Air carrier flight crew reported Master Caution light and slower flap retraction during take-off. Flight crew turned on hydraulic engine pumps and continued the flight.
Synopsis
Air carrier flight crew reported Master Caution light and slower flap retraction during take-off. Flight crew turned on hydraulic engine pumps and continued the flight.
Narrative
During takeoff from ZZZ; shortly after raising the gear we got a Master Caution light. I punched the Master Caution light to extinguish the light until we were able to look at it once we were safely airborne. The gear and flaps both came up normally; although I did notice it took a little longer for the flaps to go from 1 to up and leading edge lights out. Once we were safely away from the ground and above the terrain I hit the Master Caution recall and say the HYD annunciator illuminated on the FO's (First Officer's) panel. I looked up to the overhead panel and saw that both the left and right engine Hydraulic switches were in the OFF position with the resulting low pressure lights illuminated. I turned them both on and the annunciator extinguished as did both low pressure lights. We continued to ZZZ1 with no further issues. How the switches ended up in the off position I'm at a loss to explain. During the Before Push checklist; I remember looking at the switches and seeing the two low pressure lights illuminated (as usual with both engines off) and normal hydraulic pressure readings. Now I have to wonder if I just saw the two normal low pressure lights and the two electrical pump switches on and just saw what I normally see and missed the two engine pump switches being in the off position. But these switches being in the wrong position should have been caught twice during the two Master Recall checks in the After Start and Before Takeoff checklists yet they weren't and I don't know why. Nothing ever illuminated in front of me on my recall panel or my Master Caution light during both checks. We wondered if maybe we had a Master Caution recall panel issue that might need to be written up; so when we landed in ZZZ1; while parked waiting on marshallers I turned off each engine hydraulic switch one at a time and then back on and the Master Caution and Recall worked properly both times. My FO and I debriefed the issue and how it might have happened. We still don't know how the switches ended up in the off position. He didn't recall turning them off at any time. He did say he turned on the electric pumps during his ground ops set up due to gusty winds. As for the lack of a Master Recall alerts; I mentioned that I have seen numerous times where my FO's have pushed the Recall panel and then immediately subconsciously immediately hit the Master Caution light extinguishing an annunciator that was lit. I happened to catch them because the annunciator was on my recall panel (example FLT CNTRL when the yaw damper kicked off) and I was able to fix the issue. Since the HYD light is on the FO panel; I would not have seen it and been able to intervene if this is indeed what happened. Since the system worked properly on the ground in ZZZ1; this is the only plausible explanation I can come up with.
Second reporter narrative
As the FO (First Officer) I was the PF on this leg. Everything appeared normal until takeoff roll; but after raising the gear a HYD annunciation displayed. I maintained aircraft control and continued the takeoff while the Captain punched off the light. The gear came up normally and we raised the flaps. They came up but at a slower rate than usual. It was then that the Captain performed the recall and noticed the LOW PRESSURE lights on the ENG (Engine) HYD switches and observed the ENG HYD switches were in the off position. He then switched them back on and the Master Caution panel cleared. The rest of the flight to ZZZ1 was uneventful.After replaying the morning events in my mind I believe I know how the switches ended up in that position. I entered the aircraft first; and the winds were gusty and the yoke was moving all around; so one of the first things I did was turn on the electric hydraulic pumps to keep the yoke stable. I believe the aircraft was left with all 4 HYD switches in the OFF position; but in a cursory glance to turn the ELEC HYD switches on; that did not register. I then continued to set up the aircraft and perform my flows. What I believe happed was that during my overhead panel flow; I saw two HYD switches ON and 2 switches OFF and that looked normal to me; except it was the opposite of usual; as the 2 ENG switches were OFF and the ELEC switches were on. Then later when the gate agent came in; I was in the lavatory so the usual trigger for me to double check those switches and turn on the ELEC switches didn't happen. We got to the Before Push Checklist but since the ELEC switches were ON; the system pressure was good and I did not look directly at the switches to check all 4 were ON. At that point we started engines and taxied out and had all normal indications. I performed both RECALL checks for AFTER START and BEFORE TAKEOFF and did not perceive a HYD light on the caution panel. I do not believe HYD ever displayed during the RECALL checks as I have made the mistake of quickly punching off the Caution in the past; and have adopted the technique of verbalizing during single engine taxi After Start Checks 3 lights" prior to punching it off. This was a 2 engine taxi in this case; and I did not expect to see any RECALL lights so I think if they annunciated I would have verbalized them; but it's possible that I inadvertently punched them off; or that the light just did not illuminate. We then performed the takeoff and after raising the gear handle the HYD light annunciated."
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.