A320 SFCC/Flap SYS 1 FAULT

[m-dot]

Hi MCDU button pushers

ECAM and FCOM indicate : ENG 1 APPR IDLE ONLY with SFCC Flap SYS 1 Fault.

Trying to understand why this is so. Any help greatly appreciated

[LEVEL600]

Hi, not MCDU button pusher, at least not in flight but with SFCC1(2) faulty EIU for affected engine lose information about flap lever position. In such case Fadec commands APPROACH idle for all air phases of flight instead of MODULATED idle. Not sure how it works on ground, but I expect normal modulating idle.

[m-dot]

EIU

Thanks Level.

Care to postulate a theory as to why a manufacturer would want a higher Idle in the case of a Flap fault? (Trying to figure out airbus philosophy is probably stupid but I'm trying to think of a plausible reason)

[Goldenrivett]

Care to postulate a theory as to why a manufacturer would want a higher Idle in the case of a Flap fault?

If the system doesn't know whether the flaps are in or out, then the safest minimum power is Approach Idle.
"Allows the engine to accelerate rapidly from idle to go-around thrust"
FCOM 70-40-40 Idle Control.

[m-dot]

Ahaaaa

Thanks Golden rivet. That makes perfect sense. After 7 years of flying this bucket I'm still learning new tricks (in fact maybe I learnt it years ago and memory dumped it for something else!)

[m-dot]

Also rivet I just had a look in our FCOM (IAE) and there's no 70-40-40! Subsequently found the CFM via google. Bloody airbus!

[Nightstop]

Not sure how it works on ground, but I expect normal modulating idle

FWIW I've had a LGCIU fault which resulted in one engine at APPR IDLE on the ground when the flaps were extended. Made taxying interesting

[LEVEL600]

Thanks for experience,Nightstop.
Yes, LGCU-air/gnd issues can make your day hard...I am trying not to dispatch aircrafts under LGCIU MEL for years, just for my personal safety