Flight Instruments, Displays

Question 1

What is the purpose of the Display Processing Computers (DPC’s)?

Answer 1

• The DPC interfaces with aircraft subsystems and sensors to collect data. The collected data is then processed and displayed on the flight deck Display Units.
• Each DPC is capable of providing completely independent sources of flight information presented on the Captain’s and First Officer’s displays.

Question 2

How are outboard Display unit failures automatically handled?

Answer 2

• When an outboard DU failure is sensed, the displays will automatically reconfigure to ensure that each pilot has a PFD, and that an Engine Display is shown.
• The MFD display adjacent to the failed DU is replaced by a reduced size PFD. The left and right edges of the PFD are cropped and the AUX display is removed from the side of the PFD. A condensed version of the AUX display is placed at the top of the PFD. This allows the half-sized PFD display to fit.

Question 3

How are the standby instruments provided airspeed and altitude information?

Answer 3

• Airspeed and Altitude are computed from pneumatic pressure data provided by direct connections to the auxiliary pitot and alternate static sources.

Question 4

How is inertial position and track data provided to the FMC?

Answer 4

The ADIRU’s provide inertial position and track data to the FMC.

Question 5

How is Maximum operating speed indicated on the PFD?

Answer 5

Red and black alternating hash marks displayed as a vertical bar.

Question 6

What does the VNAV speed band on the PFD indicate?

Answer 6

• The VNAV Speed Band (magenta) indicates the FMC target airspeed during VNAV PTH descents.
• The bottom of the bar indicates the auto-throttle wake up speed.
• The top of the bar indicates the speed at which VNAV will change from VNAV PTH to VNAV SPD.

Question 7

When do the Pitch Limit Indicators (PLI’s) display?

Answer 7

Eyebrows, Amber, PLI’s. Indicates the pitch limit, (Stick Shaker activation for existing conditions). They populate when flaps are extended OR airspeed approaches stick shaker activation.

Question 8

How is the flight path angle and drift angle displayed on the PFD?

Answer 8

• Via the Flight Path Vector (EFIS control panel).
  o Flight path angle is displayed relative to the horizon line.
  o Drift angle is displayed relative to display center.

Question 9

How is standard pressure set on the altimeter?

Answer 9

By toggling the STD button on the BARO knob located on the EFIS panel.

Question 10

What does ALT DISAGREE alert indicate?

Answer 10

The Captain and First Officer’s altitude values disagree by more than 200 feet for 5 continuous seconds.

Question 11

What does IAS DISAGREE alert indicate?

Answer 11

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

Question 12

What does the AOA DISAGREE alert indicate?

Answer 12

The Captain’s and First Officer’s AOA values disagree by more than 10 degrees for 10 continuous seconds.

Question 13

What does the solid green dot along the vertical flight path vector of the Vertical Situation Display (VSD) indicate?

Answer 13

The Range to Target Speed Dot (RTSD) green spot indicates where the aircraft will achieve the FMC or MCP target speed.

Question 14

At what altitudes are decision gates on the VSD provided?

Answer 14

At 500 feet and 1,000 feet above field elevation.

Question 15

How is the HGS system controlled?

Answer 15

The HGS is controlled from a menu within the MCDU.

Question 16

What standby instruments are available?

Answer 16

• The Standby magnetic compass.
• The Integrated Standby Flight Display (ISFD).

Question 17

How is the Integrated Standby Flight Display (ISFD) powered?

Answer 17

The ISFD battery pack charger is normally powered by the Battery Bus.

Question 18

Which displays utilize failure flags to display instrument failures?

Answer 18

• The PFD
• The ND
• The ISFD