B737-700
Flight Crew Last 90 Days 136
Aircraft Equipment Problem Critical
Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft
On takeoff roll; above 100 KTS; pressurization controller failed and switched to alternate. Continued takeoff and applied QRH procedure when workload permitted. Passing 6;000 FT; ALTN controller failed and pressurization started to indicate below sea level. The Captain again applied the QRH procedure while I flew the airplane and talked with ATC. I requested a level off at 8;000 FT and informed them of the possibility of a return to the departure airport. The decision was made to return and we landed without incident. As we taxied in; I contacted Operations and they assigned us a gate and requested we contact Dispatch since they were unaware of our return. Since I was flying and monitoring ATC; I did not hear all the coordinating the Captain did. I assumed Dispatch was contacted since an emergency was not declared. I feel as a Crew; we handled the situation well.
B737-700 First Officer experiences a pressurization controller failure on the takeoff roll. Climbing through 6;000 FT the alternate pressurization controller fails and cabin altitude is noted below sea level. Crew elects to return to departure airport.