When landing on a B744 last week I noticed just after touchdown that the two more inboard sets of leading edge flaps remained retracted for landing. The outermost set (outboard of engines 1+4) were extended.
Then as we were taxiing off the runway I noticed the previously retracted flaps moving out to their fully extended position, only to be retracted again before pulling on to stand! .
I have not seen this before in numerous commercial flights.
My question is, what was the reason? Is there an operational motive, or was it a technical malfunction, or even an error by the crew?
Thanks for any input,