A B737-300 rejected takeoff below airspeed indication due to right engine N1 indication failed at 50%. Reset circuit breaker and N1 indication normal.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	547516
Time
Date	200205
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	msl single value : 140
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tower : msn.tower
Operator	common carrier : air carrier
Make Model Name	B737-300
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
Experience	flight time last 90 days : 120 flight time total : 17000 flight time type : 4500
ASRS Report	547516
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance flight crew : rejected takeoff
Consequence	Other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

We had been cleared for takeoff on runway 15R. As I advanced the power levers through about 50% N1, the #1 N1 indication increased normally and the #2 N1 indication failed at approximately 50% N1 RPM. Additionally, I heard a noise at about the same time and was not sure if it was a circuit breaker tripping or caused by the first officer. Tower was contacted and we taxied down the runway and to a hold area on the ramp. Takeoff was terminated well below any airspeed indication. The engine #2 N1 indicator circuit breaker was reset and the indicator returned to normal. We taxied back and departed. N1's continued normal for 3 legs and the receiving captain was advised of this occurrence. I believe all actions were in accordance with the company fom, but I also have some concern that the related procedures in the manual might be subject to some interpretation, hence this report.

Original NASA ASRS Text

Title: A B737-300 REJECTED TKOF BELOW AIRSPD INDICATION DUE TO R ENG N1 INDICATION FAILED AT 50%. RESET CIRCUIT BREAKER AND N1 INDICATION NORMAL.

Narrative: WE HAD BEEN CLRED FOR TKOF ON RWY 15R. AS I ADVANCED THE PWR LEVERS THROUGH ABOUT 50% N1, THE #1 N1 INDICATION INCREASED NORMALLY AND THE #2 N1 INDICATION FAILED AT APPROX 50% N1 RPM. ADDITIONALLY, I HEARD A NOISE AT ABOUT THE SAME TIME AND WAS NOT SURE IF IT WAS A CIRCUIT BREAKER TRIPPING OR CAUSED BY THE FO. TWR WAS CONTACTED AND WE TAXIED DOWN THE RWY AND TO A HOLD AREA ON THE RAMP. TKOF WAS TERMINATED WELL BELOW ANY AIRSPD INDICATION. THE ENG #2 N1 INDICATOR CIRCUIT BREAKER WAS RESET AND THE INDICATOR RETURNED TO NORMAL. WE TAXIED BACK AND DEPARTED. N1'S CONTINUED NORMAL FOR 3 LEGS AND THE RECEIVING CAPT WAS ADVISED OF THIS OCCURRENCE. I BELIEVE ALL ACTIONS WERE IN ACCORDANCE WITH THE COMPANY FOM, BUT I ALSO HAVE SOME CONCERN THAT THE RELATED PROCS IN THE MANUAL MIGHT BE SUBJECT TO SOME INTERP, HENCE THIS RPT.

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.