Flight Instruments And Displays

Question 1

Q.4.1. What is the significance of the small white bug on the PFD Airspeed Indicator during takeoff? Approach?

Answer 1

Takeoff = V2 + 15

Approach = -700: Vref+15
-800/8MAX: Vref+20

Reference: FRM B737NG/MAX 10.1.2.2

Question 2

Q.4.2. On takeoff, what is the minimum speed for flap retraction?

Answer 2

Normally, the initial flap retraction will be made at V2 + 20. V2 + 15 is the minimum speed required for flap retraction except for a Flaps 1 takeoff. For a flaps 1 takeoff, begin flap retraction when reaching the flaps 1 maneuvering speed.

Limit bank angle to 15 degrees until reaching V2 + 15.

Reference: AOM 9.2.3

Question 3

Q.4.3. What does IAS DISAGREE alert indicate?

Answer 3

The Captain’s and First Officer’s airspeed indications disagree by more than 5 kt for 5 continuous seconds.

Reference: FRM B737NG/MAX 10.1.8.5

Question 4

Q.4.4. In an NG, what is the difference between a CDS MAINT alert and a CDS FAULT alert?

Answer 4

CDS MAINT (white)— A dispatchable CDS fault has occurred.
CDS FAULT (amber)— A non-dispatchable CDS fault has occurred.

Reference: FRM B737 NG 10.1.8.2, QRH NG 10.12

Question 5

Q.4.5. What does a (NG) DSPLY SOURCE/ (MAX) DSPLY SOURCE 1 alert and the illumination of both EEC ALTN lights indicate which QRH Checklist should be used?

Answer 5

A DEU (NG) or DPC(MAX) has failed. Loss of the DEU/DPC results in a loss of signal to both EECs. The EEC ALTN lights illuminate, and each EEC reverts to the alternate mode. The root cause loss of a DEU would lead to the selection of the DISPLAY SOURCE QRH checklist but either the DISPLAY SOURCE checklist or the EEC ALTERNATE MODE checklist will address the situation.

Reference: FRM B737NG/MAX 10.1.8.2, 7.2.3; QRH NG 7.11, 10.12; QRH MAX 7.13, 10.12(opens in a new tab)

Question 6

Q.4.6. During flight below FL220 you observe a DSPLY SOURCE message on the primary flight display. Will the autopilot and/or flight director be affected?

Answer 6

Yes, below FL220 available autopilot modes and flight director commands will be affected depending on phase of flight and which autopilot is engaged.

Reference: FRM B737NG/MAX 10.1.8.2/ QRH NG/MAX10.12

Question 7

Q.4.7. When VNAV is engaged when will VNAV automatically switch from VNAV PTH to VNAV SPD?

Answer 7

When the airspeed exceeds the top of the VNAV Speed Band.

Reference: FRM B737NG/MAX 10.1.2.1

Question 8

Q.4.8. What does the lower limit of the VNAV Speed Band in the PFD trigger?

Answer 8

Lower limit will trigger autothrottle wakeup.

Reference: FRM B737NG/MAX 10.1.2.1

Question 9

Q.4.9. After performing the Immediate Action Steps, QRC, and QRH for an Airspeed Unreliable, what resource would you go to that can help determine your pitch and thrust settings as you continue with the flight?

Answer 9

Refer to the Flight with Unreliable Airspeed table in the Performance Inflight chapter of the QRH.

Reference: B737NG/MAX QRH 10.1, PI-QRH (opens in a new tab)