Fuel system

Question 1

the changeover from series to parallel to series is controlled by what

Answer 1

rpm switches in the speed sense control

and paralleling valve in the pump

Question 2

when to use paralleling mode

what is the output

Answer 2

virtually doubling the output from the pump cluster

necessary during engine startup as the rpm is low and output from the pumps significantly reduced

Question 3

fuel pump output pressure is sensed at

Answer 3

fcu fuel inlet
bypass valve
high pressure relief valve
metering valve

Question 4

purpose of the metering valve

Answer 4

schedules a fuel output of 120% of the engines actual requirement for any given engine condition

Question 5

purpose of the pressurizing valve

Answer 5

prevents fuel flow reaching the fcu fuel shut off valve until adequate pressure has built up within the fcu to correctly position the 2 servos

Question 6

electrical means of shutting down the fuel shut off valve

Answer 6

1) fuel and ignition switch off
2) press feather button
3) pull e handle
4) auto feather activated

Question 7

servo pressure regulating valve provides a constant 100psi pressure for operation of

Answer 7

1) speed servo system

2) compressor inlet pressure servo

Question 8

what is the purpose of the speed servo system

Answer 8

provide a continuously increasing supply of fuel from 0 to 92% rpm for fast, smooth acceleration without inducing a compressor surge or stall

Question 9

what does the compressor inlet pressure servo system do

Answer 9

automatically varies the fuel flow for changes in air intake pressures

Question 10

purpose of the overspeed governor

Answer 10

1) provide overspeed protection in the flight range in event of prop governor failure
2) provide overspeed protection in the ground range
3) govern rpm when low rpm is selected

Question 11

the governor reset device is used to

Answer 11

reduce engine rpm from 100%-72% for

1) noise
2) conserve fuel
3) reduce engine carcass temperature prior to shutdown. minimize coking

Question 12

what cam takes over fuel flow from 92%rpm and above

Answer 12

part throttle setting cam

Question 13

specific requirements of a TD system

Answer 13

• provide overtemp protection during start and acceleration
• scheduled TIT in normal operating range
• automatically compensate for tolerances and wear
• permit use of fuels with different calorific value

Question 14

TD system provides its functions depending on

Answer 14

td control switch position
engine rpm
power lever position

Question 15

4 adjustable potentiometers

Answer 15

start pot
normal
slope
bias

Question 16

sub modes of td system modes of operation

Answer 16

temp limiting
1-start limitin
2- normal limiting

temp controlling

Question 17

engine co ordinator inputs :

to the:

Answer 17

e handle, power lever

to the fcu, prop, td system

Question 18

major components of the fuel flow system are

Answer 18

fuel flow transmitter

fuel flow indicator

Question 19

when will a ff transmitter be drainined

Answer 19

receipt of a new engine prior to first ground run

when qec pressure fuel line disconnected