Flight Instruments & Displays

Question 1

What directly provides inertial position and track data to the associated FMC?

Answer 1

The ADIRUs provide inertial position and track data to the FMC as well as attitude, altitude and airspeed data to the displays

Question 2

If both Captain and FO pitot tubes are inoperative (damaged/blocked), how is airspeed provided?

Answer 2

The Standby Airspeed Indicator receives ram air pressure from the auxiliary pitot probe and static pressure from the alternate static ports. It provides current airspeed in knots.

Question 3

What are the standby instruments?

Answer 3

• Standby Magnetic Compass
• Standby Attitude Indicator
• Integrated Standby Flight Display (ISFD)
• Standby Altimeter / Airspeed
Indicator
• Standby Radio Magnetic Indicator

Question 4

How is the Integrated Standby Flight Display battery pack and charger powered?

Answer 4

The Battery Bus normally powers the ISFD through a dedicated Battery Pack and Battery Charger. With a loss of Battery Bus power, the Battery Pack can provide 28 volts DC power to the ISFD for 150 minutes.

Question 5

If the outboard display fails, is automatic switching available? If so, where is the PFD displayed?

Answer 5

If the system detects an operational failure on an outboard DU, the Primary
Flight Display (PFD) automatically moves to the inboard DU and the failed outboard DU blanks.

Question 6

What indicates maximum operating speed?

Answer 6

The Maximum (Vmax) Speed is indicated as red and black alternating hashmarks forming a vertical bar.

The bottom of the bar indicates the maximum safe design operating
speed as calculated by the SMYD, and is the least value of:
• Vmo/Mmo
• landing gear placard speed
• flap placard speed

Question 7

How are maneuver speeds indicated?

Answer 7

The Flap Maneuvering Speeds (green) indicate the flap maneuvering speeds for the displayed flap position. The speeds are calculated by the CDS using Gross Weight provided by the FMC and Flap Lever position from the FSEU.

Question 8

With dual FMC failures, how are airspeeds set for takeoff and landing?

Answer 8

The SPD REF (Speed Reference) Selector (Outer Knob) sets the Reference Airspeed Bugs on the Airspeed Indication when the FMC is inop.

Question 9

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

Answer 9

The Flight Path Vector (FPV) Indication (white) displays the Flight Path Angle and Drift when selected on the EFIS Control Panel. The Flight Path Angle is displayed relative to the Horizon Line, and the Drift Angle is displayed relative to the display center.

Question 10

What are Pitch Limit Indicators, and when do they populate?

Answer 10

A Pitch Limit (amber) Indication (PLI) indicates the pitch limit (Stick Shaker
activation for existing flight conditions) as calculated by the SMYD. The PLI also represents safe maneuver margins for pitch control during maximum performance climbs and windshear escape maneuvers. It is displayed when:
• flaps are extended, or
• airspeed approaches Stick Shaker activation for the existing flight conditions, regardless of flap position

Question 11

What does pushing STD on the EFIS control panel do?

Answer 11

The Barometric (BARO) Standard (STD) Switch (Inner Switch), when
momentarily pushed, selects the standard barometric setting (29.92 inches Hg/1013 HPA) for barometric altitude reference and STD is displayed.

If STD is displayed, a barometric setting can be preselected on the EFIS Control Panel Barometric Selector and is displayed in small white characters below STD.

Question 12

What is the difference in the CDS lights on the PFD and when would you see them?

Answer 12

• CDS MAINT (white) - A dispatchable CDS fault has occurred. Displayed on the ground only, prior to start of the second engine.
• CDS FAULT (amber) - A non-dispatchable CDS fault has occurred. Displayed on the ground only, prior to start of the second engine.

Question 13

What causes the airspeed (IAS Disagree) alert and where is it populated?

Answer 13

The Airspeed Disagree Alert (amber) indicates the Captain’s and F/O’s airspeed indications disagree by more than 5 kts for 5 continuous seconds.

The alert is shown on both PFDs and does not indicate which airspeed value is erroneous.

Question 14

What causes the altitude (ALT DISAGREE), and where is it annunciated?

Answer 14

The Altitude Disagree Alert (amber) indicates the Captain’s and F/O’s altitude indications disagree by more than 200 ft for more than 5 continuous seconds.

The alert is shown on both PFDs and does not indicate which altitude value is erroneous.

Question 15

What causes the angle of attack (AOA DISAGREE) alert and where is it populated?

Answer 15

The AOA Disagree Alert (amber) indicates the left and right AOA values disagree by more than 10° for more than 10 continuous seconds.

The alert is shown on both PFDs and
does not indicate which AOA value is erroneous.

Question 16

Using the Vertical Situation Display (VSD), how would you know if you will achieve target speed within a certain distance?

Answer 16

The Range to Target Speed Dot (RTSD) is displayed as a green dot and indicates where the aircraft will achieve the FMC or MCP target speed. The dot:
• is blanked within 5 kts of target speed
• reappears if speed increases 10 kts or more above the target speed
• is replaced with an unfilled dot at vector end if the target speed will not be achieved within the length of the Vertical Flight Path Vector Line

Question 17

On the VSD, altitude gates are provided at what altitude on an approach path?

Answer 17

The Decision Gates are displayed on the FMC Approach Glide Path Line or the 3-Degree Reference Line at 500 ft (amber) and 1000 ft (white) above field elevation (AFE).

The gates indicate suggested points where the aircraft should be path and speed stable on the approach.

Question 18

In addition to the PFD, which displays use failure flags to indicate system failures?

Answer 18

The Navigation Display (ND)