After an application of type iv deicing fluid; a dash 8-100 captain experiences a stick shaker from ...

Attributes
ACN	924002
Time
Date	201012
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Make Model Name	Dash 8-100
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Component
Aircraft Component	Stall Warning System
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 450 Flight Crew Total 25000 Flight Crew Type 20000
Person 2
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Commercial
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

We had been de-iced with type iv fluid. After takeoff and on climbout the stick shaker activated. We were at airspeeds from 180 to 200. There was no ice on the aircraft and it was obviously a system malfunction. We declared an emergency and returned uneventfully. We then did a maintenance flight with the mechanic onboard. Aircraft operated normally with no abnormalities. We signed off the maintenance evaluation flight as normal and then flew the aircraft on a revenue flight with no abnormalities. This was a new one to me. I have never seen this abnormality before. After talking with maintenance we learned we could have pulled left and right stall warning circuit breakers separately to determine which stall warning computer was malfunctioning. This would have helped in maintenance troubleshooting and probably eliminated the need for a maintenance evaluation flight.

Original NASA ASRS Text

Title: After an application of type IV deicing fluid; A Dash 8-100 Captain experiences a stick shaker from shortly after takeoff until landing at the departure airport. Maintenance can find no faults and an evaluation flight produces no anomalies.

Narrative: We had been de-iced with Type IV fluid. After takeoff and on climbout the stick shaker activated. We were at airspeeds from 180 to 200. There was no ice on the aircraft and it was obviously a system malfunction. We declared an emergency and returned uneventfully. We then did a maintenance flight with the mechanic onboard. Aircraft operated normally with no abnormalities. We signed off the maintenance evaluation flight as normal and then flew the aircraft on a revenue flight with no abnormalities. This was a new one to me. I have never seen this abnormality before. After talking with Maintenance we learned we could have pulled left and right stall warning circuit breakers separately to determine which stall warning computer was malfunctioning. This would have helped in maintenance troubleshooting and probably eliminated the need for a maintenance evaluation flight.

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.

After an application of type iv deicing fluid; a dash 8-100 captain experiences a stick shaker from shortly after takeoff until landing at the departure airport. Maintenance can find no faults and an evaluation flight produces no anomalies.