most commonly used pressure setting in the commercial world. That really keeps things open for private pilots who aren't instrument rated. Metric altitudes have been used for ages and will continue because their air forces' aircraft only have metric altimeters. Standard Atmosphere e.

Hg or Other countries have transition 'levels' e. In Australia, since our highest mountain is in the region of ', we have a transition altitude of ' and a transition level of FL We conduct plenty of IFR below 'David. You need to be a member in order to leave a comment. Sign up for a new account in our community.

It's easy! Already have an account? Sign in here. Donate to our annual general fundraising goal. This donation keeps our doors open and providing you service 24 x 7 x Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time.

We reset this goal every new year for the following year's goal. Sign in to follow this Followers 0. Recommended Posts. We all live under the same sky, but we don't all have the same horizon. By tcc - Tue Sep 01, I don't think using one over the other is wrong - but one may be better than the other depending on other conditions.

I tend to watch the altimeter at circuit height so I don't go too high, but fly visually once I start the descent. Fellsteruk , flybymike liked this. By Nero - Tue Sep 01, This is what I do when returning to Biggin Hill. It's at ft approx and they always say the QFE when you ask for rejoin instructions.

By Iceman - Tue Sep 01, Be aware that an altimeter can be set to QFE only when the airfield is below a certain elevation and the pressure on the day allows. In the UK, this constraint rarely matters as the highest airport licensed is Dunkeswell in Devon elevation ft and extreme air temperatures rarely cause a problem.

If you went to the US though, there is no such altimeter setting as QFE, and as the transition altitude is ft, most private pilots never get the opportunity to use flight levels either. It is not uncommon in parts of the US to have airfield elevations in excess of ft, whereupon it is simply impossible to set an altimeter to a setting equivalent to QFE.

Hence, all flying in the US, irrespective of airfield elevation, including takeoff, landing and circuits is done on the equivalent of QNH. Hence, when you takeoff and land, the altimeter should always read the airfield elevation.

You are still dangerous! You can be my wingman anytime. By Rob P - Tue Sep 01, Like 1. I operate from a glider field which on non-gliding days has nobody around to give you a QFE. I suppose I could fly the circuit at feet, but I'm happy just to wind off a little bit under ft as part of my pre-landing checks. Rob P. JAFO liked this.