A320F CFM Vs IAE

[C.M]

Hello.
There is a thought to acquire an A320 with IAE engines in my company which is using CFM only . We are investigating the implications of introducing an IAE version on all levels and I am tasked to deal with the implications from a pilot's point of view (including company manuals) . I have IAE experience from a few years ago but there is nothing like a community input to make a comprehensive list .So any input that you think is relevant to the matter is welcomed.
Thank you

PS: I don't have a clue why my company is looking into mixing IAE with CFM , it might be a leasing opportunity at the right price .

[tubby linton]

Start times are much longer on the IAE.
Continuous ignition automatically selected with flap extended.
I have also seen people new to the aircraft struggle to find the 1.05 epr rather than the 50% N1 on initial spool up.

[vilas]

In Feb 2015 I had posted the following:
CFM VS IAE Engines A320I find the following different characteristics between the two engine types.IAE engine takes longer to start than CFM.IAE engine as you open thrust for take off appears bit noisier than CFM.IAE has fan flutter that is why there is KEEP OUT ZONE between certain RPM when applying take off thrust while there is no such thing in CFM.IAE engine for circling approach OEI and flap3 is seven tons more weight restricted than CFM for circling.IAE engine aircraft have Flap full with flaps at 40 while CFM engine aircraft have flap full with flaps at 35. I don't know is it because engines size or shape.The question is with all this why would anybody want an IAE engine? Fuel efficiency may come to mind but these days nobody will buy fuel inefficient engine so they must be evenly matched. Is it price or any other advantage which overrides all this?

[C.M]

Thank you , you have made some very good points .

[C.M]

Vilas do you have some sort of a side by side comparison of performance tables ? I need to compile more official information . I would really appreciate it

[FlightDetent]

a) Ask your boss to get the FCOM for that particular MSN.
b) Print out and compare the ENG sections of DSC & ABN.
c) Done. Do not worry about missing something, the relevant stuff is up there in vilas' post.

You will need to append OM-D with the familiarization training and pilot knowledge review. The comparison from B) should be enough, embedded into your company's standard PowerPoint templates.

Pilots who did not fly the IAE before will have something to talk about and keep themselves occupied for about a year. Carefully collect their experiences and griefs to fortify those briefing notes.
i) there's something called N1 mode. The first one to use it will be completely perplexed.
ii) flying unreliable airspeed with N1 tables is busy work, the doughnuts are sorely missing.
iii) there are different limits on starter engagement/cycles. Also what is and what is not a cycle is different. Don't let your guys paint themselves into a corner or do something very costly.
iv) cross wind take-off procedure is slightly different
v) ice shedding is required after 3 mins IIRC, which is a real pain.
vi) you will love SETI with these.
vii) the oil quantities before flight are different, QT/h.
viii) it is very conducive to overthink (a different) flare and landing technique. More often than not it is the mind playing the bad tricks, not the engines' residual thrust (or lack of)

For WRIGHT BROTHERS SAKE - make sure EVERYONE knows how to spot an open cowling!!! (no, you definitely do not need to crawl for that).

[Fursty Ferret]

When my previous employer acquired a pair of IAE aircraft on a temporary basis I seem to recall that we were just sent an email with a list of differences and then set loose.

No issues of note. Bigger headache was the Thales FMGC.

[Rt Hon Jim Hacker MP]

The A321 with IAE needs very little power on the ground. Just release the brakes and off you go.

[C.M]

a) Ask your boss to get the FCOM for that particular MSN.

As a company we dont have it ( I guess ) because its an initial thought of getting one . Its mostly A320 CFM I wanted , to compare with A320 IAE which I flew some years ago and i have the manuals (I'm flying only 319s CFM the past 4 years ) .But I dug up some manuals from a company I worked as contractor for some time and found all variants needed .

[Silvio Pettirossi]

My experience flying both CFM and IAE powered A320:

- As said before, engine starts on the CFM are way faster

- Residual thrust is higher on the IAE either in ground or in flight idle. It just starts rolling when you relese the brakes and floats a bit more after retarding the thrust levers. Thrust control for taxi is also more linear and smoother on the IAE

- While its a bit easier to set the stabilization 50% N1 on the CFM than the 1.05 EPR on the IAE, in my experience, the IAEs generaly spool up nicely equal, while on the CFM powered ones, one engine seems to always hang quite a bid behind the other one at first spool up.

-Low down, the CFM feels a bit more powerful than the IAE, but up high, lets say above FL250, the IAE has noticeably more thrust reserve left beyond the cruise setting.

Personaly, my favorite is the Pratt on the NEO, lots of power and very silent!