Narrative:

Normal taxi out. Departing runway 24 at einn after V1 and before rotation, severe vibration started from underneath aircraft. Rate of acceleration decreased. At rotation speed, aircraft was difficult to unstick from runway. Vibration continued until after main wheels lifted from runway. Immediately after rotation, anti-skid inoperative light flickered on and off, illuminated for 30 seconds, flickered off and on, then stayed off. Crew left landing gear in extended position due to unknown situation. At approximately 1000 ft AGL, so noted that main gear spoiler inoperative light was illuminated. Captain called for appropriate procedure. So performed main gear spoiler inoperative light illuminated procedure - - light extinguished. After takeoff checklist was performed, crew assessed situation and contacted flight control and maintenance while remaining in the shannon area. Company was informed of the situation. Approximately 10 mins later, they informed us they desired a return to shannon. Emergency was declared, fuel dumped down to 28000 pounds. Appropriate checklists completed and approach briefing performed for ILS runway 24 einn. Approach and landing uneventful. Emergency crews inspected aircraft on runway, no abnormalities noted. Callback conversation with reporter revealed the following information: the reporter stated after takeoff and trying to determine our problem and contacting company maintenance for advice we remained in the shannon area within approximately 10 mi. The reporter said that after an uneventful landing with anti-skid off the aircraft was parked to await a mechanic from brussels. The reporter said the mechanic after troubleshooting found 2 wheel anti-skid transducers inoperative. The reporter stated that after the transducers were replaced and tested the aircraft was returned to service and operated normally. The reporter said the aircraft had no previous history of anti-skid problems.

Related reports:

Google
 

Original NASA ASRS Text

Title: A DC 8-73F ON ROTATION HAD SEVERE LOWER FUSELAGE VIBRATION. DECLARED AN EMER AND DIVERTED DUE TO A FAILED ANTI-SKID SYS.

Narrative: NORMAL TAXI OUT. DEPARTING RWY 24 AT EINN AFTER V1 AND BEFORE ROTATION, SEVERE VIBRATION STARTED FROM UNDERNEATH ACFT. RATE OF ACCELERATION DECREASED. AT ROTATION SPD, ACFT WAS DIFFICULT TO UNSTICK FROM RWY. VIBRATION CONTINUED UNTIL AFTER MAIN WHEELS LIFTED FROM RWY. IMMEDIATELY AFTER ROTATION, ANTI-SKID INOP LIGHT FLICKERED ON AND OFF, ILLUMINATED FOR 30 SECONDS, FLICKERED OFF AND ON, THEN STAYED OFF. CREW LEFT LNDG GEAR IN EXTENDED POS DUE TO UNKNOWN SIT. AT APPROX 1000 FT AGL, SO NOTED THAT MAIN GEAR SPOILER INOP LIGHT WAS ILLUMINATED. CAPT CALLED FOR APPROPRIATE PROC. SO PERFORMED MAIN GEAR SPOILER INOP LIGHT ILLUMINATED PROC - - LIGHT EXTINGUISHED. AFTER TKOF CHKLIST WAS PERFORMED, CREW ASSESSED SIT AND CONTACTED FLT CTL AND MAINT WHILE REMAINING IN THE SHANNON AREA. COMPANY WAS INFORMED OF THE SIT. APPROX 10 MINS LATER, THEY INFORMED US THEY DESIRED A RETURN TO SHANNON. EMER WAS DECLARED, FUEL DUMPED DOWN TO 28000 LBS. APPROPRIATE CHKLISTS COMPLETED AND APCH BRIEFING PERFORMED FOR ILS RWY 24 EINN. APCH AND LNDG UNEVENTFUL. EMER CREWS INSPECTED ACFT ON RWY, NO ABNORMALITIES NOTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED AFTER TKOF AND TRYING TO DETERMINE OUR PROB AND CONTACTING COMPANY MAINT FOR ADVICE WE REMAINED IN THE SHANNON AREA WITHIN APPROX 10 MI. THE RPTR SAID THAT AFTER AN UNEVENTFUL LNDG WITH ANTI-SKID OFF THE ACFT WAS PARKED TO AWAIT A MECH FROM BRUSSELS. THE RPTR SAID THE MECH AFTER TROUBLESHOOTING FOUND 2 WHEEL ANTI-SKID TRANSDUCERS INOP. THE RPTR STATED THAT AFTER THE TRANSDUCERS WERE REPLACED AND TESTED THE ACFT WAS RETURNED TO SVC AND OPERATED NORMALLY. THE RPTR SAID THE ACFT HAD NO PREVIOUS HISTORY OF ANTI-SKID PROBS.

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.