B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 181; Flight Crew Type 8000
Confusion; Distraction; Time Pressure; Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew FLC complied w / Automation / Advisory; Flight Crew Took Evasive Action; Flight Crew Returned To Departure Airport; Flight Crew Landed in Emergency Condition; General Declared Emergency; General Maintenance Action
Aircraft; Chart Or Publication; Procedure; Manuals
Aircraft was a heavy; full B737 going on a hot (102 degree) late afternoon. Takeoff required bleeds OFF. Approaching 1;000 FT clean-up on departure; we experienced Wing Body Overheat warning light for left side. We remained on SID; cleaned up the aircraft; reconfigured the bleeds; and proceeded with QRH. After completing QRH; the Wing Body Overheat light remained on and our bleed configuration was right engine bleed on only (no left engine or APU bleed on per QRH). We were now five or so miles down track and elected to immediately return to the departure airport based upon warning light status (still illuminated) and bleed configuration status (single bleed only). Aircraft was heavy (120.3 thousand pounds); which would create overweight landing situation. We decided that burning down to maximum landing weight would be an unreasonable time of over 90 minutes and elected to accept and execute an overweight landing from a visual approach. The longest runway was requested. On visual downwind; the warning light eventually went out after approximately four minutes from QRH completion.  We elected to stick with our plan of putting the aircraft on the ground from an immediate visual approach. As a precaution; we declared an emergency based upon these factors: potential problem with aircraft bleed system integrity; and a heavy weight landing that was high risk for a hot brakes situation. Our performance calculations showed the aircraft was landing overweight and would require brake cooling period after landing. Flaps 40 landing was uneventful. Rescue personnel checked aircraft and verified brake temperatures were OK. Taxied to gate.Aircraft met by Maintenance and we debriefed them on the event. Logbook annotated for our warning light and overweight landing.  My concern is that QRH for Wing Body Overheat doesn't flow well for bleeds OFF takeoff. The QRH assumes a bleeds ON takeoff so referring to the QRH immediately creates confusion; No. 1 Bleed Air Switch OFF; and then waiting because the engine bleed is already OFF and not the problem. The APU bleed is the problem. An additional problem is that following the checklist places us in an unpressurized takeoff situation with all bleeds OFF when the next step to place the APU bleed OFF is accomplished. Based upon the situation; I consequently elected to reconfigure the bleeds to normal configuration before proceeding with the QRH. This would make the checklist flow better and keep us pressurized with some Passenger cooling air from the left pack/left bleed configuration.   I definitely felt risk by choosing to reconfigure the bleeds BEFORE running the QRH; but it seemed like the logical thing to do given the situation and conditions. I'm not sure my actions would be seen as the approved manner in how I handled this malfunction. The jet was no doubt in stress. We'd had a start malfunction that necessitated a return to gate and a subsequent successful start. And; the packs had been running in high prior to takeoff in an attempt to keep the [passengers and crew] onboard cool in the 102 degree environment. The bleeds OFF takeoff no doubt further pushed the APU.  I was a bit in the yellow based upon cockpit temp and the thrash we encountered with the first aborted start. The problem is mostly a function of an [older second generation B737] on a hot day. I would suggest the QRH might be clarified with a comment toward a bleeds OFF takeoff to prevent an unpressurized situation that I audibled away from outside of strict QRH procedure.
A B737 takeoff was BLEEDS OFF with a 102 degree ambient temperature. After lift off the LEFT WING BODY OVERHEAT light illuminated; so the QRH was completed; an emergency declared; and the flight returned to land. The reporter points out that the WING BODY OVERHEAT procedure begins with the Bleeds ON; not OFF and APU air OFF; the reverse of their configuration.