Bad Aircraft Fuel Level Indication Can Lead to Aircraft Fuel Starvation.

Really Where's your Proof 

Yes I know you have read every publication put out by AOPA and the FAA and they clearly say fuel level indication is clearly a pilot error issue.  In NTSB reports they have a rubber stamp that reads like the following :

"The pilots improper pre-flight and inflight planning, which resulted in fuel exhaustion."

What most in the general aviation community opinion on this issue is referred to as Fundamental Attribution Error.  (FAE) This is where we naturally blame people, even when circumstances or conditions are the primary issue.  

Last week I wrote a blog with the intentionally provocative title: "Let's Legislate Accurate AIrcraft Fuel Level"

For this I received the expected typical responses below: 

"How about we simply look at the number of people that have fuel related accidents and see if they did a proper preflight ...which...since you keep going by FAR's is required. If they didn't do a preflight correctly...they are poor pilots...and if they are poor pilots...gauges won't make a difference. You can't save people from being stupid"

"So, how much of this is lack of awareness, poor training or just laziness I do not know. But this is one of the most preventable accidents out there that keeps happening on a regular basis. I am not convinced an AOPA video will change that.  That is the real crime. They are still happening twice a week and none of them have to."

You would actually expect this pilot response to the provocative inquiry.   In looking at this as a pilot cultural issue or a FAE  the concept of  "Just World Phenomenon" features prominently.  This is the belief that people get what they deserve and deserve what they get.   


Unfortunately, the just-world hypothesis also results in a tendency for people to blame and disparage victims of an accident or a tragedy.  It is actually a protective strategy of the mind, providing mental separation from those kind of pilots that run out of fuel.   It won't happen to me, I am not like one of those pilots.

Sorry - These are random events and they happen to good pilots - I have a files and files from Transportation Boards across the world - you are not immune.  You have a doppleganger who was just as careful as you are and ran out of fuel in their aircraft.   I am sorry to burst the protective bubble.

What appears to happen in General Aviation is that, blame for fuel starvation, falls squarely on the those pilot shoulders .  This appears to be cultural phenomenon among pilots of all types.  The primary message we hear is that education will cure the miscreants, those bad pilots that will always get into trouble.

Very rarely do we delve into the situational factors of the fuel starvation issue at hand.  Our cultural bias doesn't allow that possibility.

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Fuel indication in aviation is loathsome at best - it is not a deep 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 a functionally inoperative fuel gauge is common place in aviation.  

This is illustrated by responses from a General Aviation News inquiry as to what pilots felt about general aviation fuel level indication.

"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." 

"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."

I don't think a statement that  "Aviation fuel level indication could be improved" would fall very far from the mark. 

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Better fuel indication will lead to better decisions and appropriate warnings in aviation.  

While it seems obvious to a layperson

Strangely, Thats not the popular opinion in GA.  But here is the proof. 

EASA (European FAA) - In a Transport Aircraft study for revisions to required powerplant instruments.  EASA showed that better fuel indication would have improved the result of the 65 incidents and accidents in Transport AIrcraft - well over 70% of these accidents/incidents could have been avoided.  Transport aircraft are not GA, but it is the same mode.

CASA (Australian Civil Aviation Authority) Requires that aircraft fuel Indication in Australian aircraft meet a performance standard, every 4 years.   The reasons cited are improving the fuel starvation incident and accident rate. 

TSBC (Transportation Safety Board of Canada) Makes findings of faulty fuel indication a factor in fuel starvation events.  They point to the wide use of fuel sticks as an indication that fuel level reliability could be improved in aviation

 The fuel quantity indicators on this type of aircraft were not reliable. As a result, the pilot could not be sure of the quantity of available fuel in the left tank during flight.

Tests on the components of the fuel level indication system established that the only time the fuel level in the wing tank was shown correctly was when the tank was empty 

The Bell 214B and Bell 205 flight manuals be modified to provide information regarding the inaccuracy of fuel quantity indications, thereby allowing pilots to make informed decisions in the event of a loss of fuel boost pump pressure. 

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Cognitive Bias 

While these two points are associated with the same system and appear plain as day 

1. General Aviation Aircraft have inaccurate fuel level indication.
2. General Aviation Aircraft are prone to fuel starvation and fuel exhaustion.

A general aviation pilot won't recognize those statements as connected. 

Why: 

Anchoring Bias -  The tendency to rely too heavily, or "anchor", on one trait or piece of information when making decisions (usually the first piece of information that we acquire on that subject.

Pilot's are told to never trust the fuel gauge on the first training flight. 

Availability Cascade A self-reinforcing process in which a collective belief gains more and more plausibility through its increasing repetition in public discourse (or "repeat something long enough and it will become true.

Bandwagon Effect The tendency to do (or believe) things because many other people do (or believe) the same.

AOPA, FAA continually tell us that we need to use proper pre-flight procedure including sticks.

Confirmation Bias The tendency to search for, interpret, focus on and remember information in a way that confirms one's preconceptions

Aircraft fuel gauges only have to be accurate at zero 

You're only interested in selling senders  

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I have a passion for European Sports cars of the 50's and 60's  and I was talking with a group of MG-TC owners.  The subject of fuel indication came up and the MG owner brought out his calibrated stick.   MG T Series cars don't have a fuel gauge, they have a warning light, and Old British cars being what they are the warning light isn't a trusted component or indication of anything of merit.    

I mentioned that small aircraft use a stick as well to determine fuel quantity.  There were lots of raised eyebrows and a few quizzical looks.    The very first statement I heard was.

  "I bet they run out of gas"

  followed by 

"They can't just pull over and check with the stick can they"

I told them the various reasons why,  and they asked if something was being done to improve that.  

I told them sadly no.  A pilot will go out today after purchasing a new aircraft and obtain a stick to measure their fuel.  

It's  startling commentary, that in aviation, we use fuel measurement methods and techniques to prevent running out of fuel that were common on minimal equipment British sports cars of the 40's & 50's.  

I hope it makes us think.