B737-800 flight crew reported missing two circuit breakers that were pulled for a compressor wash during maintenance that were not noticed until cruise. The flight crew reset the circuit breakers and continued the flight to destination airport.
Synopsis
B737-800 flight crew reported missing two circuit breakers that were pulled for a compressor wash during maintenance that were not noticed until cruise. The flight crew reset the circuit breakers and continued the flight to destination airport.
Narrative
During cruise flight; Captain noticed the 'wing spar valve' valve was dimly lit. Investigated as a crew using available resources in flight deck; which was limited to information from my [application] to include AOM; ASM ; MEL; Aircraft Maintenance Logbook and QRH as to why this light was on. Captain coordinated to dispatch and Maintenance using flight phone and ACARS messages to further investigate. In that time we sent a code to Maintenance associated with the Spar Valve Light being in disagreement. It was determined through Technical Support that an engine wash had been performed the night before and to check breakers for spar valves. After examining the Circuit Breaker panel very closely it was determined that the breakers were left in the out position. Being that everything was working normally we left breakers out and inquired Maintenance who confirmed that we were in-fact safe to continue. Continued flight to destination. At the gate in ZZZ1; I was greeted with a random drug test so I didn't witness any interactions with Maintenance in ZZZ1 related to the write up but I did see Maintenance at the gate as I was being escorted to my drug test. Lack or non-requirement of Aircraft Maintenance Logbook. The engine wash was not logged and the breakers pulled where also not noted. We had no way of knowing what had gone on the night before. Had there been an entry in the Aircraft Maintenance Logbook for us to review as well as a bright collar placed on what I would consider a very important system breaker we would have easily trapped this error. It was very difficult to make out that the breakers where out because the white was very dirty; even after examining the panels closely. I have attached an actual picture as observed during the event.
Second reporter narrative
Flying a routine trip from ZZZ2-ZZZ1. Got to the airplane and I did the walk around and started the interior inspection. It turns out that I missed 2 Circuit Breakers that were out behind the First Officer (FO) headrest close to the wall. Everything was normal through taxi; takeoff; climb. We reached cruise altitude; and I noticed 2 blue lights on the overhead panel. Both SPAR VALVE CLOSED lights were on. At first; I couldn't believe what I was seeing. That's not possible I said to my FO. We started researching the QRH; AOM and the ASM. We found nothing; so I reached out to Maintenance through dispatch. They told us they would research and get back to us. ACARS message said an engine wash was done in ZZZ2 and to check the P6-3 panel. We did and found the 2 breakers out. I was immediately mad at myself for missing them on preflight. We could not understand how the engines started in the first place. Technical Support also said this wouldn't cause any issues; we continued on the ZZZ1 and landed uneventfully. Obviously; should have noticed the 2 breakers. They were probably the hardest to see from my seat. Also; after engine start; we did not see the blue lights on. It was a bright sunshine day and they don't stand out like red or amber. But; still should have seen them. I couldn't believe that it was not annotated in the log book that Circuit Breakers had been pulled. That would have caused a definite double check of the Circuit Breaker panel. Just like putting a write-up in that gear pins were installed for a tire change. Also; it would have been nice if these blue lights turned on the master caution. And; the white part of the Circuit Breaker was not really bright white so that it stood out. It was more of a faded off-white. Even when we knew to look there; it took a second to realize they were in fact out.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.