[RV7Guy]

A friend of mine is considering using one of these on his plane. It looks interesting but I have not heard of anyone using it. The system is a "sort of" FADEC. I don't like the idea of not having a mixture control especially for times when a "hot start" procedure is necessary.

Any information is appreciated.

 

[LarryT]

A friend of mine is considering using one of these on his plane. It looks interesting but I have not heard of anyone using it. The system is a "sort of" FADEC. I don't like the idea of not having a mixture control especially for times when a "hot start" procedure is necessary.

Any information is appreciated.

This Eagle EMS is made by Precision Airmotive and functions more like a car common rail port FI system. It uses electronic pulse width port fuel injection instead of continuously dribbling fuel against the intake valve like aircraft FI systems. There are sensor inputs to a parallel ECU (dual inputs, dual ECU so there is always a redundant up and running control system) that controls the injector pulse width based on a "look-up" table. Aircraft engines should actually be easier to do than car engines because speed aren't changing continuously.

My first reaction to this system was "its about time." I have done quite a bit of research and plan to go this way. At the present time, the system is only available as an original installation on engines purchased from Aerosport, G&N or Penn Yan. IMHO, this is a quality control measure so there is no question about an "amateur" installation.

Alan Jessmer is the contact person at Precision. I have found him quite helpful (and patient). Because I am a mechanical engineer he has gotten a never-ending stream of questions from me, as has Bart LaLonde at Aerosport. When Alan hasn't been able to answer a question, he gets a their engineer on the line with me.

This system was originally developed for Cessna certificated aircraft, but never saw the light of day there after Unison (another Textron Division) found out about it. Because of that history, there are some things I wish Precision would change and I have been lobbying them for the changes.
1. I would like to see automotive spark plugs, especially since ECI will sell you cylinders that are machined for auto plugs and other electronic ignition users have been auto plugs.
2. Use of alternate fuels to 100LL. The response was this was all they tested in their certificated aircraft program, but they need to consider the near-term reality of the disappearance of 100LL.
3. Requirement for a back-up battery. I would rather see a requirement for a back-up emergency alternator like a SD-8. If I can't get them to bend on this one, I will put the smallest practical back-up in (2.5A-hr?)

Larry Tompkins

 

[rocketbob]

Bottom line on these systems and their lack of popularity is a miniscule ROI. Not enough fuel savings to offset the cost of the system or its added complexity.

 

[airguy]

I'm a bit concerned about not being able to control the mixture as well - with this system I have no LOP ability at all. True, I won't ever be wasting fuel or worrying about mixture changes with altitude - but I'm so used to doing that anyway I don't consider that much of a factor. Not being able to run LOP is a major strike against them. I'll already be running redundant electrical systems anyway, as my aircraft will be electrically dependent for fuel supply in any case, so that's a wash. I wanted to be able to run one mag and one Plasma III (LS for efficiency, mag for backup) and I'm not too keen on one system handling all the ignition - this opens you up for single-point failure just like the dual mags in a single unit. Automotive spark plugs and E10 mogas would seem to be a no-brainer for me - their argument that certificated testing was not done with those items is a non-starter since they are not selling units in any appreciable quantity to the certificated market. It's time to sniff the prevailing winds and realize they have a market in the experimental world if they would be willing to make some minor adjustments.

Then there's the price - if you could recoup some of that in fuel cost by running LOP, it might be a different story.

 

[Ted RV8]

I was just at the AOPA gathering in San Jose, CA and was able to speak with Alan Jessmer there.

Double check with Precision but I do beleive a mixture control was in the works. As far as hot start it shouldn't be an issue because you won't have the fuel in the lines heating and dumping into the cylinders when hot. The only time it can get fuel is when the electronic injector is pulsed. Supposed to start in one blade under all conditions. Pretty sure it uses two seperate spark drivers that mount just like the mags. Two seperate EMS and a battery back up. Very redundant.

Because this was originally designed for the certified market it was designed with redundancy.

Believe the price was comparable to the cost of two mags and a mechanical fuel injection system if you are buying them new.

Not sure on the availability only for new engines and no retrofits.

There are some of these out in field now being used by public consumers as opposed to beta testers. Should start to here some feedback from them soon. I heard there are a couple on RV's.

Anybody on the forum running it?

Ted

 

[kbehrent]

I have the Eagle EMS system, but not flying yet.

Bart from Aerosport built me up a XP-320 C/S with the Eagle system. Bart is very knowledgeable about the system and has done a lot of testing on 320s, 360s, and even on a 390. He really sold me on the system and I trust him. I believe they have sold @ 16 units, and he runs each one for 90 minutes.

I'm finishing my RV-9A and will be flying this summer. Fortunately I have a mentor/tech counselor/RV guru helping me make it happen.

The Eagle does come with a mixture control (rheostat looking knob) that allows you to further rich/lean by a percentage. I believe it's range is +-15%. You can also hook your laptop and change the tables yourself. Currently, mine is set to run rich for breakin. Once that is complete, Bart has a new config for me to load based on his dyno testing.

You are required to have a dedicated backup battery. Actually, it should be considered as a primary battery because the Eagle runs off/thru this battery and the power mgmt module keeps it charged via the aircraft power bus. Should the voltage on the aircraft bus become less than the Eagle battery, it will stop charging and you will begin draining the Eagle battery at a rate of 1.6 amps per hr. I use a 3.6A battery which should last a good 2 hrs. You do get an indication when the Eagle is charging the battery and also when the battery drops below 11.3v.

Originally, I felt I had good enough cushion running off the Eagle battery alone given a alternator failure. However, I've just decided why take a chance so I'm going to add a SD-8 backup alternator to the mix. It's fairly cheap insurance and I am equiped for IFR flight and it eliminates the concern.

Regarding cost, It only cost me @ $2,500 more since I was planning on using the Silverhawk, 1 mag, 1 lightspeed configuration. If you were going with 2 lightspeeds, it would only had been @ $1,400 difference. It is certainly cheaper to build an engine with the Eagle installed rather than to retrofit. It's hard to sell your old stuff at the price you paid for them!

There is currently a RV6 and RV8 flying. The RV6 has been flying for a couple of years now and the RV8 was a retrofit that happened sometime after Oshkosh. There are several more like me that are getting close to flying. Check their website, they now have a links with pictures/links of other builders. I haven't sent mine in yet.

This is not a new product. Precision has been working/flying this for years. Cessna was sold on it, but Lycoming put an end to that when they decided to come out with their/partnered FADEC system. Precision just stopped trying to get in the cert market and instead launch it in the experimental market instead. Good for us!!

I believe it to be a good product and a good compromise to a full FADEC system. I would not be comfortable having the system control, fuel, timing, and prop in a single unit. Electronic fuel injection is not "bleeding edge" anymore and neither is electronic ignition. Even dual electronic ignitions aren't uncommon anymore either. There wasn't anything special required to install it, so removing it and installing a Silverhawk, mag/lightspeed won't be a real issue either.

Precision is located about an hour or so away from me so getting local support is a plus as well.

 

[Maury]

March Kitplane mag has an article on it. Fairly good article, in fact when the time comes, I'll be considering it. instead of dual electronic ign.
Rick Maury
RV 7
Tail and wings done, fus in the works.

 

[KPmarc]

"Fairly good article..."

You know how to hurt a guy...

Marc

 

[RV7Guy]

I read it

I read the article and still have several concerns. I continue to be concerned about Hot Starts. I would like to see this demonstrated in conditions where the temps are consistently above 100 degrees. This is how we operate for nearly 6 months a year in Arizona.

Secondly, the inability to run LOP. I run LOP on every flight. In the old days you leaned till the engine started to run rough and then back it back in. Yesterday when flying home from work I leaned until I reached this point. My AFS2500 registered 123 degrees LOP before the engine started to fade. At 3000 feet I don't run much above 30 degrees LOP. I get about 8.5 gph at 24 inches and 2450 RPM.

On my last condition inspection my plugs (auto) looked new. I always replace them anyway. I'm not sure this system would provide those advantages.

Other concerns include weight, added complexity and total electrical dependence. I'm sure this will be a very good system and there appears to be considerable testing being done. I'd sure like to see it being used in the extreme temperature ranges. If successful, it would work about anywhere.

This system is definitely worthy of watching as testing and hours build. I love to see new stuff and wish them the best of luck on this exciting new product.

 

[kbehrent]

I read the article and still have several concerns. I continue to be concerned about Hot Starts. I would like to see this demonstrated in conditions where the temps are consistently above 100 degrees. This is how we operate for nearly 6 months a year in Arizona.

My understanding is that Hot starts are not an issue because the computer(s) calculate the best fuel setting for starting at the current temps, settings, etc. Also, unlike the old Bendix or current Silverhawk, you get @30 lbs of pressure to the jet, not the 1-2 lbs you got from the old systems. That kind if pressure will purge any vapors really quick! Also, each nozzle in controlled individually.

Secondly, the inability to run LOP...

I don't think anybody is saying you CAN'T run LOP. You can adjust the fuel to be whatever you feel comfortable with. You will need to tell whatever shop is configuring your system what you want. If they don't feel comfortable with your settings, hook your laptop to it and change it to whatever you want. You also have the ability to lean further by additional 15% using the supplied fuel mixture knob.

On my last condition inspection my plugs (auto) looked new. I always replace them anyway. I'm not sure this system would provide those advantages.

The Eagle system uses standard aviation plugs. Due to the optimized timing and fuel mixture, I believe your plugs will be cleaner and need to be replaced less often.

Other concerns include weight, added complexity and total electrical dependence. I'm sure this will be a very good system and there appears to be considerable testing being done. I'd sure like to see it being used in the extreme temperature ranges. If successful, it would work about anywhere.

The Eagle weighs slightly less than the standard fuel injection, but close enough to call it even. Precision builds custom wire harnesses for your installation and all of its components are made to mount on the engine side of the firewall. It needs to have it's own dedicated backup battery, for which the Eagle will monitor and maintain. It only draws 1.6A, so I use a 3.6A battery which should get me 2+ hrs of flight on battery power alone. Since I am configured for IFR and I'm all electric, I've decided to add a SD-8 standby alternator (8A). Very easy to install or retrofit to an existing installation.