MAX - Flight Management, Navigation

How many GPS receivers are installed?

Two GPS sensors in the MMRs receive GPS satellite signals, left and right. The left and right GPS sensors are independent, and each provides an accurate raw GPS position to the FMC, ADIRU, and other aircraft systems.

Raw GPS is the GPS position, navigation, and timing data delivered from the on-board GPS sensors without any mixing, combining, or filtering from other on-board systems

Are IRS outputs independent of external navigation aids?

YES

What is indicated by a white ALIGN light on the IRS panel? (3)

IRS is operating in:

• ALIGN mode

OR

• Initial ATT mode

OR

• shutdown cycle

What is indicated by a white flashing ALIGN light on the IRS panel? (3)

Alignment cannot be completed due to:

• Significant difference between previous and entered positions

• Unreasonable present position entry

• No present position entry

What does an illuminated FAULT light on the IRS panel indicate?

System fault affecting related IRS ATT and/or NAV modes

What does the illumination of an ON DC light on the IRS panel indicate?

IRS operating on DC power from switched hot battery bus

How long can the right IRS operate without AC electrical power?

5 Minutes

Backup DC power to right IRS automatically terminated if AC power is not restored within 5 minutes

How long does a full IRS alignment take?

5 to 17 minutes depending on aircraft latitude

What is Automatic Navigation Realignment (ANR) and when does it activate?

Performs complete realignment automatically

• ADIRUs still in the NAV mode

• Valid GPS data available

AND

• Fast realignment is initiated

• OR

• Aircraft parks and remains motionless for 7.5 to 15 minutes

What does the illumination of the ILS light on the IRS panel indicate?

• Failure of both ILS sensor units

• Illumination of ILS light during MASTER CAUTION recall indicates a single ILS sensor unit has failed

Do the FMCs operate independently?

YES

What components comprise the FMS? (5)

The Flight Management System (FMS) is comprised of the following components:

• Flight Management Computer System (FMCS)

• Autopilot/Flight Director System (AFDS)

• Autothrottle (A/T)

• Inertial Reference Systems (IRS)

• Global Positioning System (GPS)

Each of these components is an independent system, and each can be used independently or in various combinations

Where do the FMCs receive their inertial data from?

On-side ADIRU

If on-side ADIRU malfunctions or is in ATT or ALIGN mode, FMC uses data from off-side ADIRU

How is FMC position data calculated with the loss of GPS inputs?

When external position (GPS, radio navigation) updating is not available, the FMC uses the IRS position as reference. When the IRS is the only position reference, the FMC applies an automatic correction to the IRS position to determine the most probable FMC position

How is takeoff thrust reduced from maximum takeoff thrust?

Assumed temperature higher than actual temp

Where does the FMC receive fuel quantity information from?

• Fuel Quantity Indicating System (FQIS)

AND

• Engine

OR

• Manual entries on the MCDU

What are the sources of position data to the FMC?

IRS, GPS, and navigation radios

Which input has the highest-weighted priority for FMC position?

GPS

• What criteria must be met for LNAV to engage?

• Within 3 nm of the active route leg

OR

• Intercept heading of 90° or less

AND

• Intercept will occur before active waypoint

How is a VNAV descent path calculated by the FMC?

The descent path starts at the calculated T/D point and includes waypoint altitude restrictions. The path is based on:

• E/D point

• idle thrust

• speedbrakes retracted

• descent wind speed decreasing with decreasing altitude (or loadable winds)

• applicable target speed