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Thread: Soft Altitude
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Old 12th July 2009 | 11:16
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Cough
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Joined: Jul 2000
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Jimmy,

I don't know what your pic proves. Yup, alt crz engages at any altitude, but soft alt only with a mach mode.

The quote from FCOM

On reaching the planned cruise altitude, ALT CRZ engages and A/THR maintains the speed/mach target.

Two minutes after ALT CRZ engages, if the mach mode is operative, SOFT ALT mode engages. This allows the aircraft to deviate ± 50 feet from the target altitude, thereby minimizing thrust variations and reducing fuel consumption.
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