tail wheel

If you think Mr David Paynter (Brisbane Aero) is good, his father Max Paynter was a genius!

Jabawocky

yr right

No I have not changed the RSA fuel servo from Precision at all. The engine driven pump provides a pressure, and it can vary from about 19PSI in flight to about 27 PSI with the boost pump on, but the flow rate will not change. A CMI(TCM) uses the pump (RPM dependent) to provide a pressure and the faster it goes the more it delivers. They are two different ways of delivering fuel. The Beech gauge is exactly what you describe, a pressure gauge and they are pretty crappy at that.

So, I am sorry I missed one of your questions, my apologies, I have been a bit busy myself. The Left engine was going to fail it was just a matter of when. The defect in the crank had less to do with mixture control as it did with magneto timing. Mind you the mixture management of the company combined with the advanced spark from mistimed magneto's will have made things worse.

The second engine had it been run full rich, when called for yes the preignition event would have been snuffed out, but without an engine monitor and knowing what to look for the pilot would have had no clue there was a preignition event happening. Heck we have data files of folk who have had engine monitors and recorded the whole sequence of events and still let it happen.

So the Whyalla RH engine would not have failed had it been routinely run RICH ENOUGH, and if during that flight it was run RICH ENOUGH also.

Of course had they operated these engines at 32-34" /2300 and 80dF LOP they would never have had any detonation to damage the plug ceramics. Had they run full rich in the climb instead of skimping (not rich enough) the same would apply.


Now...have I missed any more of your questions?

Will you have a crack at all mine? Do I need to re-list them? I can email you a bunch to have a go at just for fun. Or have a go yourself free of charge Advanced Pilot

I nominate three of the folk you know, give all three of these a call, Ben Bowden, David Paynter and Andrew Denyer. You have my name and details, after you call them and checked out my story, and the course value, drop me an email, I expect you will want to book in.

Jabawocky

That is POTY material right there!

yr right

Sorry Jaba you are in correct. The fuel pump has nothing to do with fuel flow in either tcm or bedix system. The fuel pumps supply fuel to the fcu. That is there only function. They do not in either system control any fuel flow to the engine. True both are different I. The way they supply fuel to the engine. But both can and do use a px gauge calibrated in fuel flow to show it's reading. Now they pick this up in different positions as we'll. tcm from the spider and bedix off the fcu.

Now had the engine been placed into full rich it would not have failed period. Start at the right move red one first to full then the blue to full and then increase the power lever forward as required to say that he did have a meter to know what's happening is just &@"/'$28. The engine was lean as and it self destructed it was not in any other mode than that. Now I u stand what px the pilot was under and now this leads to my next point. When it's all going good it's all good. When the **** hits the fan and it goes pear shape it happens so fast. You don't have a chance to look if you in a single pilot operation.

Jabawocky

Posting from your phone is not helping convey your story. I am not sure what you were trying to say here.

scavenger

Serious question: why doesn't whoever writes the POHs advocate LOP?

Second, if I attend the course and install engine monitors, do they come with an AFM supplement or similar that would make it legal to operate LOP in defiance of the stated procedures (CAR 138).

Cheers

Agrajag

To add to the wealth of evidence here, which some seem reluctant to acknowledge:

I spent many years away from flying piston engines. When I returned to it, I made it my business to learn all I could, much of which had changed in my absence. Some of it came as a surprise, but a lot of curiosity and an open mind satisfied me that it had merit.

The engine on our single is Bendix fuel injected. It has a fuel pressure sender, which measures pressure, as well as a fuel flow sender, which measures flow. Yes, I know my fuel flow, and no, it's not just pressure expressed differently. The flow meter has been calibrated to be extremely accurate, so if it departs from its normal range we will notice very quickly.

The flow isn't tied directly to pressure, because the pump supplies more than the engine needs. Our fuel pressure goes up significantly when the boost pump is switched on, and so does the flow... briefly. Then the fuel servo adjusts to the new pressure, and the flow goes right back to where it was.

I can, and have, diagnosed a partially blocked injector by means of the engine monitor and the flow gauge. It was obvious which injector was at fault, and the proof was in the contamination later removed from it. Without the monitor, and the training in interpreting it, there would only have been unexplained rough running.

A carbed engine can be run successfully LOP, because I've since done that too. It ran smooth and cool.

Now, I know I'm just a dumb pilot, so I was probably just imagining all the above. But, funny thing, this extended hallucination sure did fit very well with the theory I'd recently been taught.

Isn't learning fun!

yr right

Scavenger
Simple answer is they don't won't you to do it. It leaves them wide open to being sued if something goes wrong.
And I would think the engine monitor will not allow you to lop. To do it legally you will have to have an stc to cover you if it's not in the poh. The aircraft manufacture states what parrameters that the engine is to be run to and not the engine manufacture. Same goes for the maintenance of the engine. It is the airframe manufacturer that take pressidence over the engine manufacturer. Ie they set fuel flows rpm prop angles etc etc.

yr right

The engine on our single is Bendix fuel injected. It has a fuel pressure sender, which measures pressure, as well as a fuel flow sender, which measures flow. Yes, I know my fuel flow, and no, it's not just pressure expressed differently. The flow meter has been calibrated to be extremely accurate, so if it departs from its normal range we will notice very quickly.

The flow isn't tied directly to pressure, because the pump supplies more than the engine needs. Our fuel pressure goes up significantly when the boost pump is switched on, and so does the flow... briefly. Then the fuel servo adjusts to the new pressure, and the flow goes right back to where it was.


Sorry but do you know what you are talking about at all. Two different things
! fuel px is as it says, it measures pump px pre fcu. It leys you know if you have a edfp failure and allows you to turn your electric boost pump on which is required by certification to be able to run your engine to max power.


Now next.
The fuel flow is a px measuring gauge calibrated in fuel flow it is taken from the fcu. it is not part of the fuel px sysyem. it measures flow via px to the fuel nozzles. this is the same for both types of systems. now you also may have a digital flow vane which measures in units and not px but you will have the first system as it is mechanical and requires no power.


Now when you hit the boost pump this places more fuel to the fcu the fcu limits and bypasses the excess fuel. thus recreating the fuel balance to the engines requirements.


So may be you can explain how the Bendix RSA fuel servo and metering system works please.

Agrajag

I would also know of an EDP failure by the sudden silence! To protect against that, during critical phases of flight (such as takeoff and landing), the boost pump is switched on. And lo, the fuel pressure rises, the flow also briefly rises, and then returns to its original value. The behaviour is the same from idle to takeoff power.

This isn't theory. It's what actually happens in our aircraft... unless the gauges are participating in the same elaborate hoax.

We do indeed have a fuel pressure gauge. Like the flow gauge, it's electric. Or did I merely imagine connecting the wires from it to the sender when I installed it?

Now, of course, I'm going to have to go back to the fuel system and remove the flow sender from its inline position before the FCU, where it measures nothing but flow through it, and tee it into the line from the flow divider along with the separate pressure sender. That will make it measure pressure all right, as flow sensors clearly should.

And we must have forgotten to install the return line too. Damn, I wonder where all that bypassed fuel has gone. But since our engine isn't a Continental, I'm fairly sure we got it right. And, also because it's not a Continental, the boost pump can be run at full pace as a backup without flooding the engine into spluttering submission.

I think Jaba pointed out that not all injection systems are the same. I won't presume to expound on how all of them work. But I do know a bit about ours...

gassed budgie

IIRC, Piper used to (and perhaps still does) advocate operating some of their products LOP. I'm fairly certain that in the '83 and later Warriors you could set the engine power using just the mixture knob.

The drill was to set full throttle and full mixture then lean the mixture, reducing the RPM to the desired power setting. They covered their arses to a certain extent by suggesting that if you ran LOP above 75% for extended periods, you might damage the engine. Other than that, running LOP was fine. Evidently the O-320-D3G (I think) has quite an even mixture distribution to all cylinders, allowing for a smooth ride LOP.

So there you go yr right and others. A major GA manufacturer from over thirty years ago more than happy for people out there to operate LOP, well and truly way before it became fashionable to question decades of engine management folklore.

gerry111

yr right, Thank you so much for now not posting via your mobile phone.

(Very good advice, ONYA Jaba).

You are now so much easier to understand. If you care to re read some of your earlier postings on this thread, you'll possibly see what I mean...

Surely we should all be good friends in our rather small Australian GA world? Pilots and LAMEs. And we sure all mean well and want to have all our aircraft fly safely? So it may be a good idea for all of us keep open minds when we hear of credible information that challenges what we were all once taught.

(A confession: I'm also a convert to the APS LOP).

Aussie Bob

Here is how I get my carburetor O-360 to run lean of peak at low level.

1. Set 23 MAP 2300 RPM or thereabouts
2. Apply full carby heat (there is no useable partial setting on my plane)
3. Pull out the mixture control about 75 mm and wait for EGT to stabilise
4. Pull out mixture control until all cylinders are LOP. This takes miniscule adjustments
5. When all cylinders are LOP, push the throttle to full open.
6. Make miniscule mixture and RPM adjustments till lean "stumble" disappears (if present)

Given that I seldom fly very high this can result in the following:

27 - 28" MAP, 2300 - 2400 RPM, fuel flow around 28 - 30 LPH and cylinder head temperatures in the low 300's. Once upon a time I considered CHT of 350 good. LOP way improves this.

This gives me a cruise speed equivalent to a "normal" setting of 23 MAP 2400 RPM and 34 LPH so I am saving around 4 litres per hour or more with no trade off in speed. 4 litres is nearly 10 bucks. About $1000 per annum if I do 100 hours between annual inspections. This goes a long way towards the cost of an annual!

For this to happen I needed an engine analyzer and the confidence gained from an Advanced Pilot Course.

Does the POH allow this? Good question, my POH refers engine operations directly the the Lycoming engine book and these settings do not seem to be prohibited but it is a difficult book to read. Truth be known I don't really care, this is not a charter aircraft and 99% of the time its just me, or me and Mrs Bob on board.

Creampuff

Hi scavenger

Some POHs do include LOP power settings. But let’s assume none do and the effect of CAR 138 and all POHs is that LOP operations are illegal and your gonna’ go to gaol if you’re caught running LOP.

An engine monitor will tell you lots of useful information when the engine is running ROP. It will tell you what plug is fouled. It will tell you what injector is partially or completely blocked. It will tell you what exhaust valve is sticking. It will tell you whether all cylinders are at a comfortable margin below red line during the climb (rather than just the cylinder that happens to drive the single sensor that drives the steam driven CHT gauge). It will tell you if a cylinder is suffering pre-ignition and you may have sufficient time to take action to save your engine and your aircraft.

Most importantly for those who don’t want run at settings that dare not speak it’s name, you’ll know that all your cylinders are actually ROP, and far enough ROP that you are not beating your engine to death. (That’s what cracks me up about all the LOP disaster and illegal brigade. Many of them are probably already operating LOP, or at least with some of their cylinders operating LOP, while being blissfully ignorant of the fact. Most of the damage that yr right sees is due to not running the engine far enough ROP, or bad manufacture or bad fitment.)

In short: An engine monitor will assist you to operate safely ROP, and demonstrate to you, with actual real-life data why, for example, it’s really, really silly to run an engine at 25 degrees C ROP, and it’s really, really silly to set 25/25 in the climb on a standard CMI engine. It will also assist you to diagnose faults and save you lots of time and stress. Compare: “The lower plug on 3 is fouled”, with “The engine ran rough on left mag”.

And, if you have an engine monitor and a fuel/induction system that result in balanced F/A being delivered to each cylinder, one day, while you’re at 8,500’ and mum and CASA aren’t around, you can grab that red knob and pull it while ogling those EGT bars. (The APS guys will even teach you how to do it with your eyes closed!) And watch the CHTs go down on you ...

yr right

it doesn't matter if it cont or bendix both do the same job. fuel px is measured post pump and pre fcu. wf is measured post fcu. it can be measure as px and conveverted as I've said to read wf or you can have a vane or spool type that measures flow pre spider and post fcu and it must have a in and a out, if it doesn't have that its measuring px.


Perhaps you wont explain because you don't know ? but do enlighten me how then it measures its fuel air ratio to provide the correct settings.


Now yesterday I worked on 3 different engines including turbine types and one airframe and gave advise on one other airframe. Now its impossible for me to know each individual aeroplane that you all have but the principles are the same when setting up your system and how and what px are there. so if its read directly via px line or electrical via a transducer it still reads wf as a measurement of px unless you are using a spool/vane inline unit.

Brian Abraham

Some do, the Chieftain for example, yet if you read the Lycoming manual for the engine, it makes no mention of LOP. This of lack of consistency only adds to the confusion among some of we plebs.

The IGO and IGSO-540 was likewise approved for LOP. From the manualyr right, I might ask, if LOP is bad, bad, why then do Lycoming, in this case, approve LOP on these particular engines?

Jabawocky

The majority do, and I would guess they all do if you dig for the detail and quite looking for the express words "operate LOP".

The problem is many manuals actually give guidance (poor as it is) on how to operate LOP, the most recent one I have had my head in is the G36 Bo. It is quite explicit but is so generalised that the advice is technically poor. But hey...it is there.

Many others describe operating parameters, which while contradicted on the previous pages, are actually telling you how to operate LOP.

This misconception that the POH's wont allow it are another one of lifes OWT's. POH's often set boundary points or extremes, and in other areas they give an example, but it does not mean you have to stick to just that one example.

By the way Sunday afternoon we spend an hour or so looking at POH's and engine manuals so you learn "critical thinking" something that pilots and mechanics seem to leave behind when they learn aviation. It is a rather fun session as the awakening happens.

There are even some POH's that expressly prohibit ROP ops.....and not many folk will know that story. And it is one of the big three (C, B, P.).

Once educated you see things for what they are, but let me give you a helping hand, when reading and studying any of these manuals determine which is material provided by the engineering department and which is the sales/legal/work experience kid. This will help guide you a lot more effectively.

Agra, good observation
And most of what you see with the flow is the turbulence affect of switching on the electric boost pump.


All this debate about fuel flow and pressure started by this one posting;
What he meant is on some engines the fuel flow gauge is actually a pressure gauge with a calibrated scale on the dial to reflect fuel flow. Have a look at all the classic Beech panels and that big green faced fuel flow gauge is the one. This works a treat on the TCM engines.

If you plumbed this gauge up to the typical Lycoming it would read one value ALL the time as flow varied radically from 10LPH to 100LPH.....because the pressure is constant (relatively that is).

So lets get back to some far more educational stuff!

I have rounded up the questions I asked earlier, which yr right should try to answer as he demands nothing less of me. This is the start of the learning process. They are;

Hey I just found this post by Mick Stuped; thanks
We do not do this for profit, but we are happy to risk the expense. If John Deakin is reading this he will no doubt offer his view of the statistics so far over 13 years and thousands of students.

This has turned out to be a great thread, keep the questions coming.

43Inches

The caution applies to all leaning, ROP or LOP above 75% power including the quote "if unsure use full rich mixture". There is a statement also in the Warrior manual that states no more than 15 seconds above 75% with the mixture leaned, this is in regard to should the engine power exceed 75% power during the leaning process.

That's about 80% power at cruise altitude, not sure I would use that higher power setting at 2300 RPM on a J2BD. A 65% power setting would be around 30"/2300 at normal cruise altitudes, 33"/2400 for 75%.

Piper also advocated a leaned climb at 85% power, but it was in accordance with the chart above 75% and basically was min 27 GPH (hard fuel flow limit to 18000') max 1500 EGT and max 475 CHT.

I used to fly these things by the book and they seemed happy, including the min EGT leaning for decent rather than the 2" per minute etc... It would be good to see some monitored data on these things to see how efficiently you can fly them though.

Jabawocky

43"
We have plenty of it. If you want to see it, PM me.

I am glad you raised this, when done as I stated LOP the engine is not being abused, a ROP setting is another story. Again in the same data set I refer to above, you get to see this too. It is an eye opening experience.

The POH recommended climb settings as I detailed several posts back, and as your memory is correctly recalling is very hard on the engine. Again in the Dyno run data, we have this too. The data does not lie, and it tells a wonderful story.

The fact these engines do so well is testiment to the great engineering standards they were built to. Despite that there are kinder ways (more longevity) to operate them. In the words of George W Braly, "Its not how hard you run your engine, its how you run your engine hard!"

There are two options to generate cruise or climb power settings, one is gentler, cooler and cleaner, the other is for max everything. When one understands the full spectrum and not just the one half traditionally taught, the use of both become very effective tools in the toolkit.

Walter Atkinson

Advanced Pilot Seminars has been offering a money-back guarantee on the Live Course for over 13 years. So far, not one of the thousands of participants has asked for their money back--and that includes OEM representatives, FAA personnel and engine manufacturer reps, engine rebuliders and hundreds of LAMEs. Not one--and some came as seriously doubting Thomases.

We have also offered a $1000US reward for any repeatable data which is offered to contradict anything we present. So far, no takers.

If you don't believe what we present and what Jabba or Deakin or I say, why not take us up on that offer and offer your data?

If anything we present can be proven wrong, we want to know it more than anyone--and we're willing to pay for that education.

Remember that, without data, all you are is another person with an unsupported opinion.