ASN Wikibase Occurrence # 353490
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information.
If you feel this information is incomplete or incorrect, you can submit corrected information.
| Date: | Tuesday 15 December 1998 |
| Time: | 14:16 LT |
| Type: |  Boeing 737-232 |
| Owner/operator: | Delta Air Lines |
| Registration: | N327DL |
| MSN: | 23099/1035 |
| Year of manufacture: | 1984 |
| Total airframe hrs: | 39347 hours |
| Engine model: | P&W JT8D-15A |
| Fatalities: | Fatalities: 0 / Occupants: 56 |
| Aircraft damage: | Minor |
| Category: | Serious incident |
| Location: | Orlando, FL -
 United States of America
|
| Phase: | Approach |
| Nature: | Unknown |
| Departure airport: | Boston, MA (KBOS) |
| (KMCO) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
The auxiliary power unit (APU) was started on base leg. The first officer called for gear and flaps 15. The airplane experienced a total loss of electrical power as the gear and flaps were extended. The APU did not start, and the battery indicated between 17 to 18 volts. Checklist procedures were accomplished and electrical power was unable to be restored. A go-around was initiated, and a subsequent landing was made without further incident. Examination of the electrical system revealed the DC voltmeter in the cockpit was reading 2 volts high. The battery was discharged due to a loss of electrolyte, and there were latent shorted failures of the No. 1 and 2 generator control unit (GCU) blocking diodes. The failure mode of the diodes was not determined. The failures created an excessive current drawn from both GCUs, during the flight crews attempted APU start, immediate overload of the AC power supply input fuses internal to each GCU, loss of the No.1 and 2 generators, complete discharge of the battery, and subsequent total loss of electrical power.
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.
Accident investigation:
 |
|
Sources:
NTSB MIA99IA046
History of this aircraft
Other occurrences involving this aircraft
| 27 April 2009 | YV268T | Venezolana | 0 | Maracaibo-La Chinita International Airport (MAR/SVMC) |  |
sub |
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 10-Mar-2024 07:23 | ASN Update Bot | Added |
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2024 Flight Safety Foundation