DB's SY 737 Flight MGMT, NAV

Question 0

ALIGN light - illuminated (white)

Steady

Answer 0

The related IRS is operating in the ALIGN mode, initial mode, or the shutdown cycle

Question 1

GPS light - illuminated (Amber)

1. On recall
2. Illuminated

Answer 1

1. Failure of a single GPS sensor

2. Failure of both GPS sensors

Question 2

ALIGN light - illuminated (white)

Flashing

Answer 2

Alignment cannot be completed due to IRS detection of:
• significant difference between previous and entered positions or an unreasonable present position entry
• no present position entry

Question 3

ALIGN light - extinguished

Answer 3

1. IRS not in align mode
2. With mode selector in NAV, alignment complete and all IRS info is available
3. With mode selector in ATT, attitude info is available. Heading info is available following entry of initial magnetic heading.

Question 4

IRS Mode Selector Panel

FAULT light illuminated (Amber)

Answer 4

A related system fault has been detected

Question 5

IRS Mode Selector Panel

ON DC light - illuminated (Amber)

Answer 5

1. The related IRS is operating on DC power from switched hot battery bus (AC power not normal)
2. If on the ground, call horn from nose wheel well sounds to alert a battery drain condition exists
3. Momentary illumination is normal during alignment self-test

Question 6

IRS Mode Selector Panel

DC FAIL light - illuminated (Amber)

Answer 6

1. DC power for the related IRS is not normal

2. If the other lights are extinguished, the IRS is operating normally on AC power.

Question 7

How long does IRS alignment take?

Answer 7

Normally 5-17 minutes depending on airplane latitude (closer to poles is longer, closer to equator is shorter due to the speed you are actually rotating)