Engines - Overview, EICAS Indications, EEC

Question 1

The 777 is powered by ?

Answer 1

2 General Electric GE90-115B series engines

Question 2

Each engine is rated at ?

Answer 2

115,540 lbs of t/o thrust

Question 3

What kind of turbofans are the engines?

Answer 3

Dual rotor axial flow turbofans of high compression & high bypass ratio

Question 4

What drives the N2 rotor during engine start?

Answer 4

A bleed air powered starter motor

Question 5

The N2 rotor drives the ?

Answer 5

Engine accessory gearbox

Question 6

Each engine is equipped with a ………… actuated fan air thrust reverser

Answer 6

Hydraulically

Question 7

What are the primary engine indications?

Answer 7

N1 & EGT

Question 8

Engine power is set by ?

Answer 8

N1 in RPM percentage

Question 9

EGT is displayed in ?

Answer 9

Degrees Celsius

Question 10

EGT Amber band exceedance’s are inhibited during ?

Answer 10

T/O & GA

Question 11

Each engine is monitored & controlled by a ?

Answer 11

Dual channel electronic engine controller (EEC)

Question 12

What do the EEC’s do?

Answer 12

Receive input from the thrust levers to control the engines

Question 13

EEC Normal mode, how does it work?

Answer 13

Thrust is based on thrust lever position.

The EEC commands the fuel metering unit to adjust fuel flow until actual N1 equals commanded N1

Question 14

N1 limit protection (EEC NM)

Answer 14

At the full forward position, thrust limit protection allows full rated thrust without exceeding the max thrust limit.

Question 15

EEC Normal Mode protections?

Answer 15

N1 limit protection
Over speed protection (N1 & N2 rpm)

Question 16

EEC Idle Modes ?

Answer 16

Minimum Idle & Approach idle

Question 17

Approach Idle is a higher thrust setting than Minimum Idle, why would we want that?

Answer 17

Decreases acceleration time for a GA

Question 18

Approach Idle automatically set in flight if:

Answer 18

1. Engine anti-ice on
2. Flaps commanded to 25 or greater
3. C1/C2 hydraulic pump is inop AND flaps out of UP
4. Opposite engine bleed air valve is closed.

Question 19

EEC ‘soft Alternate mode’ ?

Answer 19

Alternate mode selected automatically, switch remains in NORM.

Selecting the mode manually is referred to as the ‘hard alternate mode’

Question 20

Is there thrust limit protection in ‘soft’ or ‘hard’ alternate modes?

Answer 20

No.

Auto throttles should be disengaged & thrust should be reduced.

Question 21

What happens to thrust in ‘soft alternate mode’?

Answer 21

No thrust change

Question 22

Soft alternative & hard alternate EEC modes have what protections?

Answer 22

Thrust reference & overspeed protection but NO thrust limit protection