AirbusPTC

A quick question about the CFM56 5B engine anti-ice system. Every aircraft I have ever flown has automatically turned on engine ignition when selecting Engine Anti-ice. According to my companies manuals this is NOT the case with the CFM56-5B engine (see below). My question is this, why does this engine model NOT need engine ignition "on" as a safety precaution against flame-out during anti-ice operation?

Topics of Interest:
A321: Considerations (Part 1) pg. 26

Engine Anti-Ice:
• When selected will not automatically turn “on” ignition.
• Do not expect “Ignition” message on ECAM when EAI is selected.

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Volume II, Ice and Rain Protection
Engine Anti-ice
pg. 30.30.3

(A321) There is no continuous ignition selected when the ENG ANTI ICE pb is selected ON.
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Thanks,
AirbusPTC

BoilerUP

Is it that hard to simply select Continuous Relight before turning the carb heats on?

AirbusPTC

?

Um no...but that's NOT the procedure. Apparently NO ignition is required when using A/I on the A321 (CFM56 B3) engines. I am trying to ascertain the reason why.

Thanks for your input though...geez.

BoilerUP

Based on what you posted, selecting EAI on doesn’t *automatically* turn on continuous ignition.

Nowhere in OP does anything say that Continuous isn’t required - only that it isn’t automatic.

Of course I don’t know what your manuals say...

AirbusPTC

I guessed you missed the sentence, "My question is this, why does this engine model NOT need engine ignition "on" as a safety precaution against flame-out during anti-ice operation?"

tomgoodman

An old DC-9 ground school instructor once asked: “What’s the difference between the A and B ignition switch positions?”
After declaring all of our answers wrong, he said: “There’s no difference. We re-wired the system to fire all igniters in either position, for a softer light-off and extended burner can life. Never bothered to change the book, though.....”

rickair7777

Not required on any A32X series. Unless it's automatic with no indications and they didn't bother to tell us. That could happen.

joepilot

The engine continuous ignition on the 727 was "automatic" in the sense that the Flight Engineer "automatically" reached up to the overhead panel and turned on the ignition switches whenever the anti-ice was selected on, and turned them off when no longer needed.

Joe

450knotOffice

My airline runs a mixed fleet of CFM and IAE powered Airbusses. Interestingy, the IAE powered airplanes DO automatically turn on Continuous ignition and present an IGNITION memo on the ECAM.

My guess is that CFM International has simply proven to the powers that be that the engine doesn't normally need ignition to be on in icing conditions.

dera

Out of curiosity, are they also mixed up with EPR vs. N1? So IAE shows EPR, CFM N1?