FLIGHT PLANNING

Top of Descent (TOD) Calculation Using the 3:1 Rule

Learn how to calculate descent distance and target vertical speed for a smooth, stabilized 3-degree glide profile.

Calculating your Top of Descent (TOD) point allows pilots to execute fuel-efficient, stabilized 3-degree descents without level-offs or speed brake deployment.

The 3:1 Rule Formula

Multiply the altitude to lose in thousands of feet by 3. For example: descending from FL330 to 3,000 ft requires shedding 30,000 ft (30 × 3 = 90 NM before the fix). Add 5 to 10 NM for deceleration.

Calculating Target Vertical Speed (V/S)

Multiply your Groundspeed (GS) by 5. For a GS of 140 knots: 140 × 5 = 700 ft/min descent rate to maintain a 3-degree flight path.

Nota Educacional

Este artigo faz parte da biblioteca educacional FOX SIM e destina-se a fins de estudo e simulação de voo. Para operações aeronáuticas reais, consulte sempre as publicações oficiais (AIP, ROTAER, NOTAM) e manuais aprovados da aeronave.

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