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Is electronic injection ?there??

SinCityJets

Active Member
I know electronic ignitions have come a long way, and are almost the “standard” now, but with some cutting edge companies like SDS and EFII (maybe others??), electronic injection is also on the scene now.

Is this technology ready to be placed at the pointy end of our lifeline in the sky? This is not so much an SDS vs EFII thread, as it is an electronic ignition vs Bendix thread.

For me, I love the dual ECU redundancy of an automotive like injection system, with no mixture knob, however I am not a fan of no mechanical fuel pump.

It seems like these full electronic systems DEMAND a back up alternator and battery for true redundancy.

I appreciate your thoughts and responses.

Chad
 
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As a bad parody....."To have electricity or not have electricity, that is the question."

The quality of the equipment is really no longer an issue IMHO. Choose your poison, and build to suit.
 
The equipment itself is automotive based and as such has proven itself far beyond the legacy systems by virtually any measure. Add redundancy and I think it would be hard to argue a scenario where the EFI system is any less reliable than a mechanical system, and in all likelyhood much higher.

Electrical delivery systems likewise are very well proven. Again, with billions of hours of service history to calculate MTBF.

The rub is the installation variability of each builder. For example, fuel systems are very simple, yet look at their role in E-AB accidents. Poor (re)design, substandard workmanship and lack of attention to detail all conspire to take down more homebuilts than just about any other mechanical cause. Now apply that same standard to a far more complex electrical system. Install a proper electrical system feeding your EFI and you are likely to increase reliability over the legacy stuff.

I think the real advance to pave the way for EFI is the fact that our panels are becoming increasingly complex and are forcing robust and reliable electrical systems. Once we finally let go of the concept that electricity is "optional", and really figure out a robust and redundant power system, then adding a fuel pump and ECU is an easy step to take.
 
...
The rub is the installation variability of each builder. For example, fuel systems are very simple, yet look at their role in E-AB accidents. Poor (re)design, substandard workmanship and lack of attention to detail all conspire to take down more homebuilts than just about any other mechanical cause. Now apply that same standard to a far more complex electrical system. Install a proper electrical system feeding your EFI and you are likely to increase reliability over the legacy stuff....

How best to design the electrical system to accommodate the level safety required? This has been the most difficult part of the decision making process for me. I'm reading as much as I can but there is lots of different and sometimes conflicting bits of advice. I have yet to see a solution that looks simple to me. I asked Ross at SDS for his recommendation which he shared. With that schematic, there is a master switch for the engine which will turn off the engine if it failed or was inadvertently closed. Granted, that design had a backup battery and switch to mitigate the risk. Perhaps I'm over thinking it but I still had my reservations.
 
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I was just talking to a friend about a local Columbia (Cessna) 400 owner that I know that had smoke in the cockpit from an electrical fault, he's now scared to fly the plane and his wife won't go near it.

So with that in mind it got me thinking what would I do in that scenario and what would I have left if I killed the master due to an electrical fault.

Eng: should keep running, Electroair and Pmag, std AFP FI with mechanical fuel pump.

Avionics: I have a backup battery bus but not knowing where the smoke is coming from I'd probably shut that off too, that would leave me with the G5 and 660 (if I was IFR I'd have the Ipad in my lap), that plenty to keep me aviating and navigating.

Anyway something to consider.
 
electricity

How best to design the electrical system to accommodate the level safety required? This has been the most part of the decision making process for me. I'm reading as much as I can but there is lots of different and sometimes conflicting bits of advice. I have yet to see a solution that looks simple to me. I asked Ross at SDS for his recommendation which he shared. With that schematic, there is a master switch for the engine which will turn off the engine if it failed or was inadvertently closed. Granted, that design had a backup battery and switch to mitigate the risk. Perhaps I'm over thinking it but I still had my reservations.
Hi Randy, You probably already know about the aeroelectic connection http://www.aeroelectric.com/ - if not, you might consider reading that book. It greatly demystified the aircraft electrical systems for me, and this understanding has given me the confidence that I would need for an all electric aircraft. A solid design, good installation practices, and understanding of how it all works will go a long way to making sure the fan up front keeps spinning.
 
no, they do not demand it. the first question that must be answered is what is the mission of the aircraft. it amazes me how much redundancy that people cram in a VFR aircraft. if you are going to be flying IFR, or in the west where airports are farther apart then more redundancy will be required. for a basic VFR aircraft a single alternator with a single battery in an aircraft with a single EI and one mag is perfectly fine. for a VFR aircraft with two EI's then I would, and have in mine, installed a small dedicated backup for the EIs. a 5 a/hr battery should power an EI for a couple of hours in the event of a total electrical failure. for an IFR aircraft I would probably add a backup alternator to power the important stuff. now start adding EFI and you add more issues.

bob burns
RV-4 N82RB
 
Hi Randy, You probably already know about the aeroelectic connection http://www.aeroelectric.com/ - if not, you might consider reading that book. It greatly demystified the aircraft electrical systems for me, and this understanding has given me the confidence that I would need for an all electric aircraft. A solid design, good installation practices, and understanding of how it all works will go a long way to making sure the fan up front keeps spinning.

I am familiar yes Mickey. I've read good chunks of it but have not gotten all of way through it. I find it quite verbose and overloaded making it less than a captivating read. Ausman's book is good but perhaps not quite comprehensive enough. I will plod through. What I have found very helpful is looking through and understanding the solutions others have posted.
 
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....So with that in mind it got me thinking what would I do in that scenario and what would I have left if I killed the master due to an electrical fault....

That is what was concerning me as well Walt. Correct me if I am wrong but my understanding is that the engine should be on it's own master and isolated from the other systems.
 
Properly designed (and fully understood) support systems are critical.

I am aware of an RV (I think it is likely that the majority of it was contract built) that had a power problem away from home.

The owner had wanted newest tech. and best of everything in his airplane. The result is an airplane that is over his head in complexity. Not necessarily when every thing is working correctly, but as soon as something goes wrong..... it can go wrong in a very bad way, very quickly.

The owner had an alternator failure away from home. He flew the (entirely electrically dependent) airplane home on only battery power, with seemingly little understanding of how close he came to disaster.

This is the type of scenario that gives me the most concern these days regarding the direction that the experimental community is headed.
Some are able to engineer reliable systems and do a well thought out installation, but many are not. Even worse is when RV's with complex systems are being sold to second owners who have zero understanding of how the systems work.

If you build an entirely electrical dependent airplane, be sure you are aware of all of the potential failure modes you need to have contingency for.

Number one on the list of design priority's should be to assure you be able to make a decision and execute a plan in just a few seconds, that will remove power from a failed portion of your electrical system, but still keep the engine running........
And please, produce some documentation so that people other than the builder can learn how the systems work.
 
How best to design the electrical system to accommodate the level safety required? This has been the most difficult part of the decision making process for me. I'm reading as much as I can but there is lots of different and sometimes conflicting bits of advice. I have yet to see a solution that looks simple to me. I asked Ross at SDS for his recommendation which he shared. With that schematic, there is a master switch for the engine which will turn off the engine if it failed or was inadvertently closed. Granted, that design had a backup battery and switch to mitigate the risk. Perhaps I'm over thinking it but I still had my reservations.

There's a lot of ways to go about it, but I do like Ross' concept that a backup battery, a length of wire, and a switch is just about the most reliable electrical system you can get. So thats how mine is setup. If there is smoke in the cockpit, I shut down the ship master and the engine continues on while I figure it out. If the source of the smoke is the ECU buss, then the engine has likely quit already anyway. The only tie to the ships system is a relay used for charging. Some use a diode here, but I have some specific reasons for manual control.

ANY electrical issue is a "land now" scenario for me and my mission accepts that. And yes, I have my reservations too, but I'm trying to think beyond my personal comfort zone and look at this logically. Having an electrically dependant engine is not something I'm used to, but does that mean its any less safe?
 
......an automotive like injection system, with no mixture knob...

Chad, the available systems are speed-density, open loop. In automotive years, speed-density was cutting edge about 1970. Heck, Ross has been building them almost that long ;)

Both SDS and EFII systems have a mixture knob, required for full control. For example, to choose between best power and best economy at the same MP and RPM, you'll need to twist the little knob.

To your question, I'm not at all concerned with the reliability of the supplied components. Like Scott, I think the growing issues will be supporting systems and operator understanding.
 
Is Electronic injection ?There??

It certainly appears to be in the case of the Vans RV12IS. ECU/fedec FI in the Rotax 912.
 
Properly designed (and fully understood) support systems are critical.

I am aware of an RV (I think it is likely that the majority of it was contract built) that had a power problem away from home.

The owner had wanted newest tech. and best of everything in his airplane. The result is an airplane that is over his head in complexity. Not necessarily when every thing is working correctly, but as soon as something goes wrong..... it can go wrong in a very bad way, very quickly.

The owner had an alternator failure away from home. He flew the (entirely electrically dependent) airplane home on only battery power, with seemingly little understanding of how close he came to disaster.

This is the type of scenario that gives me the most concern these days regarding the direction that the experimental community is headed.
Some are able to engineer reliable systems and do a well thought out installation, but many are not. Even worse is when RV's with complex systems are being sold to second owners who have zero understanding of how the systems work.

If you build an entirely electrical dependent airplane, be sure you are aware of all of the potential failure modes you need to have contingency for.

Number one on the list of design priority's should be to assure you be able to make a decision and execute a plan in just a few seconds, that will remove power from a failed portion of your electrical system, but still keep the engine running........
And please, produce some documentation so that people other than the builder can learn how the systems work.

Very good post Scott. With more EFI and EIs going on RVs these days, these are all important points to cover. One reason I don't comment more in these threads is I see many people posting massively complicated electrical systems more applicable to a Boeing than a day VFR single (in most cases). Think it through well.
 
Chad, the available systems are speed-density, open loop. In automotive years, speed-density was cutting edge about 1970. Heck, Ross has been building them almost that long ;)

Both SDS and EFII systems have a mixture knob, required for full control. For example, to choose between best power and best economy at the same MP and RPM, you'll need to twist the little knob.

To your question, I'm not at all concerned with the reliability of the supplied components. Like Scott, I think the growing issues will be supporting systems and operator understanding.

We've actually had the LOP switch since 2016 so it's often possible to not have to touch the knob if you fly at similar MAP and RPM power settings when you set cruise power. It simultaneously leans a programmed percentage to LOP and advances ignition timing to regain some of the lost power.

We'll have some new advances along this theme with the EM-6.

Totally agree- supporting electron flow is the #1 priority in your electrical system with EFI. A perfectly functional ECU is dead weight without that aspect.

Is EFI "there"? We'll this is our 23rd year of supplying ECUs for aviation and what we have now as far as kits go is much more complete than it was in 1995. Whether everyone accepts it yet, I think the answer is no. Some folks will always prefer a carb and mags and that's just fine. Fly what is comfortable for you. I often use the analogy of Glass vs. Steam gauges. Not accepted 20 years ago but widely accepted now, so much so that it's the new normal. I see EFI eventually becoming the norm as well.
 
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I was just talking to a friend about a local Columbia (Cessna) 400 owner that I know that had smoke in the cockpit from an electrical fault, he's now scared to fly the plane and his wife won't go near it.

So with that in mind it got me thinking what would I do in that scenario and what would I have left if I killed the master due to an electrical fault.

Eng: should keep running, Electroair and Pmag, std AFP FI with mechanical fuel pump.

Avionics: I have a backup battery bus but not knowing where the smoke is coming from I'd probably shut that off too, that would leave me with the G5 and 660 (if I was IFR I'd have the Ipad in my lap), that plenty to keep me aviating and navigating.



Anyway something to consider.



I had something similar to this happen I?m a low time pilot and suddenly, close to my home airport but in class C airspace got a puff of smoke and burnt wire
Smell. Killed the master I immediately , flew back and landed. Could never find the source but upgraded one fuse to a 10amo from 7.5 because I?d popped the (as I recall alternator and flap motor fuse) and others on VAF had issues with the 7.5 also without the flap on it.


Anyway searched the whole plane nothing burnt or even remotely showing signes of heat, Drove me crazy for a year.
My I pad had plugged in to a lighter port adapter but it worked fine after and didn?t smell.

A week or so ago driving in my truck damned if that same lighter outlet didn?t do the same thing with a puff of smoke. Oddly it still works and doesn?t smell of smoke if I didn?t see it myself I wouldn?t believe it.

Point is it got my attention
And I?m **** glad I have magnetos and a running airplane with the master off.


I?ve run efi. (Accel gen 7) and electronic ignition in my race cars for years with solid results but I like the carb and magnetos in my 6a . 😃. Guess I?m an old school newbie!

Had an alternator failure in a club 172 once and had to hand prop it and fly it home too. Again was loving those mags and a carb. 😃
 
Chad, the available systems are speed-density, open loop.
.

This has been my concern. In a previous life I raced cars and we used these type systems. They worked good, but required a lot of tuning to the specific car, and anytime we changed something it was back to the dyno. This worked in our racing environment, but I wonder how much is being left on the table in a generic application where you have to tune for an unknown engine.

To be honest a Bendix injector is really clever. If you get one that's properly flowed, it's probably pretty close to optimal. The problem there is getting one properly flowed. Lycoming has "rich limit" and "lean limits" for servos, and depending on where yours fell on that scale can really make a difference. Probably the biggest advantage of EFI would be consistency.

Mags belong on tractors from the 30's, and flowing servos is voodoo magic. Even if it isn't the latest in closed loop tech, EFI makes a compelling argument.

DEM
 
We've actually had the LOP switch since 2016 so it's often possible to not have to touch the knob if you fly at similar MAP and RPM power settings when you set cruise power.

I hear ya'. The point is that "No mixture knob" remains one of the BS items claimed by your competitor, and it shows up in a lot of posts from potential users...here our friend Chad.

It simultaneously leans a programmed percentage to LOP and advances ignition timing to regain some of the lost power.

Clarify please; it is in fact a simple shift, not a complete new map? When selecting the LOP position, the switch adds a pre-programmed number of degrees across the entire ignition map (same at all points), while leaning the same pre-programmed percentage across the entire MP-RPM map?

Put another way, it shifts the existing maps, rather than activating different, independent maps?
 
I hear ya'. The point is that "No mixture knob" remains one of the BS items claimed by your competitor, and it shows up in a lot of posts from potential users...here our friend Chad.



Clarify please; it is in fact a simple shift, not a complete new map? When selecting the LOP position, the switch adds a pre-programmed number of degrees across the entire ignition map (same at all points), while leaning the same pre-programmed percentage across the entire MP-RPM map?

Put another way, it shifts the existing maps, rather than activating different, independent maps?

The original intent of the LOP switch was to allow quick and easy instant leaning to LOP and simultaneously advance timing to help compensate for the slower flame speed during LOP operation when in cruise. People are using it in different ways sometimes, as an octane selector for mogas and 100LL for instance. You may advance timing without leaning, depending on selection choice.

So yes, this just shifts timing across all ranges a certain number of degrees and leans a certain percentage across all ranges.

For those typically flying similar altitudes and power settings in cruise, it accomplishes near optimal fueling and ignition timing at the flick of a switch.

We still like to have the knob for fine tuning and possible emergency use in case of a sensor failure or fuel pressure delivery problem. Some do prefer to lean via the knob, especially if flying at varying altitudes and power settings. Once properly programmed, I don't think most people flying our system touch the mixture knob too much. Planned advances on the EM-6 will make the knob less used still I believe.

We've seen settings of 4 to 10 degrees of advance used with the LOP switch depending on base timing settings, CR and how lean people run in cruise. As mentioned previously, the LOP advance is locked out above 25 inches MAP for engine safety.
 
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UH-OH!!

Ross sez: As mentioned previously, the LOP advance is locked out above 25 inches MAP for engine safety.

I'm gonna guess you can unlock that for those of us with forced induction? This could be a hugh and series problem!;)
 
Ross sez: As mentioned previously, the LOP advance is locked out above 25 inches MAP for engine safety.

I'm gonna guess you can unlock that for those of us with forced induction? This could be a hugh and series problem!;)

It's hard to get below 75% power if you are above 25 inches unless you really run the rpm way down. I'm not sure you'd want to run LOP above 75%. In any case, we can disable that feature if you desire. Don't forget to have the LOP switch position on your pre-landing checklist though. Not good to have 30-35 degrees of timing in if you have to do a go around.
 
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