Pressure And Density ATPL

Question 1

State units used for pressure in Aus and USA

Answer 1

Aus - hPa

USA - inches of mercury

1013.25 hPa = 29.92 inches of mercury

Question 2

Demonstrate the effect of flying at a constant indicated altitude from a cold region to a warm region, during which the surface pressure doesn’t change

Answer 2

Lo - hi - lo -hi

Will climb into the warm air while maintaining same indicated altitude

Question 3

State ISA

Answer 3

Air is dry and its composition is the same at all altitudes
•Mean sea level temp 15 °C
•Above 36,090 ft/-56.5 °C temp is isothermal
•1.98 °C per 1000ft to the tropopause
•Mean sea level pressure 1013.25 hPa

Question 4

State JSA

Answer 4

Does not include a tropopause
•2°C per 1000ft to infinity

Question 5

Convert ISA temp at altitude to Cº

Answer 5

Use temp lapse rate of 2ºC per 1000ft.

E.g MSL temp of 15ºC at 10,000ft, should be 15-(10x2) = -5