Atmospheric Density

Question 1

What are the effects of density on aircraft performance

Answer 1

Low density reduces lift and decrease engine thrust.
take-off distance increases and severely degrades an aircraft’s ability to climb.
Least favourable conditions are high altitude, temperature and humidity.

Question 2

What is density altitude

Answer 2

Density altitude is pressure altitude corrected for temperature. Comparing actual density to where it would be found in ISA model.
Example density at sea level airfield is 903kg/m*3
Density altitude would be 10000ft and aircraft will perform like it was at 10000ft.

Question 3

What is the significance of density altitude to pilots.

Answer 3

Strong indicator of aircraft performance.

Question 4

How is Density Altitude calculated

Answer 4

Every 1C difference from ISA density altitude will differ from pressure altitude by 120ft.
DA=Pressure Altitude +/- (ISA deviation x 120ft)

Question 5

What is the relationship between density,temperature and pressure.

Answer 5

Density proportional to pressure but inverse to temperature.

Question 6

What is the relationship between density and altitude

Answer 6

Density decrease with height at a decreasing rate.