B737-400
Flight Crew Air Transport Pilot (ATP)
Time Pressure; Troubleshooting
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft; Human Factors; Procedure
Aircraft had just come out of 'A' Check maintenance. We took off and began to climb to our assigned altitude of 17;000 FT. At about 9;600 FT we got an altitude horn and I disengaged the autopilot and asked to level off at 10;000 to trouble shoot the issue. At level off I tried to reengage both the 'B' and 'A' autopilot; but could not reengage. We ran through QRH for pressurization and decided to return due to multiple issues (autopilot and pressurization; number 2 radio not working; Captain terrain not working) since it just came out of 'A' check. Upon start-up we had a hung start on the number 1 engine and determined we had a bad right igniter on the number 1 engine. Maintenance had to also change the right igniter before we could take-off again. The avionics tech found a blown circuit breaker on the AFDS that caused the autopilot not to engage in flight (previously worked on climb). We noticed several issues all day with aircraft.The pressurization issue described above was caused by the bleeds being turned off by Maintenance personnel. Upon reading the QRH for the pressurization; the bleeds are not checked during the checklist. Other issues with the aircraft should have been repaired during the 'A' Check.
Neither the Mechanic; pilot flying or I noticed the bleed air switches had been moved to the OFF position. Under our normal operations; these switches are never turned OFF. In our climb out to 17;000 FT; at 9;600 FT the 'Cabin Altitude Warning Horn' came on. We requested and received from ATC a clearance to stop at 10;000 FT to resolve a pressurization problem. ATC asked if we are declaring an emergency; and I said 'Negative;' ran the QRH for 'Cabin Altitude Warning' with no resolve. (Note: the QRH does not mention anything about checking bleed air switches). It was at this time I elected to return. It wasn't until after we got parked; I realized our mistake and notified Maintenance Personnel what happened. I have also submitted a summary report with above and other distractions that leaded up to and after this incident. This was an early morning departure. Needed to wake up at very early to work on flight plan etc and get ready. I felt good and rested; but my normal flying is on the back side (late night to early morning) of the clock vs. front side. When picking up an aircraft out of maintenance; [we need to] be much more aware and vigilante of every switch position. Especially the ones we don't use on a regular basis. Add to QRH: (CABIN ALTITUDE WARNING or Rapid Depressurization); ADD 'Verify Bleed Air Switch(s) Position.'
B737-400 flight crew experiences several issues including lack of pressurization; after picking up the aircraft after heavy maintenance for a ferry flight. Flight returns to departure airport.