A Boeing 757-28A was on a positioning flight from Cardiff (United Kingdom) to Rome (Italy) on this day in aviation history. Onboard a crew of 8, a cockpit crew of 2 and 6 cabin crew.
The incident aircraft G-OOOD ©Les Watson
After an uneventful flight preparation, the crew lined up on the runway for take-off and after receiving their clearance the take-off was initiated. After passing V1 the crew was alerted by an EICAS ( Engine Indication and Crew Alerting System) message, R ENG HI STAGE. This indicated that;
The engine bleed system pressure is excessive
The engine high-pressure bleed air valve is automatically closed
The take-off was continued and the aircraft climbed out, once the aircraft was above the minimum safe altitude the crew carried out the applicable checklist from the QRH (Quick Reference Handbook). This resulted in the right-hand engine bleed air system being switched off, and the cruise flight level being limited to FL350. The situation was discussed with the company via the VHF radio and it was decided to continue to Rome and the aircraft continued its climb to FL350.
Boeing 757 Bleed Air System Schematic for RB 211 equipped aircraft(source public domain)
About one minute after reaching FL350 another EICAS message appeared, this time a
warning, indicating the cabin altitude was above 10.000 feet.
The flight crew donned their oxygen masks and initiated an emergency descent. During the descent, the crew noticed that the outflow valve was fully closed, but the cabin altitude was still climbing, now at 10.500 feet. As there were no passengers on board the crew elected not to deploy the oxygen masks. (They would deploy automatically when the cabin altitude would reach 14.000 feet). A MAYDAY call was made to ATC and the decision was made to divert to London Gatwick. The diversion and landing at London Gatwick were completed without further incident.
There have been several occasions where a lightweight B757 with one bleed system inoperative has been unable to maintain a cabin altitude of less than 10,000 feet.
In response to these occurrences Boeing issue a service letter (757-SL-21-055). which provides a ground procedure developed to assist operators in determining if the airplane will be able to maintain cabin pressure in flight on a single air conditioning pack.
The report on this incident can be found by clicking here.