NONE · Boeing 737-232 · 1998-12-15 · ORLANDO, FL, USA
Event
NTSB number
MIA99IA046
Event ID
20001211X11596
Type
Incident
Date
1998-12-15
Location
ORLANDO, FL, USA
Coordinates
28.419565, -81.300033
Injuries
Highest injury
NONE
Fatal
0
Serious
0
Minor
0
Uninjured
56
Total aboard
56
Aircraft
Make
Boeing
Model
737-232
Registration
N327DL
FAR Part
121
Engines
2
Damage
MINR
Conditions
Light
DAYL
Weather
VMC
Probable cause
A discharged battery due to a loss of electrolyte, and the latent shorted failures of the No. 1 and 2 generator control unit (GCU) blocking diodes (CR910) for undetermined reasons. These failures resulted in an excessive current drawn from both GCUs, during the flight crew's attempt to start the auxiliary power unit, that caused the immediate overload (opening) of the AC power supply input fuses (POR fuses) internal to each GCU, and subsequent loss of the No.1 and 2 generators; complete discharge of the battery, and subsequent total loss of electrical power. Contributing to the incident was the incorrect reading of the cockpit DC voltmeter (read higher than actual reading) allowing the flight crew to depart with an unreliable (discharged) battery.