Air carrier medium large transport takeoff abort when takeoff warning horn activated below V1.

Attributes
ACN	166013
Time
Date	199012
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : ord
State Reference	IL
Altitude	agl bound lower : 0 agl bound upper : 0
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
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 : atp pilot : instrument pilot : commercial
Experience	flight time total : 12500
ASRS Report	166013
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : atp
Experience	flight time last 90 days : 100 flight time total : 3000
ASRS Report	165911
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : rejected takeoff flight crew : declared emergency
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

While taking off on runway 22L ord, at about 110 KTS, we heard a short intermittent takeoff warning horn when we hit a bump on the runway. About 1 second later we heard the horn again as we went over another bump. At this time, I aborted the takeoff using mainly reverse thrust, with light to normal braking below 100 KTS. I returned to the gate leaving the flap handle in its present 5 degree flap position. Maintenance found a loose cam on the flap mechanism, which they repaired. This had prevented the flap from making proper contact with its position indicator. After consulting, the brake energy limitation chart and letting a new dispatch release, we made a normal takeoff.

Original NASA ASRS Text

Title: ACR MLG TKOF ABORT WHEN TKOF WARNING HORN ACTIVATED BELOW V1.

Narrative: WHILE TAKING OFF ON RWY 22L ORD, AT ABOUT 110 KTS, WE HEARD A SHORT INTERMITTENT TKOF WARNING HORN WHEN WE HIT A BUMP ON THE RWY. ABOUT 1 SEC LATER WE HEARD THE HORN AGAIN AS WE WENT OVER ANOTHER BUMP. AT THIS TIME, I ABORTED THE TKOF USING MAINLY REVERSE THRUST, WITH LIGHT TO NORMAL BRAKING BELOW 100 KTS. I RETURNED TO THE GATE LEAVING THE FLAP HANDLE IN ITS PRESENT 5 DEG FLAP POS. MAINT FOUND A LOOSE CAM ON THE FLAP MECHANISM, WHICH THEY REPAIRED. THIS HAD PREVENTED THE FLAP FROM MAKING PROPER CONTACT WITH ITS POS INDICATOR. AFTER CONSULTING, THE BRAKE ENERGY LIMITATION CHART AND LETTING A NEW DISPATCH RELEASE, WE MADE A NORMAL TKOF.

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.