Every incident is worrying and needs to be analyzed, reviewed and policies changed to ensure it doesn't happen again (as was the case with UOE, for instance). I have little detailed knowledge of how a 747 landing gear works, but I recall that the main landing gear ought to be able to drop with gravity alone.

But, this issue aside, what else has happened? -VIIO (LAS engine fire) is not, strictly speaking, BA's responsibility (the engines are owned by GE) .

Questioning BA's standard for issues and snags that happen at any airline - check avherald, to see how frequent they are - is a bit uncalled for, in my opinion. It wasn't BA that lost a widebody due to lack of cooperation in the flight deck, or that allowed an unstable person alone in the cockpit, or that flew 10+ hours with a breach in the pressure vessel of an aircraft, an occurrence played down by the CEO of that airline in a very irresponsible way.

This doesn't mean that BA can relax and rest on its laurels, obviously.

This is a misconception. Old machines, sure, do age and tend to fail more frequently, but the statistical discrepancy between one fleet of new planes and older ones is minimal (I have no data but what I know from my time in the industry, apologies), we're talking about not point something percent. Clear, when you have 30 planes, and each plane flies 2 sectors a day, and you do 400 flights a week, even a 98% reliability - for instance - means that you'll have 8 flights with planes going tech.