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.

The "Zero Fuel" Myth - You know, Fuel Gauges only Need to be Accurate when Empty

You don't really need to know what happened after this true Accident Narrative - It is evident from the beginning.

Picture Draw Jerel Draw,  jereldye.com

Prior to the incident, I received an instructional ride and completed my C-172 checkout. I then flew with a passenger and solo, three flights, for a total of 5.3 hours in the bird.

In all three of those flights.

• I observed erroneous fuel quantity indications,
• Intermittent cycling of the fuel gauges to zero.
• LH Fuel Low Level Warning light coming on intermittently. 

An [instructor] told me this condition was well  known, typical for this aircraft and not uncommon for general aviation aircraft.

I discussed the erroneous fuel quantity indications with the Chief Pilot, and asked
him if I should write them up. 

He said no, that the indications were within the spec, which requires only that they
read accurately when empty.

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The statement that fuel gauges only read accurately when empty is repeated so many times in the aviation dialog.

 You would almost have to believe it is true.

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Actually far from it.

• It is a comment you hear repeated by many pilots, the magazines & AOPA / FAA Safety Briefs.  

• It is not uncommon to have bad fuel gauges in aviation, it is frighteningly almost the rule.  

What is true: 

• Fuel gauges are "Required" aircraft instruments for powered aircraft.

• They are required to be functional by design and in operation on the aircraft   -  Specifically:

• Read fuel level from FULL to EMPTY.  
• EMPTY needs to be calibrated at "Zero Usable Fuel"
• The Zero Usable Fuel is the fuel level,  where in the worst condition - fuel cannot be drawn from the tank.

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Designing, Maintaining or Flying an aircraft with bad or in-operative fuel gauges is illegal.  

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Why is it surprising that so many GA pilots run out of fuel.

I think the answer is obvious.

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Selecting your Fate - Choosing the Proper Tank.

We read so many aviation fuel starvation accident reports and the published responses from AOPA and others  

"On March 12, 2005, a 24,611-hour ATP made a forced landing in an open field after a total loss of engine power while on a visual approach to Runway 13 at Lancaster Airport in Lancaster, Texas. He and the one passenger were not injured.
The pilot did not visually check the fuel tanks prior to takeoff and could not recall "what the fuel gauges indicated"  during the flight.
He thought both auxiliary fuel tanks were full, and both main fuel tanks were almost full.  While descending for the approach, the pilot moved the fuel selector valve from the left main tank to the right main tank" 

Here is where we believe accurate or at least functional fuel level comes into play - The pilot did not look at his gauges - if he had,  and they were operating as designed - He probably would not have switched to an empty fuel tank.

Very shortly after, the engine quit. The pilot unsuccessfully attempted to restart the engine by switching the fuel selector valve back to the left tank and cycling the throttle.  

It is interesting that the neither the FAA nor NTSB tested this aircraft's fuel gauges for operation.  They only tested the engine. 

   We have all become complacent that aircraft fuel gauges can offer little or no assistance to fuel starvation in our mode of transportation.

One aircraft manufacturer has looked at this issue and did something about it - why guess if the tank you are switching to holds fuel.   

Cirrus Aircraft has incorporated accurate fuel level - and with accurate fuel level you may eliminate switching to an empty tank.   

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Let's Elevate the Discussion about Fuel Exhaustion so it won't Bring us Down

I have been engaging with an active Aircraft Owners Pilot group about Fuel Exhaustion and it's potential causes and solutions.  As Fuel Exhaustion and Starvation span the  GA spectrum I thought I might share the dialogue.

Don’t Blame your Fuel Gauge

"According to the Joseph T. Nall report (produced by AOPA’s Air Safety Institute), 89 accidents occurred in 2010 as a result of fuel exhaustion; 11 of them fatal. And despite a decline in fuel management accidents through 2008, more recently those numbers have been reversing, accounting for eight percent of all accidents in 2010.
According to the Nall report, inadequate flight planning — failure to determine the amount of fuel required for the flight or the amount actually on board, or to verify the rate of fuel consumption en route — accounted for the largest share (48 percent)."

This was reported below in the FAA Safety Team Briefing in October 2013 and is indented in italics:

FAASafety

Briefing - Fuel Monitoring 

October 2013

The General Aviation Joint Steering Committee

Safety Enhancement Topic of the Month

Don’t Be “Fuel-ish”

While fuel exhaustion continues to be a a top ten issue for General Aviation safety - It gets very little insight or a real root cause analysis to the factors involved.  To most in the aviation field this is a simple pilot problem with a very simple answer, But there is a hidden truth lying in the commonly held belief below:  

"One of the more head-scratching aspects of fuel management accidents is simply how easy they are to prevent, as well as recognize well before they happen.Blaming a bad fuel gauge doesn’t cut it. To help prevent getting into this situation, here are some tips:"

Note:  A fuel gauge is required equipment on all powered GA aircraft and it is supposed to be accurate throughout the range from empty to the zero fuel level.  

The FAA Safety Team implies in the paragraph above that you could be flying your aircraft with a bad fuel gauge - I hope this isn't so.

§91.7   Civil aircraft airworthiness.
(a) No person may operate a civil aircraft unless it is in an airworthy condition.
(b) The pilot in command of a civil aircraft is responsible for determining whether that aircraft is in condition for safe flight.  The pilot in command shall discontinue the flight when unairworthy mechanical, electrical, or structural conditions occur.

§23.1305   Powerplant instruments.
The following are required powerplant instruments:
(a) For all airplanes. (1) A fuel quantity indicator for each fuel tank, installed in accordance with §23.1337(b).

§23.1301 (Systems and Equipment) Function and installation.
Each item of installed equipment must—(a) Be of a kind and design appropriate to its intended function.(b) Be labeled as to its identification,function, or operating limitations, orany applicable combination of these factors;(c) Be installed according to limitations specified for that equipment; and (d) Function properly when installed.

§23.1337   Powerplant instruments installation.
(b) Fuel quantity indication. There must be a means to indicate to the flightcrew members the quantity of usable fuel in each tank during flight. An indicator calibrated in appropriate units and clearly marked to indicate those units must be used. In addition:
(1) Each fuel quantity indicator must be calibrated to read “zero” during level flight when the quantity of fuel remaining in the tank is equal to the unusable fuel supply determined under §23.959(a)

And this is where the hidden truth lies,  and this is where I believe the  FAA Safety Team author missed the point - It is a subtle but significant difference and it should read as follows:

Flying an aircraft with a bad fuel gauge doesn't cut it 

If we review  -  I believe the accident chain starts at this point.

• After visually checking the fuel in the aircraft,  the pilot then got into the aircraft   put power onto the aircraft and observed that the fuel gauges did not report accurately how much fuel was in the tank.  

Or 

• The pilot observed on filling the aircraft that the gauges indicated the aircraft had more or less fuel than that required to fill to tabs as an example.

STOP RIGHT THERE - Take your aircraft to the nearest service center and have your required aircraft equipment repaired or replaced to make your aircraft airworthy.  

Don't fly an aircraft with bad fuel gauges - it is that simple.

If you are flying an aircraft with bad fuel gauges - you should have a ferry permit.     

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When you look at it from this perspective - yes the solution to fuel exhaustion may be just as easy as the brief author suggests.  

Simply mandate that required fuel level reporting equipment function properly when installed on the aircraft.  

I understand fuel level reporting is not good in GA - That they don't work is the universal complaint.  

If that is true, then this problem lies with the FAA Administrator -

1.) Did the FAA Administrator allow an Aircraft Type Certificate to be issued that ignored fuel level reporting requirements of FAR 23.1301, FAR 23.1305 and FAR 23.1337.

2.) Does the FAA enforce the requirement that this equipment is to function     throughout the life of the aircraft as designed above.

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Why have we turned a blind eye to fuel level equipment & why are fuel reporting systems treated in a different manner than any other required equipment on the aircraft. 

Because if we re-write the FAA Safety Brief and replace fuel level with another piece of required equipment ..... Frankly, it just sounds silly.   

"One of the more head-scratching aspects of airspeed management accidents is simply how easy they are to prevent, as well as recognize well before they happen.Blaming a bad airspeed indicator doesn’t cut it. To help prevent getting into this situation, here are some tips:"

Required equipment is required for a reason - let's make it that way.