scavenger,

With a "CONFORMING ENGINE" it is as easy as…….level out in the cruise, (close your eyes for about 3 seconds while quickly moving the mixture leaner. As soon as you feel the deceleration - stop. Open eyes.

Now I do it in the climb if I want to with my eyes open, not because I am any genius but once you have done it 10-20 times you can do it repeatedly. Once you know your calibrated butt is accurate it is hard to get it wrong. If you move the mixture too slowly and/or have your eyes open you will not sense the deceleration and will miss the sweet spot known as best BSFC.

This technique works at 500' and WOT/max rpm or at FL150/xxxx RPM.

Now the hidden question you ask is how do I do it sans an EMS. Well take a carby O-320 RV6 that a Airline guy I know owns, no EMS but we are 100% sure the engine is a conforming one. guess what, the Big Mixture Pull works every time. And yes that is a carby engine.

Of course if the engine was not conforming, it would not do that nicely and you would know.

Let me be clear, the ROP pilot takes off after an annual and the injectors have been out, and it is a TC/TN engine, he flies home with one cylinder leaned out to a ROP setting that is driving that cylinder head pressure and temp up through the roof, and it runs smooth as a babies bottom. No EMS therefore he never knows. But if he was familiar with the BMP technique, the first thing he would do after maintenance is do an orbit over the field and a BMP, if it played nice he would go home either LOP or ROP (both are valid if done right). If there was a F/A ratio issue he would certainly discover it and land asking the LAME to fix it.

Of course having an EMS would make the diagnosis a LOT easier.

So there ya go……ROP pilots actually need engine monitors more than LOP pilots. Add to that once LOP by BMP method, you can't hurt any engine, period. But if you are an uncertain red knob fiddler you can.

Two last points;
A: The APS class is for piston pilots and LAME's. Yes a lot of LAME's have had many great learning experiences, David Paynter from Brisbane Aero, the late Steve Hobson from Bankstown, and about 15 more I can think of.

the class is NOT a LOP class…..I will say that again, it is NOT a class about flying LOP, in fact it would be about 10% maximum. The science of combustion taught with real in cylinder engine dyno data, how that relates to what you see on an EMS, how to manage for best speed/range or whatever in all types of flight mode, how to diagnose the EMS data (and this is where 100% of pilots and LAME's learn the most) and it is where we spend the most time. Plus quite a number of life saving diagnosis in flight topics, and how to save a fortune on maintenance bills by doing the right things at the right time and saving hours of chasing problems rather than going straight to them.

This last paragraph is what the original poster was really thinking I bet. I now know who he is…..good student and great guy :ok:

B: Andrew Denyer, Leisa and myself have yet to take a profit from APS and in fact personally we are out of pocket. We leave any residual funds to ensure the classes are fully funded despite the costs and it is not cheap to put on.

While I can't speak for John George and Walter, I do know that we did the sums one day sitting down with a cold drink in Tennesse or Louisianna, and the hourly rate would be something like a dollar or less. I doubt George has ever banked a cheque, John used to send them. Think he gave up. When you realise the motivation is more about better education with science and the safety outcomes that delivers, then you might understand that profit is not even a thought let alone a motivation.

While I think of it, imagine the satisfaction when you get an email explaining how the lessons learned in class saved a family from grief because they diagnosed and dealt with a problem before it got them over the top of the Rocky Mountains, or even the many smaller helped solve a problem that saved wasting several thousand dollars in chasing it down. Last year I had a lady (over 65) who did the course discover a whole bunch of defects, some her LAME was dismissive of and telling her the EMS was just scaring her. He was wrong, she was right and the things I found were a disgrace. She saved herself thousands, and maybe her life one day as a result.

That folks makes it all worth the hundreds of hours we put in for no financial gain.

When the master class is released we will reinvest in that for the benefit of our students…..engine monitor diagnosis torture is the best way to describe it :E

IFEZ…..if we could explain that in one internet post, do you think anyone would ever come to let alone pay for a 2.5 days brain strain?

Seriously, I do not care whether you fly a Briggs and Stratten powered ultralight or a Chieftan……..the theory is all the same. If you really want a better explanation send me a PM with your phone number and I will happily chat for a bit….typing the Q&A's back and forward will kill my keyboard :bored:

Thanks for your straight answer Lead Balloon, that's what I was after. I do not disagree in the slightest.

Lead ballon
Actually with a conforming engine and fixed pitch prop, like the O-320 I mentioned above, you can simply use about a 100RPM drop before it even runs rough. ;)

Scavenger, if you want my details are in a PM shortly. :ok:

And thanks again Jabawocky. In fact I do understand you think:

which is why I was sure you would respond in the manner you did. :ok:

If it's costing you money and safety outcomes are paramount, why not post all the course material somewhere free of charge? You'd save a heap, you could still run the course for those desperate to attend, but safety would be improved for those without the time or resources to attend the course.

It's already available scavenger

"Pelican's Perch" Index - AVweb Features Article

And the online version is available, but it is not mine to give away.

And the classroom environment cannot be beaten. Hey lets ditch flying training right through to operating a jumbo, it can be learned on youtube! :eek: I think you will get what I mean.

Certainly I do, but that does not stop you from posting materials on line for free.

Given that:

do you recommend the online version, or would it be akin to:

In any case, thanks for answering, and if the materials aren't yours to post for free, but only to sell at a personal loss, I now understand your position a little better.

Aerozep, I used to run the IO-240 with Fadec. What's your fuel burn at 75% on the 235? Mine was around 23L. I should research the auto mixture setting on the Fadec in relation to EGT as its automatic and I wonder what it's doing under the hood.

Just remember you can't use EGT as an absolute number, at varying RPM the EGT absolute changes, same for MP, so everything needs to be referenced to peak to be useful as a guide.

Another thing not well understood. And not easy to teach on a forum. :ok:

I started the thread. Had no idea there was another course on, was just hoping that someone, a few young CPLs or whoever would click and start wondering about exactly what they know, or more what they know they don't know as might be the case, in Rumsfeldian.

I did the course in Perth a few years back. Thing is with the course, you'd only sign up if you were already questioning your known unknowns, which was the purpose of the thread.

squittle pop!

If you are referring to my post Jabba, you are absolutely correct. With Fadec, or at least with the Vm1000 display you have little to no information available to you on what's happening, thus I wonder what the manufacturers set it to as they claim with Fadec fitted your engine will run for eons over TBO.

and just because it seems relevant to the what do you do with no instrumentation theme:

A while back I ferried an agcat to an operator. At 1800rpm and 28" (R985, 55% power) the CHT (single probe) was showing in the redline, from memory it started at something like 210°C up to 280°C (absolute redline for this engine is an astonishing 550°F!) This is a low power setting, and I was getting around 220°C. I think it is because of the complete lack of baffling to direct the airflow to the rear of the cylinders, that's my guess.

Before I did the APS course I would have just sat it there for the next few hours because frankly there isn't much you could do about it. But being a hubristic know it all I thought hang on.. and pulled the mixture back until the seat-o-meter felt that deceleration just so, and added a sprinkle of "MP and voila! CHTs dropped to around 200°C, airspeed much the same. With absolutely nil engine monitoring save the CHT I knew this was a happy, smooth running LOP round engine, just by what the CHT did. Just gotta look at what's printed on the APS T shirts.

Ok to spruik the T-shirts?

(The ag boys didn't like the look of the exhaust pipe at all when I landed, I'm sure they sooted it up soon enough though. Buggered if I know how these engines survive in actual ag operations - slow, no baffling, max continuous power... now there is a good argument for the superior reliability of turbines, compared to what I'm guessing happens to these motors)

Thanks Lead Balloon & Jabawocky for your responses.


Jabawocky - PM sent :ok:

Three things you should NEVER discuss: Politics, religion and LOP!

Jaba, I don't know why you bother with threads like this. Those that want to learn more about the engines they operate will make up their own minds about whether or not to attend one of your courses, and those that don't ........ well, who really cares!

Dr :8

PS: For the record, I have done the APS course!

I haven't done the course but I have read all of Deakin's info as well as a lot of others. What seems to be missed by the pilots who haven't read up is that it really has nothing to do with LOP, but correct mixture settings as a whole. I have never ran LOP and unless I end up an owner I'm never likely to.

But, now having the knowledge I operate ROP in a much safer way, I know when to, and how much to lean by and understand why a blanket rule of 50F ROP CAN be abusive to the engine. I have an understanding of what the needles are trying to tell me (yep, those unreliable single point ones, but if it's all you have then it's the best that you can do), and if nothing else, I am now thinking about what the engine is going through after complying with my requested power/mixture settings, rather then setting 50F ROP religiously at all power settings/stages of flight/ conditions etc. So I think even if nothing's changed, because of company SOP etc, the understanding is priceless.

And tightarses wanting stuff for free, I spose they run round town giving away theirs and other peoples' property?

Thanks Forkie for the tip :ok:

But really, the last post is more the point, we teach whole of operation by scientific methods as you well know. But the diagnosis element is the big thing. That is where the major benefit is.

Give 99% of pilots and engine monitor and they are a dog watching TV, it is that simple. They might think they know what they are seeing but being able to diagnose with it is another matter.

And I enjoy the banter, there has been not much else of interest on prune in months so it makes a change! :)

That's because it's the quickest practical way to achieve the scientifically-proven desired setting for a conforming engine, cleared. ;)

PS: The single most important reason for my decision to attend an APS course was the opportunity to meet and draw on the wisdom of a person who's forgotten more about piston aero engine operation than anyone has ever learned in the third world of GA that is Australia - Mr John Deakin. You can't do that by reading on-line materials.

Clearedtoenter, what page and complete reference please.

I get the same 'feelings' with every landing in the Tiger Moth......'specially in a > 15Kt X/wind......

Cheers..Lots of 'em..:ok::ok::ok: To ALL who fly 'Tigers'....