B737-800
Flight Crew Last 90 Days 392
Situational Awareness; Distraction
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
As we were leveling off at an intermediate altitude; we were assigned a climb and the Captain selected the altitude in the MCP. I verified the altitude and noticed the Vertical Speed window +2500. I assumed the Captain knew we were in Vertical Speed. I was distracted putting charts away when I heard the autopilot disengage (we were at the top of the minimum maneuvering speed). The Captain took control of the aircraft; pitched down slightly to increase airspeed and; as a result; we descended approximately 500 FT. We resumed the climb and VNAV was engaged.
During climb and approaching FL230; we were given clearance to FL410. As I selected 410 in the MCP Altitude window; I must have missed that the pitch mode entered the Vertical Speed mode. I must seriously step up my CRM procedures and my efforts at verbalizing; verifying; and monitoring of the automation systems.
B737-800 was climbing in Vertical Speed mode; unnoticed by the flight crew. A near-stall and altitude excursion resulted.