Time, running out of fuel and fuel gauges

A couple of points with regard to running out of fuel:

1. I think many pilots forget about the time factor (i.e. keeping track
of it) once they are a few months out of student training.
2. I think teaching that the fuel gauges are useless (which is very
common) is teaching a dangerous myth.

With point (1), if you keep good track of time it's almost impossible to
get lost, certainly during daylight VFR. My instructor certainly harped
onto me about the importance of keeping note of time (not just time off,
but time passing X on your route). Many pilots I've flown with don't (or
worse still rely on VOR/DME or GPS).

With point (2), so far I've only flown one aircraft with truly useless
fuel gauges. Few people ever bother looking at them because:
1. they do a visual fuel inspection before the flight
2. they know the fuel burn and endurance of the aircraft
3. they have been taught that the fuel gauges are useless

But 3. is most often wrong. Even though I've never been in a light plane
with particularly precise fuel gauges, all but one light plane I've
flown has had fuel gauges which were good enough for performing a cross
check.

I'll now tell you a story about how I avoided running out of fuel.

About 3 years ago, I got checked out in a C182, the 1960 model (which
was the only year model to have a swept tail but no rear window, if I
remember correctly). It also doesn't have fuel tanks as big as the later
C182. However, I knew all of this as well as pertinent information (such
as fuel burn) from reading the manual before getting checked out. Our
flying club required a short open-book written exam for any plane you
were getting checked out in to get everyone to at least look and try and
remember all the pertinent information, including computing a weight and
balance and fuel burn calculations.

So a couple of weeks after first getting checked out, I have the plane
booked for a long trip from Houston to Utah. Knowing I wouldn't be able
to get fuel the next morning since I was setting out at 6am, I went out
to Houston Gulf the night before and checked the fuel so I could get it
topped off if necesary. I got on the little ladder and looked in the
tanks, and it looked full, so I went home. I filed my IFR flight plan
that evening, so I could just get ready, and go out to the airport and
fly.

I did another visual check of the fuel as part of my preflight - yep,
still full.

So off I went, climbing to altitude, and got the engine leaned out
nicely. The weather had turned out to be much better than forecast, but
I still went IFR - after all, there was a high overcast and it was still
dark. My first leg was long enough that I'd have only an hour worth of
fuel on landing.

Passing over Waco, I cross-checked my time en route with the fuel
gauges. They showed a little LESS than expected; they had been
indicating F on departure. About 45 minutes on, they were showing
sufficiently less than I expected that I decided to land before
reaching my intended fuel stop. I told ATC I wanted to change
destinations, got the field in sight, canceled IFR and landed.

The FBO had just opened. They topped the plane off. When I did the
visual check, I noticed what I thought was full wasn't really full - now
it was truly full, I realised the fuel being an inch below the filler
neck was actually the best part of an hour's worth of fuel! Looking at
my fuel receipt, I calculated I'd have landed at my original intended
destination with only 15 minutes of fuel left. Any vectoring or holding
could have quite easily blown that. Had I ignored the fuel gauges as
being useless, that's what would have happened. After topping off, I
noticed the fuel gauges indicated slightly over the F mark instead of
being right on it - rather like my car really.

So my lesson is - keep track of time AND cross check time and your
expected fuel burn with the fuel gauges. If the gauges show less than
expected, land and check it out. They might well be right.

Of course we'll never know - but perhaps the fuel gauges on that Archer
that ended up in Lake Michigan were telling the pilot all along that he
was running out of fuel. Perhaps he hadn't leaned the mixture right,
perhaps he hadn't kept track of time and had a higher headwind than
expected and perhaps his flight plan said he'd make it with adequate
reserve. And perhaps the fuel gauges were telling him all along, but
he'd been admonished never to trust them, so never even thought to
include them in his normal cross-check.

--
Dylan Smith, Castletown, Isle of Man
Flying: http://www.dylansmith.net
Frontier Elite Universe: http://www.alioth.net
"Maintain thine airspeed, lest the ground come up and smite thee"