Question regarding Stall Margin for IAE engine on A320
The chief pilot from our airline just returned from a conference by IAE. The big issue surrounding IAE engine in 2018 were incidents of frequent engine surge during idle descent at low altitudes (around 5,000 ft) many of them unrecoverable. I guess pretty dangerous situation to deal with and unfortunately very frequently happening.
Well, they have disseminated advanced copy of new page that will be inserted in the new edition of FCOM as always. AIRBUS is known for their frequent updates of their books, which doesn't bother me. So, they now want us to turn on engine anti-ice below 10,000ft in order to improve stall margin (I'm guessing this means to increase stall margin), especially when the A/C has its packs or bleeds off for any reason (For instance, the MEL may have O procedure that requires the crew to have them off)
I could just procedurally understand this and apply it in real life, that's easy. But I want to get a little deeper technically and scientifically with the help of smart people in aviation because I just can't seem to understand.
As far as I understand, for IAE engines, it pulls hot air bleed from the 7th stage to use as engine anti-ice. So pulling bleed out of its 7th HPC stage at Let's SAY idle open descent phase of the flight going into our destination, how is turning on the engine anti ice going to help increase stall margin so that we won't run into situations of engine surge/stall where we may have to land with only one engine operative.
Please explain it in both laymans term and professional term, your help would be greatly appreciated guys. Thanks.
AJE from KOREA