Engine Checks

[The500man]

I suppose that also highlights the use of maximum continuous power rather than full power in high speed cruise or extended climbs.

I discovered that an aircraft with an injected engine may not actually require the manual selection of alternate air when intake icing occurs as this can be automatic. Varying amounts of alternate air can be automatically selected depending on the severity of the blockage.

We can then cross check the EDM with primary instruments and if both agree then it is very quick to realise that there is an actual problem rather than a gauge problem.

Sounds like a useful bit of kit but presumably it must have duplicate probes to do this?

[englishal]

Yea, you fill up the CHT holes in the heads with probes, you put EGT probes in each cylinder exhaust, new oil pressure and temp sensors (Lycomings have space for second oil temp sensor), RPM sensor, Manifold Pressure sensor, Carb temp probe, TIT probe, fuel flow sensor and OAT probe.

[goldeneaglepilot]

With all those extra goodies, when does it get to be too heavy to take off? Does anyone run courses into how to understand the data stream being thrown back!!!

Easy answer to all the problems - PT6, Difficult to fit on the Kit Fox though.

Joking aside - keep it simple will get you out of most problems

[Big Pistons Forever]

Originally Posted by goldeneaglepilot

keep it simple will get you out of most problems

Not a particularly useful statement.

So Joe/Jane PPL is flying along and the engine starts to run rough, what would you expect him/her to do under the guise of "keeping it simple" ?

[Jabawocky]

The solution to most of this is good education (lacking at ALL flight schools) and good instrumentation.

With good education and practises, you are less likely to suffer serious problems, as they usually start as minor ones. These you fix long before they are major.

Detonation - May be caused by leaning at high power settings and is unlikely to be noticeable unless severe.

Pre-ignition - Usually indicated by roughness, backfiring and a sudden increase in CHT.

Detonation is hard to create in a normal environment with a conforming engine on conforming fuel. However, short of having an all cylinder EMS and alarms set wisely you will never detect it in mild to medium to severe forms.

Pre-ignition is not likely to show you any signs either, until it is all too late, and this may be as soon as a few minutes from when it started. In a car perhaps, but not in a plane. Unless you see a CHT rising at a rapid rate, you will not know. Without an EMS and wisely set alarms, you will not know. You will not hear any backfiring! Folk who have had preignition failures and had engine monitors to capture the data, did not know anything apart from a weird CHT reading.

So in short, the engine monitor AND education in what it is really telling you (not from the local aero club or flight school who know nothing) are the best things you can invest your money in.

There are several good EMS products around to suit either certified or experimental aircraft and the only good source of education on the planet that I know of is at Advanced Pilot

Anyone who argues otherwise, is simply wrong, they are entitled to be wrong, but just don't follow their blind ignorance, your family will appreciate your vigilance.

[peterh337]

Time for another LOP thread?

[Big Pistons Forever]

jabowocky

Your absolute statement that "everyone else is wrong" is correct for the 2 % of the GA fleet where the aircraft is fully instrumented and you always fly the same aircraft. The second point is important because all engines run a bit differently and the true value of engine organizers is seeing the subtle deviations from normal that are indicators of a potential problem that you will only get to know from hours and hours of watching that engine.

For the other 98 % of the GA community and other than Peter 337, what I am guessing is everybody else reading this thread, your advice is completely and utterly useless.

The vast majority of GA pilots will be flying aircraft with only the basic engine gauges of RPM, oil pressure, oil temperature and ammeter. "Advanced" engine instruments likely not found in most aircraft, will only consist of a basically useless single probe EGT, and or CHT and maybe a carb temp gauge.

Therefore IMHO the knowledge delta isn't about a pilots not knowing how to run LOP, it is how to properly lean a carburated engine with no good EGT information.

Similarly the lack of knowledge and skill for recognizing and dealing with carb ice at the PPL level is truly frightening.

Finally while crude and insensitive the oil press and oil temp gauge will usually give you warning of an impending internal engine mechanical failure if you pay attention to what they are saying.

One pet peeve of mine is how few instructor insist on checking that the engine is making full static RPM at the beginning of the takeoff run.

A while ago I was asked to help out at a flying school. On the first lesson, flying a C 150, I thought the engine was a bit rough on runup. Sure enough on the takeoff as soon as the student had applied full throttle I checked the RPM and it was 150 RPM below the POH minimum static RPM range. We rejected the takeoff and maintenance confirmed a dead cylinder and metal in the filter which resulted in an engine change. The sad part of this story was that when the news of the engine condition became known the dispatcher said " You know the instructors have been complaining for 2 weeks that that airplane was a dog "

Ok you and Peter can now get on with obsessing about LOP operation in privately owned high performance aircraft

And goldeneagle pilot still waiting for your thoughts on "keeping it simple"

[Jabawocky]

BPF

Forgive me if I have this wrong, but this forum section is private flying, not ab-initio training, and I would think even there a greater need for education exists. So I do not subscribe to your 2% theory. We should not be catering for the lowest common denominator, we should be trying to raise the bar. Always!

As you say, all engines run a bit different, but you know, the subtle differences are not that significant. I can get out of one and into another and if something is amiss it is not found by absolute numbers (except where is rather obvious) it is from trends. Believe me, if you have a preignition event, it will not be hidden in the subtle differences you mention.

For the other 98% of people, I think the rest of my post is even more relevant as it requires even greater understanding to operate with a high degree of efficiency sans the instruments. Sure you can run around full rich all day long, but for the most part people use aeroplanes to go places, not just do circuits. Well at least here they do anyway!

will only consist of a basically useless single probe EGT, and or CHT and maybe a carb temp gauge.

Indeed! However with some really good knowledge, you can get by with this operationally, running LOP even, however it is sub optimal in fault diagnosis. In fact the carby temp sensor is a very useful tool for running a Carby engine LOP

As this thread is about engine checks, having an EMS really helps in knowing things are right or wrong Vs only thinking they are right or wrong. The point here being, if the readers of this thread have any influence at all on the machine they operate, they should be thinking harder about this. For example, you have a slightly rough engine doing a runup/mag check, done LOP or at peak you can detect the fault and most likely diagnose exactly what it is. Done ROP and no instruments, you might not even detect the problem that is developing over time. This in itself can save thousands of dollars in mechanics bills. Being able to taxi to the workshop and say, No5 cylinder bottom plug needs replacing sure beats the hours and hours of hit and miss diagnosis and maintenance.

Not having this stuff and dismissing its promotion to those who do not is kind of like saying, hey, back 40 years ago we did not have seat belts, ABS, radial tyres, disc brakes, coil springs and airbags. So why buy that BMW, or better still buy it but rip out all that complicated and heavy stuff. Those who still drive around in less capable cars today do so with greater safety than years ago, why? Because they do not know how many accidents they have avoided because everyone else is driving better equipment and not hitting them. Same goes for aviation technology.

Therefore IMHO the knowledge delta isn't about a pilots not knowing how to run LOP, it is how to properly lean a carburated engine with no good EGT information.

Indeed, however I wonder how many can actually do this, and to do it really well you do need another instrument not even mentioned thus far. But I digress.

A while ago I was asked to help out at a flying school. On the first lesson, flying a C 150, I thought the engine was a bit rough on runup. Sure enough on the takeoff as soon as the student had applied full throttle I checked the RPM and it was 150 RPM below the POH minimum static RPM range. We rejected the takeoff and maintenance confirmed a dead cylinder and metal in the filter which resulted in an engine change. The sad part of this story was that when the news of the engine condition became known the dispatcher said " You know the instructors have been complaining for 2 weeks that that airplane was a dog "

Education in flying schools, dummed down, full of Old Wives Tales, resistant to change to data based facts, and taught by 200 hour pilots who know nothing about flying more than to pass an exam, which are often full of the above problems as well. So am I surprised at your story.....not one bit!

[Jabawocky]

Time for another LOP thread?

Peter, start one if you want, but make sure it is full of really good questions and not some bunch of bozo's sprouting all the same crap I hear from usually old and respected but not very wise men.

[Big Pistons Forever]

Jabawocky

I guess we will have to agree to disagree on your theme as the proportion of the GA fleet equipped with a full boat engine analyzer, at least in Canada, is so small that operating techniques based on its use are like the SOP's for flying a jet, interesting but ultimately irrelevant to the average private aircraft pilot; like the person who started this thread.

Originally Posted by Jabawocky

Indeed! However with some really good knowledge, you can get by with this operationally, running LOP even, however it is sub optimal in fault diagnosis. In fact the carby temp sensor is a very useful tool for running a Carby engine LOP

I do have a question about the above comment. Personally I have operated the following GA carburated engines:

Continental, C65/C85, O200, O300, O470, O520,

Lycoming O235, O 320, O360, O435, O540, and

165 hp Franklin

I have never been able to lean any of these engines to true LOP because they all will start to run rough due to the inherent poor mixture distribution. SO I am quite interested in what engine(s) you are talking about and what technique you use to achieve smooth operation at LOP.

[Rod1]

Why do people think the probes etc are too heavy? A Rotax 912 comes with most of the probes as standard and adding coolant temp and EGT’s adds very little weight. Most of the Rotax powered machines I know are very well monitored with 2 X EGT, 2 X CGT, Oil Temp, Oil Pressure, Water temp, volts, and in some cases fuel flow. It is the old stuff which is reliant on out of date tec. It is true that most instructors find all this info confusing but adequate engine monitoring is a huge help in preventing a small issue growing into a failure.

Rod1

[Pilot DAR]

Anyone who argues otherwise, is simply wrong, they are entitled to be wrong, but just don't follow their blind ignorance, your family will appreciate your vigilance.

Huh?

I argue otherwise. Engine monitoring systems are a nice to have, and very handy for diagnosing some engine problems in very rare occasions. Diagnosing engine problems is great, if you get it early, and if you're in time to fix early. For that, I support their use - if the pilot knows what they are looking at. But if that problem has already shown symptoms in flight, you're also having to deal with it and fly the plane, perhaps as an inflight emergency. I have certainly flown with pilots of abnormally well instrumented aircraft, who were paying so much attention to the indications, that they forgot to fly the plane - and what they were seeing was really of little benefit to them anyway by that point.

All certified aircraft have engine operating instructions - just follow them! Keep the engine properly maintained, and serviced with the proper liquids, operate it as instructed by the manual, and it will run. The few pennys you might save by extreme leaning and other tactics are lost on a carburetted engine, because as Big Pistons correctly points out, no carburetted engine has fuel flow even enough to each cylinder to run "properly" leaned - that's just the way it is, and you the pilot cannot change that, so just pay for the fuel, and fly the plane. The only way a scanner can help with leaning is to assure that you are leaning to the leanest cylinder when reading the indication, and allowing you to find a power setting which has a more equal fuel distribution than other power settings, so your leaning is more meaningful. In reality, however, the generic "lean 'till first rough, then enrichen to smooth again" instruction works about as well as watching a scanner for 10 minutes while fooling with the mixture.

I have installed scanners for certification flight testing, where data collection well beyond the scope of any GA pilot was required. Two were for detonation testing - that's a whole other discussion, other than to say that if you operate as instructed, you will not detonate the engine. Incorrect leaning of an otherwise properly operated engine can cause damage, but not because detonation is a factor in that damage.

Both my planes do have multi cylinder scanners (left over from testing), and both are carburetted. All the scanners tell me is that I don't really need them 99.95% of the time! I do not peak, or lean of peak lean, as both engines prohibit it (same logic as not over speeding or over stressing it). Their only real benefit is that you can log a changing trend - if you notice in time, and you can identify which cylinder is sticking an exhaust valve or fouling a plug, in real time, and that's informative on the very rare occasion it happens. Though if you stick a valve, and have only that cylinder repaired, you're fooling yourself (and your family may thing you not vigilant!). Other than that, the operating instructions for the engine describe what you need to know to operate it the way it was approved. What else were you thinking to do?

My guidance is not blind in saying the forgoing, as I am delegated to certify the designs of these engines, including detonation testing. I write operating and maintenance manual supplements. The first thing we look for are safe operating margins, and instructions, which if followed, keep the engine well within those margins. People choose a certified aircraft [and engine] for the security of knowing it has been thoroughly tested. It has, so operate it the way is supposed to be. I am unaware that any aircraft has been certified as requiring an engine scanner as a part of it's type design - because they are not really needed!

If someone wants to install one, by all means. Don't let it distract you from the safe operation of the aircraft. Use it to follow (not circumvent) the engine manufacturer's operating instructions. And learn to use it properly. Most flying schools probably struggle to employ instructors who are conversant with the different scanner types, their relevance, and their correct operation. And students hardly want to spend an extra 5 hours of flight training costs to learn what it is telling them, and the relevance.

My family appreciates that I keep myself current and recent, and that I operate the aircraft legally, safely, and in accordance with it's instructions. More than that, they do not ask of me....

[Jabawocky]

I do have a question about the above comment. Personally I have operated the following GA carburated engines:

Continental, C65/C85, O200, O300, O470, O520,

Lycoming O235, O 320, O360, O435, O540, and

165 hp Franklin

I have never been able to lean any of these engines to true LOP because they all will start to run rough due to the inherent poor mixture distribution. SO I am quite interested in what engine(s) you are talking about and what technique you use to achieve smooth operation at LOP.

In my experience, some of those but not all. All the lycomings, the bigger CMI's and no idea on a franklin or a piper cub, but there is a half chance they will too.

Of course you would need to have some instrumentation and education to do it. Refer to my first post.

And I should say, Radials are better, and you must have a well maintained "conforming" engine. Otherwise you are chasing your tail, but it soon helps fix induction leaks and plug/ignition deficiencies when you do try!

I hope you are not thinking of leaving the dark side now are you?


PS: this stuff is not something that can be taught on a internet forum so I am not about to try here. As Walter Atkinson will tell you, we can't just give you a cook book with a recipe, you need to learn to cook before you become a master chef!

[Big Pistons Forever]

Originally Posted by Jabawocky

In my experience, some of those but not all. All the lycomings, the bigger CMI's and no idea on a franklin or a piper cub, but there is a half chance they will too.


PS: this stuff is not something that can be taught on a internet forum so I am not about to try here.

Can't be taught on an internet forum eh

That must be the new internet code for "I don't really know what I am talking about"

[Jabawocky]

Believe what you will.....

I am not going to debate point by point here, if I did I would spend hours and hours and still not get the message across. So here is something to prompt your interest further, or just ignore it. But do not take all the others down with you when I say they should be educating themselves further. That is like telling your kids, don't worry about high school, all you ever need you get in Primary school.

It is funny that the ones who always argue against this stuff are always those who do not have it. Both instruments and education. It never ceases to amaze me how many people do not know what they do not know. (myself included)

I argue otherwise. Engine monitoring systems are a nice to have, and very handy for diagnosing some engine problems in very rare occasions. Most problems most of the timeDiagnosing engine problems is great, if you get it early, and if you're in time to fix early.Yep, and you get a chance at early rather than at the worst possible time without For that, I support their use - if the pilot knows what they are looking at.Ahh yes we do agree, time for an APS class for all of them! But if that problem has already shown symptoms in flight, you're also having to deal with it and fly the plane, perhaps as an inflight emergency.And knowing exactly what the likely problem is will help you make the right call I have certainly flown with pilots of abnormally well instrumented aircraft, who were paying so much attention to the indications, that they forgot to fly the plane - and what they were seeing was really of little benefit to them anyway by that point. Because they believe the instrument will do it all for them, they need EDUCATION. The rest of your observation is 100% correct

All certified aircraft have engine operating instructions - just follow them!No, not always and I can show you some that are very poor or bad Keep the engine properly maintained,YEP and serviced with the proper liquids,YEP operate it as instructed by the manual, and it will run.And some will run a lot longer if you do not follow that manual, the secret is knowing which is full of BS The few pennys you might save by extreme leaningExtreme?? engines stop and other tactics are lost on a carburetted engine, because as Big Pistons correctly points out,Incorrectly points out no carburetted engine has fuel flow even enough to each cylinder to run "properly" leaned - that's just the way it is,Not True and you the pilot cannot change that Yes you can, some more so than others, so just pay for the fuel, and fly the plane. The only way a scannera what? can help with leaning is to assure that you are leaning to the leanest cylinder when reading the indication bad advice, and allowing you to find a power setting which has a more equal fuel distribution than other power settings,you are now going from stone cold to luke warm... so your leaning is more meaningful. In reality, however, the generic "lean 'till first rough, then enrichen to smooth again" instruction works about as well as watching a scanner for 10 minutes while fooling with the mixture. It might in some but how would you know? And 10 minutes....geez you just proved my point. If it takes that long to lean an engine how long does it take for a pre-flight? You can do two complete GAMI Lean tets for injector tuning in that time. I lean and set up in under a minute, maybe 30 seconds at any level from 1000' up into the FL's

I have installed scanners for certification flight testing, where data collection well beyond the scope of any GA pilot was required. Two were for detonation testing - that's a whole other discussion, other than to say that if you operate as instructed, you will not detonate the engine. Never read a Piper Chieftan manual then huh? Incorrect leaning of an otherwise properly operated engine can cause damage, but not because detonation is a factor in that damage. Ohhh, how so? I do want to hear about this? How exactly did you do detonation testing in flight, with which engine and what data collection probes? I am genuinely interested. Incorrect leaning does cause longevity issues over a long period of time, not just in a 2 minute abuse period. Temperature and cylinder pressures are the things. And these are a result of incorrect leaning. The truth is if you are on the Lean side of Peak EGT you are less likely to do damage by getting wrong, than you are on the Rich side. So the point here is if you operate ROP which is a perfectly valid method for some ops, make sure you do it right. On the lean side there is far more margin for error, except at very high powers such as 1000' WOT and full bore RPM. If you are smart with numbers you can still do this just with fuel flow alone on a conforming engine.

Both my planes do have multi cylinder scanners (left over from testing), and both are carburetted. All the scanners tell me is that I don't really need them 99.95% of the time! I do not peak, or lean of peak lean, as both engines prohibit it (same logic as not over speeding or over stressing it).You are kidding me...which engines are these? You do realise the big radials of Connie and DC6 days had a TBO some 4-5 times longer when run LOP FACT not folk lore! LOP has lower stress on EVERY engine, where do all the you beaut modern diesels run? Their only real benefit is that you can log a changing trend - if you notice in time, and you can identify which cylinder is sticking an exhaust valve or fouling a plug, in real time, and that's informative on the very rare occasion it happens. Though if you stick a valve, and have only that cylinder repaired, you're fooling yourself Not true at all(and your family may thing you not vigilant!). Other than that, the operating instructions for the engine describe what you need to know to operate it the way it was approved. What else were you thinking to do?

My guidance is not blind in saying the forgoing, as I am delegated to certify the designs of these engines, including detonation testing. I write operating and maintenance manual supplements. The first thing we look for are safe operating margins, and instructions, which if followed, keep the engine well within those margins. People choose a certified aircraft [and engine] for the security of knowing it has been thoroughly tested. It has, so operate it the way is supposed to be. I am unaware that any aircraft has been certified as requiring an engine scanner as a part of it's type design - because they are not really needed!

If someone wants to install one, by all means. Don't let it distract you from the safe operation of the aircraft. Use it to follow (not circumvent) the engine manufacturer's operating instructions. And learn to use it properly. Most flying schools probably struggle to employ instructors who are conversant with the different scanner types, their relevance, and their correct operation. And students hardly want to spend an extra 5 hours of flight training costs to learn what it is telling them, and the relevance.

My family appreciates that I keep myself current and recent,Excellent!! As we all should and that I operate the aircraft legally, safely, and in accordance with it's instructions. More than that, they do not ask of me....

Enough for today.....

[Jabawocky]

Can't be taught on an internet forum eh

That must be the new internet code for "I don't really know what I am talking about"

No it is code for, to educate properly a few minutes here and there with banter on an internet forum, with all the distractions from morons on the sidelines, would take something like 10 years.... or it would feel like it.

The APS guys are continualy teaching free of charge on some internet forums, however they have found the bulk of the information does not sink in. When placed in a class room for several days with lots of good materials, real dyno runs and explaining the science of combustion properly, eventually folk start to understand things rather than just know a few things.

I have a friend who is a former NASA space shuttle astronaught, if I asked hime to get on here and explain a certain aspect of space shuttle missions, he would laugh at the prospect, but get you in a briefing room surrounded with the right stuff for a few days, and you too would learn what they know.

This is the wrong form of media for such things.

If I started now, all it would do is cause a squabbling mess and have a thread closed, and you would be none the wiser for it.

So it is code for read my previous post and seek the education from those who provide it very well indeed.

That must be the new internet code for "I don't really know what I am talking about"

That reminds me of Burt Reynolds in Smokey and the Bandit.....

Little Enos: I think you're just a little bit scared.
Bandit: That's real good psychology. Why don't you say something bad about my mother?
Little Enos: Your momma is so ugly...

At 1min 3 seconds

Smokey and the Bandit (1/10) Movie CLIP - A Real Challenge (1977) HD - YouTube

[peterh337]

One pet peeve of mine is how few instructor insist on checking that the engine is making full static RPM at the beginning of the takeoff run.

I agree 100%

For a non instrumented engine, flown by various people at various times, and "maintained as usual", it is likely to be the only warning of a proportion of e.g. the camshaft getting gradually relocated to the oil filter

Example

I sent that report to a couple of respected US engine shops and both said the oil filter would have been full of metal - chromium specifically.

Re weight, it is not significant. I would think my EDM700 installation weighs about 2-3kg, with all the probes.

However I think accurate fuel flow, in the form of a GPS-linked totaliser, is equally important if one is to go places with confidence.

The APS guys are continualy teaching free of charge on some internet forums, however they have found the bulk of the information does not sink in. When placed in a class room for several days with lots of good materials, real dyno runs and explaining the science of combustion properly, eventually folk start to understand things rather than just know a few things.

That's true but do you need to know the internals of combustion, to configure an engine correctly for each phase of flight? No.

This is an attempt of mine at condensing what one needs to know and I think it is short enough.

Internet presents the greatest learning medium by far, for the 99% of pilots whose initial training was prob99 p1ss poor. I suppose its value is going down for various reasons (forums filling up with banal ex-Iphone one-liners is my favourite ) but if you ask a decent question (worded like you actually care for a useful reply, which is itself a skill) in the right place you will eventually get a decent reply. I learnt far more from the internet than I learnt from JAA & FAA PPL, FAA CPL, FAA & JAA IR theory.

[Maoraigh1]

Nobody has said listen to the engine. I mainly fly with an O200, just RPM and electrical oil temp and press - whose readings have on two occasions been affected by a bad connection. In the last year, we've spotted two potential problems early by responding to a slight changes in engine sound.

[Jabawocky]

Peter

That's true but do you need to know the internals of combustion, to configure an engine correctly for each phase of flight? No.

I would counter that claim with a Yes! I like your simplified article link, however there are a few things in there that need editing and refining. The biggest problem I have with it though is it is a "cookbook" approach, and not a thorough understanding approach. Herein lies the problem. It talks about "deep LOP" whatever that is? 80LOP is not deep LOP, it would be at low powers say 65% but at 80% or more it is the exact place you need to be. So here a cookbook approach does not work for all people in all missions.

This is why I say there is a difference between knowing stuff and understanding stuff. There is a big difference. Have you done an APS course? If not you should, you will enjoy it. Worth every penny.

You are quite correct in your assessment of flight training schools.

To finish up, I can believe you when you say you learned far more from the internet than any of the FAA/JAR etc training books. Problem is, they are full of little gems, that are all wrong!!

The truth of the matter is, and APS survey their students going in and out and analise how well they perform as teachers every time, and it has proven that the internet in random forms of information is not the best teacher. What is a better teacher is a well structured, "building block" approach to educating. You must understand some critical things to move onto the next phase. (Anyone remember missing some critical maths classes ) So their course is structured that way. The APS ONLINE course is cleverly constructed so that you can't progress until you understand via small quizz sessions at milestone points.

I have searched, there is nothing better.

[Big Pistons Forever]

Originally Posted by Jabawocky

To finish up, I can believe you when you say you learned far more from the internet than any of the FAA/JAR etc training books. Problem is, they are full of little gems, that are all wrong!!

.

The only thing I think that is "all wrong" is your assertion that you alone represent the sole provider of correct information. I post on things I think are of value to the pprune community but I would be the last guy to say "this is the only way to do XXX". I make a big effort at presenting not only the "what" but also the "why" for everything I post on. That way readers can see where I am coming from and decide if my information or advice has any value to them.

IMO your posts are just a waste of internet bandwidth and so I will not use up ppruners time with any further responses to your comments.