10 / 20
Maintaining a constant Flight Level and IAS, an aircraft flies into a colder airmass.
Choose the correct statement:
  • A
    Mach number stays the same, but there is an increased risk of high speed buffet and a shock stall.
  • B
    Mach number increases. There is a risk of a high speed warning.
  • C
    Mach number decreases, There is a risk of a low speed warning.
  • D
    Mach number stays constant.

Mach number = True Air Speed (TAS) / Local Speed of Sound (LSS)
LSS = 38.96 √ Absolute Temperature (K)

  1. IAS = 1/2 p V2 (Where V = TAS)
    When flying into a colder airmass, density "p" increases. In order to maintain IAS constant, TAS (V) must decrease.

  2. LSS will decrease in colder air.

As both TAS and LSS decreases, Mach number will not change.

Your Notes (not visible to others)



This question has appeared on the real examination, you can find the related countries below.

  • United Kingdom
    6
  • Austro Control
    5
  • Portugal
    5
  • Hungary
    4
  • Spain
    3
  • Greece
    2
  • Latvia
    2
  • Poland
    2
  • Sweden
    2
  • Hong Kong
    1
  • Iceland
    1
  • Norway
    1
  • Pakistan
    1
Keyboard Shortcut Use Keyboard Shortcuts