I think I understand that de-rates are used to reduce the power of the engines on takeoff/during climb to reduce the strain placed on them when full power is not needed.I wasn't aware bump was available on smaller planes but watching the recent AOA video it seems otherwise. Am I right in thinking that, in simple terms, bump simply gives a bit more power if needed? Are there any real world examples people can think of where you would use bump? Are there any limitations on it's use?ThanksNick

I think I understand that de-rates are used to reduce the power of the engines on takeoff/during climb to reduce the strain placed on them when full power is not needed.I wasn't aware bump was available on smaller planes but watching the recent AOA video it seems otherwise. Am I right in thinking that, in simple terms, bump simply gives a bit more power if needed? Are there any real world examples people can think of where you would use bump? Are there any limitations on it's use?ThanksNick

I guess its something like this =)Copied from airliners.net "It is not a derate or flex. It is EXTRA power.100% power is usually TOGA but............On V2500 engines if performance neccessitates you can select BUMP thrust to give you a little extra power that is higher than the normal TOGA power setting.It is armed by pressing a red button found at the back of the thrust levers after both engines start only on V2500 powered aeroplanes. There is no varying the power. It is a set thrust rating.It is not the preferred method of getting away because it really wears the engine down a lot and one BUMP take off costs roughly the same as 7 TOGA take off'sIt's essentially a turbo button "Seems like some of the CFM engines have it too now.

That description above is regarding the A32x series. I was unaware the 737 had bump, but it appears so, and it appears to be a selection from the Fmc. Another question, as I understand it Bump thrust increases engine wear, so will it be more likely to have an engine failure overtime if you continuously use the bump option??

Sounds a bit like Overboost on the MD-11, except the MD-11 has a overboost bar on the throttles which you can push passed if it is required.I used it once in FSX (PMDG MD-11) leaving Bermuda island when I suddenly got very choppy winds as I was taking off in a thunderstorm, I was beyond V1 but the winds shifted quickly, I thought I was never going to safely depart the ground but overboost helped.

Yes bump thust is extra power BUT it has to be selected BEFORE you take off. It isnt just "There" when you need it. We use it every now and then coming out f places like Maui heading back to Vancouver. And yes, it is hard on the engine. But going off the end of the runway into the weeds is harder on it.JackColwill