The CiES Brand

A WORKING STATEMENT FOR OUR BRAND

From the beginning, CiES has been driven by innovation. Our first invention was the world-renowned magneto resistive fuel level sensor this same sensor that is used today on the most popular aircraft in the world.

Since our breakthrough in fuel level that begins in 2003, we’ve accelerated our strong culture and track record of innovative technologies that solve real-world challenges for our customers.  

More recently, we pioneered automated fuel tank selection system for a global aviation company,  developed a wireless propane vehicle fuel level sensor, & a marine fuel level sensor that addressed whether the boat is on open water or in the harbour. 

By accurately monitoring fuel level and providing an updated range capability, operators avoid breakdowns, protects valuable high pressure fuel systems, reduce environmental impact, and save money at the pump. 

Today, CiES delivers customer-driven innovation to a diverse spectrum of industries and applications– from automotive to industrial production, to off-road/heavy-duty equipment, marine to agriculture, aerospace and oil level sensing solutions that protect and perform.

5000 Aviation Fuel Level Senders

After two years of production we have crossed a major milestone.

There are 5000 CiES Inc Fuel Level senders in the field or more appropriately, in the air.

What does that mean for our customer base or our potential customer base?  

The CiES Magneto Resistive Fuel Level system is proven and a good solution for fuel level measurement in a variety of applications.

We have proven the concept in what may be the harshest environment for fuel level measurement - aviation.  By proving ourselves in the aviation world we literally can take this method anywhere.


Our quality is phenomenal - out of the 5000 units in the field we have yet to take one out of service.
   
Can you say the same for your fuel level solution?

Vans RV CIES Fuel Level Sensor

VANS RV Fuel Level Sensor

CiES Van's Fuel Level Sender

On announcement of the TSO and the patented CIES Fuel Level system on  Cirrus production aircraft,  we were approached by several RV owner/builders.  They asked us if we could build a fuel level sensor for the popular Van's Aircraft Series.

We thought about it - it was easy to do (on initial thought) used the same housing as the Cirrus System.  The same circuit card,  But the devil is in the details.

We can easily produce a Digital Fuel Level Sensor that fits the Vans Aircraft Tank - For all models of Van's Aircraft - Ok RV-3 thru RV-9 and the RV-10 

Stewart Warner Fuel Level

Yes - This is a more expensive solution than the Stewart Warner sender sold by Van's.  








In looking at the alternative used by the builder community - A Capacitive sensor formed in the tank  -  this sensor uses outside electronics to sense the amount of fuel in contact between two metal plates.    

Capacitance is a compromised solution for aviation fuel level - the no moving concept is good if it works all the time or doesn't need cleaning or temperature calibration. 

The capacitive system used in some Van's aircraft is not set up for replacement or maintenance - something the Big Boy OEM capacitive probes employ.  

 Capacitive probes should be cleaned occasionally, as fuel born debris or corrosion is caused by moist air that is introduced on descent in every aircraft cannot be avoided.  -  moisture severely degrades the capacitive system, both in output and the degradation of the system itself.   

Simple capacitive solutions do not accommodate different types of fuel.  Fuels can have a vastly different dielectric constant - and this translates directly to fuel level. AutoGas is close but not the same as AVgas and ethanol is grossly different. Auto fuel with high ethanol blend ratio 10-15% will actually read falsely up to twice as high if used in a tank that was calibrated for Avgas. 

OK -  at CiES we have solved fuel level in the Cirrus, Gipps, Partenavia, Quest aircraft with float based sensors -  a radically different sensor system to locate the float in the tank  - but it is float sensor none the less.    

What is happening in the Van's aircraft world to give a nearly universal complaint that the Steward Warner Float Gauge doesn't measure full fuel - However a user built capacitive plate that is only 3 inches further outboard does.   This didn't pass the sniff test.  Floats by design - float on the surface of the fuel and you miss some.  

In review of the RV tank and wing dihedral, a capacitive plate may not measure full fuel as well.

Lenny Iszak Rendering of the Van's RV Fuel Tank

There are limitations to float design,  the last 0.25 inch of potential travel is limited when the float hits the skin.  This is a well known and in an aircraft fuel tank, a quarter of a inch can represent many gallons.  


 But from what we heard  in these nearly coincident fuel sensing systems - capacitive and float - they could be off.

So the general assumption in aviation is that float sensors are not as effective.  That is generally what we hear in the certified world as well.

So we set out to discover what could be going on.  The first thing  we found was that RV provided a rather approximate bend diagram for the Stewart Warner sensors.  The Stewart Warner sensors have a bit of lateral play and they seemed in our models to contact structure or other items in the tank prior to hitting the skin.   OK several owners had modified their Stewart Warner float attachment to limit this possibility.  Well we can do a good job in measuring the fuel in blue.

We have very conclusively proved in the Cirrus G5 aircraft and others that a float sensor can measure full fuel, it can be very accurate and very reliable - and we know that we can do the same in an RV Aircraft tank.   We may need to look at a multi sender installation.

If we put a little thought and a quality assembly we could achieve good results each and every time 

CIES we believe we could get you something just a little bit better.  


Stay tuned - something simple to operate and understand - a communication method that has real immunity to poor connections or induced voltage - a fuel sending unit that is robustly built to measure fuel in the light aircraft environment.  

This FAA approved fuel level reporting system is a better solution over the capacitive sender system and most likely equal in monetary or personal effort when it is all said and done.

Our sensor have the added benefit of being field replaceable and easy to diagnose.  

What happens when your capacitive system fails to operate.    The CIES fuel Level sender doesn't need to be cleaned - ever - and frankly is pretty darn simple.

We have 5000 units in the field - Zero issues, problems or returns

The output is now resistive, voltage, digital frequency or CANBUS 

We took exceptional care to insure we reduced the float size to minimize issues with float / structure interference.

For a Van's aircraft we will offer a full replacement transferable warranty for 10 years for unmodified senders. 

Yes I know - you could build your own and you are - but when it comes to fuel level reporting - spending a little more gets you something - like this reaction from our customer

WOW - this is a must have -  Maybe you'll think so too 

  

If you do - let us know 

Video of the Cirrus SR22 Retrofit

Post by CirrusPilot.

If You Trusted Your Aircraft Fuel Gauge?

How would you operate your aircraft

If you knew, at all times, how much fuel you had.

Hard to imagine, isn't it ?

Did you ever have that feeling that you might have put in the wrong fuel starting amount?

Did you really see fuel wash over the tabs?

Doubts about fuel level can creep into any flight.   

The statistics of fuel starvation, fuel exhaustion and fuel related loss of power events bear that out.  

But it is interesting to see that with a change in technology for fuel level reporting to Magneto Resistive Senders.

Some pilots are finding an opportunity to operate differently.

CirrusPilot

Commenter Dialogue:

I'm always surprised you do not fly your 22t topped off, were you taught to fly with minimum fuel? Maybe it's a West Coast thing, but my Cirrus SR22 is always sitting full and I fuel it every time it is at home.

Response:

Plane is hangared. Full tanks are heavier and the performance is affected. I carry 20g extra to a location like Vegas.

New Advertisement - Cirrus SR22 Retrofit

Cirrus SR22 Fuel Level Retrofit

Feedback on the the CiES system....

While my aircraft (NA G3 #3813 Perspective) was at Leading Edge Aviation in Tampa for an annual, I had the CiES digital fuel system installed. The crew at LEA had recently received the benefit of Scott Philben's tutelage on the intricacies of this installation, and I was in line next for the retrofit. Two points of observation:

From This

1 - Fuel quantities are now precise and crisp. No longer do I tend to disbelieve fuel gauge indications because of erratic needles.

 Now there is no "negotiating" with myself of how much fuel I probably have. The installation includes calibration at 2 gallon intervals from "Zero Fuel" empty to full.  In my opinion, the replacement round gauge on the center panel is superior to the Perspective MFD indication.  Fuel quantity and balance is abundantly clear.

To This

2 - Choice of shop doing the work is very important. With the changes in wiring harnesses among all the iterations of Cirrus aircraft, there are a several unique and significant distinctions for each application. You need a knowledgable, detail-oriented, and thorough installer. I was fortunate to have one at Leading Edge Aviation.

Contact Steve Miller if you want this job done properly.




Finally, thank you Scott Philben for extending the OSH incentive, motivating me to get this system in my airplane. After seeing the results, I think the discount I received should more appropriately have been a premium paid to you. 

Parody on a Recent AOA Advertisement

Fuel Gauges: Do they Indicate Properly

Fuel Gauges: Do they Indicate Properly?

by Tom Bennett, Civil Aviation Safety Inspector, Aircraft Maintenance and Manufacturing, Prairie and Northern Region, Civil Aviation, Transport Canada

There have been multiple incidents of fuel exhaustion over the past few years. In the last issue of the Aviation Safety Letter (ASL), you read about fuel starvation due to improper fuel selector condition. In this article, I would like to talk about another common factor in fuel starvation incidents: fuel gauges that do not indicate properly.

Some incidents were very public, whereas most incidents went unnoticed with the exception of being listed in the Civil Aviation Daily Occurrence Reporting System (CADORS). Some incidents were directly related to poor fuel management by the flight crew(s); however a few came as a surprise to the flight crew, as the fuel gauge(s) still indicated there was fuel in the tanks. An accurate reading of the fuel gauge may have prevented many of these occurrences.

There is some confusion about the need for serviceable fuel gauges. This confusion is especially prominent in the general aviation world. As both an aircraft maintenance and manufacturing inspector and an enforcement investigator, I have heard statements like: “The gauges have never worked properly. I just keep track of time in my tanks,” many times.

Such a statement is contrary to Canadian Aviation Regulation (CAR) 605.14(j)(i), which states: “No person shall conduct a take-off in a power-driven aircraft for the purpose of a day VFR flight unless it is equipped with a means for the flight crew, when seated at the flight controls to determine the fuel quantity in each main fuel tank […]”. This regulation is then carried through in sections 605.14, 605.15, 605.16 and 605.18 of the CARs, to apply to all power-driven aircraft in all nature of flights (day/night visual flight rules [VFR]/instrument flight rules [IFR]).

Furthermore, many aircraft must have their fuel gauges working as per their type certificates. For larger aircraft, especially transport category aircraft, the fuel gauges can be deferred by means of the minimum equipment list; however, this usually involves using other measuring devices installed on the aircraft and making complex calculations.

A common factor in fuel starvation incidents:
fuel gauges that do not indicate properly

Recently, a commercial pilot was fined because one of his fuel gauges was not working while he was operating an aircraft. In this case, as in others, the fuel exhaustion caused substantial damage to the aircraft during the forced landing. The pilot applied to the Transportation Appeal Tribunal of Canada (TATC) to seek relief from the $750. The TATC upheld the Minister’s decision.

The Aviation Enforcement Branch has also sanctioned aircraft owners and operators for unserviceable fuel gauges found during Transport Canada’s oversight activities. The maximum sanctions for an infraction under CAR 605.14, 605.15, and 605.16 are $3,000 for an individual and $15,000 for a corporation. The maximum sanctions for an infraction under CAR 605.18 (IFR) is $5,000 for an individual and $25,000 for a corporation. Inspection, maintenance and repair of a fuel indication system seem less costly, in my opinion.

Another common excuse I hear is that the gauges have always displayed faulty readings or they are too difficult or expensive to calibrate. As an aircraft owner, if you rely on this flawed thinking you are exposing yourself to numerous risks. First and foremost, you risk running out of fuel. This can lead to personal injury/fatality and damage/loss to the aircraft. Second, you are exposed to regulatory action by enforcement (fine or suspension). I think we can all agree that none of these are pleasant outcomes.

For the aircraft maintenance engineers (AME) in this scenario, I have not yet seen an inspection where the functionality of the fuel quantity indication system is not checked. Be careful what you sign for on the inspection forms and subsequently, the maintenance release. Following manufacturers’ instructions for inspection, maintenance and repairs will never lead you astray.

Most pilots and AMEs are aware that any accident or incident results from a series of events; there is never just one cause. Anything we can to do tighten up against the possibility of an error is a step in the right direction. 

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Crown Copyright and Licensing, Public Works and Government Services Canada
Crown Copyright Clearance CCL FILE # 2011-33369
(c)Transport Canada, Aviation Safety Letter Issue 1/2011

AeroviePilot iPad Application Demonstration

USA Today - Unfit for Flight - An In-Depth look at the Editorial Opinion

The USA Today statement suggests that juries awarded in all the aircraft manufacturer cases presented by the author of  Unfit for Flight.  That is simply not true, most of the cases were resolved with judgements.  Having been involved in several aviation product liability cases,  I know personally that these judgements are accepted to mitigate the economics of both time and money.  It is not as USA Today suggests proof positive of conviction in these product liability matters,  it is just another shade of grey as to where the fault might lie and as we know,  shades of grey imply reasonable doubt.

There is a significant issue here - Several law firms target the aviation market, as the issues and procedures of aviation are arcane and not well known among the general public.  This issue was well documented in the discussions surrounding the General Aviation Revitalization Act of 1995.  

The aviation specific trial attorneys know this very well and work to be depicted as experts or teachers as they explain to the juries what they should know about aviation.   It is a definitive bias and a slip of the blindfold on justice.  Whenever a significant aviation tragedy occurs you will find these lawyers set up as media aviation experts across the spectrum of video entertainment.  Expert recognition of these lawyers by the public is key to their sucess rate.

If these trials were held with a "jury of peers" i.e. other pilots - rarely would some of these cases ever darken a courtroom. In keeping with the Opinion aspect of the reports and editorial follow on  -  that is mine.

Case in point - In the three part expose - the author Thomas Frank  talks with a pilot and his crash story.  In this story the pilot relates that a bolt on his engine sheared in flight causing him to lose power.  The FAA and NTSB were all over this pilot about fuel exhaustion and maybe rightfully so.  So let's look a little closer as to why their line of questioning shouldn't have been dismissed offhand.

In the story,  the owner found an expert to redirect the responsibility in this crash.  This aviation expert related that all the fuel was lost when the wing hit a tree - just prior to hitting the ground.  Nice story for non pilots / non aviation savvy people and a good example of talking "aviation" around the general public.  Like I related above,  this story might hold up in front of a jury - just as it was presented to the readership of USA Today. 

The fact that most aircraft have fuel tanks in both wings - makes you question the pilots assertions about his fuel quantity, it also opens a line of questions and thoughts.  This tree did not stop the aircraft, but only damaged a wing.   Did the tree damage both wings?   All the fuel was gone - the only logical conclusion is that the tree damaged both wings equally and in the similar location.    Aircraft fuel tanks in this pilots wing are segregated into separate cells,  some of which have check valves to keep fuel flowing to the engine.  So now having a little information about aircraft, this is what the author Thomas Frank is telling us ....  

• This pilot hit a tree,  that significantly damaged, but did not stop the aircraft.
• The damage was significant enough to empty the remaining fuel and was symmetrical to both wings.
• This damage opened up both multi cell fuel tanks in a similar manner  and in the milliseconds between hitting the tree and ground - all of the fuel disappeared from those fuel tanks and leaked down the trunk of that tree. 

Really...... the limited facts of this story don't hold up to investigative reporting ... Thomas Frank did aviation a disservice by not digging deeper than only the superficial elements of this example.   Mr Frank simply accepted these pilot statements as factual with the support of a court judgement, and an FAA Airworthiness Directive.   If Mr Frank sought out an unbiased aviation expert to discuss these issues, he might have developed a better understanding.

So blindly accepting the expert opinion of what happened to the fuel and knowing that the bolts in question were indicated to have issues in acrobatic and helicopter aircraft just added literal fuel to the fire of Mr. Frank's article. 

One could make an equal unsupported story that the engine starved for fuel and coughing and bucking with the uneven fuel distribution - could have created similar stresses to those encountered in acrobatic or helicopter operations  -  and thus sheared the bolt.  This bolt that the pilot proudly holds, now appears as an icon, saving this pilots dignity.

The above is a story - I believe equal to the author Mr Frank's expose'.   Neither may be true - but there are facts in his story that make a pronouncement of absolute guilt on the part of the engine manufacturer in this case difficult to buy.

Ok so while we are on the subject of fuel starvation - The FAA's rebuttal of the Mr Frank's opus needs a similar examination.  The FAA Administrator clearly indicates "running out of fuel"  is a pilot issue.  This blanket statement piece really needs a closer examination by the FAA.

This comment exposes an issue that has not been handled correctly by the FAA, in my opinion.   By her statement, it indicates that this issue is being ignored from the top down - The admonition that fuel according to the FAA  is a "Preflight" pilot issue.  This line of reasoning ignores that aircraft are required to have working fuel indication by the regulations.  The idea that "preflight" is the only time you know how much fuel you have,  indicates the general lack of satisfaction of fuel indication systems in aircraft.  

Fuel indication in aviation is loathsome at best - it is a dark secret that most aircraft fuel indication systems are marginal from the start.  When you compound a marginal system with poor or no maintenance,  you can make a general statement that an inoperative fuel gauge is common place in aviation.  

Fuel starvation then becomes an aviation issue - and maybe - just not a pilot issue.  

So given Mr. Frank's expose - yes there are issues of safety and yes they need to be improved.  But are we all asking the right questions.

 

USA Today "Unfit for Flight"

There has been a lot of discussion in the aviation community about this 3 Part Expose' Series in      USA Today - Most of our aviation community agree that - we should strive to make aviation safer.  Most of us on this side of the fence,  also agree that the condemnation of manufacturers in this industry was - just a little slanted.  I happen to know several of the players and the other side to many of the examples and lawsuits presented.   It is not as cut and dried as the articles suggest.

Mr Bertorelli - who I respect as an aviation journalist and pilot - made several good points in his Blog  As most people are aware - Aviation is the "most regulated business in the world".  In this industry we laugh at drug and medical device companies - because they have it easy.    In this environment how could an outside news agency find fault with our industry.    Given the economics of this particular business,  it isn't profitable to do a bad job.   Paul stated all of this in his blog very clearly:

There’s wide agreement that over regulation has had a hand in getting us into this mess, so further regulation — of manufacturers or more stringent training requirements —won’t get us out of it.   The entire community just doesn’t have the stomach for it. And neither do I, frankly.  Not to mention the utter lack of any economic engine to drive it all.

I was however struck today with one of Mr. Bertorelli's responses to this safety issue - and because an element of the rebuttal involved a segment of the aviation industry that I have become quite familiar.

At this point, we work on fuel level systems in aviation and most recently the automotive industry.

We have a unique but very narrow viewpoint.

GA Safety: All Heat, No Light

Excerpt from Paul Bertorelli's Blog 

As a refreshing change, the USA Today report almost tried to cast pilots as steely eyed but hapless victims of shoddy manufacturing and outdated aircraft designs. Were it only so. None of us have to look in the mirror to know that although out-of-the-blue mechanicals do cause accidents, preventing every one of that category wouldn’t change the accident rate much.

Even in some of the egregiously poorly prepared reports, the pilot obviously did something stupid—like flying into bad weather, overloading the airplane or, a perennial favorite, running the tanks dry because the fuel gauges aren’t accurate.  

That last item is a cultural thing in which automotive knowledge contaminates aviation thinking. It’s like that GEICO commercial; everybody knows the gauges aren’t accurate and we have means to work around this deficiency. 

Using a crash as a means of highlighting it seems somehow unsporting. Yeah, the stupid gauges should work, but no, they don’t.  So buy a totalizer or learn to use a watch.
But unless you, as the owner or pilot, take personal responsibility, your 35-year-old Cessna 172 is not going to be fitted with more accurate fuel gauges. 

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Unfortunately neither the NTSB or FAA equate "Bad Fuel Gauges" to Fuel Exhaustion,  but it is interesting that Paul does state this in his blog.  It is quite common to report to the NTSB or FAA after an accident that the fuel gauges are not accurate in your damaged aircraft.  There is no consequence to those statements.  If your flight plan did not indicate average fuel burn - look out.  

I also agree that fuel level is a cultural thing in aviation - I am not familiar with the GIECO reference Paul equates - but fuel level in automotive applications is barely adequate, the website tankonempty.com illustrates this very well.  The issue in aviation, is that for most small aircraft, the fuel level system was taken from a ground vehicle system, think automotive, tractor, truck - This system, was barely adequate for an automotive application as illustrated by the website above  - and this system really struggles with fuel quantities that are 3 times larger, and the fuel and vehicle movement that occurs in aviation.

When we talk to people outside aviation - and we state things like Paul's statement "Yeah the stupid gauges should work, but no, they don't"     - they look at first puzzled and then to a each non aviation person we have stated this quizzes us back "Don't small aircraft run out of fuel"  Yes they do. 
   The National Highway Transportation and Safety Administration - NHTSA in a recent automotive recall for bad automotive fuel fuel gauges on Chevrolet Trucks stated that the there was an obvious safety issue with having bad fuel gauges  - specifically from the recall announcement:

"If a customer runs out of fuel without any warning from the fuel gauge, it will cause the vehicle to stall and increase the risk of a crash, the company said."

In aviation, as Paul Bertorelli stated for fuel level  - "we have work arounds". 

-------------------------------------------

As I am focussed on a small aspect of the aviation safety issue - and this is seemingly the common aviation response to a significant issue. 

Because from where I am sitting -  maybe the pilot of the 35 year old Cessna 172 should at the least have the fuel gauges checked and calibrated at annual. 

If the gauges are too far gone - he should have the maintenance facility send in a Service Difficulty Report to the FAA - let the Feds know we have an issue out here in the field.   Let's quit making excuses or work arounds for equipment that should and by law be required to function correctly. 

I think we as a community should start questioning these common assertions and take off the cultural blinders.  

-------------  

I think we all want to make aviation safer - including USA Today.

Fuel Gauge INOP for initial CFI Check Ride

A Posting from Pilot Instructor Forum 

Hi all,

I am taking my initial CFI check ride this weekend. I went out to fly the airplane (C-R182) from the right seat to practice some maneuvers before the check ride. But, I realized the left fuel gauge is indicating zero no matter how much fuel is in the tank.

It sounds to me like the issue is somewhat controversial. I've heard "fuel guages only need to be accurate when the tank is are empty" and I've also heard that per 14 CFR 91.205 (b) 9 the airplane needs to be equipped with an operable "Fuel gauge indicating the quantity of fuel in each tank".

I tend to agree that the fuel gauge needs to be operable, but there's no time to get the fuel gauge repaired before the check ride. Any advice?

-----------------------------

Yes, per §91.205 a fuel guage for each fuel tank is required for day / night VFR and IFR flight is required to be operational.
You could argue as others did that it only has to “correct” when on empty and I would agree but it has to read something. The other way of looking at it is that the fuel guage has to read something other than empty when their is fuel in the fuel tank.
If your airplane has an approved MEL, it might be allowed to be inoperative provided you verify the amount of fuel in the tank, but for your initial CFI test do not take a chance of busting because of an unairworthy aircraft.

---------------------------------

Remember the Tomato Flames acronym.  F is for fuel gauge.  You must have a functioning fuel gauge.  The acid test is safety.  Do you feel safe flying an airplane with an inop fuel gauge.  I would tend to want to get a ferry permit to get it to a repair facility, or better yet, get it fixed where it sits if you can.  There are too many fuel exhaustion accidents (preventable) per year to take a chance like this.  I know this sounds a little over-reaching, but as a CFI, you are the prime example to the flying public.  To show your willingness to take a chance on an inop fuel gauge sends a dangerous example to your potential students that the Pilot Examiner or FAA Safety Inspector should flunk you for.  Get it fixed then take your exam.

------------------------------------

“I tend to agree that the fuel gauge needs to be operable, but there’s no time to get the fuel gauge repaired before the check ride. Any advice? ”Seems like a no-brainer to me.  You have an unairworthy airplane you’ve been training in and you’re contemplating taking a checkride in it?  for a CFI? BTW, Part 23 says the fuel gauge must be *calibrated* to read 0 when there is no usable fuel in the tank.  Being calibrated to read 0 doesn’t mean that this is the only indication that needs to be accurate.  All scales must be calibrated at a certain weight, and the error increases the further away from that weight that you get.  Even so, the error is usually required to be within a certain range.  Part 23 doesn’t publish that range, but likely there is one.  Someone I know has requested an LOI on the topic from the FAA’s General Counsel’s Office, but it won’t be available until October.

Note: That letter was not published by the FAA General Counsel 
----------------------------------

In reading the above responses a couple of thoughts come to mind.  While by regulation the fuel indicators must function, relying on them for anything other then an indication of possible fuel present is more dangerous then not having a guage at all.  Our flight school had 36 aircraft and there wasn’t a guage in any of them that was even close to accurate.   Many times a student pilot or CFI would request fuel for a plane by reading the guages (without comfirming visually) only to find the tanks topped off.   And conversely, taking off with what they thought were full tanks only to land an hour later with one tank dry.The comment:” There are too many fuel exhaustion accidents (preventable) per year to take a chance like this.  I know this sounds a little over-reaching, but as a CFI, you are the prime example to the flying public.  To show your willingness to take a chance on an inop fuel gauge sends a dangerous example”

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While I wholly agree with the assertions that physically checking and monitoring the fuel quantity using known values is the best practice, the reg is very clear about what is required to be working at all times.  If you fly with a fuel indicator broken (which it clearly is), then you are essentially shooting yourself in the foot.  Yeah, you might get away with it, but then again, you might not.Also, in regard to MEL’s, 91.213 is very specific that any equipment required to be in operation by regulation (such as 91.205) by default can’t be included among the inoperative equipment in an MEL.

Flying with an Inoperative Fuel Gauge - Legal or Not?

A Forum Dialogue about Fuel Gauges in Aircraft

I'm not sure where to post this so I guess I'll just post it here.

So today while pre-flighting my club's 172. I flipped on the master switch to check the fuel gauges. The right fuel gauge, indicated correctly. While the left fuel gauge however, was pegged on empty, even though there was full fuel in the left tank.   I know that fuel gauges should only be accurate when they are empty,  however under 91.205 it states that an operative fuel gauge(s) indicating the quantity of fuel in each tank has to work for a VFR day flight.

I asked the mechanic and he frowned upon me and gave me a lecture on how "fuel gauges should only read zero when empty blah blah," and that I could still fly the airplane.

Wearily I went and asked of one of the CFI's in the FBO and he told me If there is fuel in the tank and the gauge indicates zero or empty then its just an inaccurate gauge. If however, there is no fuel in the tank and the gauge indicates fuel, then that is an inoperative guage.

My question is, I am legal to fly? And what are you thoughts on this? I really dont want to be nit-picky about regulations on the airplane that I fly but, that is my name going into that logbook and I just didn't want to risk it.
Thanks!

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"You wrote this, so it should answer your question.  A further question could be: What is so critical about flying the particular mission you're seeking to (a pleasure flight), that would require you to go against the above? Especially if something were to happen on that flight that attracted Fed attention, related or even unrelated to the inop gauge? Would the club back you then?"

-----------------------------------------

"Tell the club to fix their stuff. There's no excuse for that kind of Mx laziness, and allowing it or making excuses for it with the "kick the can down the road" mentality they seemingly have, only perpetuates the problem."

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I'd say no, till it is either fixed or deactivated in accordance with the MMEL.The whole "it only has to be accurate at zero" argument to me is moot, It is currently at zero AND it is not accurate.   A broken clock is right twice a day.

 --------------------

Dip your tanks and use those numbers in your calculations. Flt time x Rate of fuel burn = Gallons of fuel needed then add in your fuel reserves. I don't rely on what a fuel gauge in a 172 says.

 ------------------------

Personally, I wouldn't fly it. I certainly don't want to nitpick a plane apart, but the thing is, the fuel gauge isn't doing anything *at all*!

--------------------------

I'd fly a plane that had a gauge reading "some fuel" when there was, indeed, some fuel in the tanks, and reading "empty" when it's empty.

--------------------

But having a gauge sitting on "empty" 100% of the time isn't acceptable, in my opinion. What's the point in even having the gauge then? Might as well just draw a picture of a gauge on the panel with magic marker, because it would be just as useful.

---------------------

Ultimately, I'd pull the "would you rent this plane to a fed?" question on them. If they wouldn't be willing to show it to a FSDO inspector, they need to fix it.

---------------------

Notice where the "zero" comes from. It is a guideline for when the fuel gauge must read zero. This is to keep manufacturers from using zero "total" fuel when calibrating the gauge instead of "usable". Other than that there is no mention of gauge "accuracy" in the reg

Also.
Notice the word "operable" in the Part 91 reg?Is the gauge in an "operable" condition if it is always reading zero? No.

Is the gauge in an "operable" condition when reading inaccurately? No.

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I've talked to the maintenance officer for the club and he said he will check it out tomorrow. But I'll definately crank her over and taxi her next time if it ever happens again. Thanks! For all your guys input, it really helps a lot. I knew it wasn't legal,

But yet for some strange reason the mechanics and CFI's at the FBO had a million ways to explain and get around it.

Aircraft Fuel Mismanagement Cause and Effect

Aircraft Fuel Mismanagement - Cause and Effect

This is what we know about aircraft fuel instrumentation 

• "Maybe they’re also more in the habit of keeping an eye on the clock in flight, even sneaking the occasional glance at those notoriously inaccurate fuel gauges."  
• "Airplanes are legendary for having inaccurate fuel quantity gauges"
• "These devices are notoriously inaccurate, showing empty when there are gallons left in the tank and showing full for the first 1/2 hour."
• "Aircraft fuel gauges can be notoriously inaccurate."
• "Without a means of measuring fuel flow, you must rely on the aircraft fuel gauges or total time of flight. Aircraft fuel gauges are notoriously inaccurate (they are only required by the FAA to read accurately when displaying empty)." 
• "Aircraft fuel gauges have a well-deserved reputation for being unreliable and the FARs only require that fuel gauges read correctly when they are empty!"
• "Second, as others have said aircraft fuel gauges have historically been poorly designed and grossly inaccurate. Many will indicate something significantly different in a climb vs a descent and there are some airplanes with fuel gauges that are designed to read full until a substantial amount of fuel has been consumed."
• "Don’t bet your life on your fuel gauges, visually check the fuel level by “dipping” all tanks. Some aircraft models have notoriously unreliable fuel gauges."
• "All light aircraft gauges are notoriously, infamously and reliably, unreliable."
• "FAA safety guidance information states that fuel gauges are subject to malfunctions and errors, and certification regulations only require that a fuel gauge read “zero” during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply. Therefore, fuel gauges should not be depended upon for checking the fuel quantity in a tank"
• "Sounds great in theory, but I have not yet seen an accurate Cessna fuel gauge, Ever. A fairly expensive AD would be the only thing that would ever change that."
• "Unfortunately, fuel quantity gauges in aircraft are often inaccurate at quantities above zero. While this does not mean that they can be ignored, it does justify the use of another tool to provide a more accurate total picture of the fuel quantity."

... and on and on and on and on and on.

This is who takes the blame.

• "The pilot's inadequate preflight preparation, which resulted in fuel exhaustion, and subsequent loss of engine power during cruise flight."

• "The pilot's inadequate in-flight planning/decision which resulted in fuel exhaustion. A contributing factor in the accident was the pilot's inadequate preflight planning/preparation to ensure an adequate fuel supply was available for the intended flight."
• "The pilot's inadequate preflight planning which led to fuel exhaustion and subsequent loss of engine power."
• "A loss of engine power due to fuel exhaustion during approach, inadequate preflight planning/preparation by the certified flight instructor (CFI)."
• "The pilot's inadequate preflight inspection, which failed to determine the fuel supply in each fuel tank, and his mismanagement of the fuel supply, which resulted in fuel starvation."
• "A loss of engine power due to the pilot's inadequate preflight planning which resulted in fuel exhaustion."
• "The pilot's inadequate preflight planning and his failure to verify fuel consumption during flight that resulted in fuel exhaustion and subsequent collision with obstacles and the ground."
• "The pilot's departure with insufficient fuel for the planned flight, and his improper in-flight fuel management, which resulted in a total loss of power in both engines due to fuel starvation."
• "The pilot's inadequate preflight planning and failure to verify the amount of fuel onboard the airplane prior to departure, which resulted in loss of engine power due to fuel exhaustion."
• "The pilot's inadequate preflight preparation and failure to verify the fuel supply, which resulted in fuel exhaustion and subsequent loss of engine power."
• "The pilots improper preflight planning and preparation which resulted in a loss of engine power due to fuel exhaustion."
• "The pilot's failure to refuel, resulting in fuel exhaustion and a subsequent loss of engine power."
• "The pilot's inadequate preflight and mismanagement of the fuel supply, which resulted in fuel exhaustion."
• "The pilot's inadequate preflight planning of fuel required for the flight that resulted in fuel exhaustion and the subsequent loss of engine power."
• "A total loss of engine power due to fuel exhaustion as a result of the pilot's inadequate preflight fuel planning."
• "A total loss of engine power during a go-around due to fuel exhaustion as a result of the pilot's inadequate preflight planning."
• "The inadequate preflight inspection by both pilots, resulting in a loss of engine power due to fuel exhaustion."
• "A total loss of engine power due to fuel exhaustion as a result of the pilot's inadequate preflight planning."
• "Improper planning/decision by the pilot, which resulted in fuel exhaustion due to an inadequate supply of fuel."
• "A loss of engine power during approach due to fuel exhaustion as a result of the pilot's fuel mismanagement."
• "A total loss of engine power due to fuel exhaustion as a result of the pilot's inadequate preflight fuel planning."

... and on and on and on and on and on.

I am suggesting the aviation community take a closer look at the causes and effects of Fuel Exhaustion and Fuel Starvation events. 

Fuel Exhaustion - Are We Set Up To Fail

Our expectations are so low for aircraft fuel level gauging systems, They are hardly ever relied on.

In fact when we educate new pilots this is typically what is said.

• The first one is taken from the AIM

FUEL REMAINING—A phrase used by either pilots or controllers when relating to the fuel remaining on board until actual fuel exhaustion. When transmitting such information in response to either a controller question or pilot initiated cautionary advisory to air traffic control, pilots will state the APPROXIMATE NUMBER OF MINUTES the flight can continue with the fuel remaining.

All reserve fuel SHOULD BE INCLUDED in the time stated, as should an allowance for established fuel gauge system error.

• The second one from the Irish Aviation Authority

Aircraft fuel gauges can be notoriously inaccurate so it more reliable to “dip” the tanks to establish how much fuel is onboard. However, make sure that your dipstick is calibrated to suit your aircraft type, the aircraft is parked on level ground and the fuel level has been allowed to stabilise before you dip.

• The final one from AOPA  Flight Training Magazine

Use the clock - not the fuel quantity indicators on the panel - as your fuel gauge. In other words, plan and track your fuel consumption based on endurance, not range. Unlike range, endurance is not at the mercy of winds. Besides, those fuel gauge indicators probably won't be very accurate except when they read empty - a setting you should never see. 

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In fact the pilot mantra given to prevent Fuel Starvation and Exhaustion is  "PREFLIGHT, PREFLIGHT, PREFLIGHT  

So what do we normally look for in a PREFLIGHT inspection - tires, brakes, oil level, security of the flight controls, condition of the prop, security of the fuel caps.   Basically all the stuff you can't check in flight.

The implication here is - you have only one chance per flight to check your fuel level - & that one chance is at your PREFLIGHT inspection.  - If you avoid that critical step, you are flying on borrowed time buddy.

Here is the rub  - you are supposed to be able to monitor your fuel level throughout your time in the air.

Another Pilot Mantra could just as easily be be "INFLIGHT, INFLIGHT, INFLIGHT.  That INFLIGHT scenario would be the pilot comparing anticipated fuel level, to actual indicated fuel level.  This would be the pilot vigilance stuff, you know the cross checks of fuel remaining from the calculations to what is onboard.  

Fuel Gauges are required instruments and found on all powered aircraft - So yes the FAA actually expected them to work.  ---  I bet you are surprised.

You are, by design, supposed to be able to see how much fuel you have at any time while you are in the air.   It is the law, it really is, and it really is a good idea.

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In 1974 (yes that long ago) the NTSB initiated a study on Fuel Starvation,  in this study,  they found that there were some aircraft that rarely had a fuel starvation event,  and they also found some aircraft that were prone to the issue - Most aircraft as you might guess were average in this regard.

SO what this study pointed out, it didn't really come right out and say it,  but it was pretty clear that fuel exhaustion wasn't just a pilot thing  - 

If it were, pilots being human - some good, some bad & most of them average would equally suffer fuel starvation in any aircraft.  It would not matter which aircraft you flew.

An average pilot in an average aircraft might have a fuel starvation event - but not really that likely.

An average pilot might never experience a fuel starvation in "X" model aircraft, but that same pilot might be assured of a high probability of fuel starvation if he flew "Y" model aircraft 

As General Aviation is slow to change - some of those aircraft are still in production.  In fact some of those aircraft in the study are still flying.

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So what did the Aircraft Manufacturers recommend in the 1974 Report:

• Two manufacturers recommended a separate Low Fuel warning system. 

• One manufacturer recommended that a more accurate and reliable fuel level system be developed. 

• One manufacturer believed that a "one tank system" would be beneficial.

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So what did the NTSB recommend in the 1974 Report:

• Specification for a low fuel level warning that would operate independently of the existing fuel gauging system.

• Specification for a more accurate type fuel quantity gauging system. 

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That was 40 years ago - so 

Where Are We Now! 

I am guessing from the picture,  that we are still on the road to find a solution.