Height vs Altitude vs Flight Level

18 Sep 2014 11:43 - 18 Sep 2014 11:43 #18058 by Rafdave
Height vs Altitude vs Flight Level was created by Rafdave
When I'm controlling on here I will undoubtedly refer to all 3 of these terms at different times and I have been asked in the past why they are different so hopefully this will provide some sort of explanation.

A flight level is based on a Standard Altimeter Setting(SAS) this is 1013Hpa or 29.92 Ins. All aircraft flying above certain altitudes (different all over the world but at the minute its 3000ft in the UK) should have this set to aid de-confliciton between aircraft.

A height is based on a pressure that has been corrected for the airfield elevation of where you are making approach (QFE). so when you sit on the ground at the airfield and have this pressure set your altimeter should read zero (or pretty damn close). This is what is used for making an approach to most uk military airfield.

An Altitude is based on a pressure that has not been corrected for airfield elevation (QNH). Most civil airports and aircraft use a QNH. When you land with a QNH set your altimeter should read the airfield elevation above mean sea level.

in the UK we have regional pressure settings(RPS) which are valid for 1 hour and are the lowest forecast QNH for that whole area. any aircraft flying on this pressure is also operation on an altitude. Similar systems exist in different countries all over the world.
The uk RPS map is below
Attachments:

Please Log in or Create an account to join the conversation.

19 Sep 2014 11:37 #18084 by Algernon
Replied by Algernon on topic Height vs Altitude vs Flight Level
Dave, do you know how the Typhoon deals with barometric altitude? Nowhere can I find any function to adjust the barometric altimeter's pressure setting, and thinking about it, it's probably not very difficult to do it automatically these days, but I don't know for certain.

Please Log in or Create an account to join the conversation.

19 Sep 2014 13:01 #18085 by Rafdave
Replied by Rafdave on topic Height vs Altitude vs Flight Level
I'll see if I can find out but its definitely not automatic. Each aircraft operating together has to set a common pressure setting. Regardless of whether this pressure is actually accurate in that specific bit of space.

Without a common pressure on each aircraft it makes safe operation in a training environment seriously difficult

Please Log in or Create an account to join the conversation.

19 Sep 2014 13:45 #18091 by Rafdave
Replied by Rafdave on topic Height vs Altitude vs Flight Level
From your bible Algy:

"Barometric pressure is set via the left glare shield.
Following any change to this setting the new value is
displayed on the HUD for 5 seconds as a four digit
readout."

As to exactly where im not sure but Mary is home from uni and im off out so I hope this helps in someway.
The following user(s) said Thank You: Algernon

Please Log in or Create an account to join the conversation.

19 Sep 2014 14:41 #18095 by Algernon
Replied by Algernon on topic Height vs Altitude vs Flight Level
Hmmm, looks like I was searching for the wrong term. I do remember that now - I think it's perhaps in the miscellaneous subsystem of the Manual Data Entry Facility (on the left glareshield).

Please Log in or Create an account to join the conversation.

Moderators: Rafdave
Time to create page: 0.141 seconds
Powered by Kunena Forum

Latest Forum Posts

PM Notifications

You are not logged in.

PM Mailbox

You are not logged in.