Narrative:

I was conducting an initial operating experience with a first officer (first officer) who is new to the aircraft. As we started our takeoff roll the flight deck door swung open. A flight attendant immediately closed the door and it was indicating locked. I was positive I checked the flight deck door 'open' light during the after start checklist and it was out. I believe the door became unlocked during an electrical power transfer issue caused by me.when I called for the after start checklist; I was momentarily distracted while watching the first officer perform his flows. I neglected to turn on the engine generators at the beginning of the flow. When the first officer turned off the APU; we momentarily lost power (I immediately caught the mistake right when he was turning off the APU). I believe this may have electrically unlocked the door.contributing factors: not much sleep the night before.this was our first flight together.I flew 2 days last week after not flying for 6 months.it was right at dawn and I had the lights on dim just as the sun was starting to shine into the cockpit. I may have seen the blue generator off bus lights if the switch was on bright.

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Original NASA ASRS Text

Title: Air carrier Check Airman reported not following the published checklist due to fatigue and not having flown in the last 6 months.

Narrative: I was conducting an initial Operating Experience with a First Officer (FO) who is new to the aircraft. As we started our takeoff roll the Flight Deck door swung open. A Flight Attendant immediately closed the door and it was indicating locked. I was positive I checked the Flight Deck door 'OPEN' light during the After Start Checklist and it was out. I believe the door became unlocked during an electrical power transfer issue caused by me.When I called for the After Start Checklist; I was momentarily distracted while watching the FO perform his flows. I neglected to turn on the engine generators at the beginning of the flow. When the FO turned off the APU; we momentarily lost power (I immediately caught the mistake right when he was turning off the APU). I believe this may have electrically unlocked the door.Contributing factors: Not much sleep the night before.This was our first flight together.I flew 2 days last week after not flying for 6 months.It was right at dawn and I had the lights on dim just as the sun was starting to shine into the cockpit. I may have seen the blue Generator OFF BUS lights if the switch was on bright.

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.