Took off on one mag accidentally - did I hurt my engine?

[Magman]

There were wonderful things said about Dry Vacuum Pumps replacing wet.

And the Tiara engine. LASAR mags too.

Aviation History is filled with developments that never quite came to fruition.


There is no such thing as “ just a Slick or Bendix/TCM mag”. Both mfg. make

numerous models that are only approved for certain applications. The extremely

low volume of POSSIBLE sales eliminates any economy of scale.

 

[Magman]

IMHO There are a couple cheap parts that should be replaced ANY time a

mag is apart for ANY reason. They are the Impulse Coupling Spring ( 5) and

the Carbon Brush (28). Bendix and others share these items by function.


There are other components to be addressed at the 500 hr or Overhaul times.

Some require automatic replacement while others can be inspected or adjusted

and re-used.


The Carbon Brush is a “wear item” similar to a pencil. While in use the wear rate

increases. The carbon wear particles stay inside the mag. At times they

“ self destruct” and fill the mag with conductive particles that permit

“ Cross Firing”.


As previously stated; periodic maintenance is needed. Running until it stops

working is at your own peril.

 

[Dan Thomas]

And since the electrical system is the most neglected system on a private aircraft I doubt any inherent reliability from EIS will be noted in the big picture.

Yup.

The Surefly has no internal backup for the inevitable times the electrical system fails. That's why, for STCs on certified aircraft, you can only install one Surefly mag. You must retain one of the "primitive, outdated, clunky, old-fashioned" mags because it will keep firing when the power to the Surefly fails, and it will also keep firing when the Surefly itself decides to quit.

The E-Mag is hybrid magneto and electronic ignition device, all in one box that looks like a magneto. If the airplane's electrics fail, the E-Mag reverts to being an old-fashioned fixed-timing magneto. I'd like to get a look inside one to see if it still uses points, or if the magneto's rotor and coil are just powering the electronic module when the power fails.

 

[Sundancer]

This is a Slick magneto, apart:

View attachment 117771

Almost all of that stuff is metal. The distributor housing, bearing support, gears, coil wrap and points cam are plastic for reasons of electrical insulation. What would you suggest instead? Metal will not work.

The electronic mag will be full of plastic as well, for the same reasons. Ever done any electronic building or repair? Ever looked at the schematic for a simple AM-FM radio? Here's one:

View attachment 117772

Every resistor, capacitor, transistor, wire, coil, and IC is mostly plastic. That electronic mag will be full of plastic stuff. Real tiny plastic stuff. I am not surprised that SureFly and others are encountering problems. As I said elsewhere in another thread, the car manufacturers do not put their electronics on the engine. Just a few sensors, whatever is absolutely necessary, is on that vibrating, hot engine. They learned a long time ago to keep the sensitive stuff somewhere else, and I am baffled why Surefly didn't do the same. I predict that they will eventually have to do it.

LOL! I didn't mean to malign mags, just commenting on my surprise at their mechanical complexity once I looked inside- and yeah, I was an Inertial and Radar Navigation Systems (32874) tech before moving to aircrew. Electrons I'm good with - of mechanical ignition internals I was ignorant. I have the general idea - the engine drives the mag, the mag provides the spark. It was the Larry Lightbulb inner workings that were new to me.

 

[Sundancer]

If you research the failure data you'll find of all the components on your typical opposed engine the magnetos are the most reliable items. Even the mags that do fail, most are operator induced from lack of performing recommended maintenance or addressing OEM upgrades. As long as the engine turns a good mag will give spark. EIS on the other hand requires an external electrical source to provide the same. And since the electrical system is the most neglected system on a private aircraft I doubt any inherent reliability from EIS will be noted in the big picture.

Sounds like a pretty good argument for replacing one mag with an EIS, then? The advantages of improved power and fuel efficiency, and a mag to keep if running if the EIS quits? I might guess fuel systems are more neglected than electrical systems, but that's a question for an A&P.

 

[Magman]

Slick produced the LASAR, which was an earlier type hybrid mag about 20 +

years ago. Since discontinued, I have never seen one!

Most Techs can deal with mags to some extent. If special tools are required to

replace a unit it may be a good idea to carry them with YOU!

Special Tools can be pricey and few people will buy and not use.

fyi. I admit I have done that though!

 

[Dan Thomas]

I might guess fuel systems are more neglected than electrical systems, but that's a question for an A&P.

Nope. Other way around. If anything gets done at the annual, it's usually the fuel strainer being cleaned. The electrical stuff is mostly ignored until it quits, so alternator failures are terribly common, as their brushes wear out. Alternators should be opened up every 500 hours for inspection, but most don't get it. The rest of the system is largely ignored, too, so that connections corrode or come loose. Contactors fail as their contacts burn (arcing on opening) or they oxidize with age. High-amperage circuits like landing lights tend to burn out their switches as the contacts in them oxidize, introducing resistance and consequent heating, but they're not caught unless the mechanic gets under the panel at annual and has a good look. He'd see the discolored wire insulation near the terminals, sometimes even see the plastic body of the switch deformed from the heat. But nope, it doesn't get looked at until it smokes.

As long as enough, clean fuel reaches the carb or fuel servo, the engine will run. Carbs and injection systems give very little trouble aside from fuel pumps. But when the engine hesitates or acts up, most people automatically blame the fuel, when in fact around 90% of the trouble is ignition. Tired mags that haven't had their 500-hour checks, ancient plugs or leads, whatever. Electrical stuff is the biggest source of problems, but it's the least-understood aspect with many mechanics.

 

[Bell206]

Sounds like a pretty good argument for replacing one mag with an EIS, then?

Not really. Statistically I prefer the established odds with 2 good mags and state the same when asked my recommendation on EIS in its current application. But if you believe EIS is the ticket then rock on. My experience with externally powered engine control devices is different.

I might guess fuel systems are more neglected than electrical systems, but that's a question for an A&P.

As noted above the electrical system is #1 with no close 2nd in my experience fixing them. The next item on the neglect list in my book is an accurate empty weight and equipment list. After that it runs the gamut depending on the type of aircraft and the type of owner.

 

[Magman]

The root cause of these issues is the Owner of Part 91 aircraft.

Many of them have minimum understanding of the systems.

Alternator Brushes, pressurizing the exhaust and Mag 500 Hrs are not mandated

per App D.

Fortunately most of my clients will follow my suggestions or what the

mfg. states.

 

[Sundancer]

Not really. Statistically I prefer the established odds with 2 good mags and state the same when asked my recommendation on EIS in its current application. But if you believe EIS is the ticket then rock on. My experience with externally powered engine control devices is different.


As noted above the electrical system is #1 with no close 2nd in my experience fixing them. The next item on the neglect list in my book is an accurate empty weight and equipment list. After that it runs the gamut depending on the type of aircraft and the type of owner.

I'll defer - my experience with EIS is limited to something less than 200 hours in a 172. Not much time to make an informed decision, except to note the advantages seemed significant. The airplane had an EIS and PowerFlo exhaust - the fuel and power benefits were noticeable - the 160 hp was indistinguishable in performance from a 180 I was flying in the same period, subjectively perhaps a bit better.

 

[Dan Thomas]

I'll defer - my experience with EIS is limited to something less than 200 hours in a 172. Not much time to make an informed decision, except to note the advantages seemed significant. The airplane had an EIS and PowerFlo exhaust - the fuel and power benefits were noticeable - the 160 hp was indistinguishable in performance from a 180 I was flying in the same period, subjectively perhaps a bit better.

Oh, the elecronc ignition does indeed improve the power. Just getting the timing to the optimum point for any given RPM and MP will do that, and the hot spark improves it further. No denying that it works.

When it works. It's the electronics, mounted on that hot, vibrating engine and depending on the ship's power that I don't like.

Lycoming's iE2 engine, totally electronic fuel and ignition, has the ECU and Power Module mounted elsewhere, not on the engine. The electronic ignition itself is mounted atop the engine, where it's cooler, but it remains to be seen how effective that will be. Hot-soaking after shutdown will still be a factor, as will the vibration.

 

[Bell206]

except to note the advantages seemed significant.

My comments were never about how it functions only how reliable it is. As you point out and mentioned above EIS has its advantages over magnetos but doesn't have the same reliability rate. The weak link outside the internal issues is all EIS needs external power to function with even the E-Mag needing power for engine start. FADECs fall into the same category but their system requirements are handled differently than EIS. Regardless, I'm sure one day EIS may reach the same proven reliability rates as those ancient magnetos. However, if the DA62 that made an emergency landing in Dallas after the failure of its 5 independent electrical power sources is any indication of current state of electrically powered engine control in the reciprocating world it may still take some more time than anticipated.

 

[asicer]

Lycoming's iE2 engine, totally electronic fuel and ignition, has the ECU and Power Module mounted elsewhere, not on the engine. The electronic ignition itself is mounted atop the engine, where it's cooler, but it remains to be seen how effective that will be. Hot-soaking after shutdown will still be a factor, as will the vibration.

I believe the Electroair EIS is also laid out like that (sensor in a mag housing, other stuff elsewhere).

 

[mondtster]

Slick produced the LASAR, which was an earlier type hybrid mag about 20 +

years ago. Since discontinued, I have never seen one!

Most Techs can deal with mags to some extent. If special tools are required to

replace a unit it may be a good idea to carry them with YOU!

Special Tools can be pricey and few people will buy and not use.

fyi. I admit I have done that though!

I have only seen one LASAR system installed. The reason I got to see it was because a transient guy had it on his airplane and it had failed...

I was able to fix the problem but you needed special tools to properly time it. I was able to get it close enough to being timed right (this was on an experimental aircraft/engine) that the owner could get the airplane over to another airport where a friend of mine had the correct timing tools. Hopefully this guy learned his lesson and carried the tools with him, although it likely wouldn't have done any good at most airports because a lot of mechanics are afraid to actually open a magneto or electronic ignition and fix problems.

I prefer magnetos on my own aircraft, despite there being some advantages to electronic ignitions. I visit some very remote areas of the US and Canada and magnetos are something that have the potential to be fixed onsite with minimal tooling. Electronic ignitions would not offer the same simplicity and a failure may turn a minor delay into a serious problem. Magnetos also have the same advantages when visiting the more populous areas of North America, so even if I visited those areas exclusively I would still prefer having a pair of well serviced magnetos over an electronic ignition.

 

[Dan Thomas]

Hopefully this guy learned his lesson and carried the tools with him, although it likely wouldn't have done any good at most airports because a lot of mechanics are afraid to actually open a magneto or electronic ignition and fix problems.

That there. Many have never serviced a mag, and they're afraid to. They need to get the Slick and Bendix manuals and an old mag and fool with it. They are not complicated. You just need a few tools to get it set right.

Many years ago when cars were using points-and-condenser ignition (the battery-powered version of magnetos), a large percentage of guys could fix an ignition failure at the side of the road, with minimal tools. I did it several times. The advent of electronic ignition changed all that. Yes, the EI delivers a nice, hot spark at the right time, and does it for a very long time, but when it quits, you are stuck, and the bill will not be nice.

The Lycoming iE2 all-electronic engine deals with the power supply problem by having a dedicated small permanent-magnet alternator on the back of the engine. It takes over the power supply when the ship's power fails. There is a power module on the firewall (or behind it) that manages that. That little alternator does not have anything to do with the airplane's electrical system. It's for the engine's needs only. But it is also one more thing to inspect and maintain. These engines will never be maintenance-free. Not if you want to live to a ripe old age.

 

[Magman]

What is recommended TBO ( years and hours) on these systems?

Field or Factory- only servicing?

They still gave Leads and Plugs to act up.

Just like mags!

 

[Bill]

Goofball, I sure hope you manage your airport better than you managed your airplane.

 

[flyingron]

Just don't do what Rod Machado calls the "click-click-click-BANG!" mag check. If you turn it off, either let it die, or yank the throttle back before turning it back on.

 

[flyingron]

Neat thing about the MVP-50 is it flags a dead (or grounded) mag on the RPM indicator (and lights up the master caution).

 

[Magman]

When someone does the “ BANG!” part they always look around to see if

anyone noticed .

Unfortunately; the explosion in the muffler may rupture the Can

and cause CO poisoning .

It‘s not to be taken lightly..

 

[rotormatic1]

Hi,

I made the boneheaded mistake of not going back to BOTH after doing my run up and took off on the L mag. I noticed my climb performance was more sluggish than usual and the engine didn’t sound quite right. Once I climbed to 3,000ft and leveled off, I reduced power, leaned and noticed my EGT gauge was running much hotter than usual. I glanced down and did a check of everything, and found I was on one mag. I switched it to BOTH and bingo, back to normal indications. I would suspect I ran on the single mag for about 5-7 minutes before I noticed it. Did I damage my O360 engine by climbing out and such on one magneto?

If there is no special inspection in the engine or airframe maintenance manual for flying on one mag (due to failure or pilot action), doesn’t seem to be a issue..

 

[David Falkenstein]

Hi,

I made the boneheaded mistake of not going back to BOTH after doing my run up and took off on the L mag. I noticed my climb performance was more sluggish than usual and the engine didn’t sound quite right. Once I climbed to 3,000ft and leveled off, I reduced power, leaned and noticed my EGT gauge was running much hotter than usual. I glanced down and did a check of everything, and found I was on one mag. I switched it to BOTH and bingo, back to normal indications. I would suspect I ran on the single mag for about 5-7 minutes before I noticed it. Did I damage my O360 engine by climbing out and such on one magneto?

I made the same mistake in a 172 at night in 3000 foot untowered runway. Immediately when the wheels left the ground the stall horn started to go off. I was too far down the runway to feel comfortable aborting but fortunately all my training kicked right in (I had about 110 hours at the time). First thing I did was lower the nose slightly to silence the stall warning then I fixated on nailing best climb speed as I could see the shadows of the trees at the end of the runway coming my way. I didn't mention anything to my two passengers and just focused on aviating. I flew over the trees in the dark honestly not knowing if my wheels were going to clip them (fortunately they didnt). I continued to focus on best climb until I got to around 500 feet. I then started a very gentle turn to return towards the airport while continuing to climb slowly. After the turn I started my engine checklist and that is.when I found the key set to B instead of Both. clicked it back to both and got back on my course. I definitely got a good rush of adrenalin especially when I wasn't sure I was going to clear the trees but overall I felt really good about how I responded and how my training subconsciously took over. I remembered the saying that a crash is normally a series of mistakes strung together. I made a mistake leaving the magnetos at B but my training kept me from stringing others along with it. I could have stalled the plane, I could have tried to land it and go off the runway, I could have not focused on best climb speed and have not cleared the trees, I could have made too steep a turn back to the airfield (combined with low power a recipe for a stall), etc. It was a great learning experience and despite my stupid mistake, it boosted my confidence as a pilot.

 

[Magman]

If it affected your performance that much my guess is it did not meet

Minimum Static RPM on TO roll. My suggest is folks put a tape marker

NEXT to Tach to enable a quick check.

 

[flyingbrit]

If running big pistons at low rpm on one spark plug could cause engine damage, then Harley Davidson would have some serious reliability problems.


….oh…..wait.

Fact: A stock Milwaukee Eight has a bore almost identical to a "small bore" Continental O-200 or O-300.