B737-300
Flight Crew Last 90 Days 175
Distraction; Time Pressure; Training / Qualification; Workload
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew FLC complied w / Automation / Advisory
Aircraft; Chart Or Publication; Manuals; Procedure
[The] Captain asked for a bleeds off takeoff. We had an operating APU and the left pack had just been MEL'ed so we configured based on an operating APU. Since the left pack was not operable; we actually departed unpressurized and should have used that configuration for the bleeds and packs. That procedure would have included additional action items for our analog system. Upon reconfiguring after takeoff; we received an Auto Fail light and Standby light on the pressurization panel. We leveled off at 8;000 FT; ran the appropriate checklists; notified Dispatch; and continued to our destination. The controller was MEL'ed on arrival. Prior to departing; we were briefed by the arriving crew about an incident that occurred on takeoff. The incident involved a loud noise and vibration at approximately 10;000 FT that resolved when they reduced their power setting. They noticed no unusual engine indications and thought it might be a gear door seal. We thoroughly checked the aircraft and then decided to try operating the left pack. It made a very loud noise and we called Maintenance Control to get their thoughts on how to proceed. They thought we had a bad air cycle machine and suggested we call local Maintenance to have it checked out. It was confirmed inoperable and MEL'ed. Because of the delay for Maintenance and knowing we had a short (11-hour scheduled) overnight; I was rushed and not as vigilant as I should have been with regard to our Release. I knew an increase in gross weight would be required for the additional fuel burn and quickly assumed a bleeds off takeoff would be necessary (it was 29C OAT) and I found myself headed down that road without checking the Release for that change. I should have paid closer attention to our Release and the performance data before jumping to the conclusion that a bleeds off takeoff was required. I should have taken the time to analyze our configuration and pressurization status before departure and configured to use the right pack and APU. [To prevent this] a note in the performance material; MEL; or AOM that alerts a crew to use the unpressurized takeoff procedure for a bleeds off takeoff with the left pack inoperable or to configure using the APU and the right pack.
Upon reconfiguration after takeoff; we received an Auto Fail light and a STBY light. We leveled off at 8;000 FT; ran the appropriate checklists; notified Dispatch; and continued to our destination uneventfully.We should have read the entire Release. The new Release and load sheet arrived together just before push and we were too eager to get moving after a long delay. We should have stopped to analyze the configuration and pressurization status prior to takeoff. There should be a note in the MEL and AOM that when the left pack is inoperative; a bleeds off takeoff should not be accomplished. The AOM states that an unpressurized takeoff should be accomplished when the APU is inop only. Moreover; the performance data allows a bleeds off takeoff in this case because it does not specify left/right pack in the MEL.
A rushed B737-300 crew made a BLEEDS OFF takeoff with an MEL'ed Left pack but should have used APU air and the right pack for a pressurized BLEEDS OFF takeoff.