Section XI - Flight Management, Navigation

Question 1

Approximately how long does it take to accomplish a normal IRS alignment? How long does it take for a high latitude alignment?

Answer 1

Approximately 10 minutes for normal; minimum of 17 minutes for high latitude.

Question 2

What is the significance of the following lights on the IRS panel?

Answer 2

1. ALIGN (flashing):
   a. No Present Position
   b. Unreasonable Position
   c. Significant difference between previous and entered positions.
2. ALIGN (steady):
   a. The IRS is operating in the ALIGN mode, the initial ATT mode, or the shutdown cycle.
3. ON DC: Normal AC power for the related IRS has failed and the IRS is operating on DC backup power from the hot battery bus.
4. DC FAIL: DC backup power for the related IRS has failed. IF the other lights are extinguished, the IRS is operating normally on AC power.
5. FAULT: A system fault is affecting the related IRS ATT and/or NAV modes has been detected.

Question 3

What information does the Inertial Reference System provide?

Answer 3

1. Calculates airplane position
2. Acceleration
3. Track
4. Vertical speed
5. Ground speed
6. True and magnetic Heading
7. Wind speed and direction.

Question 4

What is the range of degrees latitude in which Magnetic reference is available with respect to the IRS?

Answer 4

Magnetic reference is provided between:

73 degrees north and
60 degrees south latitude.

Above these latitudes only TRUE HEADINGS are available.

Question 5

What is the normal power source for the Inertial Reference System (IRS)?

Answer 5

AC power from the left and right electrical systems.

*The main battery (via the hot battery bus / standby power system) is used as an alternate power source. Power to the right IRS is limited to 5 minutes to save battery power.

Question 6

How could one obtain attitude information in the event an IRS alignment error were to occur in flight?

Answer 6

Attitude information can be obtained by moving the selector to the (ATT) position. The IRU enters the Align mode for 30 seconds which the airplane should stay in straight and level flight. This re-levels the system and provides an attitude reference.

Question 7

How many ATC transponders are installed?

Answer 7

There are two ATC transponders are installed.

They are controlled by a single control panel and provide normal transponder functions and altitude reporting.

Question 8

. T/F: If electrical power is interrupted and returns to a Flight Management Computer, it is not necessary to re-enter aircraft performance data on the PERF INIT page.

Answer 8

FALSE;
After the restart the performance data must be re-entered on the PERF INIT page. The route previously in use must be reactivated.

Question 9

What system is responsible for the management of the Autothrottle?

Answer 9

THRUST MANAGEMENT COMPUTER

Question 10

How many ILS receivers are installed?

Answer 10

Three ILS receivers are installed

Question 11

When must a full IRS alignment be accomplished ?

Answer 11

When the time from last full alignment exceeds 18 hours

Question 12

Which IRU would load shed on a aircraft with one HDG ? How about aircraft with no HDG installed ?

Answer 12

HDG installed:
The right IRU after 5 minutes.
No HDG installed:
The left and center and 5 minutes.