Narrative:

On the takeoff roll; the first officer (first officer) called 80 KTS. I transitioned inside to crosscheck airspeed and noted it at approximately 48 KTS. By the time I was able to make a decision to abort or not; we had accelerated to a point that I felt was too fast to abort safely. I chose to take the aircraft airborne. At approximately 200 ft; I transferred control of the aircraft to the first officer; assuming that he had the reliable airspeed indicator. Climbing to 3;000 ft; we crosschecked other airspeed indicators to try and determine the most reliable source. We did have IAS disagreement lights; but they extinguished at level off at 3;000 ft. All indications appeared to align with one another and I took back control of the aircraft. Starting to climb out of 3;000 ft; the auto-throttles disengaged and we once again began to receive erroneous airspeed indications. I passed the controls to the first officer and we began a pitch/power controlled climb. My airspeed continued to climb as the aircraft climbed. A crosscheck with the hgs and standby airspeed indicator did not yet reveal that my indications were erroneous. Passing through 7;500 ft; we got the airspeed overspeed clacker and lowered the nose and added power to ensure safe flight. At that point; we were able to define; for the most part; that my instruments were at fault. We confirmed with departure that what they showed aligned with the first officer's instruments. We climbed and leveled at 10;000 ft. My instruments showed 417 KTS and the first officer's indicated about 250 KTS. We got the weather from approach and proceeded direct to ZZZ. En route; we decided to declare an emergency because we were down to one valid airspeed indicator. We broke out between layers at 10;000 ft and continued in VFR conditions the remainder of the flight. As we descended; my airspeed indicator started to decrease. Around 7;000 ft the airspeed clacker stopped. We planned a flaps 30 landing. As we configured the aircraft; we realized that the aircraft would not allow flaps 30 because of my airspeed indications. The airspeed slowed far enough on the final segment to allow the flaps 30 to deploy. The landing and taxi to the gate was uneventful.

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Original NASA ASRS Text

Title: A B737-700 flight crew reported erroneous airspeed indications on the Captain's side; apparently from a pitot/static system problem. They declared an emergency and a normal landing ensued.

Narrative: On the takeoff roll; the First Officer (FO) called 80 KTS. I transitioned inside to crosscheck airspeed and noted it at approximately 48 KTS. By the time I was able to make a decision to abort or not; we had accelerated to a point that I felt was too fast to abort safely. I chose to take the aircraft airborne. At approximately 200 FT; I transferred control of the aircraft to the FO; assuming that he had the reliable airspeed indicator. Climbing to 3;000 FT; we crosschecked other airspeed indicators to try and determine the most reliable source. We did have IAS disagreement lights; but they extinguished at level off at 3;000 FT. All indications appeared to align with one another and I took back control of the aircraft. Starting to climb out of 3;000 FT; the auto-throttles disengaged and we once again began to receive erroneous airspeed indications. I passed the controls to the FO and we began a pitch/power controlled climb. My airspeed continued to climb as the aircraft climbed. A crosscheck with the HGS and standby airspeed indicator did not yet reveal that my indications were erroneous. Passing through 7;500 FT; we got the airspeed overspeed clacker and lowered the nose and added power to ensure safe flight. At that point; we were able to define; for the most part; that my instruments were at fault. We confirmed with Departure that what they showed aligned with the FO's instruments. We climbed and leveled at 10;000 FT. My instruments showed 417 KTS and the FO's indicated about 250 KTS. We got the weather from Approach and proceeded direct to ZZZ. En route; we decided to declare an emergency because we were down to one valid airspeed indicator. We broke out between layers at 10;000 FT and continued in VFR conditions the remainder of the flight. As we descended; my airspeed indicator started to decrease. Around 7;000 FT the airspeed clacker stopped. We planned a flaps 30 landing. As we configured the aircraft; we realized that the aircraft would not allow flaps 30 because of my airspeed indications. The airspeed slowed far enough on the final segment to allow the flaps 30 to deploy. The landing and taxi to the gate was uneventful.

Data retrieved from NASA's ASRS site as of April 2012 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.