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A B737-400's TR1 circuit breaker popped on approach causing the loss of numerous navigation; communication and aircraft systems. The aircraft had a history of this malfunction but the circuit breaker was reset and the aircraft released again for this flight.
| Attributes | |
| ACN | 924863 |
| Time | |
| Date | 201012 |
| Local Time Of Day | 0601-1200 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | B737-400 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Initial Approach |
| Flight Plan | IFR |
| Component | |
| Aircraft Component | DC Rectifier |
| Person 1 | |
| Function | Captain Pilot Flying |
| Qualification | Flight Crew Air Transport Pilot (ATP) |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical |
Narrative:
APU generator on MEL; on ILS approach; TR1 [circuit breaker] failed causing auto pilot; yaw damper; 1 electric hydraulic pump; 2 fuel boost pumps; air speed bug; com radios; auto brake; antiskid; passenger PA; flight attendant interphone and other items to fail. I took over flying; shut off auto brake; discussed added landing distance with antiskid inoperative and decided to land. When we turned off the runway the first officer could not contact ground control. I placed the standby power switch to battery allowing us to talk to ramp and go to the gate. The flight attendants then informed us when on final that the emergency lights came on they attempted to contact us without success. Then when they could not contact each other they prepared for a brace if needed. This aircraft had a history of this and the circuit breaker was reset and signed off. If this had happened to a new crew in IMC the outcome could have been much different.
Original NASA ASRS Text
Title: A B737-400's TR1 circuit breaker popped on approach causing the loss of numerous navigation; communication and aircraft systems. The aircraft had a history of this malfunction but the circuit breaker was reset and the aircraft released again for this flight.
Narrative: APU generator on MEL; on ILS approach; TR1 [circuit breaker] failed causing auto pilot; yaw damper; 1 electric hydraulic pump; 2 fuel boost pumps; air speed bug; com radios; auto brake; antiskid; passenger PA; Flight Attendant interphone and other items to fail. I took over flying; shut off auto brake; discussed added landing distance with antiskid inoperative and decided to land. When we turned off the runway the First Officer could not contact Ground Control. I placed the standby power switch to battery allowing us to talk to ramp and go to the gate. The Flight Attendants then informed us when on final that the emergency lights came on they attempted to contact us without success. Then when they could not contact each other they prepared for a brace if needed. This aircraft had a history of this and the circuit breaker was reset and signed off. If this had happened to a new crew in IMC the outcome could have been much different.
Data retrieved from NASA's ASRS site as of April 2012 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.