Optimal Cruise Altitude Selection: The Art of Compromise

By the PilotLeague Team - Fuel Efficiency Module #2

In the skies of Microsoft Flight Simulator 2024, every foot of altitude matters. Climbing higher means thinner air and less drag, but it also demands considerably more energy. Knowing how to select your optimal cruise altitude (OPT ALT) is what separates a casual pilot from a captain who truly manages fuel efficiency.

In this guide, we break down the three key factors that dictate your cruise altitude, explain the Step Climb technique, and show you how PilotLeague tracks your vertical profile in real time.

Track Your Cruise Efficiency

PilotLeague monitors your cruise phase in detail, analyzing fuel flow against altitude for every second of flight.

PilotLeague tracks your cruise altitude decisions and their impact on fuel economy:

Fuel Flow vs Altitude: Identify whether you were cruising at the most efficient flight level.
Step Climb Timing: See if your altitude changes were well-timed as fuel burned off.
Wind Impact Score: Understand how wind conditions affected your ground speed and overall efficiency.

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This is the second article in our Flight Economy course. Make sure you've mastered the Fuel Planning Basics before diving into altitude optimization.

Optimum vs Maximum Altitude

The optimal altitude is not the maximum altitude. It's the point where the ratio between ground speed (GS) and hourly fuel consumption (Fuel Flow) is at its best. Beyond this point, engines lose too much thrust and efficiency drops.

The 3 Factors That Dictate Your Altitude

1. Aircraft Weight

The heavier the aircraft, the more lift it needs, and therefore denser air. A fully loaded aircraft cannot reach its end-of-flight optimal altitude right from takeoff. This is where the Step Climb technique comes in.

2. Temperature (ISA)

Cold air is denser and more favorable for engine performance. On a hot day, your optimal altitude will be lower than normal. Always check ISA deviation before selecting your cruise level.

3. Wind at Altitude

This is the killer factor. Sometimes climbing to FL380 saves fuel burn, but puts you in a 100-knot jetstream headwind. In that case, staying at FL320 with weaker headwinds is often more fuel-efficient overall.

The Step Climb Technique

As you burn fuel, your aircraft gets lighter. Its optimal altitude increases. To stay efficient on a long-haul flight, you should climb approximately 2,000 ft every 2 to 3 hours. PilotLeague lets you see the immediate impact of each Step Climb on your consumption curve.

Analyze Your Vertical Profile on PilotLeague

The PilotLeague dashboard displays a cross-referenced graph between your altitude and your Fuel Flow:

Optimal Level Detection: Visually spot the moment where your consumption per nautical mile was at its lowest.
Wind Analysis: See how your ground speed (GS) evolved during altitude changes.
Cruise Score: Receive a bonus if you maintained an altitude close to flight plan recommendations.