THE PRESSURE ALTIMETER

Question 1

In the International Standard Atmosphere, the mean sea level pressure is ……., the lapse rate of temperature ……. between MSL and ……. and is isothermal up to …….. The numbers missing are:

Answer 1

b. 1013.25 mb; 1.98°C per 1000 ft; 36 090 ft; 65 617 ft.

Question 2

An aircraft taking off from an airfield with QNH set on the altimeter has both static vents blocked by ice. As the aircraft climbs away the altimeter will:

Answer 2

a. read the airfield elevation.

Question 3

When flying from low pressure to high pressure, without resetting the altimeter datum, the barometric error of an altimeter will cause the instrument to:

Answer 3

d. underread the true altitude of the aircraft.

Question 4

The errors affecting the pressure altimeter are:

Answer 4

c. instrument, position, manoeuvre induced, temperature, barometric, lag.

Question 5

An altimeter with ……. set on the subscale will indicate ……., but with ……. set, the altimeter will show …….

Answer 5

a. 1013; pressure altitude; QNH; altitude.

Question 6

7. An aircraft has one altimeter set to QFE and one to aerodrome QNH 1000 mb. If the airfield elevation is 300 ft, immediately before take-off the altimeter with QFE set will read ……. and the other ……. If the QFE altimeter is set to 1013 when passing through the transition altitude 3000 ft, it will read …… (Assume 1 mb = 30 ft).

Answer 6

b. zero; 300 ft; 3390 ft