We are putting in a JPI EDM-900 which has the option for primary fuel quantity display. I'd like to replace the mechanical fuel gauges in the wings (which are useless in flight anyways and I always dip the tanks on the ground) with electric senders to use with the EDM-900. Has anyone done this and either found a STC or filed a 337? What brand and model?

Thanks,
Ace

I have a '53, mechanical gauges. The wings however are '58 or '57 with the electric gauges. Cessna has issued a letter indicating which wings are compatible with which airframe....so if elcectric gauge system wings may already be approved for your airplane. So replace that electric system with your system as a basis of approval. Or just buy an already approved system.

Mike

Aerospace Logic Digital Fuel Level gage... I think -5. The CGR-30P from EI also does that... replace the fuel senders!

Its the FL202... thats what I put in my C-180A: http://www.aerospacelogic.com/index.php ... duct_id=56

gunny

I presume the EDM is certified to replace the original engine indicating instruments?

JPI should have part numbers in their installation instructions for senders, either resistive or capacitive, that work with the EDM-900. If not then you should have gone with the EI

Seriously tho, a quick call to JPI should set you on the right path...

Do the electric guages give an equivalent to the red "Do Not Take-Off" information
that is on the mechanical wing root guages?

Just Curious
Chris C

Research Cies senders. They are compatible with your engine monitor. They out perform resistive and capacitive senders.

CiES sounds like the ticket. Thanks for the heads up.

https://www.ciescorp.net/cessna.html

Glad to share what little I've managed to learn about! JPI needs to know your intended senders when you order. Cies will gladly take your call if you have questions for them.

I have been emailing and calling cies for over three weeks now, no response. Anyone have any idea what's up?

Odd. I spoke to them 6-8 weeks ago. Hope all is well in their camp. He has a blog. Is it active?

Ace007 wrote:.... I'd like to replace the mechanical fuel gauges in the wings (which are useless in flight anyways and I always dip the tanks on the ground) with electric senders to use with the EDM-900...

Are the electric senders to be some sort of capacitive-reading devices, or cork bobbers hooked to an electric sender instead of a dial? If the latter, they might not be be any more reliable than the "useless in flight" gauges you have now. FWIW most if not all of the fuel totalizers I've seen depend on the user entering "fuel added" info by hand.

Interesting that you wanna go from mechanical to electric. A buddy of mine building up a Pacer is going the other way-- he's installing a set of PA-18 tanks with sight gauges, instead of the stock PA-22's electric sending units & panel-mounted gauges.

hotrod180 wrote:

Ace007 wrote:.... I'd like to replace the mechanical fuel gauges in the wings (which are useless in flight anyways and I always dip the tanks on the ground) with electric senders to use with the EDM-900...

Are the electric senders to be some sort of capacitive-reading devices, or cork bobbers hooked to an electric sender instead of a dial? If the latter, they might not be be any more reliable than the "useless in flight" gauges you have now. FWIW most if not all of the fuel totalizers I've seen depend on the user entering "fuel added" info by hand.

Interesting that you wanna go from mechanical to electric. A buddy of mine building up a Pacer is going the other way-- he's installing a set of PA-18 tanks with sight gauges, instead of the stock PA-22's electric sending units & panel-mounted gauges.

While I realize some of our members are resistant to technology that has popped up since the time of The Beach Boys these Magnetic sensors from CIES are very cool.

https://www.ciescorp.net/magnetic-field-fuel-level.html

Certainly the best option for those of us with a modern engine analyzer. I almost wish my original Cessna resistive senders would go tits up forcing me to get some.

hotrod180 wrote:

Ace007 wrote:.... I'd like to replace the mechanical fuel gauges in the wings (which are useless in flight anyways and I always dip the tanks on the ground) with electric senders to use with the EDM-900...

Are the electric senders to be some sort of capacitive-reading devices, or cork bobbers hooked to an electric sender instead of a dial? If the latter, they might not be be any more reliable than the "useless in flight" gauges you have now. FWIW most if not all of the fuel totalizers I've seen depend on the user entering "fuel added" info by hand.

Interesting that you wanna go from mechanical to electric. A buddy of mine building up a Pacer is going the other way-- he's installing a set of PA-18 tanks with sight gauges, instead of the stock PA-22's electric sending units & panel-mounted gauges.

The electric, "cork bobbing" gauges can be digitally filtered to get at a better estimate of truth. The mechanical ones bounce from empty to full in the bumps. The electric ones eliminate the tunnel and the need to cut holes in the headliner as well. Either way I only use them to let me know if a hole in the tank miraculously formed during the flight.

We are around, the Holiday was especially busy working a new FAA certification program. Lots of phone calls, easy to miss someone along the way. We have been supporting a lot of C180 & C185's lately.

https://vimeo.com/179533390

Thanks for checking in Scott. I spoke to your office yesterday, and my name is nearing the surface of your backlog. Shipment should be late next week. I'm more encouraged that you have such a backlog than I am impatient for the product, but hurry it along anyway, OK?

CiES has both and will soon have more. We work very effectively with JPI where we are recommended by JPI as the fuel sender to utilize.
We communicate with all JPI units 900 & 930 with a simple digital signal. This signal is square wave frequency which is similar to fuel flow or tach signal. Noise Immune, connection resistance immune - simple.

The sending units while intentionally resembling a traditional float sender, but the similarity of our system to legacy fuel senders ends there.

We utilize a sophisticated non-contact
angular sender utilized in the automotive industry for Brake by wire, steer by wire, throttle by wire, Cam and crankshaft positioning for stop /
start and vehicle stability control. Utilizing an electronic non contact sensor allows also have onboard electronic processing. Motion of fuel is always present in aircraft fuel tanks, we are able to read the actual float position & average it over time to provide a constant and steady fuel level output.

The issue with mechanical senders and rheostat readings is that traditional analog gauges can tolerate some degree of contact loss present in all traditional fuel level sensors as these senders were designed for applications other than aviation . MFD engine instruments are not so generous with loss of signal.

We have virtually all the OEM business for aviation as we represent an economic and functional alternative. Our success in the OEM market and the volume it generates allows us to build electronic retrofit senders priced at a level just slightly above a resistive McFarlane new sender or an Airparts of Lockhaven rebuilt sender

Very nice. But do you have an STC for replacing mechanical gauges in a 1955 C180?

Thanks!

The best way to figure out fuel level in a tank is fly it until the engine stops than go to the other tank, a good fuel flow meter will get you closer to empty than any gauge!!!
DENNY

DENNY wrote:The best way to figure out fuel level in a tank is fly it until the engine stops than go to the other tank...

Until the day you switch tanks, and find it empty due to an unseen fuel leak, or that you have an obstructed vent line that prevents fuel flow, etc.

Wouldn't it be nice to ALSO have an accurate-reading fuel gauge to tell you that your "other" tank has the quantity remaining that you believe it has? Or to be able to notice that you're losing fuel from that tank due to an otherwise unnoticed leak? That way you could immediately switch to the "leaky" tank and use all the fuel you possibly can before it goes overboard, then switch back to your known good, working tank. And wouldn't it be nice to know how much fuel is actually left in that "good" tank, so you can plan to divert if necessary?

DENNY wrote:...a good fuel flow meter will get you closer to empty than any gauge!!!
DENNY

While that may be true with mechanical float gauges that were certified years ago, I would suggest checking in with your experimental amateur built buddies who are flying with Dynon, Garmin G3X, GRT, and other systems that provide highly accurate fuel level indications... Several of them use magnetic-type floats (similar to what CIES is certifying and bringing to market), while others use capacitance-based probes that are likewise very accurate.

I flew several LSA aircraft (Sport Cruisers, Remos, and CTLS – all of them Dynon equipped) whose digital tank level readings were 100% confirmed when refueling to the filler neck (full, per the book). Likewise, my friend who put magnetic senders (sourced from EI, along with his CGR-30P) into his Rockwell Commander 114 says his "fuel remaining" on the gauges tracks within 1/10 gallon with the fuel remaining shown by the fuel flow instrument, and both show "fuel remaining" that matches within a tenth or two when he refills the tanks.

[#RANT MODE = ON] We, as pilots, have been complicit in allowing the industry to get away with supplying fuel gauges that are a joke. We make up all kinds of reasons why "real pilots" don't need fuel gauges, even as we watch our friends and acquaintances kill themselves running out of fuel. In this day and age, when technology can solve this problem so easily, it is ridiculous the lengths that we go through to justify NOT making the change! How many more of our friends have to die before we become convinced that we need accurate fuel gauges? [#RANT MODE = OFF]

I, for one, applaud the efforts of CIES (and others) to bring accurate fuel level indications to the cockpit. The Bearhawk Patrol I'm building will have dual fuel level sensors: a highly accurate fuel level sensor connected to a gauge on the panel, backed up by a direct-reading sight tube visible from within the cockpit (though slightly behind the pilot's head). Oh, and it will also have a fuel-flow meter to track actual usage versus indicated fuel levels. The "difference" (if any) would likely indicate a fuel leak...

I found the price list on your website, Scott, and while a tad more than MacFarlane's, it's certainly competitive. Specific question: does your STC AML include the Cessna P172D? Over 13 years of ownership and the installation of many different non-OEM items, I've found that many vendors/manufacturers seem to have left my airplane off their AML, even if they cover every other Cessna ever made.

Now a couple general questions: I see that there must be a separate power wire run to the senders, as opposed to the single ground wire used by other senders. What circuit do you recommend tying into, or must a separate circuit be run? What is the amperage requirement and recommended circuit breaker? Can I assume these are also compatible with OEM gauges?

Thanks.

Cary