B737NG PFD Barometric Indications
As I understand QNH/STD selection via the EFIS box on the NG:
If you have STD selected and then 'twist' the QNH knob (or barometric selector) in either direction, the preselected QNH (the white numbers) always starts from 1013. Can anyone confirm this or did I dream it? The only reference I can find in the systems manual is pasted below:
1 Barometric Settings (green)
Indicates the barometric setting in either inches of mercury (IN) or hectopascals (HPA) as selected on the EFIS control panel.
Display is boxed amber if numeric is set and airplane is climbing above transition altitude, or if STD is set and descending below transition flight level.
2 Preselected Barometric Setting (white)
STD is displayed when the Barometric Standard (STD) switch is selected on the EFIS control panel.
When STD is displayed, a barometric setting can be preselected on the EFIS
control panel barometric selector and is displayed in small white characters below STD.