B737 Undifferentiated or Other Model
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Air Transport Pilot (ATP)
Confusion; Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Overcame Equipment Problem
Human Factors
We had accomplished the Before Start Checklist as the passengers were boarding and all switches were in the correct position. After the 'A' Flight Attendant completed her Welcome PA; I gave my Welcome PA from the Forward Galley. As I reentered the cockpit to take my seat; I hit my head on the overhead panel; which I am sure many of us have done before. I looked up and did not notice anything out of place. We accomplished the Before Push Checklist and began our push and started engine #2. We only had 10 PSI duct pressure; 15% N2 and no oil pressure. The First Officer even asked if everything was set correctly and we verified the APU was running with its Bleed On and the Packs were off. We recycled the switches and failed to get more duct pressure. We terminated the engine start and referenced the Aborted Engine Start QRH; but it did not provide any useful information for our situation. I called Dispatch and talked to Maintenance Control. He asked about all of the settings on the Air Conditioning panel; which were correct; then asked if everything else was correct; like Wing Anti-Ice. That was the culprit. That small switch was bumped On and neither of us caught it; and there is no light illuminated to tell you it is on. Lesson Learned: you can't start the engines with the Wing Anti-Ice switch on.
B-737 Captain reported inadvertently bumping into and turning on the wing anti-ice switch when reentering the cockpit before engine starts.