Takeoff Alternate Requirements
Determine if a takeoff alternate is required based on weather and regulations.
When Required (FAR 121.617)
- Weather below takeoff minimums
- 1-2 engines: if unable to return and land
- 3+ engines: if unable to continue to destination on remaining engines
- Alternate must be within 1 hour at OEI cruise speed
Alternate Weather Requirements
| Engines | Ceiling | Visibility |
|---|---|---|
| 1-2 Engine | 1500 ft | 2 sm |
| 3+ Engine | 800 ft | 2 sm |
Takeoff Alternate Regulations
FAR 121.617 - Domestic Operations
A takeoff alternate is required for supplemental operations when weather at the departure airport is below landing minimums. The alternate must be within one hour flying time at normal cruise speed (one-engine inoperative for multi-engine aircraft).
FAR 135.217 - IFR Requirements
For Part 135 IFR operations, if the weather is below the authorized minimums, the pilot must have an alternate airport that meets weather requirements and is within a reasonable distance.
Part 91 Operations
Part 91 does not specifically require a takeoff alternate, but pilots should consider operational requirements and ensure ability to return or divert safely.
Key Considerations
- Takeoff alternate weather must be at or above alternate minimums at ETA
- Consider fuel requirements for return and alternate
- Check NOTAMS for alternate airport status
- Verify approach capabilities at alternate (ILS, GPS, etc.)