Commercial Pilots who don't know about piston engines

[Walter Atkinson]

**do you believe it is possible to teach anybody in as little as 2 mins to safely operate a carbureted engine LOP; without limitation on altitude or power, and without engine monitor, using only seat in the pants feel for the "big mixture pull"? As claimed by your Australian colleague.**

Absolutely. I have done that on multiple occasions. (I taught my Aussie colleague!) It takes about 15 seconds if injected, 2 minutes if carbureted. How you might ask?

Carbed engines have notoriously poor F:A ratios and as a result many think it impossible to run them LOP. Not so. It is NOT imbalanced air--it is imbalanced fuel. The key is finding the optimal IAT using carb heat to get the fuel which has been atomized to become vaporized (I am hesitant to spend hours typing what can be demonstrated in under a minute in the airplane). Once this happens, the F:A ratios will be well balanced. I have accomplished this on radials as well as flat engines. I've personally accomplished this on most Cessnas, Pipers and many other carbed engines. Use the minimal carb heat to get the lowest DIFF number and you're good to go.

It only requires a single-probe EGT and a carb temp gauge.

It is important to appreciate that IF the F:A ratios are balanced all cylinders will be at very nearly the same mixture and the engine will run smoothly LOP. (And better ROP) This is how the engine is SUPPOSED to be. It does not matter how the fuel is delivered to the cylinders. Injected engines have this accomplished by having balanced nozzles (like GAMIjectors), while carbed engines use optimal vaporization to accomplish this. This is not my discovery. About 15 years ago, I read it in the small print (6pt. type footnote) of a 1935 engine operation manual; tried it on various carbed engines and found it to work quite nicely.

Consider this: If the engine is "conforming"--having balance F:A ratios, healthy ignition, no induction leaks and is being operated on the proper fuel--it will run smoothly across the entire mixture range, including LOP. Non-conforming engines will "seem" to run smoothly ROP because the differences in mixture, etc, between the cylinders is masked by the fact that the HP curve is so flat in the commonly useable range of ROP mixtures. Your Mark One calibrated butt doesn't feel the differences when ROP. It does when LOP.

SO..... if you run ROP, you need an engine monitor MUCH more than if you run LOP! If you have a conformity problem LOP, the engine will let you know by running rough. Not so if ROP.

WAIT! You did ask if ANYBODY could learn this in under 2 min.? Hm???????? I'd say "almost" anybody. They have to be willing to challenge what they know that isn't so. <g>