# NTSB Incident ATL91IA017
> **FOKKER F28 MK0100** · 1990-11-11 · ATLANTA, GA, USA · NONE
## Event
- **NTSB number:** ATL91IA017
- **Event ID:** 20001212X24563
- **Type:** Incident
- **Date:** 1990-11-11
- **Location:** ATLANTA, GA, USA
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 75
- **Total aboard:** 75
## Aircraft
- **Make:** FOKKER
- **Model:** F28 MK0100
- **Registration:** N850US
- **FAR Part:** 121
- **Engines:** 2
- **Damage:** —
## Conditions
- **Light:** DUSK
- **Weather:** VMC
## Probable cause

FROZEN MOISTURE IN THE STABILIZER ACTUATOR HYDRAULIC SERVO VALVE WHICH RESULTED IN REDUCED MOVEMENT OF THE SERVO VALVE AND LIMITED ITS ABILITY TO RESPOND TO FLIGHT CONTROL INPUTS. THE LACK OF RESPONSE FROM THE SERVO VALVE RESULTED IN THE JAMMED STABILIZER MESSAGE. A FACTOR WAS THE INADEQUATE DESIGN OF THE SERVO VALVE WHICH PRECLUDED MOISTURE DRAINAGE.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=ATL91IA017) · AI Analytics · CC0 1.0*