A dispatcher is planning a Part 121 domestic IFR flight and checking whether a destination alternate airport is required under 14 CFR 121.619. Under what forecast weather condition at the destination is an alternate NOT required?
- AFor at least 1 hour before until 1 hour after ETA, ceiling at least 2,000 feet and visibility at least 3 statute miles
- BFor at least 1 hour before until 1 hour after ETA, ceiling at least 1,000 feet and visibility at least 2 statute miles
- CFor at least 2 hours before until 2 hours after ETA, ceiling at least 1,500 feet and visibility at least 2 statute miles
- DAt the exact ETA only, ceiling at least 3,000 feet and visibility at least 5 statute miles
Show answer & explanationAnswer & explanation
Correct answer: A. For at least 1 hour before until 1 hour after ETA, ceiling at least 2,000 feet and visibility at least 3 statute miles
14 CFR 121.619(a) provides that a destination alternate is not required for a domestic operation if, for at least 1 hour before through 1 hour after the estimated time of arrival, weather reports or forecasts indicate the ceiling will be at least 2,000 feet and visibility at least 3 statute miles. This is a stricter, flat standard than the 91.169 alternate rule used in Part 91 operations.
Why the other options are wrong
- B. 1,000-2 does not meet the 121.619 domestic threshold.
- C. The time window and minimums specified do not match 121.619.
- D. A single-point check at ETA only does not satisfy the regulation's time window requirement.
Domestic Alternate Requirement (121.619)
Rule determining when a destination alternate airport is required for Part 121 domestic IFR operations, based on forecast ceiling/visibility around ETA.
- Time window is 1 hour before to 1 hour after ETA
- Alternate not required if ceiling ≥2,000 ft and visibility ≥3 SM throughout window
- If conditions are below this, an alternate airport must be listed in the dispatch release
Memory trick: '2 and 3, no alternate for me' — 2,000 ft / 3 SM window