Take Off Flaps - 210

[kiwiblue]

Hitting the Thread Drift Reversal Thyristor!!!

I've been sitting on my fingers, waiting for someone else (anyone???) to pick up on this...

Originally Posted by 206Dog

I, like ForktailedDrKiller have also used full flap on one occasion in the C210, in my case with 4 pax, 15KG bags each and 4hours fuel.

Hitting the switch to the 'Full Flap' position (at gross weight yet), ballooning up over whatever it was you needed to avoid in ground-effect, then bleeding the flap back off again does not a full-flap departure make!!! Your flaps probably never made it to full extension! Something you should be eternally grateful for. As you should know, you'll gain most benefit from your flaps between 12 and 16 degress, from memory; after that, it's basically pure drag (increasing exponentially) -which in any Cessna I've ever flown, will drag you straight back into the ground, despite your current power setting or heroics with the pole.

So despite the fact that you had selected full-flap, the flap motor probably allowed only to or slightly beyond best CL before you started bleeding flap off again.

drifting again...

CC: Have read your posts re T/O power settings with interest -and I agree with what you're saying (read my previous on the subject). However, with regard FF -not all CSU equipped aircraft enjoy the advantage of a FF gauge, calibrated or otherwise. Most do, as they should, but some including BN2, C182, CSU equipped C172 (can't remember the model designation), Piper PA28 and I'm sure others, don't.

Just a thought

[Jamair]

Kiwiblue: Carburetted CSU-equipped aeroplanes don't (generally) have FF gauges but they do have a system to acheive the same effect Chuck was discussing. In those aircraft, selecting full throttle will activate an enrichening feature in the carb to add additional fuel to the mix for high-power operations, thus moving the overtemp and detonation danger zone well clear. For this reason, unless otherwise specified in the POH AND ENGINE manual, one should not reduce throttle setting after takeoff, but allow the MAP to reduce itself as you climb. Once stablished in the cruise, then you reduce the MAP as desired. If your cruise height is at or above FT height, you reduce the throttle slightly until you see the first reduction in the MAP, then leave it. This will remove the additional enriching feature while maintaining max available MAP.

CSU C172 is colloquially known as a Super Skyhawk; designated a Hawk XP, runs a 180HP injected engine. Then there was the 175 Lark and the 177 Cardinal.

[kiwiblue]

Yep, thanks Jamair, well acquainted with the full-throttle auto-rich 'feature' on some (not all) carburetted CSU engines. My point however was related solely to the lack of a FF gauge in some carburetted and injected CSU engines and the points CC was making in that regard.

Originally Posted by Jamair

...until you see the first reduction in the MAP

Why wait that long or reduce throttle that far??? Just watch your EGT -that will tell you instantly when your throttle is far enough back to have disabled the autorich!!!

[Jamair]

Yep; true and fair enough.....if yer got an EGT! Not all have, nor do they necessarily work .....just another good reason to invest in a decent engine monitor.

Oh yeah, the other good reason to pull the throttle back to the first movement of the MAP, is to introduce some turbulence into the induction tract via the butterfly; aids in mixing and subsequent even burning. Clearly seen on a electronic monitor - sorry Gaunty, never been in a Cessna with a WORKING 'economy meter' but agree with the premise.

[gaunty]

Ahhh which brings us to the correct use and interpretation of the Cessna Economy Mixture Indicator the correct use of which enabled one in any particular type, to trade say 3% of speed for up to increase in range of 15%.

You got the choice between Best Power, (max speed) thru Recommended Lean to Best Economy.

I also wonder how many power computers are still out there and in regular use. How else does one set a % power in order to achieve flight planned KIAS and Fuel consumption?? Or indeed work out exactly what power you are getting.

[Chimbu chuckles]

Easy when operating LOP...simply multiply FF, in USG/hr, by 14.9 which equals HP. Divide by rated hp to get % hp.

example: Operating at 60 liters/hr FF.

60 liters/hr = 15.87 usg/hr

15.87 x 14.9 = 236hp

236/300 x 100 = 78.6%

I do this calc airborne when the mood takes hold...but equally you could have a card with calcs pre done for various FFs.

It becomes reasonably important to know when operating in very cold air (read dense)...say mid winter in Victoria. If you only use a target CHT, say 380F, you can actually damage your engine by operating it inadvertantly at power setting in excess of rated HP.

Gaunty I would be very interested to see exactly where the Cessna economy mixture setting power settings took you ref peak EGT vs %hp...it has been > 20 years since I even laid eyes on one.