20 / 20
While cruising level, severe turbulence affects the aircraft’s capability to maintain the height-keeping requirements for RVSM. How should the pilot inform ATC?
  • A
    “Not RVSM any more due to turbulence”
  • B
    “RVSM not approved due turbulence”
  • C
    “Unable RVSM due to turbulence”
  • D
    “Negative RVSM”

ICAO Annex 10, Volume II

5.2.1.5.8 The following words and phrases shall be used in radiotelephony communications as appropriate and shall have the meaning ascribed hereunder:
UNABLE “I cannot comply with your request, instruction, or clearance.”

Note: UNABLE is normally followed by a reason

  • RVSM stands for Reduced Vertical Separation Minima. RVSM relies on accurate instrumentation, navigation, as well as good height-keeping. If the pilot is unable to comply with an ATC requirement, he/she should report "UNABLE"

Your Notes (not visible to others)



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

  • France
    27
  • Spain
    10
  • United Kingdom
    10
  • Germany
    5
  • Poland
    5
  • Austro Control
    4
  • Czech Republic
    3
  • Greece
    3
  • Sweden
    3
  • Iceland
    2
  • Portugal
    2
  • Bulgaria
    1
  • Romania
    1
  • Thailand
    1
Keyboard Shortcut Use Keyboard Shortcuts