CFM LEAP (neo) Engine warm up time
 

On the CFM56 (CEO) engine we only need 2 min warm up time before setting takeoff power.

For the new CFM Leap (neo) engine we need 3 min warm up time if the engine is considered "hot". But for a cold engine we need at least 5 min for the adequate thermal stabilization.

My question is: anyone knows what is the definition of a cold engine or when de we consider the engine is "cold"? The CFM only says "Hot engine condition is usually stated when the engine has been stopped within less than 8 hours"...

Going by that logic, a cold engine is one that has been stopped for more than 8 hours.

Really don't think this is worth looking into too much, getting to grips with the non essentials. 2 minutes or 3 minutes doesn't matter, by the time you start do your checks and taxi 5 minutes would have passed anyway.

But for Single-engine taxi out, it’s good to know when to start the second engine.

Well, maybe 8 hours is understandable in southern Spain, but maybe it can be questionable in Montreal during wintertime... just saying.

It is a very simplistic way of see things. It depends on the airport you operate or if you perform SETO, etc.