Narrative:

Prior to departure no MEL items were listed [as deferred]. We departed on schedule; pushed back; and upon left engine start I noticed an amber engine bleed left EICAS message was displayed. I queried the ca (captain) and first officer (first officer); and the ca responded that the [maintenance release] now listed a MEL for a bleed pressure sensor status message. I was also busy coordinating with the flight attendants about the short taxi; so my attention was diverted among several issues. I fished out the [maintenance release]; read it as best I could in the dim light; and determined that there was a left engine bleed issue relating to a bleed pressure sensor; and that the message could be displayed as part of the MEL. We then departed. In cruise flight; and after I returned from my rest break; I again inquired about the bleed failure; and that there are usually some operational limitations that go along with that. In our case; there were none. I checked the air schematics page and saw that; in fact; we had no bleed air from the left engine; and were using the bleed air from the right engine only. I again read the MEL and it sounded like we might have been given the wrong MEL for the issue we were facing; or the issue we were originally MEL'ed for had become a larger issue. With what we were seeing; we should have been given MEL 361 rather than 362. The ca sent a message to [maintenance control] who agreed that the issue we had was different than was MEL 362 would have covered. [Maintenance control] provided a 777 [flight manual] reference to this issue; and ultimately a reset of the bleed switch was performed; which allowed the left engine to again supply bleed air normally. The flight continued and landed at the intended destination without issue. The ca sent in an elb message regarding the engine bleed.

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Original NASA ASRS Text

Title: B777 First Officer reported incorrect MEL assigned resulting in abnormal operational pneumatic configuration.

Narrative: Prior to departure no MEL items were listed [as deferred]. We departed on schedule; pushed back; and upon left engine start I noticed an amber ENG BLEED L EICAS message was displayed. I queried the CA (Captain) and FO (First Officer); and the CA responded that the [Maintenance Release] now listed a MEL for a bleed pressure sensor Status Message. I was also busy coordinating with the flight attendants about the short taxi; so my attention was diverted among several issues. I fished out the [Maintenance Release]; read it as best I could in the dim light; and determined that there was a left engine bleed issue relating to a bleed pressure sensor; and that the message could be displayed as part of the MEL. We then departed. In cruise flight; and after I returned from my rest break; I again inquired about the bleed failure; and that there are usually some operational limitations that go along with that. In our case; there were none. I checked the AIR schematics page and saw that; in fact; we had no bleed air from the left engine; and were using the bleed air from the right engine only. I again read the MEL and it sounded like we might have been given the wrong MEL for the issue we were facing; or the issue we were originally MEL'ed for had become a larger issue. With what we were seeing; we should have been given MEL 361 rather than 362. The CA sent a message to [Maintenance Control] who agreed that the issue we had was different than was MEL 362 would have covered. [Maintenance Control] provided a 777 [flight manual] reference to this issue; and ultimately a reset of the bleed switch was performed; which allowed the left engine to again supply bleed air normally. The flight continued and landed at the intended destination without issue. The CA sent in an ELB message regarding the engine bleed.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.