Oeb 197/1 (cfm56)

[TO MEMO]

I believe most of you have read this OEB already! that`s the latest red OEB about Eng stall. It says applicable to Engines with EGT margin deterioration greater than 75ºC.

My question is, how to you set that value?

[nnc0]

Set the value?

I didn't give the OEB much though as a survey of our engines indicate the margins were well above our actual margins and with an eye on efficiency, well above anything we would have let the engines approach before addressing.

Still though, from what I recall - there's nothing to set.

The margins are monitored by your engine folks. Engines come out of overhaul and operate at a certain EGT specific to the conditions. Over time, as the engines wear/age, the EGT for the same conditions increase to the point where you get to the EGT margin deterioration mentioned in the OEB.

The only action I see would be for your engine folks to advise crews which engines are susceptible to the problem.

[Ditsche]

Hi Guys,

There have been an OIT from AI in December 2008. Only maintenance with the readings fresh after release of engines from the shop is able to determine the actual degration. This OEB creates a lot of confusions.

Ditsche

[TO MEMO]

nnc0,

Thanks! Got the chance to talk with the engines guys...
They came up with the same explanation you did!

Thanks