Flight Managment, Navigation Flashcards
How many GPS receivers are installed?
Two. Left and Right.
Are IRS outputs independent of external navigation aids?
IRS outputs are independent of external navigation aids.
What is indicated by an ALIGN (white) light (steady) on the IRS panel?
- When operating in either the:
o ALIGN mode
o Initial ATT mode, or
o Shutdown cycle.
What is indicated by a flashing ALIGN (white) light on the IRS panel?
- Significant difference between previous and entered positions or an unreasonable present position entry, or
- no present position entry.
What does an illuminated FAULT (amber) light on the IRS panel indicate?
A system fault affecting the related IRS ATT and/or NAV modes has been detected.
What does the illumination of an ON DC (amber) light on the IRS panel indicate?
The related IRS is operating on DC power from the switched hot battery bus (AC power not normal). If this occurs while the aircraft is on the ground, the call horn in the nose wheel sounds, providing an alert that a battery drain condition exists.
How long can the right IRS operate without AC electrical power?
- With the loss of AC power, the IRS switches to the Switched Hot Battery Bus.
o Back up DC power to the right IRS is terminated after five minutes.
o Two fully charged batteries have sufficient capacity to provide standby power to the left IRS for a minimum of 60 minutes.
How long does a full IRS alignment take?
5-17 minutes.
What is Automatic Navigation Realignment (ANR) and when does it activate?
- When a fast realignment is initiated or the aircraft parks after a flight and remains motionless for at least 7.5 to 15 minutes with the ADIRU’s still in NAV mode and valid GPS data available, the ANR mode will perform a complete realignment automatically.
- To prevent an ANR, pilots should perform an initial full IRS alignment (MSU to OFF, then to NAV).
What does illumination of the ILS (amber) light on the IRS panel indicate?
- Indicates a failure of both ILS sensor units.
- Illumination of the ILS (amber) light during a Master Caution Recall indicates a single ILS sensor has failed.
Do the FMC’s operate independently?
- The right FMC operates in synchronization with the left FMC.
- yes.
Where do the FMC’s receive their inertial data from?
Usually, the FMC’s receive inertial data from their on-side ADIRU. If the on-side ADIRU malfunctions or it is in the ATT or ALIGN mode, the FMC uses the data from the other 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 a 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?
- Via an ACARS message to the N1 page.
- alternately, the pilot can input Thrust setting and assumed temperature on the N1 page.
Where does the FMC receive fuel quantity information from?
- The FMC receives fuel quantity data from the Fuel Quantity Indicating System (FQIS) and from the engine or from manual entries into the MCDU.
- The fuel quantity source is selected on PROG 5/5 page. Selections include TOTALIZER (default) and CALCULATED.
