(1) ATM - Practical Altimetry Flashcards
What 3 types of barometric pressure is available? (3)
- QNH
- QFE
- QNE (Standard pressure)
What is QFE? (2)
- 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? (1)
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? (1)
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? (1)
“The vertical distance of a level, point or object considered as a point measured from a specified datum
What is Altitude? (1)
The vertical distance of a level, point or object considered as a point measured from mean sea level
What is Elevation? (1)
The vertical distance of a point or level, on or affixed to the surface of the earth, measured from mean sea level
What is Aerodrome Elevation? (1)
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)
Pressure relationships diagram
Elevation calculation diagram
QNH calculation diagram
QFE calculation diagram
What is Flight Level? (1)
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
300m (1000 ft) intervals above FL 195
150m (500ft) intervals up to FL 195
Changes of reference diagram
What is Transition Altitude? (2)
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 Transition Level? (4)
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:
- CAS: QNH of major AD
- Outside CAS: Based on the local aerodrome QNH
Determining the TL diagram
What is the Transition Layer? (1)
The airspace between the transition altitude and the transition level
4 Altimetry questions
See slides 24-27
