Para essa pergunta, tenha em mente esses trechos do 14 CFR 25.107 - Velocidades de decolagem.
"(d) VMU is the calibrated airspeed at and above which the airplane can safely lift off the ground, and con- tinue the takeoff. VMU speeds must be selected by the applicant throughout the range of thrust-to-weight ratios to be certificated. These speeds may be established from free air data if these data are verified by ground takeoff tests."
e o VR deve ser:
"(iv) A speed that, if the airplane is rotated at its maximum practicable rate, will result in a VLOF of not less than —
(A) 110 percent of VMU in the all-engines-operating condition, and 105 percent of VMU determined at the thrust-to-weight ratio corresponding to the one-engine-inoperative condition; or
(B) If the VMU attitude is limited by the geometry of the airplane (i.e., tail contact with the runway), 108 percent of VMU in the all-engines-operating condition, and 104 percent of VMU determined at the thrust-to-weight ratio corresponding to the one-engine-inoperative condition."
Minha pergunta é: por que ter uma aeronave com limite de geometria leva a VLOFs mais baixos? É porque, como a aeronave não consegue alcançar o ângulo de parada devido a sua limitação, a VMU para tais aviões é maior que a velocidade de estol e, portanto, o coeficiente máximo de elevação não foi alcançado e, portanto, oferece uma maior margem de segurança ?