Engine Systems Flashcards
What is the time limit for TOGA?
5min or 10min OEI
When is the Fuel used indicator reset?
1st start Master switch on
What start faults does the FADEC protect against?
Hot, Hung, Stall, Failed light up and TL not idle.
What will the FADEC do if Start Fault
FAULT on
Turns off Fuel and Ign
Dry crank for 30sec at max motor
What will happen if residual EGT above 250deg?
Will do an auto dry crank during start. To get below 250deg
How does FADEC start an engine in the air?
Will decide whether enough windmiling or needs assistance.
What happens during a Auto Start procedure?
Master switch on, Start Valve open IGN 30 sec after (immediately in air) Fuel HP 30sec after Master on N2 rise Oil PX IGN FF EGT EPR
What are the normal indications after start?
2-4-6
N1 20%
EGT 400deg
N2 60%
What N2 will start valve close?
43%
What are the three Idle modes?
Reverse, Approach and Modulated. Reverse Idle is slightly higher than forward reverse thrust.
What is the lowest speed with full reverse?
70kts
What is modulated Idle and when is it selected?
Regulated Idle according to bleed system and ambient conditions. In air with flaps lever at zero. On ground if no reverse.
What is Approach Idle and when is it selected?
Regulated according to altitude and not bleed demand. Selected when flap lever not zero. Allows a quicker spool up time.
What are the two FADEC modes?
EPR and N1
When will it go to N1 mode?
Manually or when EPR not sensed by failure of P2 and/or P5 sensors. Will also go to degraded N1 with Emergency Elec Config
What is the difference between EPR and N1 rated?
Thrust is set to N1 rather than EPR
What is degraded N1 mode?
Basically you wont have any protections for N1 limit.
What do you loose with N1 mode?
Autothrust and A Floor protection.
How do you change from FLX to MCT?
Go out to TOGA or CL then back to FLX/MCT.
Which IGN are used during Start?
Alternates during first automatic start. Both in Manual start. Cut out at 43%. Both IGN in the air.
How do you turn on Continuous IGN after a start?
Start switch back to Norm then Start/IGN.
What is a windmiling quick relight?
If you accidently switch a master off in flight, if within an envelope it will try an auto restart.
When FADEC aborts the start how long is the dry cranking sequence?
30sec
In an Automatic start, what will happen if you forget to set the master switch to on?
After 30sec the Pack Valves will open.
