B737-800
Flight Crew Last 90 Days 173
Confusion
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; General Flight Cancelled / Delayed; General Maintenance Action
Human Factors; Aircraft; Procedure
This was the first flight of the day for us. I was on the ramp when the aircraft arrived preparing for my walk around. The airplane was parked at the gate with number one engine running for an unusually long time. Ground power was hooked up. Oddly; I could hear the IRS horn in the nose well over the engine noise; indicating to me that they had no a/c power in the aircraft. I finished my walk and headed up to the jet way. The deplaning Captain met me there. He said that they had a minor electrical problem at the gate and it had been reported to them by ZZZ maintenance. He said that the aircraft lost a/c power when ground power was hooked up; and that after that it would not accept power from either the ground or number one generator. He said that maintenance was aware and told him to recycle the battery switch and then the aircraft would accept power. I asked if his malfunction was in the book and he said no; that everything was now normal. I asked him to relay the same message to my Captain and I began my cockpit preflight. Everything looked normal and boarding and preflight were uneventful. The APU was MEL inoperative. We prepared for a ground air start followed by a crossbreed start of number two. Number one started normally; but when we attempted to put its generator on the line; we lost all at power. The aircraft would not accept either engine generator or ground power. We were dark up front and on emergency power in the back. The Captain shut down number one and recycled the battery switch as the previous Captain had reported. The aircraft accepted ground power. We deplaned our customers and called maintenance. Captains must write up all observed malfunctions. Stop passing problems on to the next crew.
Gate ground power connect anomaly. It is important to note that our aircraft was MEL'd with an inoperative APU.Upon arrival at our gate; we taxied into the gate with only the #1 engine running. The ground crew connected ground power as normal. The blue ground power light on the overhead panel illuminated and volts and frequency indicated normal. When I selected ground power; the ground power blue light went out and the #1 engine generator was knocked offline. After another failed attempt at reconnecting ground power; I shut the #1 engine down. We continued to trouble shoot and after being unsuccessful and without power; I moved the battery switch briefly from 'ON' to 'OFF' and back to 'ON.' This action restored aircraft power. It is important to note that this action is not part of a procedure; but an action that I felt was necessary in a reasonable attempt to regain power. At that point; all electricity was regained and operations appeared normal. A crew change was scheduled and oncoming crew was briefed on our gate power anomaly.
Two B737-800 flight crews describe strange electrical problems that occur during gate arrival for the first crew and departure for the second crew. The aircraft would not accept ground power; then would not accept aircraft generator power without first turning the battery power off then on. The aircraft is grounded and turned over to Maintenance.