OWLS explained

OWLS is a mnemonic used by general aviation airplane pilots to assess an unprepared surface for a precautionary landing.^[1]

Like all mnemonics this check has become part of aviation culture and folklore.

OWLS:

• Obstacles
• Wind direction
• Length of surface
• Surface condition and type

Notes and References

1. Kaiser, John W.: How to Fly Book - Cessna 150, page 37. Victoria Flying Club, 1977.