B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 80; Flight Crew Type 21500
Situational Awareness; Human-Machine Interface; Communication Breakdown; Distraction
Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Other / Unknown
Flight Crew Took Evasive Action; Flight Crew Overcame Equipment Problem
Human Factors; Weather
Pushed back normally from the gate five minutes early after normal boarding. After engine start; tug crew cleared off. Called for After Start Checklist. While doing the checklist; (in anticipation of a turnout) I looked to the right and asked to confirm that right side of aircraft was clear. Checklist completed with recall pushed and no lights; but not really (the packs were in off and I didn't verify First Officer flow complete as I should have). I missed that the First Officer had not actually placed the packs to auto. Taxi out was normal. We again recapped the earlier discussed max takeoff due to gusty winds and the anticipated turn and climb out at 250 KTS due to the winds; and routing after takeoff. Takeoff clearance call was missed by the First Officer on the parallel taxiway and I responded. Called for the Before Takeoff Checklist as we turned the corner short of the runway. First Officer read the checklist and I missed that the packs were off. I saw and called out what I expected to see; not what was actually set. Not rushed or in a hurry; just plain missed it when I looked at the First Officer actually touching the switches as he read the checklist. First Officer flying; max takeoff normal due to gusty winds and previous loss of airspeed on approach to landing. Climb out was normal with ATC conversations. TRACON frequency change and slight delay between 6;000 FT and 9;000 FT due to coordination. Next check-in and ATC conversation with Center occurred as we passed through 10;000 FT in climb to assigned FL 190; still climbing at 250 KTS due to gusty winds and turbulence. Upon check-in with Center; we again asked for on course vector. Between 12;000 FT and 14;000 FT; we finally finished talking with ATC and almost immediately got the beeping horn and the Cabin Altitude lights on the forward panel. I immediately commanded a descent as I assessed the situation. I took control of the aircraft from the First Officer and directed the First Officer to don his mask and establish comm. I pulled the power to idle and opened the speed brakes for the descent. As I pulled my mask out to don it; I made a quick call requesting a lower altitude and descent to at least 10;000 FT. The First Officer then confirmed his mask was on and he could talk. I gave him control of the aircraft and told him to continue the descent and talk to Approach Control. I put my mask on and established communication. We were cleared to descend and make a turn to 330 degrees. As we continued to descend; I asked for a vector toward the departure airport where we could set up a holding pattern (if need be) as we determined our problem. No emergency declared. I looked at the pressurization panel and all looked normal. (Packs were in auto) with the cabin altitude holding steady around 10;000 FT. We continued to descend and I completed the QRH items. I then established communication with the departure station and Dispatch through a radio patch. First Officer was still flying and now also talking to Approach. Initially we both questioned the cabin altitude and adequate pressurization. Initial agreed decision was to do a return to get the aircraft fixed. As we discussed the situation between ourselves and Dispatch; the cabin altitude stabilized normally. I mentioned that I had never seen or heard of an aircraft not pressurizing with the packs in auto; but then again things happen. The First Officer then told me that they were in off in the climb out. I asked him again about the switch positions and he again told me that they were off. I told him that they were definitely in auto when I checked the panel in the descending turn back to the departure airport. He admitted that when he looked at the panel after putting on his mask; he had found them in off and placed them to auto. I did recall seeing/hearing him throw some switches as we started the descent; but it didn't register until he told me what he had done. At the time; I think I thought he had gone too high; but when I looked at the panel in the descent; the switches were in auto where they should have been. No more thought to that until our discussion. With the situation newly assessed as a crew issue and no actual system malfunction; my question was now whether we had enough fuel on board to continue to our planned destination. I queried Dispatch and their calculations matched what the FMC was computing. We would arrive with 5.6+ LBS fuel. We agreed that our fuel state was adequate to continue and he made note of that. We coordinated our request with ATC and proceeded to our filed destination. Landing was uneventful. We shut down at the gate with 5.2 LBS. No emergency declared. No emergency masks deployed. No system malfunctions. I take full responsibility for: 1) Distracting my First Officer with a question as he was reading the checklist after start and before taxi. 2) Not verifying his flow completion as I normally do. 3) Not physically catching the fact that the packs were in off vice auto when the First Officer touched the switches and when he read the Before Takeoff Checklist. Do not interrupt checklist reading with a question that could have waited 15 more seconds and verify (as I normally do) switch positions after flow completion by First Officer. I thought I saw the packs in auto when the First Officer touched the switches prior to takeoff. I think my mind saw what I expected to see and I responded as such. More attention to detail.
A B737-700 Captain distracted the First Officer during taxi out for takeoff and both pilots missed the pack switches in the OFF position until the CABIN ALTITUDE WARNING sounded at about 14;000 FT.