Beta Backup And Lockout

Question 1

When and why does the beta Backup system activate

Answer 1

If a PCU malfunctions, the beta activated to prevent the Prop entering the ground beta range

Question 2

How does the Beta Backup system work?

Answer 2

If the Prop enters the ground range with power levers in flight range, a beta back up signal supplied by the low blade angle switch serves a signal to the feathering solenoid valve which dumps metered oil pressure driving the blade towards coarse (feather)

Question 3

What indication will crew get if the beta backup protection is continually activated?

Answer 3

Cycling of the propeller ground range light

Question 4

What is the beta lockout system designed to prevent

Answer 4

Prevent the propeller from entering the ground beta range in flight if power levers are brought below flight idle during flight

Question 5

What is the beta lockout system comprised of?

Answer 5

Beta warning horn
Revised beta Backup enable logic
Re worked NP rpm guage that incorporates an NP threshold trigger
Automatic engine ECU MANUAL reversion logic
Automatic engine igniter activation logic

Question 6

What happens when the beta lockout system is activated?

Answer 6

Warning horn sounds
Reversion to manual on affected ECU
NP trigger activated (NP >1000rpm) this creates a signal for the prob blade to be coarsened (using the same feathering solenoid at the beta backup system)
Engine ignition automatically activated for approx 60sec

Question 7

What happens when the beta lockout system is activated?

Answer 7

Warning horn sounds
Reversion to manual on affected ECU
NP trigger activated (NP >1000rpm) this creates a signal for the prob blade to be coarsened (using the same feathering solenoid at the beta backup system)
Engine ignition automatically activated for approx 60sec