A Part 121 air carrier is preparing a dispatch release for a domestic flight. The destination airport has a precision approach, but the latest weather forecast for the estimated time of arrival (ETA) indicates ceilings of 300 feet and visibility of 1/2 statute mile. What is the minimum weather forecast for the destination airport to avoid listing an alternate, assuming standard alternate minimums for the approach?
- ACeilings 1,000 feet and visibility 3 statute miles for at least 1 hour before and 1 hour after ETA.
- BCeilings 600 feet and visibility 2 statute miles for at least 1 hour before and 1 hour after ETA.
- CCeilings 800 feet and visibility 2 statute miles for at least 1 hour before and 1 hour after ETA.
- DCeilings 2,000 feet and visibility 3 statute miles for at least 1 hour before and 1 hour after ETA.
Show answer & explanationAnswer & explanation
Correct answer: C. Ceilings 800 feet and visibility 2 statute miles for at least 1 hour before and 1 hour after ETA.
According to 14 CFR 121.619(b), for a Part 121 domestic operation, an alternate airport is not required if, for at least 1 hour before and 1 hour after the ETA, the weather forecast indicates ceilings of at least 800 feet and visibility of at least 2 statute miles for an airport with at least one non-precision approach, or ceilings of at least 600 feet and visibility of at least 2 statute miles for an airport with at least one precision approach.
Why the other options are wrong
- A. This is incorrect; these are higher than required.
- B. This is the minimum for a precision approach, but the question asks for the condition to AVOID listing an alternate, which is for a non-precision approach, or for a precision approach the conditions are 600-2.
- D. This is incorrect; these are significantly higher than required.
121.619 Destination Alternate Rule
14 CFR 121.619 specifies the conditions under which a Part 121 domestic flight requires a destination alternate airport to be listed on the dispatch release.
- Alternate not required if weather is forecast to be above certain minimums.
- Minimums depend on the type of available instrument approaches at the destination.
- Forecast must be valid for 1 hour before and 1 hour after the Estimated Time of Arrival (ETA).
Memory trick: Don't Alternate if Weather's 1 Hour Good.