Cowl flaps question regarding 182s

[Ted]

@Ted DuPuis

I’m retired from answering engine questions I’ve answered 500 times before.

 

[SkyDog58]

That's pretty much to be expected. Mostly because non-mandatory techniques vary among pilots.

Seriously... mandatory items seem to vary as well.

 

[midlifeflyer]

What does your POH/AFM say? Go by it. Mfg'r knows best due to thousands of hours of flt testing.

Are you talking about the testing that stopped 50 years ago?

 

[midlifeflyer]

Seriously... mandatory items seem to vary as well.

Unfortunately true.

 

[Steegie]

Are you talking about the testing that stopped 50 years ago?

Yes, 50 years ago. Have the results changed over time?

 

[midlifeflyer]

Yes, 50 years ago. Have the results changed over time?

No but understanding has, although I'm not sure what results those are - perhaps the same ones which led to recommending leaning the engine into what is now described by people much smarter than I as the "red box" and keeping it there for hours?

In this case, the concerns over "shock cooling" have been shown to be far less of a problem than the mythology would suggest. Whatever validity it might have when talking about a quick drop from cruise power to idle, dropping from 20-21"" to 12-15" and ultimately to idle for the descent from pattern to touchdown with the cowl flaps open isn't going to do much of anything according to the mechanics I know, while keeping them closed means one more item to look down at and take care of on a go-around.

 

[Steegie]

No but understanding has, although I'm not sure what results those are - perhaps the same ones which led to recommending leaning the engine into what is now described by people much smarter than I as the "red box" and keeping it there for hours?

In this case, the concerns over "shock cooling" have been shown to be far less of a problem than the mythology would suggest. Whatever validity it might have when talking about a quick drop from cruise power to idle, dropping from 20-21"" to 12-15" and ultimately to idle for the descent from pattern to touchdown with the cowl flaps open isn't going to do much of anything according to the mechanics I know, while keeping them closed means one more item to look down at and take care of on a go-around.

You can take the advice of some mechanics.....some you can not. Personally I don't take flight instruction from a mechanic. Use your own experience given the wx conditions in which you are flying.

 

[EdFred]

Yes, 50 years ago. Have the results changed over time?

stellar mechanics and formation haven't changed over billions of years, but our knowledge of them has.

 

[455 Bravo Uniform]

Amazing that no one has done back to back open vs closed temperature logging on descents and pattern to landing. Maybe that’s because it’s no factor? That’s my only theory.

Another would be a somewhat structured poll of owners and their practices vs top overhauls. Again, one would think someone might have done limited research and drawn some conclusion, valid or not.

 

[Sinistar]

So do it twice with closed?

Duh, was supposed to closed for first and 'open' for the second. Thanks for calling that out.

Amazing that no one has done back to back open vs closed temperature logging on descents and pattern to landing. Maybe that’s because it’s no factor? That’s my only theory.

Another would be a somewhat structured poll of owners and their practices vs top overhauls. Again, one would think someone might have done limited research and drawn some conclusion, valid or not.

No ****! With all these fancy engine monitors our there you think we'd have so much raw data we'd be sick of it. If/when we get a engine monitor I will do it. But it will probably be a necro thread at this rate