Evansville Airport
Aircraft Accident/Incident Report

Evansville, Indiana 47701
Wednesday, November 23, 1994 12:34 CST

NTSB Narrative Summary Released at Completion of Accident

THE FLIGHT CREW REPORTED THAT WHILE DESCENDING FROM CRUISE IN PREPARATION FOR LANDING, THEY NOTICED THAT THE HORIZONTAL STABILIZER WAS NOT RESPONDING TO TRIM INPUTS. THE AUTOPILOT WAS DISENGAGED, AND BOTH NORMAL AND ALTERNATE MODES OF STABILIZER TRIM WAS ATTEMPTED WITHOUT SUCCESS. THE CREW FOLLOWED THE JAMMED STABILIZER APPROACH CHECKLIST, AND WAS ABLE TO EFFECT PITCH CHANGES BY BOTH CREW MEMBERS EXERTING FORCE ON THEIR CONTROL YOKES. POSTINCIDENT INSPECTION OF THE STABILIZER DRIVE ACTUATOR DISCOVERED NO HYDRAULIC LEAKS. THE ACTUATOR'S GEAR BOX WAS DRAINED, AND FOUND TO CONTAIN APPROXIMATELY ONE OUNCE OF MURKY, SLUDGE-LIKE HYDRAULIC FLUID. THE GEAR BOX IS REQUIRED TO BE FILLED WITH SEVEN OUNCES OF HYDRAULIC FLUID. THE ACTUATORS ARE SHIPPED FROM THE MANUFACTURER ESSENTIALLY DEVOID OF HYDRAULIC FLUID, WITH INSTRUCTIONS THAT THEY MUST BE FILLED PRIOR TO SERVICE.

NTSB Probable Cause Narrative

the failure of company maintenance personnel to adequately service (fill) the horizontal stabilizer drive actuator with hydraulic fluid.

Event Information

Type of Event Incident
Event Date 11/23/1994
Event Day of the Week Wednesday
Time of Event 1234
Event Time Zone Central Standard Time
Event City EVANSVILLE
Event State INDIANA
Event Country --
Zipcode of the event site 47701
Event Date Year 1994
Event Date Month 11
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport EVANSVILLE
Event Location Nearest Airport ID EVV
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 418
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 1250 Central Standard Time
Direction of event from weather observation facility (degrees) 0
Weather Observation Facility ID EVV
Elevation of weather observation facility 418
Distance of event from weather observation facility (units?) 0
Time Zone of the weather observation CST
Lighting Conditions Day
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Clear
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 15
Air Temperature at event time (in degrees celsius) 9
Dew Point at event time (in degress fahrenheit) -6
Wind Direction (degrees magnetic) 310
Variable Wind Indicator Unknown
Wind Speed (knots) 13
Wind Velocity Indicator Unknown
Wind Gust Indicator Not Gusting
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) --
Intensity of Precipitation Unknown
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries 0
On Ground, Minor Injuries 0
On Ground, Serious Injuries 0
Injury Total Fatal --
Injury Total Minor --
Injury Total None 53
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 5037
NTSB Notification Source --
NTSB Notification Date Nov 23 1994 12:00AM
NTSB Notification Time 1600
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 6 2000 12:36PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N479AU
NTSB Number CHI95IA045
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage None
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name FOKKER
Aircraft Model F-28-4000
Aircraft Series Identifier F-28-4000
Aircraft Serial Number 11228
Certified Max Gross Weight 71000
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 50
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Aug 4 1994 12:00AM
Airframe hours since last inspection 734
Airframe Hours 18679
ELT Installed No
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name USAIR
Aircraft Owner Street Address PITT. INTN'L AIRPRT, BOX 12346
Aircraft Owner City PITTSBURGH
Aircraft Owner State PA
Aircraft Owner Country
Aircraft Owner Zipcode 15231
Operator is an individual? --
Operator Name
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address
Operator City
Operator State
Operator Country
Operator Zip code
Operator Code
Owner has at least one certificate Yes - certificate holder
Other Operator of large aircraft? No
Certified for Part 133 or 137 Operation Unknown
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger/Cargo
Type of Flying (Per_Bus / Primary) Unknown
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code PIT
Departure City PITTSBURGH
Departure State PA
Departure Country
Departure Time 1236
Departure Time Zone EST
Destination Same as Local Flt crash at destination city
Destination Airport Code
Destination City
Destination State
Destination Country
Specific Phase of Flight Descent
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Jan 2 2001 10:30AM
User who most recently changed record dbo
Since inspection or accident --
Event Location Runway Number and Location 0
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --