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"A 12 Step Program" UCAP #235

Posted: Wed May 18, 2011 1:45 am
by gmarshall
Looks like rumours are swirling about the black-box contents from AF 447. Sounds like they were downloaded successfully, but they're being tight lipped about the contents.

So, long story short, no new info (I guess good news that the downloads seem to be working), and as usual, the media is jumping the gun on sketchy information.

http://blog.seattlepi.com/aerospace/201 ... -447-crew/

Re: "A 12 Step Program" UCAP #235

Posted: Fri May 27, 2011 9:40 pm
by RigaRunner
Jack, I sure wish you could draw Dave and Jeb out on the question of "leaning the engine."

My instructor in a Cessna 172 left me with nothing more than a simple rule: "When you reach about 3000 feet, pull the mixture back until the engine falters, then push it in a little bit, and keep flying."

You guys were tantalizing with your comments about "rich of peak" and "lean of peak" and the various conditions when you would want one or the other. But, the details were just beyond reach.

Could you come back to that subject again?

Re: "A 12 Step Program" UCAP #235

Posted: Sat May 28, 2011 9:07 pm
by champguy
So much depends on the sophistication of your engine monitoring instruments. Unless you have an EGT for each cylinder and acurate metering control, ie. fuel injection rather than a carbruettor mixing generally for all cylinders, Much more than general leaning is impossible. Also depends on how hard you are running the engine.
With a simple, unsophisticated engine and carb set up on my Champ, I lean just as you were taught, at all times unless climbing with full power. After about 7500 feet, the engine cannot produce more than 75% power so it is at cruise already even throttle wide open.
Running rich when not necessary for extra cooling on climbout, wastes gas, money, and fouls plugs and valve stems.