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for a 182Q the POH specifies for maximum climb to use 2400 RPM and full power with given speeds (78 KIAS for Sea Level, reducing to 72 at FL100). It specifies that the mixture may be leaned at 5000ft or above.

In order to become the best possible parachute ops pilot I can be, I'd like to improve my best rate of climb. We've got CHT monitoring but I can't find good suggestions on how to lean for best power whilst keeping the mixture agreeable for the engine at max power using the cylinder head temps.

If somebody could point me to a reputable source I could use to learn more I'd be delighted.

Alternatively; what methods do you employ to improve the climb? Every minute is valuable for dense parachute ops.

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  • $\begingroup$ Sorry, I'll reword it to Parachute jumping. $\endgroup$ Jun 27, 2022 at 15:33
  • $\begingroup$ Leaning won’t change your power just your fuel consumption. Air is the limiting factor- you just need to make sure you have enough fuel to ensure all the air is used. $\endgroup$
    – Jim
    Jun 27, 2022 at 18:28
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    $\begingroup$ Don't you also lose a bit of power when the mixture gets too rich? In a C172 we start leaning at 3000 in a climb, and you usually see the RPM increase a tad. There we lean on the EGT until it just "comes back alive". $\endgroup$ Jun 27, 2022 at 18:31
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    $\begingroup$ @RobertDiGiovanni - Or even just getting a “climb” prop instead of the general-purpose stock one. $\endgroup$
    – Jim
    Jun 27, 2022 at 20:20
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    $\begingroup$ It's a 182, so it's a constant speed prop. $\endgroup$
    – John K
    Jun 27, 2022 at 21:02

1 Answer 1

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Don't bother will all that. Without a proper 6 channel Exhaust Gas Temperature gauge, and fuel injection, you can't hope to do any of that sort of anal-retentive leaning to the nth degree kind of stuff. The O-470-U is carbureted, so you can't get even mixtures in all cylinders in the first place and without an EGT, leaning by ear and manifold pressure is all you have.

Leave it rich to 5000 ft, then lean to onset of roughness + a bit of rich and just leave it. Watch the CHTs and if they climb out of the green, either speed up or enrich some more (assuming cowl flaps are fully open). You could futz around with the leaning to get to peak power, based on manifold pressure, but because it's declining as you climb you'd have to level off to do that, so it's not worth the trouble, although if you are listening carefully you might be able sense the best power sweet spot by playing with the mixture during the climb.

Focus more on being kind to the engine, which makes the owner happy, and planning your route during the climb to get to the level-off altitude, aligned on the proper ground track toward the Spot, with a minimum of screwing around, and that will make owner and the jumpers happy. You will save way more fuel and time by arriving at the Spot as efficiently as possible, by anticipating where you need to fly to, than by any leaning protocol.

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  • $\begingroup$ Thanks, that's very useful information and a well written reply. $\endgroup$ Jun 28, 2022 at 9:24

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