This needs to be read with google translate, unless you can read French.
I leave Grenoble on a beautiful afternoon to introduce my friends to my new passion for aeronautics. My plan was to make a local north, fly over Lake Annecy, and return via Chambéry. I estimate that for this flight I need 55 L of fuel, counting my calculation very widely. Arrived on the plane, I notice that the gauge is slightly under 2 and therefore decides to go to the pump. After many tests, I see that the BP card (or that the terminal) does not work, and not finding a member of the ICC nearby I decided to take off all the same and go to refuel in Chambéry if I estimate do not have enough. When I got downwind at LFLB, a thought came to my head: "and if the BP card did not work there either, there is no one to help me? The integration and take-off may consume too much fuel for the return, plus the gauge tells me about 28 L "I decide to continue.The rest of the flight runs smoothly, and when I park the plane in the shed, the gauge indicates 70 to 80% of the small 1 is about 20 L. That’s what I write on the log book.
The next morning, I’m sent the picture of the gauge: there is almost nothing left: about 12 L! Well below the minimum touchdown: 19L
Actually, the best part is in the footnotes:
The day of my flight it was very warm, around 30C, it is therefore possible that the fuel expanded that day and made me overestimate the quantity. During the night it would have cooled off (note: and contracted, not written, but implied in the text).
That said, I have no idea what fuel burn the a/c in question (a DR 400/120) has, so perhaps this was even legal (certainly not wise !!) for day VFR?
That website is quite amazing, that’s a lot of declarations
denopa wrote:
That website is quite amazing, that’s a lot of declarations
It looks a bit like the NASA reports in FAA-land.
“the fuel expanded that day and made me overestimate the quantity. During the night it would have cooled off”,
I will be more concerned with high fuel burn due to “air expansion” (mixture and density) than “fuel expansion” (quantity), the former somehow incorporate the latter and the residual effect is really small? However, the big factor is to know how much usuable fuel you have in the tanks at the start of the flight given conditions (not the day or night before), I used to rely on the Tech Log entries or Refueler Meter and Gauges but mistakes happen, of course nothing better than having full fuel (and not taking off?) or stick measurement (wrong one? up side down?)…
The day of my flight it was very warm, around 30C, it is therefore possible that the fuel expanded that day and made me overestimate the quantity. During the night it would have cooled off
Is this avgas, or liquid hydrogen? Avgas expands approx 0.1% per degC.
Actually I am joking; I struggled to find any liquid whose thermal expansion is within an order of magnitude of being relevant. 0.2% is about the highest.
That website is quite amazing, that’s a lot of declarations
Do you get some sort of legal protection if you post a report there? @nestor might know.
I expected 100 time smaller than air but 0.2% per 1C really? Unless it so hot that to boils, I think one would already forgot about fuel stick wood/platic or aircrat fuel tank size expansions…
The site is all about learning from other pilots’ errors in a no blame environment.It is a site operated by FFA which recognises that pilots make mistakes and sometimes stuff happens. All FFA members are encouraged to report errors, misjudgments, failures, call them what you may and however minor so that others can learn something from them unless of course they are perfect and never make mistakes.
The DR 400-120 averages about 25 litres an hour.
@Peter French culture and French law is very different to British law in terms of legal protection for this sort of activity and within the FFA licence there is a legal service provided.
Forgot to mention, Robin 400 fuel gauges are notoriously inaccurate.
gallois wrote:
The site is all about learning from other pilots’ errors in a no blame environment.
gallois wrote:
French culture and French law is very different to British law in terms of legal protection for this sort of activity and within the FFA licence there is a legal service provided.
Could you elaborate please? I think this is quite interesting for pilots in France.
It appears that pilots who make a self-declaration essentially admit guilt (or neglect, …) publicly, although in a somewhat anonymous manner. Do they do this out of altruism, or is there a legal benefit for them through this mechanism, similar to NASA reports in the US? (I understand that through FFA they have legal protection, but wouldn’t they have this anyways, even without the report?)
Gallois there was no intention to compare France with the UK or any other country. It is merely an interesting concept that voluntary disclosure of an offence offers a protection from prosecution. In most legal systems a voluntary and full disclosure will make the defendant look “better” in a court case (I have personal experience of that 
) but the only other formal immunity scheme I am aware of is the one run by NASA in the US (and that has certain exceptions).
In any case, what that pilot did was dumb, but not illegal. I am sure he acted as trained… dodgy fuel planning is SOP in PPL training almost everywhere, as I well know
