Incident · 1990-11-11

NTSB case ATL91IA017 · FOKKER F28 MK0100 · Part 121

What the record says

Event date: 1990-11-11
Event type: Incident
Highest injury level: No injuries
Aircraft: FOKKER F28 MK0100 (N850US)
Operating rule: Part 121
Operator: USAIR Operator named in NTSB report
Operated by (per NTSB report): USAIR

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.

Source: NTSB case ATL91IA017

Flight crew

Flight-crew details for this event aren't in the NTSB database extract we hold (its coverage starts with 2008 events) — a gap in our data, not an absence of crew.

Facts as the NTSB records them — GroundCheck adds no judgement. Preliminary records may be revised as the investigation proceeds.

All incidents →