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Showing posts with label AVWEB. Show all posts
Showing posts with label AVWEB. Show all posts

Friday, April 18, 2014

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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Friday, April 11, 2014

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.







Saturday, April 5, 2014

Fuel Starvation in a Modern Technologically Advanced Aircraft.

It is common to believe that technological advances can mitigate the dangers inherent in operating vehicles.  The automobile airbag is one of the best examples - it was first hard to convince us all we needed one - now every new car has 10's of them.  It was a safety idea that worked.   

One of the most difficult Safety Issues in Aviation - Especially light aircraft is Fuel Exhaustion. 

And we have a strong belief that modern aircraft with modern tools can mitigate this problem.  
There is a definite trust in the pilot community that fuel totalizers (fuel range calculators) mitigate the danger inherent in running out of fuel in a small aircraft.   This is the technological advance intended to help alleviate fuel starvation events for small aircraft.   For those not in the aviation field - you are guessing correctly that running out of fuel in a small aircraft is not a good thing. 
So lets look at a recent Fuel Starvation event in a modern Cirrus SR20.  
The National Transportation Safety Board provides a Probable Cause for this accident that occurred in Parker AZ - 
I included it below -
Before the first flight of the day, the pilot visually checked the airplane’s fuel quantity through the fuel tank filler necks, observing what he believed to be full tanks.  He subsequently checked the fuel gauges, which indicated that both wing tanks were less than half full.  Surmising that the gauges were faulty, the pilot departed on a short flight to a local airport to pick up a passenger.  After picking up the passenger, they departed for a cross-country flight.
So this subject pilot observed full tanks (he actually looked at the fuel in the tank),  and then checked to see what his gauges read.  Then this Cirrus pilot with an "obvious" discrepancy between his observed fuel and his fuel gauge reading,  proceeded on his planned cross-country trip.   
It is my conjecture that he entered full fuel on his fuel totalizer.  The totalizer is a system that uses fuel flow and a pilot entered quantity to provide a range of travel.  Systems like this are common in boating and you see them in your car as a fuel range.   So this pilots "trusted" fuel reporting system supported his  observation.   
This pilot then departed with in his words "faulty gauges"  - and in violation of Federal Law Title 14,  Part 91 -  included below:
§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.
So this pilot operated his aircraft with with an un-airworthy mechanical condition based on his observation of fuel level.  

In fact if you ask a pilot friend if they are currently flying an aircraft with a faulty fuel gauge you will get a nearly unanimous answer that yes in fact they are.

Typically they will soften the blow and let you know, 

  • That they have never run out of fuel.
  • They can look in their fuel tanks on the ground to see how much fuel they have. 
  • They will tell you that a stopwatch will let them know when to land.
  • And aircraft typically are operated at one speed - so fuel consumption per hour is fixed.  I have 50 gallons of fuel - we burn 10 gallons an hour - so we can go 5 hours maximum - and today we will only fly 3 hours.
  • Some will even tell you that they have a Totalizer - and it's far more accurate than any fuel gauge 
As you can correctly guess - this law, the one that requires working fuel gauges in aircraft, is not enforced.  Nobody is getting busted, and frankly nobody is worried about it either.    
But this pilot didn't break the law -  the fuel gauges were right and his aircraft was in the legal words of the law - airworthy -    The only thing this pilot did was err in his observation of the fuel level in the tank.   Human error it happens all the time  
So a little more conjecture based on what we know of the Cirrus SR20 aircraft   -  This pilot in believing his gauges to be wrong,  he then ignored the the multiple low fuel level messages that occurred during flight.   You could think of these aircraft warnings as a low fuel warning lights - that first come up amber and then change to red as the fuel is being depleted out of the tank.
These low fuel messages were warning him of an impending fuel emergency,  most likely where he could have taken action and landed safely.   But this pilot appeared to have trusted his  "Fuel Range Map -  and his fuel range on that map was based on his erroneous fuel level observation and his range map was counting down from a full tank of fuel.   He might even have carried a stopwatch to let him know at what time he would have run out of fuel.
This is the cultural issue in aviation  - 
  • Pilots find it acceptable,  actually common to fly with a faulty fuel gauge.
  • Pilots expect that the fuel gauge is misleading and proceed to fly anyway.
  • Pilots were trained to ignore their fuel gauge   
  • Pilots continue to run out of fuel in their aircraft 

If this pilot trusted his fuel gauge - and then used it as a cross check to his fuel level observation - he would have exited the aircraft on the ground  and re open the fuel tank and reviewed his observation.   In fact as he made a short hop to pick up a passenger -  he could have rechecked the fuel level twice.   If I we use this aircraft's  Pilot Handbook Checklist - a visual tool that pilots use to insure everything is working as it should,  prior to flying - he would have looked at his fuel gauges a minimum of 10 times,  and he then ignored his fuel gauges each and every time.

Fuel Starvation - or running out of fuel is a leading cause of aircraft accident, injury and death.


So what are the FAA, NTSB and the Pilot Organizations doing about this -  


Well, not surprisingly

  They too want to ignore the fuel gauge.





Again nearly all pilots were trained to do so.

In the most recent video & safety bulletin put out by AOPA and a they have placed a lot of effort to train this pilot to visually observe the fuel in his tank
Pilots, due to the cultural influence can't grasp the idea that a working fuel gauge could possibly mitigate fuel starvation.
  

It never occurs to them.

And it is really is a head in the sand approach,  As these pilots are all cross checking each other, and sharing their own experience.   

Just like the airbag, we were resistant to add safety, as it added cost, and we doubted the benefit - but the value of the lives it as saved has made it more than worth it.  

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Let's change the culture in aviation and quit making excuses and ignoring equipment that doesn't perform to the aviation standard .

Sunday, February 23, 2014

CiES Fuel Sender - In the News - March 2014 Aviation Consumer

In the March 2014 Issue of Aviation Consumer the CiES Cirrus Fuel System Retrofit is reviewed.


As we have talked about in previous blog posts - Cirrus G1 / G2 retrofits are a challenge.  The results and review were favorable and represent what can be obtained on the early series aircraft.   Later model Cirrus G3's can achieve nearly perfect results.

Please look to 


for more information and other informative articles

Saturday, February 2, 2013

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.