A B737-200 rejected takeoff at 50 KTS due to aircraft yawing to left with left engine uneven thrust ...

Attributes
ACN	621197
Time
Date	200406
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : oak.airport
State Reference	CA
Altitude	agl single value : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sea.tower
Operator	common carrier : air carrier
Make Model Name	B737-200
Operating Under FAR Part	Part 121
Flight Phase	ground : takeoff roll
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : multi engine pilot : cfi pilot : commercial pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 17775 flight time type : 10000
ASRS Report	621197
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi
Experience	flight time last 90 days : 85 flight time total : 5620 flight time type : 85
ASRS Report	621320
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	flight crew : rejected takeoff
Consequence	other other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

On initial application of takeoff power and at approximately 50 KTS, aircraft yawed to the left and a loss of thrust was noted on the left engine. A decision was made to reject the takeoff. The engine was shut down and the aircraft returned to the gate. Inspection revealed that the #1 engine compressor was damaged. Supplemental information from acn 621320: the captain then requested the trucks be rolled as a precaution, and notified the passenger and flight attendants. We determined the #1 engine was the cause of the vibration and asymmetrical thrust on the takeoff roll. The violation ceased after the #1 engine was shut down. Initial determination was a blown turbine.

Original NASA ASRS Text

Title: A B737-200 REJECTED TKOF AT 50 KTS DUE TO ACFT YAWING TO LEFT WITH L ENG UNEVEN THRUST AND UNUSUAL VIBRATION.

Narrative: ON INITIAL APPLICATION OF TKOF PWR AND AT APPROX 50 KTS, ACFT YAWED TO THE L AND A LOSS OF THRUST WAS NOTED ON THE L ENG. A DECISION WAS MADE TO REJECT THE TKOF. THE ENG WAS SHUT DOWN AND THE ACFT RETURNED TO THE GATE. INSPECTION REVEALED THAT THE #1 ENG COMPRESSOR WAS DAMAGED. SUPPLEMENTAL INFO FROM ACN 621320: THE CAPT THEN REQUESTED THE TRUCKS BE ROLLED AS A PRECAUTION, AND NOTIFIED THE PAX AND FLT ATTENDANTS. WE DETERMINED THE #1 ENG WAS THE CAUSE OF THE VIBRATION AND ASYMMETRICAL THRUST ON THE TKOF ROLL. THE VIOLATION CEASED AFTER THE #1 ENG WAS SHUT DOWN. INITIAL DETERMINATION WAS A BLOWN TURBINE.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

A B737-200 rejected takeoff at 50 KTS due to aircraft yawing to left with left engine uneven thrust and unusual vibration.