Master Warnings

Question 1

L FUEL PRES LO R FUEL PRES LO Trigger? Possible Causes? Drill?

Answer 1

Trigger: Pressure Sensed in the Collector Tank fuel line is <10PSI Failure of Engine Driven low pressure fuel pump

Note: Engine driven low pressure pump is installed on the same drive shaft the 2 external oil scavenger pumps. Monitor oil temp/pressure after illumination of this annuciator

Question 2

CABIN ALT HI

Answer 2

Trigger: Cabin Altitude pressure sensed at >5.25+/- 0.15 PSI

Possible Causes: Cabin Altitude exceeds 10,000ft

Note: Sensor activates at 9500’ to 10000’ when cabin altitude is climbing and deactivated at a maximum of 8,500’ when the cabin altitude is high

Question 3

CABIN DIFF HI

Answer 3

Trigger: Cabin differential pressure sensed at > 5.25 ± 0.15 PSI

Possible cause: Cabin differential pressure high

Note: Nominal cabin pressure is 5.0 ± 0.1 PSI and overpressure relief valve (Poppet) activates at 5.1 PSI

Question 4

L OIL PRES LO R OIL PRES LO

Answer 4

Trigger: Oil pressure sensed at < 60 PSI

Possible cause: Oil pressure failure

Note: The L/R OIL PRES LO annunciators and oil pressure gauge receive their data from separate sensors; both should to be used to confirm a problem.

Question 5

L ENVIRO FAIL R ENVIRO FAIL

Answer 5

Trigger: Disagreement between switch position and valve position or valve is not powered

Possible cause: Environment air duct over pressure (Activates at > 44 ± 1 PSI) and/or over temperature (Activates at > 500 ˚F ± 10˚F)

Note: Nominal air duct pressure of 37 ± 3 PSI and temperature of 450˚F ± 25˚F. Both annunciators also illuminate as part of the T-Test system check. Note: The L ENVIRO FAIL annunciator will illuminate whenever the left generator bus is unpowered.

Question 6

CABIN DOOR

Answer 6

Trigger: Any of the 5 internal microswitches is indicating that the door is NOT secure.

Possible cause: Cabin door open or not secure

Note: The 5 microswitches are: 2x cam lock latches, 1x doorsill, 2x handle latches

Question 7

CARGO DOOR

Answer 7

Trigger: Any of the 5 internal microswitches is indicating that the door is NOT secure.

Possible cause: Cargo door open or not secure

Note: The 5 microswitches are: 2x cam lock latches, 1x doorsill, 1x handle latch, 1x latch pin

Question 8

L BL AIR FAIL R BL AIR FAIL

Answer 8

Trigger: 18 PSI not sensed

Possible cause: Melted or failed bleed air failure warning line or system off

Note: Nominal pressure in warning line (EVA tubing) is 17.5 – 19.0 PSI. Both annunciators also illuminate if both ENVIRO switches are placed in the INST & ENVIRO OFF position.

Question 9

L AC BUS R AC BUS

Answer 9

Trigger: The 115v AC Bus is unpowered

Possible cause: AC Bus has an inoperative inverter or either 115v bus or 26v bus has a short

Note: When the L/R 115v AC Bus is unpowered the same side 26v AC Bus is unpowered. Either annunciator will also illuminate when the respective AC Bus switch is turned off.

Question 10

A/P TRIM FAIL (If Autopilot Installed)

Answer 10

Trigger: Autopilot trim servo has reached its maximum operational limit

Possible cause: Improper trim or no trim from autopilot trim command

Note: Pilot flying should hold yoke with both hands for autopilot disconnect as force required to maintain the aircraft’s attitude may be higher than normal.

Question 11

A/P DISC (If Autopilot Installed)

Answer 11

Trigger: Autopilot data computer failure

Possible cause: Autopilot is disconnected by means other than pilot’s switch

Note: Crew may re-engage autopilot after selecting the opposite computer. However, the pilot flying must be on the same side as the autopilot data computer being used.