Cowl Flaps Question

form810 said:
Closed on approach. Open on Go-Around. Because: Amplitude of Heat.

If it's too hard to understand this and recall it at appropriate moments during the flight regime... Well then, I guess just avoid aviation and go back to whatever you do when you're not bungling up an aircraft and putting people or equipment at risk.

There's a checklist for both Approach/Landing and Go-Around. Like the two departures at SFO, BOTH of these checklists should be briefed BEFORE commencing the approach.
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So, in light of my "condescending" and/or fancy language responses, I'd just like to reiterate what I said in my initial response. You know, the response that engendered all the vitriol hurled upon me in this thread.

Here's the freaking A36 checklist:

cklist_pilot.indd

DESCENT

  1. Altimiter ..................................................................... SET

  3. Cowl Flaps ........................................................ CLOSED

  5. Power .............................................. REDUCE AS REQ’D

    to maintain below desired max KIASRPM first to 2000, then Throttle

  7. Mixture............................................. ENRICH AS REQ’Donly enough for smooth operation

  9. Engine Temperatures ...................................... MONITOR

  11. Flaps and Landing Gear ................................. AS REQ’D

    CRUISE - DESCENT


APPROACH

  2. Landing Light .............................................................. ON

  4. Fuel Selector Valve ...........................SEL FULLER TANK

  6. Power ....................................................... 17”, 2300 RPM

  8. Mixture....................................................... NO CHANGE

  10. Flaps ............................................................ APPROACH

  12. Airspeed............................................................ 110 KIAS

  14. Trim ........................................................................... SET

  16. Seat Belts and Shoulder Harnesses.................. FASTEN

  18. Seat backs ............................ POSITION FOR LANDING

  20. Writing Desk .....................................................STOWED

  22. Avionics .....................CONFIRM SET FOR APPROACH

    BEFORE LANDING


  2. Landing Gear ...........DOWN; VERIFY 3 GREEN LIGHTS

  4. Flaps ....................................................................... FULL

  6. Airspeed.............................................................. 90 KIAS

  8. Propeller .................................................... NO CHANGE

  10. Mixture....................................................... NO CHANGE

  12. Yaw Damp.................................................................OFF

BALKED LANDING / MISSED APPROACH


  2. Power .............................................................. MAXIMUM

  4. Pitch................................ EST CLIMB ATTITUDE 100 Up

  6. Positive Climb Rate.......................................ESTABLISH

  8. Flaps ........................................................................... UP

  10. Landing Gear .............................................................. UP

  12. Cowl Flaps ............................................................ OPEN

If all you haters troll accusers are as good at reading as you imply you are, perhaps you can understand what the manufacturer said in its A/C Ops checklist (despite that checklist's several linguistic errors).

I NEVER condescended. I just presented. If you HATE the fact that I know what I'm talking about without having to revert to a reference doc, well, you KNOW what you need to do, right?!?

I'm just here to help... or, apparently... to royally piss folks off! (yes, Clarissa, that IS a grammatical faux pas. Never end a sentence a preposition with!)

Haven't INTERNALIZED!?!

I think NOT. I think I've internalized this stuff so profoundly that it JUST. PISSES. YOU. OFF!!!
 
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I stand by that statement, STEVE.

If you consider that to be condescending, that's your misfortune and NONE of my own.

But it's definitely the misfortune of your passengers!

If you can't even bother to read the checklist, Steve, then don't bother.

If you don't possess the capacity or education to understand the physics/logic behind the checklist, go do something else. PERIOD...

I'm OUT on this one!

I'm sure that makes you VERY happy. :)
 
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bimmerphile said:
leaving the gear down by accident on a go around will probably elevate CHTs more than leaving cowl flaps closed
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When I was a tower controller, the guy who put his gear up on a VFR go around was often the guy on final with the his gear up. I always leave my gear down (SEL) on a go around.

I like the idea of opening the cowl flaps on final. Why not?
 
Richman said:
Soooo, my take....

I don't think shock cooling is really that big a thing...I mean, what happens when you fly through rain? Talk about quenching. I'm all for not tormenting your engine unnecessarily, but this was one of those things I wasn't particularly religious about. I'm sure more than one person has packed it in by doing an unreasonable amount of fussing with the engine trying to keep it warm and not really paying attention to the flight path.
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I like everything you said Richman.

I agree, the shock cooling thing is way overblown, if it exists at all. To be clear, I don’t torture my io520 and don‘t find the need to shock cool.

However, I got my ME in 1978 when feathering an engine in training on the Lyco 540 was a common thing to do. We went takeoff power to feather (or simulated feather) as soon as the gear doors closed student after student. I worked there for three + years and never saw a wrench on the Aztec engines.

I guess flight schools don’t feather engines below 5’000 AGL anymore. Hell, we never got to 5,000 in ME training.
 
fholbert said:
I like everything you said Richman.

I agree, the shock cooling thing is way overblown, if it exists at all. To be clear, I don’t torture my io520 and don‘t find the need to shock cool.

However, I got my ME in 1978 when feathering an engine in training on the Lyco 540 was a common thing to do. We went takeoff power to feather (or simulated feather) as soon as the gear doors closed student after student. I worked there for three + years and never saw a wrench on the Aztec engines.

I guess flight schools don’t feather engines below 5’000 AGL anymore. Hell, we never got to 5,000 in ME training.
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I think there is a different dynamic going on there. If you ask me, most "legacy engines" are amazing in their longevity, durability and reparability. I know people like to bust on them, but there's a reason they haven't been replaced, or even really modified....they work, sometimes after sitting months, continue to work, and can be repaired, in place, with relatively little effort.

That said, the metallurgy is, eh, vintage. And if I'm being honest, isn't well understood by today's engineers. If the engines are left to sit, you get corrosion almost right away unless you have some funky oil additives like Camguard. You can't use better oil because of the lead in the fuel. Mobil tried once, and it cost them, dearly. That corrosion causes all sorts of "micro problems" that can come back to haunt you, and over time, they add up to bigger problems like abnormal cylinder wear, cam spalling and other "gateway" issues.

But back to the point. Flight school airplanes are run constantly. They leak, but who cares because when belch out oil, everything gets lubricated and there is a constant cycle of clean oil being introduced. They run, and are run hard, and that keeps them clean, from a wear standpoint. Corrosion has almost zero chance to get started. That adds up to an ideal wear situation, and I've seen engines go 3,000 hours plus with nothing more serious than a valve seat that needed to be honed (and if your A&P is legit, honed in place). Bottom ends, especially Continentals, will run almost forever under those circumstances.
 
fholbert said:
When I was a tower controller, the guy who put his gear up on a VFR go around was often the guy on final with the his gear up. I always leave my gear down (SEL) on a go around.

I like the idea of opening the cowl flaps on final. Why not?
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Because then you are a horrible pilot. :D

The shock cooling thing? Even if it exists, by the time you are on final you have already made significant power reductions. I always check the temp before opening, but, really, the risk of shock cooling by opening on final is the same as the risk of shock cooling when turning off the runway 30 seconds later per the manual.

this thread isn't about shock cooling or engine damage, it's about blind obedience instead of thought. The guy probably still leans to 50° ROP.
 
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MidlifeFlyer said:
this thread isn't about shock cooling or engine damage, it's about blind obedience instead of thought. The guy probably still leans to 50° ROP.
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Bingo. The hilarity being it comes from a guy who rails against people's inability to think for themselves.
 
MidlifeFlyer said:
The guy probably still leans to 50° ROP.
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That's pretty close to what the performance numbers in the book say to do in my airplane. But, like many airplane owners, I could care less about EGT and pay much closer attention to cylinder head temps. In airplanes that aren't mine, I do what the owner wants. Which I've never seen to be unreasonable.
 
drunkenbeagle said:
That's pretty close to what the performance numbers in the book say to do in my airplane. But, like many airplane owners, I could care less about EGT and pay much closer attention to cylinder head temps. In airplanes that aren't mine, I do what the owner wants. Which I've never seen to be unreasonable.
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In my idle time, I dabble in airline history, and I having been in GA for so long, I love GA history as well, where you can find it (not so easy). Google Books is a good place, since they have Flying Magazine back to 1926, but I look for other stuff as well. I have a set of ABC's Wide World of Flying, and those were "new" when I started flying the late 80's. I look back at stuff that was "new" like the amazeballs GEM engine monitor, where you could monitor all 6 EGTs/CHTs at once!

Sure, GPS was a game changer, but engine management is another biggie. Single point CHT, maybe single point EGT (but probably not). Just lean to roughness and richen a half turn. I'd bet a LOT of "problem" engines were simply cooked.
 
Ian_J said:
You idiots need to pay attention. When someone writes something IN ALL CAPS, you’d do well to listen. They mean business and know what they’re talking about.
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Not BAD advice. Still, by all means, carry on. Or, go strike for ONE week of work a month for $500k! Frankly, my dear, I don't really give a ... rat's ass.
 
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