B737 flight crew reported that the autopilot disengaged after inadvertently turning off hydraulic pumps instead of anti ice system during climb. Crew reestablished all systems after recognizing their error.
Synopsis
B737 flight crew reported that the autopilot disengaged after inadvertently turning off hydraulic pumps instead of anti ice system during climb. Crew reestablished all systems after recognizing their error.
Narrative
Day 1 Leg 1 of 3 day trip. First flight with each other. Both commuters from Location A. Both commuted in early morning for a XA:55 report. During our pre brief my FO did mention flying into the sun as a threat. In our climb out just as we were about to reach our initial top of climb of FL 320 at about FL 280 we broke out of the clouds and as PF I went to reach over to turn off the engine anti ice and at that moment a glare from the sun obstructed my vision and I didn't confirm with my PM about turning off the engine anti ice and I unintentionally switched the hydraulic switch instead. A few moments later the autopilot disengaged and I immediately realized why and told the FO what it was; but my failure was as PF I should have asked my PM to re-engage the hydraulic switch and turn off the engine anti ice but instead; I tried to do it myself and the plane started to veer off course. I had my hands on the yoke but as I was looking up at the panel the aircraft started to veer right; and the FO immediately said check path and I immediately corrected and began to get back on course. The FO then placed direct ZZZZZ in L1 of the box and selected LNAV and verified LNAV on PFD (Primary Flight Display) - announcing these actions. He then began to correct the issue and I re-engaged the AP (Autopilot). The entire event only lasted a few seconds; but I failed in my VVM (Verbalize; Verify; Monitor) skills and should have allowed the PM to correct the panel as I was hand flying the plane at that moment. I will do a better job of verifying when I'm manipulating any switches in flight.
Second reporter narrative
FLT # ZZZ-ZZZ1Undesired Aircraft StateCA-PF / FO-PMDay 1 Leg 1 of 3 day trip. First flight with each other. Both commuters from Location A. Both commuted in early morning for a XA55 report.Just past ZZZZZ1 (on ZZZZZ SID); Prior to ZZZZZ2 (enroute waypoint)Near FL290 while in a climb to FL340.Flying ECON speed; CI 10; 30 minutes ahead of schedule so somewhere around 280 kias.During the climb we had passed through clouds; CA/PF announced and turned on Engine Anti-Ice (EAI). Once above clouds both of us forgot the EAI was on. I do not remember the altitude that EAI was turned on. CA/PF trapped the error; announced they were turning the EAI o' and I saw in my peripheral vision their right hand reaching up and turning switches o' first and ignition switches o' second. Soon after this we got the warning for auto-pilot disconnecting. I announced the light and extinguished and looked left to verify the CA/PF was in control of yoke. They were and they didn't know what caused it to turn o'. They tried to engage CMD A again. Then I saw their right arm go up and turn switches o' and they announced they had turned o' two hydraulic pump switches instead of the EAI switches. Simultaneously I saw we were turning right o' course to ZZZZZ2 and said 'Check Path'.Pausing here - in retrospect; I think the CA/PF was focused on switches on the overhead panel and not flying while I was focused on the PFD (Primary Flight Display) and the incorrect flight path.Once I said 'Check Path' it brought their attention to flying the aircraft; which they did correctly by hand flying a left turn back to get on course to ZZZZZ2. Our climb to FL 340 had slowed to approximately 500fpm but we were still climbing. While they hand flew the left turn - manually with a shallow bank angle for the altitude and the climb; I placed direct ZZZZZ2 in L1 of the box and selected LNAV and verified LNAV on PFD - announcing these actions. Once I was satisfied the CA/PF was hand flying correctly back to on course; I finally looked up and saw all four hydraulic pump switches were o' and four Low Press lights illuminated. Then I noticed the EAI switches were still on. I announced these hydraulic switch lights and position and then began to turn them back on. All on; the low press lights went out and I turned the EAI switches o'.Next the CA/PF did re-engage the AP CMD A. We re-cycled Direct ZZZZZ2 in the box again and both verified that LNAV and VNAV functions were correct; with the climb still to FL340. At this point I began a verbal debrief saying that we fixed the undesired aircraft state and what I did not do correctly was call upset" (push roll thrust stabilize) In retrospect I think it's because in my mind - the autopilot clicked o' and we were turning right o' course but still climbing with a safe airspeed for the conditions so I didn't assess the situation as an upset at the time. The CA/PF stated they must have accidentally turned o' 2 hydraulic pump switches instead of the 2 EAI switches. For an unexplained reason when they went to fix that - they ended up turning the other two hydraulic pump switches o' instead. I attribute this to going too fast combined with some anxiety.After this short verbal debrief. I pulled up the QRC on EFB (Electronic Flight Bag); checking for HYD low Press lights there; then went to non-normals in QRH (EFB) and found non-normal for four low pressure lights. Since I knew this was a pilot induced problem; I did not follow step one. Step two was Yaw Damper switch - ON - I looked on the overhead and saw that the Yaw Damper was in fact o'. I announced this find to the CA/PF; showed them my EFB page and the Yaw Damper Light on and they watched me as I turned it on and verified the Yaw Damper light extinguished.At this point the event was over; and I wrote some notes on it. I believe the startle factor was a major contribution to turning o' incorrect switches."
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.