Choosing Cruise Flight Levels in Flight Simulation
After you create a plan, NG ROUTE shows a CRUISE recommendation such as FL350 or FL380. That value is not random — it follows common IFR conventions adapted for sim use. Understanding the logic helps you brief altitudes confidently and notice when wind data should push you higher or lower.
Semi-circular rule basics
In RVSM airspace, eastbound magnetic tracks (000°–179°) typically use odd flight levels (FL330, FL350, FL370…). Westbound tracks use even levels (FL320, FL340, FL360…). NG ROUTE estimates your great-circle heading and applies this pattern when suggesting cruise.
The goal is vertical separation between opposite-direction jets. Your sim ATC may not enforce it, but flying the correct level trains real-world habit.
Distance drives altitude
Short sectors under 200 NM might suggest FL240–FL250 because climb and descent consume a large fraction of total time. Medium hops between 200 and 500 NM step into the low thirties. Long routes above 1,500 NM aim for upper thirties or FL390 on capable airframes.
The aircraft ceiling in NG ROUTE also caps suggestions — an A320neo will not be sent to FL430.
Wind aloft chart integration
Below the terrain profile, the wind bar chart shows headwind and tailwind components along track at cruise. Strong headwinds increase ETA; tailwinds shorten it. If you have flexibility in the sim, try rebuilding the plan after mentally noting whether a level 2,000 feet higher or lower would exit a jet streak — NG ROUTE does not auto-optimize for wind yet, but the chart gives you the hint.
Top of climb and top of descent markers
Map markers T/C and T/D assume a nominal climb and descent profile from the suggested cruise level. If you level off early for ATC restrictions in an online network, your actual T/C point shifts. Treat markers as planning guides, not FMS hard limits.
When to override
- Mountainous areas — ensure terrain clearance margin; sometimes a lower level early in cruise is safer until past ridges.
- Step climbs — long hauls often climb as weight burns off; you can restart cruise higher mid-flight manually.
- Online VATSIM/IVAO — obey ATC assigned levels even if they differ from the suggestion.
Quick reference
| Route length | Typical jet cruise (eastbound) |
|---|---|
| < 200 NM | FL250 |
| 200–500 NM | FL330 |
| 500–1500 NM | FL370 |
| > 1500 NM | FL390 |
Westbound values are usually 1,000 feet lower per the semi-circular rule.
Use the CRUISE line as your initial MCP target after departure clearance. Fine-tune with wind information and aircraft performance once established in level flight.