Human Error in Aviation Accidents

[Whirlybird]

Yesterday I posted the following on the thread concerning the pilot who was recently prosecuted by the CAA for running out of fuel:
Has anybody read the book "The Naked Pilot"? It describes various airline accidents, many of them wellknown, all caused by HUMAN ERROR. The pilots concerned were experienced, well trained, and the errors shouldn't have happened...but they did. Mistakes DO happen. No-one is perfect all the time. This sort of thing happens time and time again...and just once is too often.

So, let's leave this case out of it for a minute, and talk generally. WHY, in this day and age, do we have unreliable fuel gauges? WHY, if the R22, and others, can have reliable gauges and also a low fuel warning light, can't other aircraft? WHY do we continue with this ridiculous situation of using THREE different units for fuel? WHY don't we make the system, if not completely human-error-proof, at least more so, since whether forgiveable or not, these accidents DO happen?

Condemning and prosecuting is easy. Why aren't we looking at the real issues?


It was suggested I post it as a new thread, as a topic for discussion. So...over to you....

[DRJAD]

Hmmm, I couldn't agree more with the sentiment expressed in the extract.

I know there is an argument running along the lines of 'keep it (mechanical management in the aircraft) simple' presumably so that there is less to go wrong. However, we now have such sophisticated, powerful, and cheap electronic systems for monitoring virtually everything that it would surely be possible without too much extra cost to provide a primary and secondary fuel/engine management system on GA aircraft. The principle should, of course, be extended to all those aircraft systems where pilot interface problems occur, e.g. carburettor heating, CO emissions, etc.. Integrated systems, with standardized, consistent human/machine interfaces are needed.

There are, I understand, several instances where this sort of system is being designed into new aircraft, but what is really needed is a path (i.e. I mean manufacturer, engineer, and licensing authority) to get such systems into the legacy of existing aircraft at such a cost as to make it attractive to owners and operators to upgrade.

No doubt some would say that such systems would remove the direct, 'hands on' aspects of flying, and put the pilot at a remove from the raw experience. I can see the point, but I think, on balance, that there is more to be gained from increasing safety for all by utilizing modern methods in an appropriate way.

[Northern Highflyer]

I couldn't agree more.

There are many systems which could be improved but I suspect it will boil down to £££££ as usual.

I find it incredible that the fuel guages are so unreliable, almost to the point of useless. I think I am right in saying that the guages are also calibrated in US gallons which just adds to the confusion.

There has to be a more reliable way to display fuel levels more accurately.

[Flyin'Dutch']

Of course it would be better if fuel gauges were reliable, engines never failed and the weather was always VMC with a nice headwind on take off and landing and a tailwind during the en-route portion of a flight.

But that is not real life.

Nor is the fuel gauges alleged inaccuracy other than a contributing factor to the incident referred to.

Whether you like it or not flying requires people to make assessments of a multitude of (?complex) issues.

These factors should be taught and trained during the initial training for your licence but after that it is still upon us to update us so that we keep ahead of the game.

Unfortunately this does not guarantee, but gives a reasonable assurance, that you will not come up against a major cropper.

Attitudes displayed on 'that' thread which ooze the 'holier than thou' opinion are not helpful nor is this 'lets blame it onto the fuel gauges'

The big tin that had to be deadsticked a little while back had proper gauges I am sure.

Indeed to get rid of US/IMP and liters as different units would be a start but would require some fundamental changes in peoples' (and not in this case people as individuals) attitudes but would still require the conversion from liters to pounds.

(BTW there is no reason at all why you as an individual not can do all your measurements, calculations in liters and stick to one unit)

Incidents like these give us an opportunity to learn from other people's actions. We are all human and are all open to the pitfalls that others have already fallen into. By making a careful analysis from the material which is presented before us we can do that and put the ruler of our own standards and past performance against it. As others have said, if we are honest rather than judgemental, we will probably see that at times we were only saved by some luck, rather than our perceived wisdom and assumed skill.

FD

[DRJAD]

FD,

Yes, I agree, in general, with your argument. Nothing absolves the individual of the responsibility properly to plan the flight, and properly to manage the flight.

I, personally, do not see why GA should not take advantage of modern equipment and methods to make the decisions involved in that proper management, to which I alluded, above, so as to inform those decisions more completely.

[strafer]

think I am right in saying that the guages are also calibrated in US gallons which just adds to the confusion.
So exactly what should American guages, manufactured in America, for American aircraft be calibrated in?

WHY do we continue with this ridiculous situation of using THREE different units for fuel?
What do you suggest Whirly - Americans change to metric, everbody change to American or we all go back to Imperial?

PS How's the Esparanto coming along?;)


There's a simple answer (and problem) to the other points raised above - MONEY!

[Evo]

In an ideal world we would have one set of units for fuel, distance, whatever, but that's not going to happen - as strafer says, what's wrong with an American aircraft having gauges calibrated in US gallons?

However, one thing that I do think is daft is when an individual country cannot be consistent with itself; why does the FAA like to mix statute and nautical miles, for example? I've had IR practice questions using no fewer than four different units for distance... :rolleyes:

[bluskis]

My ASI has statute and nautical miles engraved on it, or at least the speeds associated with those units, my POH uses mph for performance, but the world was assembled by sailors so the FAA is correct in trying to ensure pilots can cope with both.

Why do the Swiss insist in using metres on their half million topo for heights, we are not mountaineering when we fly, and unfortunately multiplying metres by three is not safe enough.

Its horrifying to sit in the cockpit of some European aircraft and look at meaningless dials.

Mixed units I am afraid are with us for some time to come, and will remain a trap for the unwary or the hasty.

[Genghis the Engineer]

I'm strongly of the view that very many human-error accidents can be prevented by better design (which includes better documentation).

If anybody's interested, I recommend a book called "Design for Safety" by David Thurston which covers the subject very well. Thurston has some strong views, but I have to say, I agree with about 95% of them.

G

[tonyhalsall]

I had a very close call early in my private flying life indeed no more than five or six hours after I had achieved my licence.
I had been flying Warrior 161's in Norway and Cherokee slab wing 140's in Blackpool. The Warriors were calibrated in knots and the Cherokee in mph. I had been in Norway for four months and flown about five hours in a Warrior and came back to Blackpool. Heavily laden I tried to rotate at the more familiar 'knot' speed. After a couple of seconds of shaking and buzzing I landed again very heavily, fortunately with no damage to anything but my pride and three disturbed passengers
At the time I blamed the aircraft until it suddenly dawned what a silly and basic mistake I had made.
A close call, entirely my fault and a lesson not forgotten - but do we need mph, knots and now km/h?
Tony

[Genghis the Engineer]

I can cope with ASIs in kph - it's so different from kn or mph that it never phases me.

But somehow I don't think I'll ever quite come to terms with altimeters in meters.

G

[LowNSlow]

Car manufacturer's solved this problem decades ago. When did you last see a car fuel gauge that quotes litres or gallons (US or Imp). They simply have a needle traversing a linearly calibrated (OK I know they LOOK round) scale from E(mpty) to F(ull) via different graduations acording to the maker. Regardless of the shape of the tank(s) the needle (generally, there are some exceptions) sweeps the scale in proportion to the amount of fuel burned.

HOW HARD CAN IT BE TO APPLY THIS TECHNOLOGY TO AEROPLANES!!!

My Auster has a rotating scale fuel gauge similar to that fitted to a Champ. As long as you remember it under-reads by 3 Imp Gallons on the ground and 2 Imp Gallons in the air, it is extremely accurate for an instrument manufactured in 1946. It is accurate to the gallon as I have verified at the pumps many times.

[Mike Cross]

While DRJAD is undoubtedly right that all sorts of improvement are possible there are some basic issues he has not brought out.

New aircraft and components are being produced that design out some of the problems, however much of the GA fleet is old. My own is worse than most, the prototype having flown in 1938 with this one constructed ten years later.

It is not uncommon to find oneself in a commercial airliner that is over 20 years old or in a Cessna or Piper from the 1970'es. Retro-fitting technology that was not readily available when the aircraft was designed is an expensive business.

When a design is certified a Type Certificate is issued to the manufacturer. Subsequent changes require a Supplemental Type Certificate (STC). While the costs of obtaining a Type Certificate are amortised over all production aircraft the cost of obtaining an STC are met only by those owners who choose to have that particular modification.

While new designs introduce improvements they also introduce new problems. It's an old adage that you get owt for nowt and higher performance seems to go hand in hand with more challenging handling.

Mike

[Flyin'Dutch']

Hi Mike,

You really need to give a Cirrus a go.

Great ergonomics and very easy to fly.

They got it right!

FD

[BEagle]

Personally I agree that accurate 'relative' fuel quantity gauges would be preferable to the rubbish we currently tolerate. But if fuel is issued in litres (and, for those who still haven't learned to pronounce 'aluminium' correctly, that's LITRES not' 'liters'), then the conversion to other units should be simplified and standardised wherever possible.

Mph and statute miles really have no place in aviation any more. It took Uncle Spam a while to accept Celcius, so heaven knows how long it'll be before they finally stop the statute miles nonsense in aviation......

[Kingy]

Chaps,

No problems with the fuel guages on my aircraft.. they are all float and wire types. Brilliantly simple, very accurate and ultra reliable.

The problem is not that the guages on your average spamcan are old technology - it's that they're not old enough !!

Kingy (crawling back under a rock) :D

[Chuck Ellsworth]

Here I go again, getting involved in a discussion I should just ignore..... B U T.

There are realities in being a pilot that each of must understand to be a safe and skilled pilot.

Aircraft are fluid in that they can be manufactured in one country under the certification rules of that country and then like fluid they flow all over the earth.

There will never be commonality in measurements or methods of displaying or describing them, therefore we as pilots must be thouroughly familiar with each and every aircraft we fly.

If you bend an aircraft or get prosecuted for operating an aircraft in contrevention of that aircraft's operating manual and or type certification you have only one person to blame...yourself.

Those of us who fly many different aircraft in many different countries learn to never, ever take it for granted that we know everything we are trying to do, the secret is in when in doubt do not fly until you completly understand the issues and then triple check everything you do.

With that mindset and a whole lot luck you may fly forever incident, accident and procecution free.

Your friendly advisor: :D

Chuck

[englishal]

Must agree, you go by what is written in the POH. If speed is in MPH, then you use MPH (& only old aircraft specify MPH), if your fuel is supplied in litres but your POH specifies US GAL (note: 3.8L as opposed to 4.54 IMP GAL) then you should be able to convert. If you can't then there is no place for you in aviation :D

EA

[LowNSlow]

BEagle just a quick point, Sir Humphrey Davy, discoverer of aluminium, actually called it aluminum, a name which was in general use until the Royal Society insisted that the name be changed to end in ium as per other substances eg sodium, radium, beerium etc. So our transatlantic brethren are actually using the original name for the aformentioned ductile, light metal :uhoh:

[bluskis]

So the Royal Society should have removed the N making it alumium for consistancy.

Personally I find it easy to accept either while in the place of use, but a tongue twister for a few months while rebasing.

[Whirlybird]

Chuck,

Of course you're right. BUT we are all trained to do that, we do it, and still accidents happen, caused by the factors we're talking about, sometimes with very experienced people. Maybe there was never any place for them in aviation. But if that's so, how do you identify the people who shouldn't be flying, who might have that accident years and years down the line? And most people learn from ONE mistake, but sometimes that one is catastrophic and therefore too many. People are human, not machines; they sometimes make mistakes. You know that...I know you do. ;)

WHY are so many people here saying things can't change? WHY are you so defeatist? We have one language for radio communications; OK, the French ignore it sometimes, but most of the time it works. Aviation HAS changed over the years, in many ways. So why not in some relatively minor ways that might make for safety?

[Genghis the Engineer]

I'd suggest that there are four brackets here:-

- Things that should be standardised and fixed in the name of safety. To pick one example, the colour markings on an ASI to show limitations, another would be the standard "T" instrument layout in IFR equipped aeroplanes.

- Things that really should be changed in the name of safety. This is difficult because opinions may differ but I'll offer a couple of suggestion - tank transfer systems that allow you to inadvertently select "off" without a positive separate action, retractable gear aeroplanes that allow you to select full flaps but not gear-down without warning you, springy seats that amplify crash loads onto the pilots spine, aircraft that can too-easily be loaded out of CG limits.

- Things that may be changed, but only with great care and clear documentation for pilots - for example the way engines are mechanised (look at the difference between a Lycoming and a Rotax-914 to show how things can be improved - a single lever power control or automatic carb heat have much going for them but pilots need to be educated in their use). Another might be used of an AoA indicator for approach conditions / low-speed warning, etc.

- Things that may be freely changed so long as good safety practices are followed throughout - for example construction materials.


Surely the important question is how we determine what falls into which category?

G

[bluskis]

And what ever is changed in the name of standardisation, there will be many pilots who will have to relearn, with the inevitable lapses.

I am not sure if the cost of changing to metric in the UK was measurable but I am sure it cost lots of noughts after the digits.

[Chuck Ellsworth]

Whirley:

You are correct, everyone makes mistakes and the best insurance we have to try and limit the number of mistakes is proper training and recurrent training.

Unfortunately we will all screw up in one way or another, however the very important items such as running out of fuel is preventable by taking the time and confirming that you do in fact have sufficient fuel before you even pick it up into the hover. :D

Changes in Aviation are limited by two main problems, bureaucrats who are resistant to any thought process and money.

Speaking of different information in the Aviation field the one that always gives me problems is the IOAO visibility given in meters in the METARS, I learned in miles and knots and the mental picture imagining the runway vis in meters always makes me stop and carefully examine what I am reading.

Chuck