(1) ATM - Practical Altimetry

Question 1

What 3 types of barometric pressure is available? (3)

Answer 1

• QNH
• QFE
• QNE (Standard pressure)

Question 2

What is QFE? (2)

Answer 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

Question 3

What is QNH? (1)

Answer 3

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

Question 4

What is QNE? (1)

Answer 4

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

Question 5

What is Height? (1)

Answer 5

“The vertical distance of a level, point or object considered as a point measured from a specified datum

Question 6

What is Altitude? (1)

Answer 6

The vertical distance of a level, point or object considered as a point measured from mean sea level

Question 7

What is Elevation? (1)

Answer 7

The vertical distance of a point or level, on or affixed to the surface of the earth, measured from mean sea level

Question 8

What is Aerodrome Elevation? (1)

Answer 8

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)

Question 9

Pressure relationships diagram

Answer 9

Question 10

Elevation calculation diagram

Answer 10

Question 11

QNH calculation diagram

Answer 11

Question 12

QFE calculation diagram

Answer 12

Question 13

What is Flight Level? (1)

Answer 13

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

Question 14

Changes of reference diagram

Answer 14

Question 15

What is Transition Altitude? (2)

Answer 15

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)

Question 16

What is Transition Level? (4)

Answer 16

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

Question 17

Determining the TL diagram

Answer 17

Question 18

What is the Transition Layer? (1)

Answer 18

The airspace between the transition altitude and the transition level

Question 19

4 Altimetry questions
See slides 24-27