Altimetry

Question 1

What is a Dyne?

Answer 1

A dyne is the force required to produce an acceleration of 1cm/s^2 to a mass of 1 gramme

Question 2

What is a millibar?

Answer 2

A millibar is 1000 dynes per cm^2

Question 3

What is the definition of Height?

Answer 3

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

Question 4

What is the definition of Altitude?

Answer 4

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

Question 5

What is the definition of Elevation?

Answer 5

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

Question 6

What is QFE?

Answer 6

The observed atmospheric pressure at aerodrome level

Question 7

What is QNH?

Answer 7

The atmospheric pressure at mean sea level

Question 8

For a threshold QFE to be published, how must threshold elevation relate to aerodrome elevation?

Answer 8

The threshold elevation must be 7ft or more below aerodrome elevation

Question 9

What is Aerodrome Elevation?

Answer 9

The elevation of the highest point on the landing area

Question 10

What is Regional Pressure Setting?

Answer 10

The lowest forecast QNH within an altimeter setting region

Question 11

What is the regional pressure setting used for?

Answer 11

Flight below the transition altitude away from the aerodrome. Used by en-route aircraft to ensure terrain separation

Question 12

When flying towards an area of low pressure, what happens to an aircraft if the pilot fails to update the altimeter setting

Answer 12

Vertical distance above the ground will decrease even if the altimeter shows a constant altitiude

Question 13

When are regional pressure settings published?

Answer 13

Published at H hour for the period H+1 and H+2

Question 14

What is a flight level

Answer 14

A surface of constant atmospheric pressure related to a specific pressure datum of 1013.25mbs and separated from other such surfaces by a specific pressure interval

Question 15

What is the Transition Altitude?

Answer 15

The altitude at, or below which, the vertical position of the aircraft is controlled by reference to altitude

Question 16

What is the Transition Level?

Answer 16

The Lowest Flight Level available for use above the transition altitude

Question 17

What is the Transition Layer?

Answer 17

The airspace between the Transition Altitude and the Transition Level (Never greater than 500ft)

Question 18

Who determines the Transition Altitude?

Answer 18

Within Controlled Airspace
The transition altitude is determined by the controlling authority and is based on the QNH of the major aerodrome within the controlled airspace

Outside Controlled Airspace
The transition altitiude is determined by the aerodrome authority and is based on the aerodrome QNH

Question 19

What is the QNE?

Answer 19

It is the reading in feet, on an altimeter when the aircraft is at aerodrome or threshold elevation within 1013.25mbs set on the subscale

Question 20

When is the QNE used?

Answer 20

When the QNH is outside the limits that can be set on the altimeter subscale