Why do maximum takeoff weights vary between products?

Differences in calculated weights may occur due to:

• Improved Calculation Engines
• Enhanced iteration methods for V1, level-off heights, and obstacle clearance
• Updated Aircraft Data Files
• Digitized using improved tracing software (minor variances expected)
• Additional Aircraft Capabilities

Newer aircraft (e.g., Citations with CPCalc) benefit from extended second segments and slope corrections not available in legacy ATLAS

Are all versions valid?
Yes—as long as you use the associated V speeds and level-off heights from the same report.

Do not mix data from different products or the FMS (e.g., using a weight from ATLAS with level-off height from iPreFlight).