Dash 8-100
Flight Crew Air Transport Pilot (ATP)
Flight Crew Total 3800; Flight Crew Type 2500
Human-Machine Interface; Situational Awareness
Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; General Maintenance Action
Human Factors
We flew with the flaps in the 5 degree detent the entire flight which exceeded the speed restriction of 148 knots with the flaps at 5. We cruised at 180 knots for the flight. The event was realized on approach when I called for the flaps to 15. The event occurred because of our lack of awareness that the flaps were not retracted to the 0 detent at 1;000 FT AGL and also not realizing the mistake when doing the after takeoff checklist and an insufficient scan of the instruments in cruise. We immediately contacted Dispatch and Maintenance control to have the airplane inspected.
DHC8-100 First Officer reports flying the entire leg with the flaps left inadvertently at the 5 degree position. The published flap speed was exceeded by 32 knots.