Primary Flight Display Symbols

Over or High Speed Protection

Over Speed or High Speed Protection is activated when airspeed exceeds VMO + 6 knots or MMO + M.01. When it is active:

  • The autopilot disconnects
  • High speed aural warning is heard
  • Automatic pitch trimming stops
  • Bank angle limit is reduced from 67° to 45°
  • High speed protection can be overridden, but side stick nose-down authority is reduced and a positive pitch-up command is introduced
  • Positive spiral static stability is introduced to 0° bank angle (instead of 33° bank angle in normal law), so that when the side stick is released it always returns to 0° bank angle instead of 33° bank angle
  • If the stick is released, the airplane continues to pitch-up until the airspeed slows to VMO/MMO at which point the high speed protection is deactivated and normal control laws are restored