Define V1, Vr, V2. How does each interact with takeoff performance?
What they are really probing: FAR 25 frame.
Model answer
V1: decision speed. Max abort speed (must stop within ASDA), min continue speed (must take off within TODA). Vr: rotation speed, where pilot pulls back to initiate rotation; must be ≥ V1 and ≥ 1.05 Vmca. V2: safety speed, min single-engine climb speed (≥ 1.13 Vsr, ≥ 1.10 Vmca), achieved by 35 ft AGL after liftoff, second-segment 2.4% climb gradient required. V1 bounded by Vmcg below, Vr above. Heavier weight = higher V1/Vr/V2. Shorter runway = lower V1. Contamination = lower V1 + further constraint. Tie to UAL ops: EWR runway 4L is short (10,000 ft, sometimes shorter for displaced threshold) — V1 typically lower than ORD/IAH; performance margins tight in summer heat.
What fails this question
- — Vague definitions
- — Forgetting Vmcg constraint
- — Not knowing 2.4% gradient
Follow-ups they ask next
- — What's second-segment?
- — Vmcg constraint?
- — EWR vs ORD performance?