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An unusual twin accident - fuel exhaustion?

I just don’t understand the thought process that gets people into this position

If you don’t have a GPS linked fuel totaliser, you don’t need a “thought process” to run out of fuel.

You just need to make some calculation errors.

You don’t need a dodgy fuel system to do it, either – loads of SEPs with just 2 tanks run out of fuel.

Administrator
Shoreham EGKA, United Kingdom

If you don’t have a GPS linked fuel totaliser, you don’t need a “thought process” to run out of fuel.

What is a “GPS linked” fuel totaliser?

I doubt there is a lot of actual calculation going on. Probably just guessing. People didn’t all just run out of fuel before fuel totalisers came along.

You don’t need a dodgy fuel system to do it, either – loads of SEPs with just 2 tanks run out of fuel.

Indeed, almost all avoidable by not running your fuel state down to the wire.

Last Edited by JasonC at 16 Nov 21:17
EGTK Oxford

A “GPS linked” fuel totaliser is invaluable. It tells you not only your current fuel and fuel burn, but also how much fuel you will have at each waypoint and how much you will land with.

It is standard with a JPI and a Garmin GPS (I have a 760 Twin and a 530W) and it is absolutely fantastic, I love it to bits.

One thing I use it for on a turn-round is to work out during the flight if I will need fuel on arrival.

I do think that we need to distinguish this accident from an SEP running out of fuel because the tanks were dry. This pilot had nearly an hour’s fuel left. The issue was poor management of a poorly designed system, not running the tanks dry.

Last Edited by Timothy at 16 Nov 21:37
EGKB Biggin Hill

For avoidance of doubt, let me state that my comment about the EGTs telling you immediately about a fuel flow issue applies to an EDM-type instrument.

It may not apply to an old “pointer” instrument which may well have a massive EGT probe with a slow response time and anyway is probably not in the pilot’s field of view.

I have seen the EDM response for real; an event I prefer to not see again even though it lasted only some tens of seconds… The downloaded data also shows the response time constant to be of the order of 1 second (using the JPI probes; the EI probes are reportedly thicker).

Administrator
Shoreham EGKA, United Kingdom

It tells you not only your current fuel and fuel burn, but also how much fuel you will have at each waypoint and how much you will land with.

But only if you don’t change altitude or power setting or both. And only if the wind does not change much either. And it knows nothing about your approach path, possible shortcuts or delays. Contrary to what I wrote above, I think that our FMS actually has a “GPS linked” totaliser of some kind. The only thing I use it for is to get a rough estimate of the fuel remaining at destination for calculation of the landing mass and landing speeds. But the figure it shows during cruise is usually at least 300lb away from the actual figure at touchdown.

EDDS - Stuttgart

GA fuel totalisers such as in my G1000 also don’t calculate new wind vectors for turns. So it applies your current ground speed to every leg. They are helpful as a gross error check.

EGTK Oxford

But only if you don’t change altitude or power setting or both.

It takes care of that as you go along. Obviously it doesn’t know about future changes but normally one doesn’t do those – the enroute sector is flown at the same power setting, usually… (in light GA).

And only if the wind does not change much either.

That’s true. However, if you look at my trip writeups, where I usually talk about the LFOB, it is amazing how good a prediction it is. At TOC, settled in cruise, it is usually within 1-2 USG of what I will land with 700nm later. I think the reason is partly because as you progress along the programmed route, stuff like wind makes less and less difference to the outcome.

I would never fly seriously without it – not least because there is no other technology which gives you even an accurate instantaneous fuel flow.

Administrator
Shoreham EGKA, United Kingdom

I completely agree with Peter. This is a question of not allowing the perfect to be the enemy of the good.

I find LFOB very accurate in general, but I am also aware of its limitations. Given the absence of realistic better alternatives, it has to be a whole lot better than sticking a dipstick in at the beginning and hoping. I don’t really understand the arguments of the naysayers. It probably would have saved these two lives.

The only time it didn’t help me is when I had a genuine bladder tank leak, and lost about 100 litres overboard, resulting in an engine failing for fuel starvation, but a rapid switch to the other tank and it picked up.

EGKB Biggin Hill

I am intrigued by the criticsm of a pilot for trying to to save money on fuel when airlines do it all the time. This aircraft had adequate reserves on board, sadly in the wrong places. It is not the first fuel related incident on the C310 which has an unnecessarily complicated fuel system for a light aircraft.
The pilot’s failure to recognise the fuel situation was then compounded by his failure to recognise the loss of power which at approach settings is quite understandable. The report sums it up quite well;

Given that the situation developed quickly, it is not certain that the pilot would have been fully
aware of the exact nature of the problem, although he was probably aware (as discussed
later) of the low fuel state in the main tanks. The speed had apparently been allowed to
drop below the minimum approach speed, which may be due in part to the loss of power as
the left engine became starved of fuel.

When teaching MEP I always point out that it is the incipient failure that can pose the greatest threat because it may go unnoticed until power is increased, if that results in uncontrollable assymetry, there really is only one option, close both throtles and land straight ahead, a very difficult decision to make if you have not considered it in advance.

I would not waste my time looking at guages at this point, the aircraft tells you everything you need to know.

You mean you ran the tank dry on takeoff?? :-)

Sorry for my late reply.
When I landed after 3:40, I just made it off the runway. I used every drop.

EGBE - Coventry, United Kingdom
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