12. Practical Altimetry - ATM1 Flashcards
What is QFE?
Atmospheric pressure at official aerodrome level
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 Height?
“The vertical distance of a level, point or object considered as a point measured from a specified datum.”
“The vertical distance of a level, point or object
considered as a point measured from a specified
datum.”
What is this definition?
Height
What is Altitude?
“The vertical distance of a level, point or object
considered as a point measured from mean sea
level.”
“The vertical distance of a level, point or object
considered as a point measured from mean sea
level.”
What is the definition?
Altitude
What is Elevation?
“The vertical distance of a level, point or object
considered as a point measured from mean sea
level.”
NOTE - Aerodrome elevation is the elevation of
the highest point on the landing area.
A separate threshold elevation is published if it
is 7ft or more below the aerodrome elevation
and for precision approach runways.
“The vertical distance of a point or level, on or
affixed to the surface of the earth, measured
from mean sea level.”
What is this definition?
Elevation
What is a flight level?
A surface of constant atmospheric pressure,
which is related to a specific pressure datum,
1013.25 hPa, and is separated from other such
surfaces by specific pressure intervals.
2000 ft (600m) intervals above FL 290 except RVSM aircraft in RVSM airspace (FL290 - FL410) then
1000 ft (300m)
1000 ft (300m) intervals above FL 195
500ft (150m) intervals up to FL 195
What is 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.
What is 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.
Determined as follows:
In controlled airspace normally based on QNH
of major aerodrome.
Outside controlled airspace based on the local
aerodrome QNH.
What is the transition layer?
“The airspace between the transition
altitude and the transition level.
At least 1000ft
