Aircraft Accident/Incident Report

Romulus, Michigan 48174
Thursday, February 20, 1997 10:27 EST

NTSB Narrative Summary Released at Completion of Accident

The captain said that after departure, 'the first officer needed excessive right wing down trim to maintain a wings level attitude. The left outboard roll spoiler indicated approximately one-half deployment on the PFCS (Powered Flight Controlled Surfaces).' The crew maintained control of the airplane with trim and control wheel input. The crew declared an emergency, returned to the airport, and landed the airplane without further incident. A postincident inspection revealed that the left outboard roll spoiler was 'deployed approximately half-way.' An examination and disassembly of the roll spoiler servoactuator revealed that a plug (PN A50993-1), which had been fusion-welded into the base of the piston (PN A50992-1), had separated and lodged itself between the base of the piston and the shims, restricting the piston's movement. Dowty Aerospace (the manufacturer) had recorded seven previous failures of fusion welds in pistons on DHC-8 roll spoiler servoactuators before this incident.

NTSB Probable Cause Narrative

a fractured fusion weld in the piston of the roll spoiler servoactuator, which allowed the plug at the base of the piston to separate and jam the piston. A factor relating to the incident was: the inadequate design of the airplane's roll spoiler servoactuator piston.

Event Information

Type of Event Incident
Event Date 2/20/1997
Event Day of the Week Thursday
Time of Event 1027
Event Time Zone Eastern Standard Time
Event City ROMULUS
Event State MICHIGAN
Event Country --
Zipcode of the event site 48174
Event Date Year 1997
Event Date Month 2
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport
Event Location Nearest Airport ID
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 --
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 927 Eastern Standard Time
Direction of event from weather observation facility (degrees) 30
Weather Observation Facility ID DTW
Elevation of weather observation facility 640
Distance of event from weather observation facility (units?) 1
Time Zone of the weather observation EST
Lighting Conditions Day
Lowest Ceiling Height 20000
Lowest Non-Ceiling Height 0
Sky/Lowest/Cloud Conditions Unknown
Sky Condition for Lowest Ceiling Broken
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 3
Air Temperature at event time (in degrees celsius) -1
Dew Point at event time (in degress fahrenheit) -2
Wind Direction (degrees magnetic) 130
Variable Wind Indicator Unknown
Wind Speed (knots) 3
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) 30
Density Altitude (feet) 680
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 26
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 5009
NTSB Notification Source --
NTSB Notification Date Feb 20 1997 12:00AM
NTSB Notification Time 933
Fiche Number and/or location -used to find docket information IMAGE
Date of most recent change to record Dec 8 2000 12:07PM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N828MA
NTSB Number CHI97IA073
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 de Havilland
Aircraft Model DHC-8-102
Aircraft Series Identifier DHC-8-102
Aircraft Serial Number 333
Certified Max Gross Weight 27000
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 39
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Feb 18 1997 12:00AM
Airframe hours since last inspection 26
Airframe Hours 10466
ELT Installed Yes
ELT Activated Unknown
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name RAINIER AIRCRAFT LEASING, INC.
Aircraft Owner Street Address 7755 EAST MARGINAL WAY
Aircraft Owner City SEATTLE
Aircraft Owner State WA
Aircraft Owner Country
Aircraft Owner Zipcode 98109
Operator is an individual? --
Operator Name MESABA AIRLINES
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 7501 26TH AVENUE SOUTH
Operator City MINNEAPOLIS
Operator State MN
Operator Country
Operator Zip code 55450
Operator Code MALA
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 Yes
Departure Airport Code DTW
Departure City
Departure State
Departure Country
Departure Time 1007
Departure Time Zone EST
Destination Same as Local Flt --
Destination Airport Code TYS
Destination City KNOXVILLE
Destination State TN
Destination Country
Specific Phase of Flight Cruise
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 --