Cruise Climb

Cruise Climb is a flight technique where the aircraft gradually climbs during the cruise phase as it burns fuel and its weight decreases, allowing it to reach higher (and more fuel-efficient) altitudes.

In the standard atmosphere, the optimum cruise altitude increases by approximately 1,000–2,000 ft for every 10,000 lb of fuel burned. Cruise climb allows the aircraft to follow this optimum altitude continuously.

• Ideal for fuel efficiency — maintains optimum altitude as weight decreases
• Not always permitted by ATC due to traffic separation requirements
• Alternative: Step climb — periodic discrete altitude increases (e.g., FL350 → FL370 → FL390)
• Step climbs are the practical implementation of cruise climb in controlled airspace