Narrative:

We were getting ready to push off the gate. We were all closed up and ready to go. A ramp agent told the captain that it appears something is leaking on the right gear strut. [We] powered the hydraulic system down and called maintenance control. They arrived in just a few minutes. Said they were not sure where the leak was coming from. Asked that the captain turn the hydraulic pumps back on. After a few minutes they asked us to lower the flaps. After several more minutes they asked the captain to operate the speedbrakes. After that they asked us to raise the flaps and power down the hydraulic system as a speedbrake actuator was leaking. They took care of this problem. Came to the cockpit and signed off the logbook. We taxied out for takeoff on runway 17R. The captain was the pilot flying. We started our takeoff roll and everything was normal. The airplane was accelerating normally. As we accelerated and were approaching V1 I called out 80 knots. The captain looked down at his standby as indicator and we were now at V2 +. The best course of action at this time was to rotate and climb as opposed to aborting above V2. The captain rotated and we agreed my airspeed was in error and I started making callouts based on the captain's airspeed indicator. Shortly afterward we raised the gear and continued a normal climb. Selected LNAV at 400 feet. Shortly afterwards we got the aural and visual EICAS warnings with IAS disagree annunciated. This continued as we cleaned up. We both went through the airspeed unreliable memory items. Referenced the rudder ratio procedure then verified we completed the checklists per the boeing 757 QRH. As my airspeed gradually caught up to the captain's we started getting more EICAS warnings. Now we had a rudder ratio as well as the mach speed. We declared an emergency and wanted to level off at 5;000 feet. We had already been handed off to departure. He told us to maintain 5;000 describe our situation when we had time. We took a heading of 200 degrees. The captain turned the autothrottles on and turned on the center autopilot. Carefully guarding the controls and throttles. They seemed to work normally and make the appropriate corrections based on the captain's selection of airspeed. We needed some time to work this problem as there were several systems now failed and we needed to come up with our best assessment the best that we could. Departure turned us gradually east. We changed our speed up to 270 knots and then slowed to 230. My airspeed constantly lagged behind the captain's and every time there was it sensed a 6-8 knot difference the EICAS would annunciate IAS disagree. The captain called the number 1 flight attendant and told him we were going to have to return to the departure airport. Gave him his test items and reassured him everything was fine. We slowly descended to 3;000 feet when north east of ZZZ. We requested a 10 mile final. The captain started configuring and used 30 flaps and no autobrakes. Our weight was 203;000 at this time. Ref + 5 = was 139 knots. We had a slight cross wind from the east. Glideslope on the overhead IRS and on the CDU position reference page agreed. Intercepted the localizer and then glideslope. Fully configured. Touched down on 17C at 141 knots. Full reverse. The aircraft decelerated normally. The captain did not use any brakes until about 70 knots. We slowly exited the runway and stopped in the middle of the high speed and taxiway mike as this would give more room for the arff to work with. The captain told the passengers to remain seated. Called the number one and told them the same and do not let anyone get up. The fire chief checked in promptly said we looked ok; however there was a little smoke from the area of the right main gear. He investigated it and determined it was nothing serious. He used his infrared scope thing to check brake temps. The left main was 200 C however he said the right main was showing 800-1;000 C. We decided that cannot be right; everything would be melting and fuse plugs would have blown by now. The APU was running he asked us to shutdown the engines so he could put some fans on the right main gear as soon as possible. We did as he instructed. I called ramp and told them that we would have to be towed from our present position. We agreed that the temperature given to us on the right main gear had to be in error. He checked back in and said the temperature on the right main had dropped down to about 150 C and the left main gear brake assembly was about 100. Maintenance said it would be at least 15 minutes before they could get a tow bar and get to us. The fire chief said that the situation was well under control and if we wanted to start our engines back up and taxi on our own; we could at our discretion. We started our engines and went to the gate. We were met by several mechanics as well as a maintenance supervisor. We told them what happened the best that we could. The captain made several entries in the logbook and we were finished flying for the day.

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Original NASA ASRS Text

Title: A B757-200 First Officer airspeed indication error was detected at V1. The takeoff was continued and during climb EICAS alerted IAS DIAGREE; RUDDER RATIO and MACH so an emergency was declared; the QRH completed and the flight returned to the departure airport.

Narrative: We were getting ready to push off the gate. We were all closed up and ready to go. A Ramp Agent told the Captain that it appears something is leaking on the right gear strut. [We] Powered the hydraulic system down and called Maintenance Control. They arrived in just a few minutes. Said they were not sure where the leak was coming from. Asked that the Captain turn the hydraulic pumps back on. After a few minutes they asked us to lower the flaps. After several more minutes they asked the Captain to operate the speedbrakes. After that they asked us to raise the flaps and power down the hydraulic system as a speedbrake actuator was leaking. They took care of this problem. Came to the cockpit and signed off the logbook. We taxied out for takeoff on Runway 17R. The Captain was the pilot flying. We started our takeoff roll and everything was normal. The airplane was accelerating normally. As we accelerated and were approaching V1 I called out 80 knots. The Captain looked down at his Standby AS indicator and we were now at V2 +. The best course of action at this time was to rotate and climb as opposed to aborting above V2. The Captain rotated and we agreed my airspeed was in error and I started making callouts based on the Captain's airspeed indicator. Shortly afterward we raised the gear and continued a normal climb. Selected LNAV at 400 feet. Shortly afterwards we got the Aural and Visual EICAS warnings with IAS DISAGREE annunciated. This continued as we cleaned up. We both went through the Airspeed Unreliable Memory items. Referenced the Rudder Ratio procedure then verified we completed the checklists per the Boeing 757 QRH. As my airspeed gradually caught up to the Captain's we started getting more EICAS warnings. Now we had a RUDDER RATIO as well as the MACH SPEED. We declared an Emergency and wanted to level off at 5;000 feet. We had already been handed off to Departure. He told us to maintain 5;000 describe our situation when we had time. We took a heading of 200 degrees. The Captain turned the autothrottles ON and turned on the center autopilot. Carefully guarding the controls and throttles. They seemed to work normally and make the appropriate corrections based on the Captain's selection of airspeed. We needed some time to work this problem as there were several systems now failed and we needed to come up with our best assessment the best that we could. Departure turned us gradually east. We changed our speed up to 270 knots and then slowed to 230. My airspeed constantly lagged behind the Captain's and every time there was it sensed a 6-8 knot difference the EICAS would annunciate IAS DISAGREE. The Captain called the Number 1 Flight Attendant and told him we were going to have to return to the departure airport. Gave him his TEST items and reassured him everything was fine. We slowly descended to 3;000 feet when north east of ZZZ. We requested a 10 mile final. The Captain started configuring and used 30 flaps and no autobrakes. Our weight was 203;000 at this time. Ref + 5 = was 139 knots. We had a slight cross wind from the east. Glideslope on the overhead IRS and on the CDU POS REF page agreed. Intercepted the Localizer and then glideslope. Fully configured. Touched down on 17C at 141 knots. Full reverse. The aircraft decelerated normally. The Captain did not use any brakes until about 70 knots. We slowly exited the runway and stopped in the middle of the high speed and Taxiway Mike as this would give more room for the ARFF to work with. The Captain told the passengers to remain seated. Called the Number One and told them the same and do not let anyone get up. The Fire Chief checked in promptly said we looked OK; however there was a little smoke from the area of the right main gear. He investigated it and determined it was nothing serious. He used his infrared scope thing to check brake temps. The left main was 200 C however he said the right main was showing 800-1;000 C. We decided that cannot be right; everything would be melting and fuse plugs would have blown by now. The APU was running he asked us to shutdown the engines so he could put some fans on the right main gear ASAP. We did as he instructed. I called Ramp and told them that we would have to be towed from our present position. We agreed that the temperature given to us on the right main gear had to be in error. He checked back in and said the temperature on the right main had dropped down to about 150 C and the left main gear brake assembly was about 100. Maintenance said it would be at least 15 minutes before they could get a tow bar and get to us. The Fire Chief said that the situation was well under control and if we wanted to start our engines back up and taxi on our own; we could at our discretion. We started our engines and went to the gate. We were met by several mechanics as well as a Maintenance Supervisor. We told them what happened the best that we could. The Captain made several entries in the logbook and we were finished flying for the day.

Data retrieved from NASA's ASRS site 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.