Historical FAR V1 Definition :
(Prior to March 1, 1978)
[FAR Paragraph 25.107(a)]
V1 – Critical engine failure speed.
“V1 is the critical engine failure speed. It shall not be less than the minimum speed at which controllability by aerodynamic controls alone is demonstrated during the takeoff run to be
(Prior to March 1, 1978)
[FAR Paragraph 25.107(a)]
V1 – Critical engine failure speed.
“V1 is the critical engine failure speed. It shall not be less than the minimum speed at which controllability by aerodynamic controls alone is demonstrated during the takeoff run to be
adequate to permit proceeding safely with the takeoff using average pilot skill, when the critical engine is suddenly made inoperative.”
(March 1, 1978)
[FAR Paragraph 25.107(a)(2)]
V1 – Takeoff decision speed.
“It cannot be less than VEF plus the speed gained with the critical engine inoperative during the time interval between the instant the critical engine has failed and the instant the pilot has recognized and reacted to the engine failure by application of the
first retarding means.”
Current FAR V1 Definition :
(March 20, 1998)
[FAR Paragraph 25.107(a)(2)]
V1 – No longer described as “Takeoff decision speed”
“It cannot be less than VEF plus the speed gained with the critical engine inoperative during the time interval between the instant the critical engine has failed and
the instant the pilot has recognized and reacted to the engine failure, as indicated by the pilot’s initiation of the first action to stop the airplane.”
(March 1, 1978)
[FAR Paragraph 25.107(a)(2)]
V1 – Takeoff decision speed.
“It cannot be less than VEF plus the speed gained with the critical engine inoperative during the time interval between the instant the critical engine has failed and the instant the pilot has recognized and reacted to the engine failure by application of the
first retarding means.”
Current FAR V1 Definition :
(March 20, 1998)
[FAR Paragraph 25.107(a)(2)]
V1 – No longer described as “Takeoff decision speed”
“It cannot be less than VEF plus the speed gained with the critical engine inoperative during the time interval between the instant the critical engine has failed and
the instant the pilot has recognized and reacted to the engine failure, as indicated by the pilot’s initiation of the first action to stop the airplane.”
