in Pilot Notes

Vmcg, Vmca and Vmcl Speeds Explained!

Vmcg, Vmca and Vmcl primarily stands for minimum control speed on ground, air and in approach and landing.

Vmcg

Vmcg is the calibrated airspeed during the take-off run at which if critical engine fails, it is possible to maintain control of aeroplane with use of primary aerodynamic controls alone (rudder) to enable safe takeoff. In determination of Vmcg it considered that recovery will be done on a path parallel to center line within maximum deviation of 30ft laterally either side.

Vmcg must be established with:

  • failure of most critical engine
  • aircraft in take-off configuration
  • maximum available take-off power or thrust on operating engine
  • most unfavorable center of gravity
  • aeroplane trimmed for take-off
  • most unfavorable weight in range of take off weights

Vmca

Vmca is calibrated airspeed at which if critical engine become inoperative it is possible to maintain the control of aeroplane and straight flight with maximum bank angle of 5 degree. Vmca ensure during the recovery aeroplane should not enter any dangerous attitude or require exceptional pilot skill, alertness or strength to prevent a heading change of more than 20 degrees.

Vmca must be established with:

  • failure of most critical engine
  • maximum available take-off power or thrust on the engines
  • most unfavorable center of gravity
  • aeroplane trimmed for take-off
  • maximum sea level take-off weight

Vmcl

Vmcl, minimum control speed during approach and landing with all engines operating is calibrated airspeed at which if critical engine fails it is possible to maintain control of aeroplane and maintain straight flight with angle of bank of not more than 5 degree.

Vmcl must be established with:

  • aeroplane in most critical configuration
  • most unfavorable center of gravity
  • aeroplane trimmed for approach with all engines operating
  • most unfavorable weight
  • go-around thrust setting on operating engines