IFR flight plan: Information required

In plain English

When filing IFR you must name an alternate airport unless the 1-2-3 rule is met: from 1 hour before to 1 hour after your ETA, the destination forecast is at least a 2,000 ft ceiling and 3 SM visibility. If an alternate is required, it must meet its own published (or standard) weather minimums.

Key points

• 1-2-3 rule: ETA ±1 hour, ≥2,000 ft / ≥3 SM means no alternate required.
• If required, the alternate must meet its alternate minimums.
• Standard alternate minimums: 600-2 (precision) / 800-2 (non-precision) when none are published.

Common pitfalls

• Picking an alternate that itself has no instrument approach or is below minimums.

*This is a plain-English summary for study only. The official 14 CFR text on this page is controlling — always read the current regulation.*