Narrative:

The first officer was flying. On the takeoff roll, I called '80 KTS.' first officer said ' I have no airspeed, call V1.' I called V1 and vr. Rotation and lift off were normal. With a positive rate, first officer called 'gear up' -- I raised the gear and first officer established a normal climb. At 500 ft AGL, I switched the CADC switch to both on 1 -- first officer airspeed returned. Rest of flight was normal. At destination, maintenance found pitot hose disconnected from CADC 2. Decision to continue takeoff was based on favorable conditions and the experience level of both pilots -- combined with system knowledge. Captain's instruments and standby airspeed indicator were normal. The first officer was a 10000 hour pilot with lots of right seat instructor time and was familiar with cross cockpit instrument scan. This form submitted because a logbook entry was made and an investigation is underway to determine if the #2 CADC was tampered with due to strained labor relations and animosity toward the company and the pilots from maintenance. Supplemental information from acn 210824: at the 80 KT call I said I had no airspeed and asked the captain to be sure to call speeds for me. (And I picked his airspeed up on my scan). My airspeed then was normal so we elected to continue our route (the route and destination WX was good). On climb the right air data system climbed and went overspd giving a false warning which we eventually cancelled, but it drove us nuts at a busy time with ATC.

Related reports:

Google
 

Original NASA ASRS Text

Title: ACR MLG HAS LOSS OF 1 AIRSPD INDICATOR ON TKOF.

Narrative: THE FO WAS FLYING. ON THE TKOF ROLL, I CALLED '80 KTS.' FO SAID ' I HAVE NO AIRSPD, CALL V1.' I CALLED V1 AND VR. ROTATION AND LIFT OFF WERE NORMAL. WITH A POSITIVE RATE, FO CALLED 'GEAR UP' -- I RAISED THE GEAR AND FO ESTABLISHED A NORMAL CLB. AT 500 FT AGL, I SWITCHED THE CADC SWITCH TO BOTH ON 1 -- FO AIRSPD RETURNED. REST OF FLT WAS NORMAL. AT DEST, MAINT FOUND PITOT HOSE DISCONNECTED FROM CADC 2. DECISION TO CONTINUE TKOF WAS BASED ON FAVORABLE CONDITIONS AND THE EXPERIENCE LEVEL OF BOTH PLTS -- COMBINED WITH SYS KNOWLEDGE. CAPT'S INSTS AND STANDBY AIRSPD INDICATOR WERE NORMAL. THE FO WAS A 10000 HR PLT WITH LOTS OF R SEAT INSTRUCTOR TIME AND WAS FAMILIAR WITH CROSS COCKPIT INST SCAN. THIS FORM SUBMITTED BECAUSE A LOGBOOK ENTRY WAS MADE AND AN INVESTIGATION IS UNDERWAY TO DETERMINE IF THE #2 CADC WAS TAMPERED WITH DUE TO STRAINED LABOR RELATIONS AND ANIMOSITY TOWARD THE COMPANY AND THE PLTS FROM MAINT. SUPPLEMENTAL INFO FROM ACN 210824: AT THE 80 KT CALL I SAID I HAD NO AIRSPD AND ASKED THE CAPT TO BE SURE TO CALL SPDS FOR ME. (AND I PICKED HIS AIRSPD UP ON MY SCAN). MY AIRSPD THEN WAS NORMAL SO WE ELECTED TO CONTINUE OUR RTE (THE RTE AND DEST WX WAS GOOD). ON CLB THE R AIR DATA SYS CLBED AND WENT OVERSPD GIVING A FALSE WARNING WHICH WE EVENTUALLY CANCELLED, BUT IT DROVE US NUTS AT A BUSY TIME WITH ATC.

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.