FLCH opens window with knots displayed
Thread Starter
Joined: Apr 2008
Posts: 1
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From: nowhere
FLCH opens window with knots displayed
But never seems to open it with a mach number displayed on Boeing's(in my experience anyways). Is there a reason for this as mach can be subsequently selected.
Joined: Aug 2009
Aviation Qualifications: ATPL
Posts: 616
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From: GPS L INVALID
I never noticed this, but it does make sense to me - flying current IAS will keep you reasonably within the envelope whether you are climbing or descending, maintaining Mach will result in a large change in IAS and a higher chance of hitting a limit.
Joined: Jan 2000
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From: FL410
On our fleet of NGs it opens up in whatever mode is commanded in CLB/CRZ/DESC pages.
e.g. If climbing KIAS before conversion to calculated Mach it opens in KIAS, descending from cruise level opens in Mach, unless the KIAS calculated for initial descent is equal to or lower than descent Mach number.
At lower (e.g. FL250) cruise levels, it always defers to KIAS
As described above in our FCOM 2:
e.g. If climbing KIAS before conversion to calculated Mach it opens in KIAS, descending from cruise level opens in Mach, unless the KIAS calculated for initial descent is equal to or lower than descent Mach number.
At lower (e.g. FL250) cruise levels, it always defers to KIAS
As described above in our FCOM 2:
IAS/MACH display and airspeed cursors display target speed.
Last edited by Skyjob; 25th September 2014 at 08:33. Reason: FCOM reference
