How Much Do You Want to Know About How to Operate your Lycoming

[cliffy]

How much do you want to know about how to operate your 4 cylinder Lycoming?

There have been A&Ps who have had their license yanked when the FAA came a knockin' because they thought they knew more than Lycoming on how to maintain the engine

https://www.lycoming.com/sites/default/files/O-HO-IO-HIO-AIO %26 TIO-360 Oper Manual 60297-12.pdf

[PT20J]

Yes, that book came with our engines. But, I’m missing your point. Operating and maintenance are different concepts. Help me understand. 

[201Steve]

Also not tracking, but to keep with the spirit, can you cite an example of an A&P who’s license was yanked for their Lycoming 4 cylinder theory, and what that theory was?

[cliffy]

Well for one there is a thread going on right now relating to when and how to do oil and filter changes with some varying thoughts

Oil and filter changes are covered here in this manual designed by the engine manufacturer

To the point of an A&P having his certificate yanked?

Know of one who advocated that after overhaul the owner should just "fly it like he stole it" instead of following the Lycoming approved break in system. Feds came knocking and pulled his license for a while. They're take?

"What makes you think you know more than the guys that built the engine rather than follow established and approved procedures?"

No different than not following directions to change internal star washers on magnetos ANY TIME THEY ARE LOOSENED no matter how slightly. Many mags have fallen off due to this alone.

We had one just a year or two ago have a forced off field landing in a dirt field just for this very item. But someone decided that they wouldn't follow the Lycoming procedure and just do it their way. (Also FAA policy on locking devices- lock washers, safety wire, etc.)

I know of one Fed inspector (many years ago) whos thing was to find planes with chromed spinners and ground the airplane. The owners would always ask "why?"  and his response was "find me any  approved procedure that allows one to chrome a spinner".

The same goes for polished propeller blades. Find me any manufacturer approved procedure that allows a prop to have a polished surface. Thy all require some sort of surface coating to avoid corrosion. If push came to shove the polished blades lose. 

Just sayin' s&*t happens when you least expect it.  Every Fed inspector is different and I've seen some dozzys in 55 years especially with the new guys just coming onboard and wanting to make a name for themselves. 

 

 

Edited March 13, 2021 by cliffy

[hammdo]

Curious if you are saying this is a ramp inspection or something else...

 

https://pilot-protection-services.aopa.org/news/2019/june/01/be-prepared-ramp-checks-and-what-you-should-know

https://www.aopa.org/news-and-media/all-news/2013/january/22/kathy-surviving-ramp-check

https://www.pilotmall.com/blogs/news/faa-ramp-check-the-10-things-you-should-do

https://www.pilotmall.com/blogs/news/faa-ramp-check-the-10-things-you-should-do

 

-Don

 

[cliffy]

I'm not quite sure where you are coming from with the ramp check idea but-

We had one member several years ago come back to his airplane after a ramp check when he wasn't there and it had a grounding tag on it. Turned out he had dents and corrosion visible from the outside that the inspector grounded it for.

IIRC it went to the graveyard.

The chrome spinner deal was always a ramp check initiation

Polished prop blades would quite possibly be a ramp check issue

The entire point of my post being that everything involved in maintaining CERTIFIED airplane has an APPROVED procedure. Casting about by doing things in a different way has consequences that sometime do not seem apparent and many times times result in legal issue or a BIG safety issue 

On my own Mooney I caught an imminent engine catastrophic failure by following the 50 hr oil change routine with cutting the oil filter apart to have a look see. If I had decided "on my own" because I didn't have time to check the filter to just drain a refill the oil and go 100 hrs to a filter, my airplane would be in the grave yard today. 

The only way we keep our little part of the aviation world safe is to follow the program. Its a two edged sword here. One side cuts to safety issues and the other only cuts to legal issues. Either way it cuts. Your choice.

 

 

Edited March 13, 2021 by cliffy
added text

[EricJ]

On 3/13/2021 at 9:31 AM, cliffy said:

Polished prop blades would quite possibly be a ramp check issue

Polished blades are okay on some Hamilton Standard propellers and many steel-bladed propellers.

Quote

On my own Mooney I caught an imminent engine catastrophic failure by following the 50 hr oil change routine with cutting the oil filter apart to have a look see. If I had decided "on my own" because I didn't have time to check the filter to just drain a refill the oil and go 100 hrs to a filter, my airplane would be in the grave yard today. 

The operator's manual you cited just says to change the filter on the 50 hour inspection, and only says to change the oil (the filter isn't mentioned) on the 100-hour inspection.   To me that's a 100-hour filter change interval and a 50-hour oil change interval.   Is changing the filter every 50 hours (or more frequently) contrary to the operating manual?   A strict reading would suggest so.

Edit:   This is in reference to the Lycoming xO-360 Operator's Manual initially cited above.  Also, the OM 100-hour instructions do reference the 50-hour instructions, so the filter change is included that way. 

 

 

Edited March 14, 2021 by EricJ

[PT20J]

1 hour ago, EricJ said:

The operator's manual you cited just says to change the filter on the 50 hour inspection, and only says to change the oil (the filter isn't mentioned) on the 100-hour inspection.   To me that's a 100-hour filter change interval and a 50-hour oil change interval.   Is changing the filter every 50 hours (or more frequently) contrary to the operating manual?   A strict reading would suggest so.

The M20J S&MM says 50 hour and 100 hour inspections include changing oil and filter and the suction screens as well. 

[Guest]

Up here Transport Canada Inspectors haven’t conducted a ramp check in years that I’m aware of.  There are too few of them to worry about private airplanes, commercial ones seem to be the concern.

Clarence

Edited March 14, 2021 by M20Doc

[EricJ]

16 minutes ago, PT20J said:

The M20J S&MM says 50 hour and 100 hour inspections include changing oil and filter and the suction screens as well. 

Yes, I should have clarified that I was referring to the Lycoming operator's manual that was citied initially.

Edit:  Also, this is a good example of differences in "which instruction do I follow?"   Only the Limitations section of the POH is "FAA Approved", where the Lycoming Operator's Manual says "Approved by the FAA" on the front page.

I think there are no right answers and that it's not really productive to be afraid of the FAA splitting hairs.   No matter what you do hairs may be split for or against you.

 

 

Edited March 14, 2021 by EricJ

[PT20J]

2 minutes ago, EricJ said:

Yes, I should have clarified that I was referring to the Lycoming operator's manual that was citied initially.

 

Actually, I understood that. I was just pointing out that the Mooney manual is more specific. I apologize for being terse 

Technically though, in the case of conflicting information, I think the Mooney manual would be the final authority for a Lycoming engine installed in a Mooney, but I think you're more current on all that A&P stuff.

Skip

[Guest]

Many earlier legacy airframes don’t have a Chapter 4 in their maintenance manual, so what rules can the regulator force upon you other that FAR’s?

Airframes with a Chapter 4 would override the engine or propeller manufacturer in my experience.

Clarence

[A64Pilot]

The only real glaring example of people abdicating operations not in accordance with the operations manual is one company that says buy our products and run your engine lean of peak and keep your airspeed up etc, they even go so far as to imply the engine manufacturer, (Lycoming) are a bunch of idiots.

‘So Lycoming published a paper obviously pointed at them, to have of course the company or maybe one of the others that profit from the product to write a scathing paper about how stupid Lycoming is.

‘Oh, and by the way if you read Lycomings published breakin procedure, it amounts to “fly it like you stole it” all the initial run ins should have been accomplished prior to it being handed over to the pilot.

Edited March 14, 2021 by A64Pilot

[A64Pilot]

14 minutes ago, PT20J said:

 

Technically though, in the case of conflicting information, I think the Mooney manual would be the final authority for a Lycoming engine installed in a Mooney, but I think you're more current on all that A&P stuff.

Skip

I believe your correct, that is the Airframe manual supersedes the engine manual, and I’d bet that somewhere in the engine manual is a statement to that effect.

[Guest]

17 minutes ago, PT20J said:

Actually, I understood that. I was just pointing out that the Mooney manual is more specific. I apologize for being terse 

Technically though, in the case of conflicting information, I think the Mooney manual would be the final authority for a Lycoming engine installed in a Mooney, but I think you're more current on all that A&P stuff.

Skip

This is my understanding as well.  An example I’m aware of is the Piper Navajo engine which has three different maximum boost setting, Piper’s is the final authority and the lowest setting.

Clarence

 

[EricJ]

1 minute ago, PT20J said:

Actually, I understood that. I was just pointing out that the Mooney manual is more specific. I apologize for being terse 

Technically though, in the case of conflicting information, I think the Mooney manual would be the final authority for a Lycoming engine installed in a Mooney, but I think you're more current on all that A&P stuff.

Skip

The Lycoming manual says "Approved by the FAA" on the front page, so somebody might argue that it supercedes, but I think it'd be a bit of a stretch to do so with respect to the POH.  The manufacturer's instructions are supposed to be authoritative, especially the Maintenance Manual, which for airplanes often doesn't include a lot about the engine.   The aircraft AFM/POH limitations section is FAA Approved, which should have the aircraft-specific relevant engine limits in it.  Otherwise the engine manufacturer's documents apply in areas where the aircraft manufacturer doesn't provide guidance, and most seem to not include very much engine stuff for this reason, so that the engine manufacturer's documents apply beyond aircraft-specific limits.

My fave go-to docs are the legal opinions written by the FAA lawyers, which would be easy to bring a relevant one into a courtroom if necessary as an authoritative document.    My fave example of those is the Coleal opinion which says pilots must use "good judgement" in determining what Preventive Maintenance is.   That's a powerful FAA legal opinion to be able to have on your side.   

I think about this stuff a lot, since it appeals to my engineering side, too, and as long as I have a relevant document to point to that supports what I'm doing, I'm confident I can defend my actions if necessary.    So, yeah, if the Manufacturer's POH says you can do something, it'd be pretty tough for somebody to argue that you can't do that.   Even though the POH says to change the filter every 50 hours, it might be hard to argue you can't wait until 100 since the Lycoming manual suggests that you can do that.   My POH says it the other way, that you can run the oil for 100 hours as long as you change the filter every 50.   If it gets down to hair-splitting then it may be unlikely to be something you could have properly anticipated, anyway, just IMHO.   There are so many of these relevant documents that say different things or flat out contradict each other that it's a bit nuts, but I think it also provides opportunity for diversity in opinion and practice.   I think it's also why if you ask three different IAs about something you might get four different answers.   

[dzeleski]

I think we all forget that these POHs are 40 years old. Sometimes even more then that. We've learned a few things about airplanes and their engines in half a century. Just because something is in a 40 year old POH doesnt mean its correct in 2021. There are many things I dont follow word for word because its just flat wrong or misleading by todays standards.

For climb my 77 J says lean for smooth operations, not sure about everyone else but smooth operation is a range of several GPH for me and ranges from not great, good, to actually terrible.

For econ cruise it says run ROP by 25 degrees which is one of the most stressful settings for the engine.

For decent it says: Rich or Lean for smooth operation. So either pissing with fuel or "lean".

And for taxi it has zero recommendations for fuel what so ever.

Lyco and Cont do have their heads up there asses when it comes to fueling, ignition, and engine settings, but largely because the regulations make it so damn difficult to actually do anything new without it costing millions. Which is why we are still stuck with engine designs from the 50s, and the efficiency to go with it. That company that told lyco they are stupid is largely correct. Your car has been running lean of peak since the 90s and there is no reason why our airplanes cant follow along.

We should have 2x ignition coils per cyl, 2x injectors per cyl, 2x ECUs running in a linked active/active mode. This tech exists, yet we get to sit here and talk about 40 year old recommendations/tech as if its 100% true and cannot be changed over time as we learn. Its really pretty insane in my eyes.

[PT20J]

Actually most auto engines run stoichiometric (peak EGT) because of the requirements of three-way catalytic converters.

The BSFC of airplane engines is pretty good because they can run LOP, are unhampered by pollution restrictions, and are tuned for operating over a narrower range of power output.

Airplane engines are designed for high power/weight ratios and to run at cruise powers of 65% or higher. Auto engines care less about weight (hence they can use liquid cooling) and cruise at perhaps 10% power.

Modern automobile engines are marvelous feats of engineering, but they are different that airplane engines. Just look at how many have tried auto-to-airplane engine conversions and how generally unsuccessful they have been.

Skip

 

[A64Pilot]

A LOT of people think they know about car engines, but usually really don’t, and they try to apply this disinformation to aircraft engines, and then sit back and say how stupid the aircraft engine manufacturer is.

‘Well. I have a few eye openings for you, to start with our knowledge of recip aircraft engines has not advanced much in 70 years. The reason for that is not what you suppose, but the reason for it is the extremely deep pockets being the Military has no use for recip aircraft engines and hasn’t pretty much since WWII, so the endless research and bottomless budgets dried up long ago. Then there is the obvious economy of scale, how many new aircraft engines do you think are manufactured each year? I bet Toyota build more car engines in a single day than Lycoming and Continental do in a year.

‘Tell me what is it about aircraft excepting avionics that isn’t one Milspec or another?

But lastly for a great many reasons aircraft engines and automobiles have little to do with each other, from fuel, to being air cooled , to operating RPM and percent power output, emissions controls etc.

For example there is very little to no advantage to variable ignition timing on aircraft engines, and if you do go that route, you might want to give the folks at Hartzell Propellor a call and ask them about variable ignition timing, there is more to the system than you know.

Now, I’ll admit that Magneto’s shoud have gone the way fo the Dinosaur 50 years ago, but they do work.

‘The bottom line is that there are and have always been snake oil salesmen, and the first thing they do is take the uneducated and inexperienced and convince them that the manufacturer of a product are idiots that don’t care and well are just stupid, but buy their product because they are so much smarter and have your best interests at heart.

‘Oh, they always spin a convincing tale to those that don’t know any better.

[cliffy]

3 hours ago, EricJ said:

Polished blades are okay on some Hamilton Standard propellers and many steel-bladed propellers.

The operator's manual you cited just says to change the filter on the 50 hour inspection, and only says to change the oil (the filter isn't mentioned) on the 100-hour inspection.   To me that's a 100-hour filter change interval and a 50-hour oil change interval.   Is changing the filter every 50 hours (or more frequently) contrary to the operating manual?   A strict reading would suggest so.

Edit:   This is in reference to the Lycoming xO-360 Operator's Manual initially cited above.

 

I think one might find that when a 100 hr inspection comes due it entails  all of the 50 hr inspection plus a more detailed 100 hr inspection thereby having oil and filter at both 50 and 100 hrs, might be in the airframe manual

[carusoam]

The fun part of MS...

The suppliers people are actually members here... 

MS isn’t allowing much commercial activity...  so it’s really the tech people supporting their products...

So... even if you don’t see them every day...  somebody around here will remember who the Brand Q guy is...

Often people have their email connected to their MS account... so they receive an email whenever their name gets mentioned...

Hence the reason we want to always be nice to the vendors... you might want to ask them a question... and get a real answer...

 

Best regards,

-a-

[EricJ]

48 minutes ago, cliffy said:

I think one might find that when a 100 hr inspection comes due it entails  all of the 50 hr inspection plus a more detailed 100 hr inspection thereby having oil and filter at both 50 and 100 hrs, might be in the airframe manual

It does, and my POH (M20J) allows running the oil 100 hours as long as the filter is changed at 50.

[ArtVandelay]

All this documentation was before we had engine monitors.

I lean using the engine monitor on climbs as well as cruise.

 

The manufacturer gets the last word because they know the installation, in particular the cooling ability.

 

I question either manufacturer’s motivation:

Mooney wants performance first, and engine to last long enough they’re not going to have warranty claims.

Engine manufacturer the same, but would be better if engines didn’t make it to TBO, parts are a profitable part of the business.

 

My motivation is to get the engine to go beyond TBO, maximizing MPG while maintaining 150 knots TAS in the safest possible way.

 

Regarding oil changes, you can’t change the oil too frequently. It depends on the timing of my long cross country trips, I change oil every 30-50 hours and couldn’t care less about what the manufacturers recommends.

[carusoam]

Tom,

You nailed it!

-a-

[dzeleski]

On 3/13/2021 at 8:45 PM, PT20J said:

Actually most auto engines run stoichiometric (peak EGT) because of the requirements of three-way catalytic converters.

The BSFC of airplane engines is pretty good because they can run LOP, are unhampered by pollution restrictions, and are tuned for operating over a narrower range of power output.

Airplane engines are designed for high power/weight ratios and to run at cruise powers of 65% or higher. Auto engines care less about weight (hence they can use liquid cooling) and cruise at perhaps 10% power.

Modern automobile engines are marvelous feats of engineering, but they are different that airplane engines. Just look at how many have tried auto-to-airplane engine conversions and how generally unsuccessful they have been.

Skip

 

Not the cars ive worked with, and ive worked with hundreds. Most under load are running 12-13:1 , and 15-17:1 at highway loads. Back in the 90s honda was running their early fuel injection setups at like 18-20:1, but we then figured out that was causing worse emissions then at 15-17:1. During cold start yes, this warms the cats faster for emissions reasons. Im not saying to use auto engines in airplanes I think the raptor project displays why that doesnt work, what I am saying is to use modern electronics and control systems on the same engines with modified heads to be able to use that tech.

 

On 3/13/2021 at 9:02 PM, A64Pilot said:

A LOT of people think they know about car engines, but usually really don’t, and they try to apply this disinformation to aircraft engines, and then sit back and say how stupid the aircraft engine manufacturer is.

‘Well. I have a few eye openings for you, to start with our knowledge of recip aircraft engines has not advanced much in 70 years. The reason for that is not what you suppose, but the reason for it is the extremely deep pockets being the Military has no use for recip aircraft engines and hasn’t pretty much since WWII, so the endless research and bottomless budgets dried up long ago. Then there is the obvious economy of scale, how many new aircraft engines do you think are manufactured each year? I bet Toyota build more car engines in a single day than Lycoming and Continental do in a year.

‘Tell me what is it about aircraft excepting avionics that isn’t one Milspec or another?

But lastly for a great many reasons aircraft engines and automobiles have little to do with each other, from fuel, to being air cooled , to operating RPM and percent power output, emissions controls etc.

For example there is very little to no advantage to variable ignition timing on aircraft engines, and if you do go that route, you might want to give the folks at Hartzell Propellor a call and ask them about variable ignition timing, there is more to the system than you know.

Now, I’ll admit that Magneto’s shoud have gone the way fo the Dinosaur 50 years ago, but they do work.

‘The bottom line is that there are and have always been snake oil salesmen, and the first thing they do is take the uneducated and inexperienced and convince them that the manufacturer of a product are idiots that don’t care and well are just stupid, but buy their product because they are so much smarter and have your best interests at heart.

‘Oh, they always spin a convincing tale to those that don’t know any better.

Most people dont, true. Considering I build, race, and tune my own engines its a little different. Ive tuned many cars and motorcycles for everything from street use to racing. Piston engines are piston engines. Just because the load is a bit different or the cooling style or type is a bit different they still follow the same laws of physics.

Largely racing pushes tech forward when it comes to auto companies these days(Other then just internal R&D of course), tech that existed in motoGP and F1 decades ago exists in cars/bikes today. Current F1 engines are >50% thermally efficient, which was thought to be completely impossible just a few years ago. Just because the military doesnt need piston engines anymore doesnt mean research has stopped or dried up. Its still on going but coming from different areas, we are just not using any of that knowledge in GA aviation. Innovation as completely stopped.

My race gas is actually very similar to 100LL and ive used it in a pinch many times. A long time ago VP used to literally buy AV gas to use as there base fuel. 100LL is actually an octane of 96 if using the same pump gas measurement. The biggest difference is it has a lower specific gravity then most other fuels which means by default you run leaner with no changes. Its a common misconception that people think that 100LL is designed for lower RPM but thats not the case. its designed to have significant detination resistance because our ignition and fueling is so inaccurate that we need the head room.

There used to be air cooled auto engines too, in fact those are still being built and used/raced. Many of them have been retro fitted with modern electronics and controls systems and making significantly more power then before.

GA Piston engines and auto engines have a lot more in common then you are trying to lead on. We dont need every single new piece of tech attached to these engines due to the way we run them (constant power for hours), but many pieces that already have a ton of research behind them could be and we could gain significant improvements by using them.