Any RB211-535C and E4 experts out there?
The RB211-535C and E4 have had a number of reported contaminated air events due to engine oil contaminating the bleed air supply. RR Service Bulletin RB.211-72-7651 of 1 Feb 1985 and others refer to the issue.
A 1999 article also states:"Oil related problems on the RB211-535E4 have multiple origins. First, high oil consumption can come from extended low power operation. "All the bearing compartments on the RB211 are sealed with air, so operating the engine at low power simply means that the available sealing air is less than it would be at high power or cruise settings. It has been shown that normal oil consumption can double when the engine is run at low power for an extended period of time, such as when taxiing or just sitting at the gate...."
Are there any engineers who could please explain a bit more about the relationship between increased oil leaks and the engine at idle and also the reported pilot reports of contaminated air events occurring in the decent again with the engines at idle?
Many thanks
Last edited by FNFF; 13th Oct 2019 at 15:49.