# Incident 20201016019479I: Pilatus Aircraft Ltd PC-12/47, Portland, OR, October 16, 2020

- Type: FAA incident report (Accident/Incident Data System), as reported
- Date: October 16, 2020, 14:22 local time
- Place: Portland, OR
- Airport: Portland International
- Damage: No damage
- Phase of flight: Cruise/Level Flight
- Operating rules: Air taxi and commuter (Part 135)
- Operator: 2B5A
- Location: 45.5887° N, 122.5969° W: Placed by OpenAirDocs at PORTLAND INTL (PDX), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=45.5887&lon=-122.5969&mi=10
- Aircraft: N220JP, registered now (https://openairdocs.org/aircraft/N220JP) (OpenAirDocs)
- Registry model: Pilatus PC-12/47 (registry code 7090552, https://openairdocs.org/model/pilatus-pc-12-47) (OpenAirDocs)
- Registry engine: Pratt & Whitney Canada PT6A-67B (registry code 52158, https://openairdocs.org/engine/pratt-whitney-canada-pt6a-67b) (OpenAirDocs)
- Reported make and model: PILATUS AIRCRAFT LTD PC-12/47
- Reported engine: P&W CANADA PT6A-67B
- People aboard: 6
- Fatal injuries: 0
- Other injuries: 0
- FAA source: FAA Aviation Safety Information Portal (https://asip.faa.gov/)
- Page: https://openairdocs.org/incident/20201016019479I

## Narrative

As the FAA filed it, in capitals; the FAA replaces private details with ^PRIVACY DATA OMITTED^.

THE SEQUENCE OF EVENTS THAT LEAD TO A COMPLETE ELECTRICAL POWER LOSS ON FLIGHT #542 CAN BE SUMMARIZED AS FOLLOWS:

IT STARTED OFF WITH THE GENERATOR 1 GCU FAILURE PRODUCING VOLTAGE FLUCTUATIONS WHICH TRIGGERED A BATTERY CAWS CAPTION. IN RESPONSE TO THAT CAUTION, THE FLIGHT CREW INITIATED A BATTERY RESET BUT THE BATTERY WAS ACTUALLY NEVER SET TO ON AGAIN (AS CONFIRMED BY THE CAWS RECORDING AND OTHER EVIDENCES SUCH AS PROPELLER NOT FEATHERING DURING ENGINE SHUTDOWN AND POST FLIGHT INSPECTION FOUND THE BATTERY SWITCH TO OFF). WITH THE ABSENCE OF THE BATTERY, GENERATOR 1 VOLTAGE FLUCTUATIONS GOT WORSE EVENTUALLY LEADING TO THE TOTAL DISCONNECTION OF GEN 1. UNDER THESE CONDITIONS, GENERATOR 2 WAS THE ONLY SOURCE OF ELECTRICAL POWER. MOREOVER, THE NON ESSENTIAL BUS WAS NOT AUTOMATICALLY LOAD SHED (NON ESSENTIAL OVERRIDE SWITCH WAS FOUND IN THE OVERRIDE POSITION) AND HIGH CURRENT LOAD LIKE THE VCCS WERE STILL ON, LEADING TO THE OVERLOAD OF THE BAT/GEN2 TIE. ONCE BAT/GEN2 TIE OPENED, BEING ALSO GENERATOR 1 AND BATTERY OFFLINE, THE COCKPIT WENT COMPLETELY DARK.

PREVIOUS FLIGHT #352 UNDERWENT TO A SIMILAR SEQUENCE (GEN1 OFFLINE, NON ESSENTIAL BUS NOT LOAD-SHED) WITH THE ONLY DIFFERENCE BEING THAT THE BATTERY WAS CORRECTLY SWITCHED BACK ON AFTER RESET. GENERATOR 2 AND THE BATTERY COULD SUPPORT ALL THE ELECTRICAL LOADS UNTIL LANDING AND SINCE THE BATTERY AND THE GEN 2 LIE ON OPPOSITE SIDES OF THE BAT/GEN2 TIE, THE BAT/GEN2 TIE DID NOT TRIP.

## Other reports on N220JP (1)

Matched to the same aircraft by N-number and date.

- [Accident 20250517005879A](https://openairdocs.org/incident/20250517005879A), May 17, 2025: Pilatus Aircraft Ltd PC-12/47 (N220JP), Henderson, NV, Substantial damage. On may 17, 2025, the pilot of [privacy data omitted] was performing night currency landings (part 91). This aircraft is utilized on a part 135 certificate…

From the FAA Accident/Incident Data System. Reports are matched to registry aircraft by N-number and event date, checked against the reported make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. For accidents, the NTSB's own investigation is the fuller record.

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