Help Calibrate C182S

spiderweb

Final Approach
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Ben
I've lost my notes!

I need to calibrate MP/RPM for descents, no flaps. Please help if you know:

1) 800 fpm descent at 95 KIAS
2) 500 fpm descent at 95 KIAS
2) 600 fpm descent at 110 KIAS

I usually don't fly at less than 2200 RPM, and I don't go full prop nor do I add any flaps until DH/MDA with assured landing. But I'm open to other procedures.

Also, how soon do you lean in the climb? I don't like to touch the mixture until above 3000 DA, but the procedures at the FBO where I rent state that I should lean to 15 GPH at 500 AGL and not touch the mixture thereafter.
 
wangmyers said:
I've lost my notes!

I need to calibrate MP/RPM for descents, no flaps. Please help if you know:

1) 800 fpm descent at 95 KIAS
2) 500 fpm descent at 95 KIAS
2) 600 fpm descent at 110 KIAS
For (2) try 19" and 2200 rpm (one aboard). It's not far from that setting. For (1) try 20" at 2200. 600 fpm at 110- try 23" at 2200. These would work in a 1965 Skylane....YMMV.
 
bbchien said:
For (2) try 19" and 2200 rpm (one aboard). It's not far from that setting. For (1) try 20" at 2200. 600 fpm at 110- try 23" at 2200. These would work in a 1965 Skylane....YMMV.

I think you'll find you'll need somewhat lower MP settings than these with only one on board. For no-flaps, 100 KIAS, 500 fpm in my 182Q, it is about 2200 and 17". Bruce's experience with the '65 Skylane was with an engine that has a lower compression ratio and higher max RPM than the Q, R, or S model 182s. However, the S is very different from the Q & R as well (Lyc IO-540 instead of a Cont. O-470), so I don't know exactly how applicable our notes are for you.

On a hot day, I'll start leaning as soon as I'm above the traffic pattern (sea level departure). 15 GPH sounds like a reasonable target for climb (I have a 6-probe EGT gauge, but no FF). Setting it at 500 AGL and forgetting about it doesn't make sense though, because you'll need to continue to lean as you climb. I would suggest adjusting the mixture to your target every 1,000 to 1,500 feet, workload permitting (this should be near the bottom of your priority list, IMHO).

Jeff
 
wangmyers said:

A simpler approach is to determine the 500 fpm descent MP at cruise RPM and subtract an inch for each extra 100 fpm each additional 100 fpm. As for the faster descent speed, I'd figure on an extra 100 fpm for each 5 Kt increase in the descent speed at the same power. None of your memorized settings will work precisely everytime unless you adjust for weight and DA, so consider then as starting points to be tweaked.
 
Thanks Lance. Yesterday, I just did whatever needed to be done, and it all worked out fine. Of course, I did two visual approaches. But I did practice descending at different rates and airpseeds.

God, I love the C182!

BTW, I saw a very sexy Baron landing at FDK, and I though of you.
 
bbchien said:
600 fpm at 110- try 23" at 2200. These would work in a 1965 Skylane....YMMV.

In my 1967 Skylane, I cruise at 23"/2200 rpm, with a KIAS of about 129. A 600 fpm descent at those same settings would probably put me in the yellow arc.

Also, I find that at 15"/2200rpm, with a 500 fpm descent, I get a KIAS of 120.

Am I missing something, or is Bruce's engine that much different than mine?
 
Last edited:
mmthomas said:
In my 1967 Skylane, I cruise at 23"/2200 rpm, with a KIAS of about 129. A 600 fpm descent at those same settings would probably put me in the yellow arc.

Also, I find that at 15"/2200rpm, with a 500 fpm descent, I get a KIAS of 120.

Am I missing something, or is Bruce's engine that much different than mine?
Jeff is right, I think, there was an engine change in 1965 or 66. And this was SOME TIME AGO since I had my block of Skylane time (about 200 hrs in the 1990-91 period). And as I did not own that bird (it was poorly maintained, eventually the prop came off on rotation some years later injuring the owner/pilot) I can't vouch for accuracy. IIRC it cruised at about 130 knots with everything hanging out.

Sigh.
 
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