Resistance is Futile

When you are talking about Fuel Level.  

When we designed our new digital fuel level sender we gave a lot  of thought on how to interface with older aircraft systems.

The question was:

Could we produce an resistance output to mimic an existing resistance fuel level reporting system.  

There would be a few clear benefits:

• We could interface with many more legacy aircraft 
• Incorporation of our system in aircraft already using resistance based sending would be easier.

However some of the issues of legacy aircraft were directly related to relaying resistance through the aircraft wiring as issues with resistance can provide false or error prone signals.   Resistance measurement on an aircraft was identified by us early on in the design process as not the most favorable method for accurate fuel measurement:

• Aircraft have long wiring runs
• There are multiple sensors and connections
• The connections needed to be ordered to produce a series for multiple sensors
• There were other connections in the aircraft - bad connections produced resistance 
• There were multitudes of different resistance values even for the same aircraft
• There were amplifiers in some aircraft to address the issues above
• The wire run was subject to aircraft vibration 
• The gauge quality and accuracy in legacy aircraft was - not ideal

The favorable aspect of resistive gauging was that it was easy for the average mechanic to diagnose.

• All they needed was an Ohmmeter.

• We had heard stories of Cessna 210 Centurion and Cessna Twin Aircraft with the dreaded Cessna breakout box to tune and diagnose the capacitive system.

So what we needed was a simple digital signal that could be read with the modern equivalent of a ohmmeter  - the Digital MultiMeter (DMM).  We can now get a digital frequency output of any connected sender.

We found that Digital Frequency gave us clarity for fuel level information over all the known wiring challenges - corroded contacts, poor splices and induced signals.  More importantly it gave us a good signal or nothing - induced errors did not conspire to give bad fuel level.

What seemed more natural is that the signal was similar to that used by the fuel flow transducer.  It seemed a natural  - and we could read the read and diagnose the signal on a DMM.

When we sat down after months of delivering a fuel level sending product that had zero issues and was easy to diagnose.  ---

We had come to  realized that we had found the best method for reporting fuel level on the aircraft and a communication standard for any application we applied our product to

General Aviation News - Press Release

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Accurate fuel gauges for aftermarket Cirrus

February 12, 2013 by Ben Sclair Leave a Comment

REDMOND, Ore. – Pilots are taught from an early age to not trust their fuel gauges. Cies Inc. wants to change that with its TSO’d fuel senders. The Digital Fuel Level System is now available as a retrofit on the Cirrus-line of aircraft (SR20, SR22, SR22TN and SR22T).

The system will measure fuel volume within 3% at all levels, within 1% when fuel volume is less than 50% and display the data on an Aerospace Logic or J.P. Instruments gauge.

“I love having the fuel flow quantity on the MFD like the new 2013 Cirrus Aircraft,” said David McGregor, Cirrus SR22 owner. “But the icing on the cake is the redundancy with the new Aerospace Logic fuel gauge that sits next to the fuel selector.”

Cies is working to expand the number of aircraft models, both certified and experiment, the Digital Fuel Level System will work with. The system costs $3,000 plus 16-18 hours of installation labor.

More information from Cies at 541-977-1043.

More news coming soon 

CIES Has New European Installation Centre

CiES Inc is proud to have RGV Aviation 
join our list of Installation Centers.  They are excited to be able to offer their Cirrus customers the new CiES  Fuel Level retrofit for SR22T, SR22TN, SR22 & SR20 Aircraft.

This modification brings legacy Cirrus Aircraft the benefit of the new factory Gen 5 digital fuel level sensor solution.  

RGV - A Cirrus Platinum Service Center -  Based at Gloucestershire Airport (EGBJ), is a family run Aircraft and Avionics maintenance business established in 1973.  As an established EASA Part 145, FAA Repair Station with EASA Subpart G and Irish Aviation Authority Subpart G approval, they have the ability and capability to support you and your aircraft, regardless of your requirements.

CiES  - A design and manufacturing business to incorporated to redefine the measurement of fuel.   CiES patented technology for measuring fuel is intrinsically safe - Non contact,  highly accurate and has proven itself reliable under the harshest conditions.   We brought accurate fuel level to aviation 

What can we do for you 

The Excitement of Initiating Change or I Double Down on Dark Horses

Imagine coming up with a new and revolutionary idea.

The challenge and the excitement.  You feel your pulse quicken

The moment you first look at the prototype and realize that you might really be on to something.

You want to share it -

You have a unique vision of the way the world should be in the future.  

You develop it and refine it and when it's ready - you bring it to market 

The world is just waiting to embrace your vision............

.....well frankly no it's not 

The reality goes something like this 

"You're selling what,  you're with who, you say its on new model aircraft.  No I haven't heard about it.   What is it again, aviation fuel gauges that work  - Say again...... how accurate really  - so why didn't the factory talk about it.......something that good you'd think.

Hold on let me put you on the speakerphone......guys listen up - this salesman on the phone here tells me he's got working aircraft fuel gauges for sale ......... Hold on - Dominic here wants to know if they are capacitive ....... yeah......... they are what........ give that to me again.   AN ISO MAGNETO DOO HICKEY - no never heard of it. Lord Kelvin really.

Boy the sales pitch just runs off your tongue doesn't it - Wait Bill in the back wants to know if it comes with a set of free steak knives -   no no send me a brochure - We'll be sure to take a look.

Functioning, Accurate Aviation Fuel Gauges 

• You now have an accurate fuel level sensor. 

• It detects how much fuel is in the tanks at any moment.

• It displays the fuel tank contents on your aircraft MFD screen but is not connected with the fuel management system on the aircraft.

• You must still enter the fuel level you observed in the tanks as you have always done on the MFD.

• The aircraft will use fuel flow data to calculate what the fuel level should be.  It will present that estimate of the fuel tank contents on the MFD.

• The level sensors give a calibrated fuel level - Not just accurate at the top and bottom accurate throughout.  These sensors also output the fuel tank contents to the MFD and then display them side by side with the calculated fuel level.

• These fuel level systems ARE SEPARATE. 

• Both indicate to you the pilot,  the amount of fuel in the tanks.  SEPARATE - But they match

• Got it?    Good.