Unreliable Airspeed

Question 1

What can cause unreliable airspeed indications?

Answer 1

Blocking or freezing of the pitot/static system, a severely damaged or missing radome, or a system malfunction.

Question 2

How can flight crews recognize an unreliable airspeed indication?

Answer 2

By monitoring and crosschecking PFDs and standby instruments, and looking for IAS and ALT miscompare annunciations.

Question 3

What should be done immediately when an unreliable airspeed indication is identified?

Answer 3

Disengage the autopilot and set a target pitch attitude and thrust setting for the phase of flight.

Question 4

Where can you find the UNRELIABLE AIRSPEED procedure and relevant tables?

Answer 4

QRH Volume 2, section EMER 17.

Question 5

What should be avoided when dealing with an unreliable airspeed indication?

Answer 5

Use of spoilers.

Question 6

What reference is available below 2500 ft AGL for unreliable airspeed indications?

Answer 6

Radio altitude reference.

Question 7

What should be used for approach and landing if available during unreliable airspeed conditions?

Answer 7

Electronic and visual glideslope indicators.

Question 8

What should be done once the airplane is stabilized under correct pitch attitude and thrust setting?

Answer 8

Continue to crosscheck the flight instruments to identify reliable instruments.