The Atmosphere

Question 1

The three elements that determine air density are _____________, ____________ & _____________.

Answer 1

• Temperature,
• Pressure,
• Moisture.

Question 2

Air pressure is is the result of the _______________ of a column of air above a _______________.

Answer 2

• Weight.
• Datum.

Question 3

With increasing altitude, air pressure _______________ which causes air density to _______________.

Answer 3

• Decreases.
• Decrease.

Question 4

The atmosphere is warmed (from above / from below).

Answer 4

• From below.

Question 5

With increasing altitude, air temperature (increases / decreases) and this tends to (increase / decrease) air density.

Answer 5

• Decrease.
• Increase.

Question 6

The combined effect of pressure and temperature change with increasing altitude to ( increase / decrease).

Answer 6

• Decrease.

Question 7

The standard atmosphere (ISA) assumes that sea level pressure is ____________ in.Hg or __________ hPa, sea level air temperature is _______ deg F or _______ deg C and temperature lapse rate is ________ deg F or ________ deg C per 1000ft, air density of _________ gm/m3

Answer 7

• 29.92 in.Hg or 1013.2 hPa
• 59 deg F or 15 deg C
• 3.5 deg F or 1.98 deg C
• 1.225 gm/m3

Question 8

A low density altitude results when pressure is ___________, temperature is ____________ and the moisture content of air is ____________. The helicopter’s performance under these circumstances is (good / poor).

Answer 8

• High.
• Low.
• Low.
• Good.