N/A Airport
Aircraft Accident/Incident Report

San Antonio, Texas 78216
Wednesday, January 10, 2001 10:25 CST

NTSB Narrative Summary Released at Completion of Accident

The flight was in cruise, in icing conditions, when both engines experienced momentary power fluctuations (PF) as a result of ice ingestion. Evaluation of the flight data recorder information revealed that the left engine experienced four Type II (compressor stall) PF events, and the right engine experienced one Type I (partial/full quenching of the engine's combustor flame) PF event and one Type II event. The flight descended, the power fluctuations ceased, and the flight proceeded to land at its intended destination. The Saab 340 fleet has undergone extensive research, with regards to power fluctuations, since it was certified in the U.S. in 1985. In 1985, it was determined that ice accumulates on the engine inlet splitter lip, breaks off, and enters the engine resulting in a flame-out. An auto-ignition system was developed to provide a means to re-light the engine. Aircraft certification rules require that no accumulation of engine inlet ice occur that will adversely affect engine operation. In 2000, the FAA's position was that even though no re-design of the engine inlet was found that would preclude ice accumulation on the splitter lip, the risk associated with a PF event was acceptable. Furthermore, the FAA determined that the risk of a dual engine power loss due to the existence of an icing condition and failure of both engines' auto-ignition systems was acceptably low. Lastly, the FAA stated that inappropriate crew response risks associated with PFs combined with an in-flight shut down were quantitatively indeterminate, but deemed qualitatively acceptable by FAA certification pilots and human factors specialists.

NTSB Probable Cause Narrative

the ingestion of ice/slush into both engines, which resulted in dual engine power fluctuations.

Event Information

Type of Event Incident
Event Date 1/10/2001
Event Day of the Week Wednesday
Time of Event 1025
Event Time Zone Central Standard Time
Event City San Antonio
Event State TEXAS
Event Country --
Zipcode of the event site 78216
Event Date Year 2001
Event Date Month 1
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude --
Event Location Longitude --
Event Location Airport N/A
Event Location Nearest Airport ID --
Indicates whether the acc/inc occurred off or on an airport --
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation --
Weather Briefing Completeness Full
Investigator's weather source Pilot
Time of the weather observation
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID --
Elevation of weather observation facility --
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation --
Lighting Conditions Day
Lowest Ceiling Height 6000
Lowest Non-Ceiling Height --
Sky/Lowest/Cloud Conditions --
Sky Condition for Lowest Ceiling Overcast
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 1
Air Temperature at event time (in degrees celsius) -18
Dew Point at event time (in degress fahrenheit) 8
Wind Direction (degrees magnetic) --
Variable Wind Indicator --
Wind Speed (knots) --
Wind Velocity Indicator --
Wind Gust Indicator Unknown
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 29.92
Density Altitude (feet) --
Intensity of Precipitation Light
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 27
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 12773
NTSB Notification Source FAA
NTSB Notification Date Jan 11 2001 12:00AM
NTSB Notification Time 730
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Apr 1 2003 4:20PM
User who most recently changed record NTSB\MONR
Basic weather conditions Instrument Meteorological Cond
FAA District Office Dallas-Forth Woth, Texas

Aircraft Involved

Aircraft #1

Aircraft Registration Number N394AE
NTSB Number FTW01IA051
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? Yes
Damage None
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Saab
Aircraft Model 340B
Aircraft Series Identifier --
Aircraft Serial Number 340B394
Certified Max Gross Weight 29000
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 37
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Jan 10 2001 12:00AM
Airframe hours since last inspection 3.2
Airframe Hours 9752.2
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site Unknown
ELT Type --
Aircraft Owner Name First Security Bank
Aircraft Owner Street Address 79 South Main Street
Aircraft Owner City Salt Lake City
Aircraft Owner State UT
Aircraft Owner Country USA
Aircraft Owner Zipcode 84111
Operator is an individual? No
Operator Name American Eagle Airlines, Inc.
Operator Same as Owner? No
Operator Is Doing Business As --
Operator Address Same as Owner? No
Operator Street Address 1700 W. 20th Street
Operator City DFW Airport
Operator State TX
Operator Country USA
Operator Zip code 75261
Operator Code SIMA
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
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 Only
Type of Flying (Per_Bus / Primary) --
Second Pilot on Board Yes
Departure Point Same as Event No
Departure Airport Code DFW
Departure City DFW Airport
Departure State TX
Departure Country USA
Departure Time 912
Departure Time Zone CST
Destination Same as Local Flt --
Destination Airport Code LRD
Destination City Laredo
Destination State TX
Destination Country USA
Specific Phase of Flight Cruise
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Dec 16 2002 9:50AM
User who most recently changed record CASH
Since inspection or accident Time of Accident
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --