Practical Altimetry Flashcards
What is QFE?
Atmospheric pressure at official aerodrome level.
When QFE is set on the subscale of a pressure altimeter, the altimeter will read zero when the aircraft is on the ground at the station.
What is QNH?
Atmospheric pressure at mean sea level.
When set on the subscale of a pressure altimeter it will read aerodrome elevation when the aircraft is on the ground at the station.
What is QNE?
Height indicated on a pressure altimeter when the aircraft is on the ground at an airfield with a setting of 1013.2 hPa set on the subscale.
What is the altimeter displaying with QFE, QNH and QNE?
QFE - Height AAL
QNH - Altitude AMSL
QNE - Flight Level above the standard pressure datum
What is height?
The vertical distance of a level, point or object measured from a specified datum.
What is altitude?
The vertical distance of a level, point or object measured from mean sea level.
What is elevation?
The vertical distance of a point or level, on or affixed to the surface of the earth, measured
above mean sea level.
Where is aerodrome elevation measured from?
The highest point on the landing area.
When is a separate threshold elevation published?
A separate threshold elevation is published if it is 7ft or more below the aerodrome elevation and for precision approach runways.
What are the Flight Level intervals?
600m (2000 ft) intervals above FL 290 except RVSM aircraft in RVSM airspace (FL290 - FL410) at 300m intervals (1000 ft).
Describe the Transition Altitude
The altitude at or below which the vertical position of an aircraft is controlled by reference to altitudes.
The transition altitude is located at a fixed level and published in aeronautical information publications.
Describe the Transition Level
The lowest Flight Level available for use above the Transition Altitude.
Located at least a nominal 1000 ft above the Transition Altitude to permit the TA and TL to be used concurrently in cruising flight, with vertical separation ensured.
How is Transition Level determined?
In controlled airspace normally based on QNH of major aerodrome.
Outside controlled airspace based on the local aerodrome QNH.
