One thing useful to have come out of this debate has been that what some of us take for granted as being common knowledge is often no such thing.
For all his faults, Vince seems to have been completely unaware of the potential fuel indication and flow problems from a high wing, relatively flat dihedral aircraft with wing tanks. Most of us with experience of these types will probably be only too familiar with the potential isses, particularly those with experience of one or two of the microlights with this configuration that have had problems in the past (the Foxbat and CT spring to mind as two obvious candidates).
Vince seems to have been unaware that the usable fuel was less than the total fuel by 6 litres. He also seems to have been unaware of the fuel cross feed problem that can occur if the aircraft is flown slightly out of balance (as might be slightly more likely in a microlight that is just one-up and has no aileron trim).
In my own mind, based largely on Vince's own testimony, I'm certain that fuel starvation was the reason for the engine stoppage. I wonder if anyone thought to check the float bowls for fuel after the accident? If they were found to be empty then this would be a pretty good confirmation that this is what happened.
Having a few litres of fuel in the tank after the aircraft had run out of fuel would be completely normal for this type, of that I'm sure, so this is no proof at all that lack of fuel wasn't the cause.
How many pilot's aren't familiar with the technical details of their aircraft? It's in the syllabus for microlight pilots and I know that the old GFT included a bit on the ground at the end where the pilot was given an oral test of his/her understanding of some of the technical quirks of his/her aircraft. I wonder if this is still the case?
It seems clear that Vince was under the serious misapprehension that he had enough usable fuel for his journey, when it seems very obvious to some of us that he didn't and should have planned to take on fuel much sooner than he did.
I was always taught that trip planning included 30 mins extra reserve fuel for loitering about, extra climbs etc, plus however much extra was needed to take account of any probable en-route diversions due to weather. I think I'd have probably planned on about 45 mins to 1 hours extra fuel for the last leg of Vince's trip (Barrow to Kinloss), based on the information we've been given here.
Microlight fuel burn is notoriously susceptible to a wide variation, based on density, climb profiles, weight etc, which adds another big variable into the equation. My old microlight would cruise one-up with a burn of around 8 litres per hour, but could easily be pushed up to 12 litres per hour with a few long climbs, or in bad conditions (a 50% increase is significant if you've only got a small tank!). I always used to assume that it'd burn 12 litres per hour, then be pleasantly surprised if I didn't need to make a planned fuel stop. In my view I was being sensible, but my guess is that Vince might think I was just being daft not to assume that I'd always only burn 8 litres per hour...........
VP