NATOPS Chapter 2 EDECU HSM-50 Flashcards
The DECU receives what inputs from the cockpit?
- ENGINE SPD TRIM
- CONTGCY PWR
- ENG OVERSPEED TEST A and B
DECU receives what input signals from helicopter?
- TQ from other DECU
- NP demand
- 400hz backup power
- HMU (LVDT)
DECU sends what signals to the cockpit?
- Torque
- Np
- TGT
- Contingency Power
Hot start prevention
When TGT hits 900C with NG below 60% and NP below 50%
The DECU trips the ODV to stop fuel flow.
FUEL flow is restored when TGT is below 300 or 25 seconds.
Overridden by holding the ENG OVRSPD test button during start.
What is Transient droop improvement?
The DECU increases fuel flow to the HMU when
collective demand is increased rapidly or
in the event of rapid NR decay.
It does this by anticipating signals from the NR sensor and the collective position
Auto-ignition system
After an NP overspeed (120%) and the NP is below 120 the ODV closes and the igniters come on for 5 seconds. This process will continue until NP is controlled.
Might cause yaw kicks during relight.
The DECU resets the ___ within acceptable engine limits to maintain __ governing while automatically limiting ___
HMU
Np
TGT
How is the DECU cooled?
Scavenge airflow from the IPS
Self test of hot start prevention
Np overspeed test
