When is a take-off alternate required?

• A. Under Part 121 or 135 operations when weather is above takeoff minimums but below landing minimums for that airport or runway.
• B. Only when thunderstorms are forecast.
• C. For all flights regardless.
• D. Never required.

Answer: (A)

A take-off alternate is required when you can depart under IFR but cannot land at your intended destination due to weather. In Part 121 or 135 operations, this happens if the weather at the destination is above takeoff minimums (so a takeoff is legal) but below the destination’s landing minimums (so you couldn’t land there). You must plan a take-off alternate—an airport within reach that meets landing minimums—so you have a legal place to land if the destination remains unusable. If the destination forecast meets landing minimums, no take-off alternate is needed; if you can’t take off or if landing at the destination is clearly possible, the rule doesn’t apply. Thunderstorms alone aren’t the sole trigger.