Takeoff aborted account warning horn of undetermined origin.

Attributes
ACN	215132
Time
Date	199207
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ewr
State Reference	NJ
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : eze
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	climbout : takeoff other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : cfi pilot : atp
Experience	flight time last 90 days : 157 flight time total : 6711 flight time type : 279
ASRS Report	215132
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : rejected takeoff
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

Upon receiving takeoff clearance from tower, I applied takeoff power. At approximately 30-40 KIAS, we were alerted by what seemed to be an aural high turbine gas temperature (tgt) warning. There was no red master warning annunciation associated with the aural warning and all engine parameters indicated within their normal ranges. At approximately 40-50 KTS, I decided to abort the takeoff. I instructed the first officer to advise the tower that we had rejected the takeoff. We also advised the tower that the 'equipment' would not be required and that we would be returning to the gate. Ewr operations was advised, as well as our flight attendants and passenger. The aircraft had been written up on 2 prior occasions for this problem. As it turned out, our mechanics discovered that the first officer's airspeed indicator was causing a false overspd warning. The overspd warning emits the same sound as a high turbine gas temperature warning on the first officer made medium large transport. The both of us assumed the aural warning was turbine gas temperature related, due to the previous write-ups in the aircraft maintenance log, even though there was no associated master warning (red) annunciation. The fact that the overspd warning is the exact same aural sound certainly didn't help matters.

Original NASA ASRS Text

Title: TKOF ABORTED ACCOUNT WARNING HORN OF UNDETERMINED ORIGIN.

Narrative: UPON RECEIVING TKOF CLRNC FROM TWR, I APPLIED TKOF PWR. AT APPROX 30-40 KIAS, WE WERE ALERTED BY WHAT SEEMED TO BE AN AURAL HIGH TURBINE GAS TEMP (TGT) WARNING. THERE WAS NO RED MASTER WARNING ANNUNCIATION ASSOCIATED WITH THE AURAL WARNING AND ALL ENG PARAMETERS INDICATED WITHIN THEIR NORMAL RANGES. AT APPROX 40-50 KTS, I DECIDED TO ABORT THE TKOF. I INSTRUCTED THE FO TO ADVISE THE TWR THAT WE HAD REJECTED THE TKOF. WE ALSO ADVISED THE TWR THAT THE 'EQUIP' WOULD NOT BE REQUIRED AND THAT WE WOULD BE RETURNING TO THE GATE. EWR OPS WAS ADVISED, AS WELL AS OUR FLT ATTENDANTS AND PAX. THE ACFT HAD BEEN WRITTEN UP ON 2 PRIOR OCCASIONS FOR THIS PROBLEM. AS IT TURNED OUT, OUR MECHS DISCOVERED THAT THE FO'S AIRSPD INDICATOR WAS CAUSING A FALSE OVERSPD WARNING. THE OVERSPD WARNING EMITS THE SAME SOUND AS A HIGH TURBINE GAS TEMP WARNING ON THE FO MADE MLG. THE BOTH OF US ASSUMED THE AURAL WARNING WAS TURBINE GAS TEMP RELATED, DUE TO THE PREVIOUS WRITE-UPS IN THE ACFT MAINT LOG, EVEN THOUGH THERE WAS NO ASSOCIATED MASTER WARNING (RED) ANNUNCIATION. THE FACT THAT THE OVERSPD WARNING IS THE EXACT SAME AURAL SOUND CERTAINLY DIDN'T HELP MATTERS.

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.