Cessna Pennycap Press Release - Flying Magazine May 1968

Cessna Pennycap

Copyright Flying Magazine May 1968

Curiosity got the best of us the other day, and somebody wondered if there was a similar example to a disruptive fuel level technology in General Aviation aircraft.   I indicated that there was a different system and it enjoyed a brief and limited success.  This system came out in the late 1960's and was featured on Cessna aircraft.

I went for a magazine search for press releases, curious to see what virtues would be given to a better fuel quantity system.

This system was produced by Consolidated Airborne Systems - which still operates out of a garage location in New York state.

The headline for the article was entitled 

GAS GAUGES THAT TELL THE TRUTH 

"General aviation airplanes - those engineering marvels, this distillations of technical wisdom and aeronautical magic incarnate - use fuel measuring devices of the same arrangement that plumbed fuel quantity in automobiles since the Model A  float tipped rods that electrically drive instrument panel needles to positions approximating the volume of fuel left.  Many such devices are off by as much as 25 percent" Copyright Flying Magazine May 1968

Many mechanics swore at these systems, many are swearing at them still.  The never lived up to the billing as corrosion on these low cost systems quickly robbed them of any accuracy advantage.  If you remember - Penny was to indicate "low cost" and cap was to indicate "Capacitive"  i.e. Pennycap system by its marketing title was a low cost capacitive fuel system.

"For not much more than the cost of an annual, then you'll be able to have a fuel gauging system of honest go/no-go quality.  Can you hold in the soup for 45 minutes at your alternate, or should you declare an emergency and tell them to get you down?  Can you afford to try and get out of that mountain strip with half full tanks and your present baggage load, or are your tanks more like three-quarters full?  It can make a difference." Copyright Flying Magazine May 1968

What is old is now new again - as 48 years later for the price of an annual you can have a CiES fuel gauging system of honest go/no-go quality. 

Customer Responses - CiES Non-Contact Fuel Level

Cessna 177

Hi Scott,Our senders have been working perfectly with the Aerospace Logic gauge since installation last August. Thank you for your outstanding support in helping us work through an unrelated ground wire issue in the plane.Gregg Ridder

Mine have worked flawlessly since installation, and the accuracy appears to be extremely good. Hopefully someday I’ll be able to quantify that accuracy. I sure wish other aviation vendors cared about their customers like you do. Jerry Olson, 76 C177RG

Hey Scott,
I presume you got the original frequency senders back by now? The new ‘voltage’ type senders are working fine with my old(er) JPI 930. I did calibrate them (again) when installing them, however, they fail to indicate the full 30.5 gal on each side on the 930 when ‘full’ (JPI’s display units do not show partial gallonage). Most times the 930 reads 29 each side when “full” (full is over 30.5 gallons each side, sometimes QUITE a bit more). However, when I fill up, I can tell you the amount put in + the 930 readout of what’s left is almost spot on, close enough to more closely calibrate my K factor in the 930 installation (it’s still off quite a bit). I also double check with my fuel dipstick. And I did level the plane while calibrating, even though the Cardinal cruises nose down, so calibration methods give differing results depending on nose strut extension, attitude, cross level, etc.
Any my 930 still shows the digital amount remaining.
So I’m happy. Much better than the OEM stuff and those original gauges.  And it will get better with more flights.
Too bad you can’t get JPI to include your senders when new fuel reading units are ordered.
Marc, 76 C177RG 

Everyone, Mine are installed (Bob Russell) and interface properly with the JPI 930.  Fuel readings seem to be extremely accurate.  I can read the remaining fuel from the JPI, and then stick the tanks for a comparison.  So far, readings are within .5 gal of what I measure.  Scott, excellent product.  Thanks for supporting CFO and members.Alan, C177RG

Beech Baron CiES Magnetic Fuel Level Sender Retrofit - Part 1

Beech Baron 55 Fuel Level Senders

We received a set of Beech Baron fuel level senders yesterday.  In the coming days we will quantify the major characteristics of these senders like the arm length and position so that we can make new CiES Digital Magnetic Field Senders to accurately read the volume in the Beech Baron fuel tanks - Both the Main and Aux.  

Stay tuned for further updates and pictures.

Reliability and Continuous Improvement - CiES

Non-Contact Fuel Level Measurement

Recently we ran across an article in the Cirrus Owners Magazine  - Cirrus Pilot 

The article talks about the Continuous Improvement Process that Cirrus Aircraft utilizes in its aircraft design and production to improve reliability.

This article it discusses the complete paradigm change CiES made to aircraft fuel level measurement and Cirrus Aircraft's customer satisfaction with our non-contact fuel measurement technology.

As the article states - CiES Brought a Whole New Approach to Aircraft Fuel Level.  

An approach that changed fuel level reliability, so significantly, that it is no longer necessary to question your aircraft fuel level indication.

Take Your Fuel Level Indication to Un-Charted Territory and  Embrace the Reliability of the CiES Non-Contact, Magnetic Field, Fuel Level Solution

Parody on a Recent AOA Advertisement

Cirrus Aircraft Fuel Level Retrofit - Video

Cirrus Aircraft Fuel Level Retrofit 

We set out to change fuel level in Aviation.  We wanted to demonstrate that accurate and reliable information on fuel quantity could be accomplished in single engine and other aircraft.

The concept has literally taken off.  

We have proven they we can measure fuel in a highly dynamic environment and we can do so accurately.   


Click Here for Cirrus Inflight Video 

Aircraft Fuel Gauge Accuracy

Fuel Sensor Accuracy 

The following quoted from reference 2.

This FAR Part 91.205 fuel-gauge requirement can be seen as a corollary of a more general and more fundamental point, namely the importance of taking a layered approach to safety.

For any important task, you want to have multiple independent ways of dealing with the task, so that each way can serve as a cross-check and a backup for the other(s).

For example, the right magneto is a backup for the left magneto.  Similarly, pilots are trained to never overemphasize or underemphasize any particular instrument, but rather to scan all the instruments, cross-check them, and use all available information to build an understanding of the overall situation.

When we apply this idea to fuel, it means you should have multiple independent sources of information about the fuel quantity. 

Good sources include:

• The preflight measurement in combination with an estimate of the fuel-burn rate and the elapsed time.

• A fuel totalizer or totalizer function on the MFD.

• The fuel level gauges and by corollary the fuel level sensors

No one source should be overemphasized at the expense of the others.

Remember that having two magnetos doesn’t just make the engine twice as reliable; it makes it thousands of times more reliable.

Using gauges as a backup to a visual preflight, flight planning and totalizer makes fuel exhaustion vastly more unlikely.

CiES Inc builds accurate and reliable fuel level sensors - 

References

1.

“Pilot-In-Command Decisionmaking” (Chapter 21 of See How It Flies) http://www.av8n.com/how/htm/decision.html

2.

"Aircraft Fuel Gauge Accuracy" http://www.av8n.com/fly/fuel-gauges.htm

Digital Output - Fuel Level Sensors

Digital Fuel Level 

When you enter the term above in Google you get a variety of responses most of them showing a display indicating fuel as a digit value on a screen.

What this is a numerical  manipulation of the the analog signal that most fuel level senders provide as an output:

Simple electronic analog values are the tradition for fuel level measurment.

• Resistance
• Capacitance
• In the case of Reed Switches  - Current or No Current.

But what we have is just another way of showing what analog sensors are providing digital is display only.

Digital output at the Sender is Unique - there are several aftermarket Capacitive Sensors in the Marine industry or Telematics that use a conditioned digital output.  There are conversion processes for these senders - temperature compensation signal conditioning maybe a de- bounce (smoothing) function.

Capacitive senders take an analog signal give it a binary component and communicate the signal.

What if the native language of the sensor were digital in that each fuel level was represented by a binary stream - natively   No conversion - no compensation - and if non contact

 No issues with Fuel quality or Fuel type  - NONE .

 In fact no compatibility issues with the measured liquid in question whatsoever

When Fuel is Important or Critical to Operation
Fuel level is important but what if knowing how much remained meant the difference between an inconvenience or something more significant.

The manner in which we handle the digital output signal is proven in aviation applications -

Signal integrity is paramount - in an environment where static charge and exposure to radiated fields would bring most fuel level systems to their knees.  If you couple the requirements for vibration shock and the extremes in temperature - it is surprising that any fuel level sender works at all in aviation.

So why Digital 

• The level output is provided continually -
• The Fuel Level is reported over and over again to the gauge or display
• The signal does not suffer from signal loss or interference
• Either the complete signal is transmitted or nothing at all 
• Not effected by voltage variation
• Many more data points to map the fuel tank
• 3,800 distinct points for 80 degrees of travel possible 
• No Temperature Effects 
• No compensation
• The device will output fluid temperature if required
• Failure is hard and the results predictable
• False signaling of tank volume due to wear is virtually eliminated.

Imagine a level sender that thrives in the critical  aviation environment and think what it could do for your application.