The trick: Where do you start coming down? Distance (NM) = thousands of feet to lose × 3.

• Altitude to lose (in 000s ft) × 3 = miles needed
• Flight levels are hundreds of ft, so FL250 = 25,000 ft = 25.

Worked example: Cruising at FL350, descending to sea level — that's 35,000 ft to lose. 35 × 3 = 105 NM. Start down 105 miles out.

How to play. Each round is 12 questions. Start in CADET mode — just "thousands of feet × 3" with no airport elevation. Once that's automatic, step up to PILOT for full top-of-descent from a cruise altitude to an airport. When the trick is second nature, try TOWER — ATC step-downs against the clock with a bonus. Beat the top 10 and you'll be invited to add your callsign to the leaderboard.