How to Lean?

[ics-12766]

[ComBE]

[ComBE]

[Zach Grant L1011jock]

[ComBE]

[ics-12766]

[Zach Grant L1011jock]

[ics-12766]

[Zach Grant L1011jock]

[ComBE]

Rich, I asked George Braly about this 2001 document and this was his reply to me :


Well... I spent a couple of days testifying for the Australian Coroner's Inquest into the matter of the crash of the Whyalla Airlines Navajo on May 31, 2000. As an official expert.

Consider, also, that both TCM and Lycoming (September, of 2009) announced that they had changed their mind and that LOP was OK.

TCM even apologized for anybody in that company that had ever said anything to the contrary.


You might also read and come back to me with reactions :

Pelican's Perch #57:
The Whyalla Report — Junk Science?
http://www.avweb.com/news/pelican/182152-1.html

Also when I fly LOP there is no shaking or whatsoever on my 4 cylinder bangers. I fly LOP with cooler cylinders, not so cool that they are 'undercooled' so I disagree with you on the fact that you like it to run your engine HOT.

Fuel is for everybody the most expensive part. You have to divide the costs and not add them all togheter and then say that fuel is cheapest. I get a free overhaul in the end and will reach TBO. It has been proven constantly you can't deny the facts anymore.

[Zach Grant L1011jock]

ComBE,

I said it before, do what you want, they are your engines. As for results, Ill stick with my way for my engines based on my proven results (never have had to top any engine for operational reasons, on any airplane I have operated). I really don't know how you call 385-400 degrees F hot when the red line is 500. Heat doesn't kill as much as transients do. Turbine engines have cycle limits for this reason. Also, please don't tell me how to cost aircraft operation. I run businesses in aviation, and operate fleets of aircraft and costing is a major part of staying alive. So far even in the trying financial times we are not out of business, so i will stick to what I do there as well.

I have offered my advice, you have offered yours. Oppinions are like belly buttons, everyone has one, and that is just fine. With that said, neither of us are going to change our operation so, as far as I'm concerned, this conversation is over. Have a nice day, and fly safe.

-Zach

[ics-12766]

From the "Pelican's Perch" #57:


"...The very young pilot (22), perhaps a bit rattled (as anyone would have been), might have advanced the power on the right engine, while forgetting to increase the mixture. This is a VERY common error in training and on check rides, even with very high-time captains. We have ALL done that a time or three. When you do that, the cylinder head temperatures rise rapidly. After some short period of time (it could be as short as a few minutes) at that power setting, it is likely detonation would have begun. Another minute or two of light detonation, progressing to moderate and worse, and it would have turned into pre-ignition (a spur from a bad helicoil can easily get hot enough to remain white hot through the exhaust and intake stroke, lighting off the fuel/air mixture sometime before the spark plug's normal timing). Pre-ignition is the worst possible malfunction in the combustion chamber. This whole problem of failing to increase the mixture when the pilot increases power on the remaining "good" engine would be substantially more dangerous if there was a partially plugged injector, or if one injector was at the low end of Lycoming's 4% tolerance band, with the rest somewhere above that. This is fairly common and cannot be readily detected without a multi-probe engine monitor..."
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This quoted paragraph, from Deakin himself, certainly points out one of the risks of operating LOP, doesn't it? Granted, it takes "pilot error" in this case, but it's a risk the pilot must accept, no?


As Zach says, and I've said myself many times before in these discussions, they're your engines, run 'em any way you want Considering your fuel cost, I'm happy LOP operation is working well for you.

Like Zach, I have reasons for running the way I do, not the least of which is the lack of FAA-approved LOP data for my RAM-STC'ed engines. They're my engines

[Richard Muller]

Hallo all

I own a 1960 PA 24-250, based in Germany. This aeroplane is equipped with an EDM 700 and a Shadin Miniflow. When I try to lean with the EDM 700 in Lean Find Mode, the engine runs rough and power drops down before reaching PEAK EGT on the EDM 700.
Therefore I lean with the Shadin Miniflow. First I set eg. 65% power low or about 55% in 15000 ft, then I set to 12,3 Gal./Hr. at 65% or 10,3 Gal./Hr. at 55% as shown in the Power Setting Table – Lycoming 0-540 A in the Owners Handbook. Thereafter fine tuning will be done by set to a smooth running of the engine, that will be about 0,3 to 0,5 Gal./Hr. over handbook. At this setting the plain runs also on top speed and I had never problems with the engine and the temperatures. The EGT span in this setting between hottest and coldest cylinder is about 80 to 100 °F for the carbureted engine.
Between best power and best economy there are 5 % loss of power. Why I should set 65 % power and then I reduce 5 % by leaning too best economy? There I can set to 60% power and lean to best power.
The difference between best power and best economy my be about 1 Gal. / Hr.
To your Information, in Germany, we pay about 2,20 EURO/Liter or 12 $ / Gal.
For me is the price/miles interesting, for I fly mostly enroute. When I need less flight time, I can make more miles / TBO or inspection. When I fly 5000 miles with a C172 I need 50 hours, in the Comanche about 34 hours. The C172 must go to 50h inspection and I go additionally 16 hours. The TBO for both engines is 2000 h. With the C172 I can fly 200.000 miles, with the Comanche about 300.0000 miles.
The price for fuel between best power and best economy is for me not the major component in the all over cost/performance ratio.

Richard

[ComBE]

I understand and respect everybody's idea what about they think of running LOP.

I will close the discussion also and I love to debate about LOP or ROP.

But understand that in the near future Lycoming and Continental will change their POH to allow running LOP safely.

One big argument for me to run LOP instead of ROP is that I end up with way more fuel arriving at my destination. That is a HUGE safety issue for me giving me a lot more options.