Powerplant

Question 1

What type of engines does the S-76C++ have?

Answer 1

Arriel 2S2

Question 2

How are the DECUs powered?

Answer 2

A dedicated alternator when the N1 speed is greater than 60%, below that they are powered by the DC essential bus.

Question 3

What are the DECU inputs?

Answer 3

Engine control quadrant
Collective position sensor
Ambient pressure and temp sensors
Engine pressure and temp sensors
N1 & N2 sensors
The other DECU

Question 4

Describe Soft Limiter Logic.

Answer 4

Allows minor transient excursion in N1 to 100.5% to maintain 107% Nr.

Immediately begins to decrease N1 0.1% per second back to 100% limit.

Reset at 99.9% N1.

Question 5

Describe Ramping Function.

Answer 5

Allows an additional 1% TQ for each 1% droop in Nr below 106% up to 105% TQ which is reached at 101% Nr.

Question 6

Describe Blowaway.

Answer 6

Latched when a slow to moderate Nr decay to 100% or excessive rate of 5% per sec or more at 104% Nr or less.

Allows 2-min OEI limit of 100.5% N1 or 115% TQ, whichever overs first.

Reset over 10 sec interval when Nr is restored to above 106%.

Records 2-min N1 usage, if any.