Another 737NG pressurization question
Hi everyone,
Had an unusual experience recently. 30 minutes after leveling at cruise (about 37K), experienced a pressurization 'bump' and cabin altitude dropped from about 8K to 6K' (with rise in differential). When descending at destination, differential didn't decrease, but cabin altitude wound down to well below zero. No auto fail light or other fault indications. Went to 'Alternate' at 6K' since differential was still above 8.5psi and experienced rapid decompression to normal level for 6K' altitude, and rush of extremely cold air.
Had never seen that before. Ideas?