B737-400
Aircraft Equipment Problem Critical
Aircraft Aircraft Damaged; Flight Crew Landed As Precaution; Flight Crew Returned To Departure Airport; General Maintenance Action
Aircraft; Human Factors
During takeoff after approximately 100 KTS the stick shaker and overspeed clacker activated and remained on until after touchdown and below 100 KTS. The Captain's airspeed tape on the EHSI became erroneous. I was the pilot flying throughout the flight and handled ATC communications while the Captain worked through the QRH and did an excellent job managing the overall flight. The landing was overweight but not considered a 'hard landing.' The Captain and I both agreed that an emergency did not need to be declared with ATC. Upon arrival at the gate Maintenance found the angle of attack sensor; aircraft left; was broken. I began to mentally recall my preflight inspection: I arrived at the airplane as Maintenance personnel were operating the jetway. I boarded and performed my normal flight deck inspections. The A Flight Attendant asked me to have the Gate Agent close the canopy as it was raining. The Gate Agent happened to check for boarding and noticed the jetway was not lined up properly. I had to close the L1 door so the Agent could realign the bridge and close the canopy. I then completed my walk around and found no defects. I do not know how the angle of attack sensor was damaged. It is logical to assume that the sensor was damaged prior to pushback; but I feel I did an adequate preflight of the sensor. I would be curious to know if the Gate Agent or ground crew could recall if they perhaps noticed the sensor was damaged during pushback.
B737-400 First Officer experiences the stick shaker and over speed clacker passing 100 KTS on takeoff. Both warnings remain activated until the aircraft slows below 100 KTS after an overweight landing. The angle of attack vane is found damaged on post flight.