FAA Aircraft Dispatcher (ADX)Navigation and ATCMedium
A dispatcher is filing an alternate airport for a destination that has only a nonprecision approach available. Assuming no other minimums are specified for that airport, what ceiling and visibility must be forecast at the ETA to qualify as a legal alternate under the standard alternate minimums?
- A200 feet and 1/2 statute mile
- B800 feet and 2 statute miles
- C1,000 feet and 3 statute miles
- D600 feet and 2 statute miles
Show answer & explanationAnswer & explanation
Correct answer: B. 800 feet and 2 statute miles
Standard alternate minimums, often called the '1-2-3 rule' when used for planning, require a forecast ceiling of 800 feet and visibility of 2 statute miles for an airport with only a nonprecision approach. Airports with a precision approach use 600 feet and 2 statute miles.
Why the other options are wrong
- A. 200 and 1/2 are typical CAT I landing minimums, not alternate minimums.
- C. 1,000-3 exceeds standard alternate minimums and is not the default requirement.
- D. 600-2 is the standard minimum for airports with a precision approach, not nonprecision only.
Standard IFR Alternate Minimums
Default weather minimums used to determine if an airport qualifies as an alternate: 600-2 for airports with a precision approach, 800-2 for nonprecision-only airports.
- Precision approach available: 600 ft ceiling, 2 SM visibility
- Nonprecision only: 800 ft ceiling, 2 SM visibility
- Higher minimums may be published on some approach charts
Memory trick: '6-2 Precision, 8-2 Nonprecision' — count the letters to remember the split.