Narrative:

Red eye flight. The first event was a pushback and engine start. After the engines were started; a master caution illuminated with engine on the recall panel and eec altitude lights. We talked to maintenance and returned to the gate. Maintenance did engine runs with no return of eec altitude lights. So; we were signed off; reboarded; and taxied back out for takeoff. Around 80 knots my first officer and I noticed that the first officer's airspeed indicator dropped suddenly and we had an IAS disagree message. Then it seemed to recover somewhat; but now we were above 100 knots. My first officer's indicator was still lower than mine. After looking at our three IAS indicators and remaining runway; I called V1 and rotate at what I thought was close. On climbout our airspeed differences were inconsistent. Then as we climbed they became greater and stayed between 10 and 15 knots different; with mine slower. The standby IAS was closer to my first officer's; but the first officer's indicator seemed more erratic than mine. The standby IAS was about 3 knots less than my first officer's.we stopped our climb at FL320 instead of FL350; and told approach that we didn't want to leave radar and VHF without solving this. I called maintenance; with little help. They just said that their computers were slow; so I did a VHF phone patch with dispatch and a 3-way call to maintenance but that was taking too long and we were leaving VHF coverage; so I tried a HF phone patch; but dispatch and maintenance were unreadable. I received a free text message that said captain's discretion; so we decided that we didn't want to cross the ocean in the middle of the night not knowing what our airspeed was. We wouldn't know how much margin from barber pole to minimum speed we had; and we had nowhere close to divert. We returned to our departure airport; and we did a smooth; overweight landing with no problems. Maintenance blew out the pitot static system and did a test and we continued or flight later that morning.

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Original NASA ASRS Text

Title: This Boeing 737 crew received EEC ENG and EEC ALT Master Caution warnings after engine start and returned to the gate for maintenance attention. After Maintenance sign-off; the flight again departed; and during takeoff and climb they now noticed airspeed indicator discrepancies and received an IAS Disagree message; and returned to their departure airport.

Narrative: Red eye flight. The first event was a pushback and engine start. After the engines were started; a Master Caution illuminated with ENG on the Recall panel and EEC ALT lights. We talked to Maintenance and returned to the gate. Maintenance did engine runs with no return of EEC ALT lights. So; we were signed off; reboarded; and taxied back out for takeoff. Around 80 knots my First Officer and I noticed that the First Officer's airspeed indicator dropped suddenly and we had an IAS Disagree message. Then it seemed to recover somewhat; but now we were above 100 knots. My First Officer's indicator was still lower than mine. After looking at our three IAS indicators and remaining runway; I called V1 and rotate at what I thought was close. On climbout our airspeed differences were inconsistent. Then as we climbed they became greater and stayed between 10 and 15 knots different; with mine slower. The standby IAS was closer to my First Officer's; but the First Officer's indicator seemed more erratic than mine. The standby IAS was about 3 knots less than my First Officer's.We stopped our climb at FL320 instead of FL350; and told Approach that we didn't want to leave radar and VHF without solving this. I called Maintenance; with little help. They just said that their computers were slow; so I did a VHF phone patch with Dispatch and a 3-way call to Maintenance but that was taking too long and we were leaving VHF coverage; so I tried a HF phone patch; but Dispatch and Maintenance were unreadable. I received a free text message that said Captain's discretion; so we decided that we didn't want to cross the ocean in the middle of the night not knowing what our airspeed was. We wouldn't know how much margin from Barber Pole to minimum speed we had; and we had nowhere close to divert. We returned to our departure airport; and we did a smooth; overweight landing with no problems. Maintenance blew out the pitot static system and did a test and we continued or flight later that morning.

Data retrieved from NASA's ASRS site as of July 2013 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.