Mineapolis St. Paul Airport
Aircraft Accident/Incident Report

St. Paul, Minnesota 55111
Sunday, January 20, 1991 20:45 CST

NTSB Narrative Summary Released at Completion of Accident

THE FLIGHT CREW WAS INFORMED BY THE TOWER OF A FIRE ON THE RIGHT SIDE OF THE AIRPLANE WHILE TAXIING FOR TAKEOFF. THE FIRE PRECEEDED BY UTILIZING THE AUXILARY POWER UNIT (APU) FOR A MAIN ENGINE START. THE MAIN ENGINE START WAS ABORTED WHEN THE APU FAILED TO DELIVER SUFFICIENT BLEED AIR PRESSURE. A POST INCIDENT INSPECTION OF THE APU DISCLOSED A LIBERATED TURBINE EXDUCER BLADE WHICH CAUSED AN IMBALANCE OF THE TURBINE WHEEL, ALLOWING SMOPKE AND FLAMES TO ESCAPE FROM THE APU EXHAUST ATOP THE RIGHT WING ROOT. THERE HAS BEEN 7 SERVICE DIFFICULTY REPORTS AND 4 ACCIDENTS/INCIDENTS ASSOCIATED WITH EXDUCER FAILURES IN THIS MODEL APU IN THE LAST FIVE YEARS.

NTSB Probable Cause Narrative

THE PARTIAL FAILURE OF THE AIRPLANE'S AUXILIARY POWER UNIT, AND THE INADEQUATE COMPONENT PRODUCED BY THE MANUFACTURER.

Event Information

Type of Event Incident
Event Date 1/20/1991
Event Day of the Week Sunday
Time of Event 2045
Event Time Zone Central Standard Time
Event City ST. PAUL
Event State MINNESOTA
Event Country --
Zipcode of the event site 55111
Event Date Year 1991
Event Date Month 1
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude
Event Location Longitude
Event Location Airport MINEAPOLIS ST. PAUL
Event Location Nearest Airport ID MSP
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 841
Weather Briefing Completeness Not pertinent
Investigator's weather source Weather Observation Facility
Time of the weather observation 2050 Eastern Standard Time
Direction of event from weather observation facility (degrees) 45
Weather Observation Facility ID MSP
Elevation of weather observation facility 841
Distance of event from weather observation facility (units?) 1
Time Zone of the weather observation EST
Lighting Conditions Night/Bright
Lowest Ceiling Height 0
Lowest Non-Ceiling Height 4300
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) 0
Visibility Runway Visual Value (Statute Miles) 0
Visibility (Statute Miles) 12
Air Temperature at event time (in degrees celsius) -13
Dew Point at event time (in degress fahrenheit) --
Wind Direction (degrees magnetic) 340
Variable Wind Indicator Unknown
Wind Speed (knots) 12
Wind Velocity Indicator Unknown
Wind Gust Indicator Unknown
Wind Gust (knots) 0
Altimeter Setting at event time (in. Hg) --
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 44
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 5020
NTSB Notification Source --
NTSB Notification Date --
NTSB Notification Time 0
Fiche Number and/or location -used to find docket information 44057
Date of most recent change to record Dec 12 2000 9:11AM
User who most recently changed record dbo
Basic weather conditions Visual Meteorological Cond
FAA District Office --

Aircraft Involved

Aircraft #1

Aircraft Registration Number N295US
NTSB Number CHI91IA078
Missing Aircraft Indicator N
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? --
Damage Minor
Aircraft Fire Ground
Aircraft Explosion None
Aircraft Manufacturer's Full Name BOEING
Aircraft Model 727-251
Aircraft Series Identifier 727-251
Aircraft Serial Number 21506
Certified Max Gross Weight 172000
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 153
Number of Engines 3
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Jan 2 2000 12:00AM
Airframe hours since last inspection --
Airframe Hours --
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name FIRST SECURITY BANK OF UTAH
Aircraft Owner Street Address 79 S. MAIN ST. P. O. BOX 30007
Aircraft Owner City SALT LAKE CITY
Aircraft Owner State UT
Aircraft Owner Country
Aircraft Owner Zipcode 84130
Operator is an individual? --
Operator Name NORTHWEST AIRLINES, INC.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address DEPT. C-5000 5101NORTHWEST DR.
Operator City ST. PAUL
Operator State MN
Operator Country
Operator Zip code 55111
Operator Code NW
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
Departure City
Departure State
Departure Country
Departure Time 2045
Departure Time Zone CST
Destination Same as Local Flt --
Destination Airport Code PHL
Destination City PHILADELPHIA
Destination State PA
Destination Country
Specific Phase of Flight Taxi
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 --