Airspeed Unreliable

Question 1

What are the QRH listed indications that may be associated with AIRSPEED UNRELIABLE?

Answer 1

• Difference between Capt and FO airspeed indications
• Speed / Altitude information not consistent with pitch attitude and thrust setting
• Blank or fluctuation airspeed indication
• Continuous or intermittent stick shaker
• Amber Alerts – IAS DISAGREE, ALT DISAGREE, AOA DISAGREE, SPD or SPD LIM Failure Flag
• Erroneous minimum or maximum speed bars
• Airspeed Low Aural
• Overspeed Warning
• Erroneous FD Pitch command
• EEC ALTN lights
• Radome Damage or Loss

Question 2

If the AOA DISAGREE alert is shown, what are the QRH listed possible effects on the flight deck?

Answer 2

• Erroneous Pitch Limit Indicator
• Windshear Alerts
• Autoslat Operation

Question 3

When should the memory items be completed?

Answer 3

As soon as any abnormal airspeed indications are unreliable
**During Take Off, continue the normal take off and accomplish the memory items at acceleration altitude

Question 4

What indications can be relied upon in an airspeed unreliable event?

Answer 4

*Attitude
*N1
*Groundspeed
*Radio Altitude