B737-700
Flight Crew Last 90 Days 157
Communication Breakdown; Workload
Aircraft Equipment Problem Critical
Air Traffic Control Issued New Clearance; Aircraft Equipment Problem Dissipated; Flight Crew Took Evasive Action; General Declared Emergency
Aircraft; Manuals; Human Factors
Just after our initial descent clearance out of FL410; we got a bleed trip light on the Number 2 Engine. We started into the QRH and got a bleed trip on the Number 1 Engine. The aircraft began to depressurize at a rate of about 1;000 to 2;000 FPM. We donned our masks and established crew communication. This was very loud and was a very challenging aspect of the situation. I asked ATC for a lower altitude due to a pressurization problem and declared an emergency. We started a rapid descent and the Cabin Altitude Warning horn sounded shortly thereafter. We talked to approximately four different controllers and had several different altitude clearances while trying to work the problem. By about 25;000 FT; the trip reset was successful and we regained pressurization; but we discussed it and opted to continue our descent to 10;000 FT in case the problem came back. I notified Dispatch and the Captain made a PA advising the passengers of the issue. We told the flight attendants what was going on and they helped to clarify to the passengers the issue because the PA that the Captain gave was apparently difficult for them to hear because he had his oxygen mask on. The masks in the cabin did not drop because the cabin altitude never got above approximately 10;500 FT. By the time we worked through the checklists and finished the descent we were about 80 miles or so from destination and we decided to continue there after checking the weather and landed uneventfully. The QRH was a bit tough to get through having the Bleed Trip Off; Cabin Altitude Warning; and Emergency Descent to get through; especially with the breathing noise over the speakers and headset; ATC communication; flight attendants calling; etc.; and I can't stress enough how fast the time went by. We were already low by the time we got to the bottom part of the Emergency Descent Checklist to the part where it addresses the 'in case of a dual bleed trip' area. This should possibly be moved to the top of that checklist because of the different procedure and 290 KT speed reference in it. We both felt that we took safe and conservative actions for the safety of our passengers and crew.
B737-700 Captain experiences a dual bleed trip as thrust is reduced to begin descent from FL410. Oxygen masks are doned and QRH procedures are complied with. The bleed trip is reset passing FL250 and the passenger oxygen masks do not drop. Flight continues to destination at 10;000 FT.