B757-200
Flight Crew Last 90 Days 300; Flight Crew Total 20000; Flight Crew Type 12000
Physiological - Other
Aircraft Equipment Problem Critical
Aircraft Aircraft Damaged; Flight Crew Returned To Departure Airport; General Declared Emergency; General Maintenance Action
Aircraft
As takeoff power was applied a dull thud was heard from behind the cockpit. All engine indications were normal and the takeoff was continued. While climbing through 10;000 FT the cockpit temperature became uncontrollable. At approximately FL280 the master caution warning illuminated with an altitude warning horn; the cabin altitude was above 10;000 FT and climbing at a rate of 1;000 FT per minute. All appropriate QRH items were completed and an emergency descent was completed to 10;000 FT. Passenger oxygen masks did not deploy. ATC was informed; and we returned to the airport. Dispatch and Maintenance were notified of the aircraft status. A flap 25; overweight landing was accomplished to a successful outcome. We returned the aircraft to the gate and the passengers were deplaned.
The Reporter stated that a stainless steel duct from the left Air Conditioning Pack ruptured partially on takeoff and then completely at FL280. This failure not only caused the loss of pressurization but the sound in the cabin was so loud that the Call Button Chimes could not be heard. The duct failure occurred at a weld joint which caused the duct to peel back like a banana.
As takeoff power was applied a dull thud was heard from behind the cockpit. All engine indications were normal and the takeoff was continued. While climbing through 10;000 FT the cockpit temperature became uncontrollable. At approximately FL280 the master caution warning illuminated with an altitude warning horn; the cabin altitude was above 10;000 FT and climbing at a rate of 1;000 FT per minute. All appropriate QRH items were completed and an emergency descent was completed to 10;000 FT. Passenger Oxygen masks did not deploy. ATC was informed; and we returned to the airport. Dispatch and Maintenance were notified of the aircraft status. A flap 25; overweight landing was accomplished to a successful outcome. We returned the aircraft to the gate and the passengers were deplaned.
A B757's left pack air conditioning duct ruptured slightly at takeoff; then completely failed at FL280; causing the loss of cabin pressurization. The crew declared an emergency and returned to the departure airport.