Narrative:

Aircraft arrived bwi with #1 IRS fault. 20-30 min maintenance delay to fix problem, advised passenger. Adverse WX (windshear) departure runway 28 (ATIS advised windshear, 2 B757 aircraft prior reported plus 15 KTS on departure).first officer rotated at 161 KTS (V2+20 V2-141 KTS). Immediately after rotation, stick shaker activation, noticed first officer airspeed headed for zero. Captain took control of aircraft and continued adverse takeoff profile. As we began to analyze the problem and look for circuit breakers, we noticed no circuit breakers popped, but numerous air data computer problems, along with no altitude, time, or distance information on the IRS FMC. Also, no autoplt functions, except for control wheel steering. Decided appropriate action was an air return to bwi, as first officer airspeed was going from stick shaker to clacker speed and back. QRH references ground speed, which were also unavailable. Advised ATC of air data and airspeed problems and requested a return to bwi. Advised cabin crew, passenger, maintenance, dispatch, and operations. Changed aircraft and continued on. Supplemental information from acn 571927: loss of #1 air data computer resulting in unreliable a/south. Inbound crew had #1 IRS fault light during landing. Maintenance replaced #1 IRU and did an alignment, which fixed the problem. Preflight and taxi were normal. We did an adverse procedures takeoff with increased rotation of 161 (V2+20). Takeoff roll normal until just after rotation when I got the stick shaker and noticed my airspeed indicator decreasing through 90 KIAS. I gave the plane to the captain, whose airspeed was working. Completion of the 'airspeed unreliable' QRH revealed the following functions of the FMC were inoperative: gndspd, time, distance, and fuel remaining on the legs and progress pages. There were no popped circuit breakers. While the captain was flying, he noticed the autoplt was only working in control wheel steering mode, at this point, we decided to return to bwi. Talking with maintenance control on the next day, we found out they replaced the #1 air data computer.

Related reports:

Google
 

Original NASA ASRS Text

Title: B737-300 CREW HAD FO AIRSPD FAILURE AND A FALSE STICK SHAKER DEPARTING BWI.

Narrative: ACFT ARRIVED BWI WITH #1 IRS FAULT. 20-30 MIN MAINT DELAY TO FIX PROB, ADVISED PAX. ADVERSE WX (WINDSHEAR) DEP RWY 28 (ATIS ADVISED WINDSHEAR, 2 B757 ACFT PRIOR RPTED PLUS 15 KTS ON DEP).FO ROTATED AT 161 KTS (V2+20 V2-141 KTS). IMMEDIATELY AFTER ROTATION, STICK SHAKER ACTIVATION, NOTICED FO AIRSPD HEADED FOR ZERO. CAPT TOOK CTL OF ACFT AND CONTINUED ADVERSE TKOF PROFILE. AS WE BEGAN TO ANALYZE THE PROB AND LOOK FOR CIRCUIT BREAKERS, WE NOTICED NO CIRCUIT BREAKERS POPPED, BUT NUMEROUS AIR DATA COMPUTER PROBS, ALONG WITH NO ALT, TIME, OR DISTANCE INFO ON THE IRS FMC. ALSO, NO AUTOPLT FUNCTIONS, EXCEPT FOR CTL WHEEL STEERING. DECIDED APPROPRIATE ACTION WAS AN AIR RETURN TO BWI, AS FO AIRSPD WAS GOING FROM STICK SHAKER TO CLACKER SPD AND BACK. QRH REFS GND SPD, WHICH WERE ALSO UNAVAILABLE. ADVISED ATC OF AIR DATA AND AIRSPD PROBS AND REQUESTED A RETURN TO BWI. ADVISED CABIN CREW, PAX, MAINT, DISPATCH, AND OPS. CHANGED ACFT AND CONTINUED ON. SUPPLEMENTAL INFO FROM ACN 571927: LOSS OF #1 AIR DATA COMPUTER RESULTING IN UNRELIABLE A/S. INBOUND CREW HAD #1 IRS FAULT LIGHT DURING LNDG. MAINT REPLACED #1 IRU AND DID AN ALIGNMENT, WHICH FIXED THE PROB. PREFLT AND TAXI WERE NORMAL. WE DID AN ADVERSE PROCS TKOF WITH INCREASED ROTATION OF 161 (V2+20). TKOF ROLL NORMAL UNTIL JUST AFTER ROTATION WHEN I GOT THE STICK SHAKER AND NOTICED MY AIRSPD INDICATOR DECREASING THROUGH 90 KIAS. I GAVE THE PLANE TO THE CAPT, WHOSE AIRSPD WAS WORKING. COMPLETION OF THE 'AIRSPD UNRELIABLE' QRH REVEALED THE FOLLOWING FUNCTIONS OF THE FMC WERE INOP: GNDSPD, TIME, DISTANCE, AND FUEL REMAINING ON THE LEGS AND PROGRESS PAGES. THERE WERE NO POPPED CIRCUIT BREAKERS. WHILE THE CAPT WAS FLYING, HE NOTICED THE AUTOPLT WAS ONLY WORKING IN CTL WHEEL STEERING MODE, AT THIS POINT, WE DECIDED TO RETURN TO BWI. TALKING WITH MAINT CTL ON THE NEXT DAY, WE FOUND OUT THEY REPLACED THE #1 AIR DATA COMPUTER.

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.