My first crash

[Jan Olieslagers]

1) As it might be reported by a local pilot, sipping a drink at the bar's terrace:
" the microlight made a normal approach and circuit. Seemed a bit high and fast, though, on finals. Perhaps a pilot who is used to runways longer than our 250 m? Touchdown was at perhaps 40% of those 250 m. That could still have worked out ok, but immediately after touchdown the engine was heard to rev up again, the craft slipped off the runway sideways and came to a halt just across the concrete access road."

2) as the pilot saw it happen:
"the flight had been eventless, and no problems were to be expected. I had landed here before, visibility was excellent after the morning's haze that had lasted till noon, and scarcely any wind. I must have been less than perfectly concentrated though, as I observed I was rather high on finals, and quite fast too. But nothing to really worry about, the landing was quite acceptable. I let the craft roll at leisure and began to steer right to vacate the runway, when suddenly the engine revved up again without my ever doing anything with the throttle. I only realised the alarmingly increasing speed when it was too late, my only good reflex was to steer left for all I was worth, or I might have ended in the clubhouse. Quite stupid not to cut ignition as soon as things went wrong."

3) same pilot, after recollection:
"I had already done a nice round trip earlier that day, 50 mins to go and 60 to come back, and with the hazy weather that must have been more stressy than I realised. But it was my first flyable day since far too long and I was going to fly and fly as much as I could ever manage. For this second excursion I had originally planned EBTX Theux as a destination, but learned on the phone it was closed for runway maintenance (see how useful ppr can be?) So I choose EBLN Liernu, not very far away and a field I had already visited. I must certainly have been too relaxed, and have underestimated the difficulty of the shortish runway (I am used to having 700 or even 900 meters). I did realise I was rather high on finals, and sideslipped a good deal. I really should have decided to go around, but tunnel vision had already set in, there was no idea of a plan B in my muddled head. The landing actually wasn't bad, here came my next error, to think all was accomplished once the wheels had touched grass, and let my concentration, or what remained of it, slip away. The engine revved up again, I suppose the throttle overcame the adjustable friction by bumping from the rough terrain. When the plane was first flown, there had been some difficulty in closing the throttle fully, this was much improved by slackening the throttle friction. Too much, I realise now"

4) root cause analysis and lessons learned:
Mental fatigue was the root cause, I should not have taken off for the second trip. Perhaps not even for the first. There should be a way of objectively assessing one's mental strength before deciding to fly.
As a secondary point, the throttle friction adjustment is delicate and critical. Note this is on a Rotax 4-stroke, where springs on the carbs pull the throttle wide open and this friction control is the only counterforce.

5) corrective actions:
5a) pilot must become a better pilot
5b) will need to buy a new prop; I was after acquiring a cruise prop anyway but should have liked some more time. This will be the most expensive part.
5c) engine and reduction gear will need careful inspection, and repair as necessary. Here is most incertitude, I just hope the engine is not too bad as it is very new with just 40 hours run.
5d) the nosewheel leg is to be rebuilt from scratch. Though all fibreglass parts survived unbroken (wheel fairings and engine cowling are intact) this will involve must work, but I can luckily count on some knowledgeable and experienced fellow pilots.