QNE Vs Pressure Altitude
 

Hi, everyone! I have some questions regarding pressure altitude and QNE!!

While reading books talking about Pressure Altitude, what is from the book is that it's the altitude indicated when the barometric scale window is set to 29.92"Hg. That's somehow similar to the concept of QNE which is altitude with reference to ISA with the standard pressure of 29.92"Hg.

So I just wiki a bit but things gonna more confusing! :{:{:{In wiki, the article said that,

"The term "QNE" refers to the indicated altitude at the landing runway threshold when 1013.25 mbar or 29.92 inHg is set in the altimeter's Kollsman window and not the setting itself, as is commonly misconceived."

So what is the differences between them?? and in which situations will we use QNE??(I know we need pressure altitude as the starting point in the charts when evaluating the aircraft performance, but I have seldom heard about the use of QNE)

Thanks in advance!!:):)

Pressure settings
QFE: The atmospheric pressure read from a barometer on an airfield, which gives aerodrome pressure.

QNH: The barometric pressure at the airfield reduced to mean sea level, using the ISA International Standard Atmosphere, temperature at the airfield.

QFF: Barometric pressure at the surface reduced to mean sea level using the actual temperature at the surface.

QNE: The height indicated on landing at an airfield when 1013 mb is set on the altimeter.


From the above one can conclude that QNE is essentially used when flying Flight Levels in cruise.
QNE is not usually used for landing as it neither indicates 0' on landing, nor airfield elevation, but the difference between the two which is arbitrary information.

QNE is used on take-off or landing at high altitude airfields when you can't wind the pressure setting down far enough to set QFE. A (much more widely used) alternative is to use QNH, unless the QNH isn't available (unmanned strip etc)