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Commercial Pilots who don't know about piston engines

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Commercial Pilots who don't know about piston engines

Old 29th Jan 2016, 10:39
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Commercial Pilots who don't know about piston engines

If you are one, please, at the minimum read John Deakins old Pelican Perch articles on AvWeb, or any of Jabawocky's posts concerning engine management right here on the prunes.

If you are thinking of sticking around in GA and potentially abusing many engines over many hours I strongly recommend the Advanced Pilot course. You will be on the right side of history.

If this does not pique your interest, make you question your shiny-shoed instructors advice and make you want to dig deeper on the subject...

If you rely on old wives tales to set your mixture, think that fuel cools an engine from evaporation, pull a Continental engine back to 25" after take off.... in short, if you cannot think for yourself and are not at all curious GO AND FLY TURBINES.

They are marvellous things that by now have engineered out the requirement for any sort of deep knowledge and understanding of what's going on under the cowl.

Piston engines are also marvellous creations, even more marvellous in the eyes of some because, in the higher powered examples, you have to THINK. You can break stuff (eventually) if you don't THINK. There are expensive consequences for not knowing stuff. Some derive some sort of satisfaction at a job well done in this regard. Others think that a CHT of 460°C is fine because the absolute limit is 500°C

Never thought I'd rant on pprune but there it is. Just had our pristine, factory new, pampered, GAMI'd, EDM'd 540 defiled by yet another victim of our collective ignorance.

Also never thought I'd use emoticons

Peace

"Pelican's Perch" Index - AVweb Features Article

Advanced Pilot

Yes, I am a follower of the Holy Trinity: George, John & Walter. They are shining light where there was darkness....
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Old 29th Jan 2016, 11:16
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That's all good and well, but at the end of the day, when you're being paid to fly someone else's machines, you fly them how they want you to fly them (caveat that with 'as long as it's safe). You can't just go and fly them how you want to because you read something on the Internet.
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Old 29th Jan 2016, 11:17
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You can also degrade a turbine engine by running it just below the absolute limit or by crap handling practices too.

What's your point?


So who broke your fancy new engine? Did you hire it out to an idiot or did one of the pilots in your employ not get taught by you "correctly"? Were they following the AFM or the magical teachings on the internet?
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Old 29th Jan 2016, 11:32
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It's probably not fair to put all the blame on the pilot...

Did the operator provide adequate training? Did the owner (you) do research before leasing out the aircraft to the operator? Does the operator have a history of ****ing engines? How does he instruct his line pilots to lean the engines? Have you asked them this?

I remember my GA days. The owner of the company insisted we run the EGT right before it would cut out to save $$$$ on fuel. Not his engines so he didn't care. Not that all the pilots did that....
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Old 29th Jan 2016, 11:47
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How was your engine defiled in this case?
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Old 29th Jan 2016, 19:55
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It was flown by an employee of the manufacturer. My bad for assuming they would know what they're doing. Clearly, they wrote the AFM. In this specific case he got a number wrong from what he was actually told, and was leaning (300hp) engine to as low as 76lph at full power.

No damage done, but looking at the EDM data you can see the confusion as mixture goes down, then back up as CHTs shoot through 400°F, then down again... and so on.

Yes, the online APS course is magical.
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Old 29th Jan 2016, 20:09
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That's all good and well, but at the end of the day, when you're being paid to fly someone else's machines, you fly them how they want you to fly them (caveat that with 'as long as it's safe).
You don't know it's 'safe' unless you know how a piston engine actually functions and what the various controls actually do to its innards.

The blissfully ignorant are generally only 'safe' because most GA piston engines are engineered to take a lot of abuse. Those who run GA piston engines on the basis of data and knowledge are 'safer', because they aren't exposing the engine to unnecessary abuse.

But Lumps: You were a little naive in believing that an employee from a manufacturer would know what he was doing, given some of the demonstrable rubbish published by manufacturers.
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Old 29th Jan 2016, 20:44
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No doubt you have caught my attention.

LUMPS, are you the young fella who contacted me recently about LAME's and company folk not interested in fixing fuel flow on take off for a TC engine and with what by simple diagnosis of the EMS we think had advanced timing?

Or are you the guy who is an ex student from the Perth class? This sounds too much like their story but it is not hard to believe it is another example.

My personal opinion about owners and telling you how to do things, if you are suitably educated in the science of combustion, you should be able to convince the owner/operator that the practises need to change. And if they are really dangerous leave.

I think it is like a CP telling pilots to dive through holes on an RNAV…..(think Lockhart River type crash, not that the CP said it), just because they said to do it I doubt you would. Engine operation is similar.

Lead Ballon

Lumps……maybe you should suggest they book in for the Feb class in two weeks, only 3 spots left.
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Old 29th Jan 2016, 20:44
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But Lumps: You were a little naive in believing that an employee from a manufacturer would know what he was doing, given some of the demonstrable rubbish published by manufacturers.
Sadly, yes.

If read carefully tried to avoid blaming the pilot
another victim of our collective ignorance.
It'd be unfair as it's more of a aviation community thing.

Yes, you can bugger up turbines too with dunderheaded tactics, I just don't think they are as vulnerable to ignorance. Push the levers until the correct numbers are obtained. With pistons quite often know one knows what the correct numbers are, not helped by wrong figures in the AFM.

For example take the P&W R985 with a CHT limit of 550°F. If it was an ITT max continuous limitation in a turbine, you could assume running it at say 5-10% below the max continuous ITT would be prudent practise, typically nothing required more than routine maintenance. Run the R985 at 500°F all day and, well, you probably won't be flying all day after a while.
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Old 29th Jan 2016, 20:45
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You can also degrade a turbine engine by running it just below the absolute limit or by crap handling practices too.

What's your point?
I think his point is that with a turbine engine its all black and white in the sense that there is a power lever and needle. All the monkey needs to be taught is don't put the needle beyond that place. There is less room for dummies like in the OPs case to have heard something, run with it treating it as gospel and subsequently giving the engine undesirable treatment. I'm not saying it can't happen, but the scope for it to happen is MUCH less.

The owner of the company insisted we run the EGT right before it would cut out to save $$$$ on fuel.
The irony of this is that, at least at typical cruise settings, the engine would have been happier there than where you would have probably leaned it to.

Continental engine back to 25" after take off
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Old 29th Jan 2016, 22:30
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Now Lumps, Jaba et al, I'm not having a go at either of you and the engine operating methodologies you support. HOWEVER as mentioned in this thread, students should never just take stuff that is spoonfed to them by their instructors as gospel and do proper research, the same really can be said for LOP operation.

I'm sure you guys will agree that proper LOP needs proper engine monitoring, and properly balanced fuel injectors, not just a single EGT probe you'll find in the vast majority of GA pistons.

Now if some young (or not so young) impressionable person would read your research and then start operating a stock standard engine with 1970's era instrumentation against the owners and/or POH LOP, what are the possible consequences of doing this? Would you consider it safe if someone were to try this?

Having operated radials and a decent percentage of piston types that make up the GA fleet the most "modern" engine feature I've seen in 98% of these were fuel totalisers / digital fuel flow gauges.

Now again, I am by no means discounting the science, should I ever be silly enough to buy my own piston single/twin I will most certainly also invest in hardware that will allow me to safely operate LOP.

In the meantime I shall go back to monkey mode and push the levers on my PT6's and make sure I don't make the needles go over the line.
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Old 29th Jan 2016, 22:44
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Safe ROP operations needs proper instrumentation and engine set up, too.

That's the joke. Those who don't want to operate their engines at settings that dare not speak its name are usually blissfully ignorant of where the engine is set!
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Old 29th Jan 2016, 22:49
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Safe ROP operations needs proper instrumentation and engine set up, too.
Touche
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Old 29th Jan 2016, 22:54
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Nobody has mentioned anything about LOP operations. Of course you need the proper equipment and knowledge to be able to do it safely and correctly. The grievance of this thread is to do with people routinely doing what you should definitely NOT do period. The follow-on from that topic is the disappointment that many of us share. The disappointment that many of our fellow aviators just do not seem to care or be in the slightest bit interested in the intricacies of the trade. Back in the day when I started reading Pelican Perch it got me hook line and sinker.
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Old 29th Jan 2016, 22:55
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You don't need to be operating LOP or have all-points monitors to gain value from understanding your engine properly. I largely operate low powered carb engines, but have gained a great deal from the writing of Deakin etc.

When teaching a student about leaning I can tell them how it actually works rather than the usual "leaning too much destroys engines!" that I got when I was learning. Likewise why the engine runs rough when you lean aggressively, that it's the leanest cylinder falling off the HP curve, not the engine detonating (as many instructors I know believe).

With that said every time I fly my little O-235 I'm running LOP. If I lean till rough then enrich till smooth the leanest cylinder(s) are likely LOP, possible with some others at peak or ROP. Which is why I laugh when people say "You can't LOP without the equipment!". True I can't climb LOP etc, but how to do I know where each cylinder is on my horrible EGT spread? And unless I'm at high power settings it doesn't matter. Considering the POH tell me to operate it at the worst EGT it could it's not like things could get any worse is it?
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Old 29th Jan 2016, 23:04
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According to wishiwasupthere, that's just stuff you read on the Internet, FoolC!

All discussions about piston engine operations are implicitly about ROP and LOP, because:

- if an engine's running, each piston is somewhere on that lean curve, and

- the only way - repeat, the ONLY WAY - to be sure that you are NOT doing something that you should "definitely NOT do" is to know where each cylinder is on that curve.
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Old 30th Jan 2016, 00:35
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From experience in maintaining several commercial operators fleets most aircraft still have the old egt/cht combo. Cessna old engine clusters are especially bad for for discerning any useful information. At best you can say 'your in the green' . The scale seems non linear and wishful at best. Full engine trend monitoring is rare as operators don't want to spend the coin.
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Old 30th Jan 2016, 01:55
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Hasher, have the non precision instruments,that we know and love,been detrimental to engine longevity?
Hasn't seemed to have mattered in my limited experience.
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Old 30th Jan 2016, 01:56
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From memory the point of those articles were that owners should spend money on a proper all cylinders temperature measurement.

And the irony here is that if they did that flying a piston with that gear in it is really the same as flying turbines! Not hard to blow up or overtemp a turbine engine.
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Old 30th Jan 2016, 02:14
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As a novice pilot, I am concerned this post starts buy suggesting engine management advice should be taken from an anonymous contributor called Jabawocky, some dentist, and a lawyer. The industry is in serious trouble.
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