# NTSB Incident SEA01IA039
> **McDonnell Douglas DC-8-71F** · 2001-01-16 · Seattle, WA, USA · NONE
## Event
- **NTSB number:** SEA01IA039
- **Event ID:** 20010207X00412
- **Type:** Incident
- **Date:** 2001-01-16
- **Location:** Seattle, WA, USA
- **Coordinates:** 47.479351, -122.290641
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 4
- **Total aboard:** 4
## Aircraft
- **Make:** McDonnell Douglas
- **Model:** DC-8-71F
- **Registration:** N8084U
- **FAR Part:** 121
- **Engines:** 4
- **Damage:** —
## Conditions
- **Light:** DAYL
- **Weather:** IMC
## Probable cause

A malfunctioning relay in the aircraft's flight management system (FMS) switching matrix and associated false "on course" indication on the captain's course deviation indicator (CDI), resulting in proper localizer course alignment not being obtained or maintained and subsequent flight in close proximity to the new control tower.  The reason for the reported false "on course" indications on the first officer's CDI was not determined.  Factors contributing to the incident included low ceiling and obscuration, weak signal received by both localizer receivers due to faulty BNC connectors, and the new control tower.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=SEA01IA039) · AI Analytics · CC0 1.0*