Narrative:

We (the flight crew) were assigned a post maintenance operational check flight in accordance with maintenance procedure. During the acceptance flow; a thorough log book review was accomplished by both the PIC and sic. We did discover a previous [squawk] item for spurious windshear as well as errors with attitude and airspeed mis-comparisons. The item was a discussion point since the corrective action did not appear to address the [squawk]; however; maintenance did accomplish maintenance actions and closed and corrected the [squawk]. During the subsequent takeoff; immediately after liftoff; we experienced windshear aural and visual indications. Additionally; both left and right pilot altitude and airspeed data were mis-comparing. We decided that a return was prudent given the unknown status of indicating systems. During the remainder of the flight; neither left nor right altitude/airspeed information was reliable. Tower and departure were notified of our status and ATC was informed that accurate information from the flight deck was questionable. The remainder of the flight was conducted without incident.fortunately this issue occurred during an operational check flight with specific weather minimums. The erroneous altitude and airspeed information presented itself with as eerily similar to the air carrier Y accident scenario. Proactive detection; communication and utilization of external CRM (ATC) was incredibly important even in VMC conditions.

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Original NASA ASRS Text

Title: HS-125 flight crew reported a spurious windshear alert and erroneous airspeed and altitude indications immediately after takeoff on a post maintenance test flight.

Narrative: We (the Flight Crew) were assigned a post maintenance operational check flight in accordance with maintenance procedure. During the acceptance flow; a thorough log book review was accomplished by both the PIC and SIC. We did discover a previous [squawk] item for spurious WINDSHEAR as well as errors with attitude and airspeed mis-comparisons. The item was a discussion point since the corrective action did not appear to address the [squawk]; however; maintenance did accomplish maintenance actions and closed and corrected the [squawk]. During the subsequent takeoff; immediately after liftoff; we experienced WINDSHEAR aural and visual indications. Additionally; both left and right pilot altitude and airspeed data were mis-comparing. We decided that a return was prudent given the unknown status of indicating systems. During the remainder of the flight; neither left nor right altitude/airspeed information was reliable. Tower and Departure were notified of our status and ATC was informed that accurate information from the flight deck was questionable. The remainder of the flight was conducted without incident.Fortunately this issue occurred during an operational check flight with specific weather minimums. The erroneous altitude and airspeed information presented itself with as eerily similar to the Air Carrier Y accident scenario. Proactive detection; communication and utilization of external CRM (ATC) was incredibly important even in VMC conditions.

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.