MatzeH84

AFE power settings

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From what I have seen during my first flights, the AFE adjusts the different power settings using manifold pressure and RPM.

However, a setting with a fixed manifold pressure doesn't account for temperature and density correction. On a cold day one could exceed the maximum BMEP easily with a standard setting, while on a hot day the rated power would require more throttle.

So.. does the AFE take BMEP into consideration?

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I don't know.  I do know that the RPM/MP settings came from DC6 pilots and are what their companies use.  I'm trying to digest what you said about BMEP and temperature, I understand cooler dryer air has higher density therefore you have more the potential for more power at a given RPM/MP if the fuel air ration mixture is properly compensated. That is where things get complicated and I can't follow you.  Add the fact that we are crunching the air together at much higher than std atmos pressures and I think the temperature/density concerns have dissipated.  Regardless of the ability to distill what you suggest I guess the answer is no.  Some real world operators rely on MP.

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13 hours ago, MatzeH84 said:

From what I have seen during my first flights, the AFE adjusts the different power settings using manifold pressure and RPM.

However, a setting with a fixed manifold pressure doesn't account for temperature and density correction. On a cold day one could exceed the maximum BMEP easily with a standard setting, while on a hot day the rated power would require more throttle.

So.. does the AFE take BMEP into consideration?

An easy way to test this is to drop the temperature in the sim and do a takeoff.  Can you do that and report what happens?  I know on the A2A connie, that is a problem you have to be aware of.  Maybe there is too much of a spread on the DC-6 to ever reach that point.  I can't say I've noticed.  I flew the XP version in the winter conditions but have not done it with the FSX version yet.

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These days talking to the FE's on Everts 6 fleet(the largest operator of DC-6's in the world) the BMEP is really only used for engine failure identification and negative prop load ie to low a power setting. To low a power setting ie a zero BMEP can result in the prop driving the reduction gearbox and issues with metal chipping of the gears as teeth are put under load in the wrong direction.

They fly exclusively MP and RPM.

 

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This is interesting, thanks for the info! If you have the chance, maybe you could ask about some more details why they do not correct for rated BMEP? Just to understand what's behind..

I will do some tests on different temperatures and see what it looks like.

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