B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 143
Distraction; Human-Machine Interface; Situational Awareness
Airspace Violation All Types; Deviation - Altitude Undershoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew Returned To Clearance
Human Factors
We were given clearance to descend to FL240 from an altitude higher than FL310. As we began the descent; VNAV would not engage. I tried to enter a lower altitude so the VNAV would engage. The altitude I entered into the FMC was FL300. I thought we were all set and the descent was occurring. I later noticed we had climbed from about FL276 to FL300. We were supposed to be descending to FL240. After I noticed the aircraft level off at FL300; I immediately used Vertical Speed (V/S) to continue the descent. ATC did not notify us of the possible deviation. I think we should have monitored our FMC entries better. This would have prevented what occurred.
After experiencing some difficulty programming a clearance to descend to FL240 the Captain of a B737-700 realized that; instead of descending; the aircraft had climbed from approximately FL276 to FL300 where it had leveled.