Steven wrote:
Because they were human and sometimes make mistakes, especially under
conditions of poor visibility such as caused by having to look in the
direction of the sun near the horizon.

Why would they be looking in the direction of the sun near the horizon
instead of in the direction of the runway?

Landing on runway 24 the direction is almost the same. Also note that
the sunlight would be reflecting off things on the ground such as
rooftops, any pools of water, vehicle windows, etc. Even if you can
lower a visor to hide the sun itself, there are still lots of bright
sources of reflected light on the ground that can create glare and
distraction and make it that much easier to make a mistake and miss
seeing the plane on the runway.

Go out just before sunset and look at the sky in the direction opposite
from the sun. You should notice that it's already considerably darker
than at midday even though the sun has not yet set. Looking in that
direction a plane would be very easy to see because it would be
brightly lit by the sun and is set against a darker background sky. If
the landing light is on that would make it even more visible.

So at the time of this accident the crew of the landing plane had
relatively poor visual conditions while if the crew of the plane on the
ground had been in a position to look back they would have had
excellent visibility.

If it's truly just before sunset there isn't much sun above the horizon to
be shining in the eyes of the approaching crew.

As I recall it was about half an hour before sunset so all of the sun
was still above the horizon. But the sky at that time is already much
darker than during the middle of the day.

Presumably the purpose is to be able to respond quickly to a clearance
to take off. If the plane is angled but full power can still be
applied and the plane's path down the runway straightened out in the
first few seconds of the takeoff roll then no time would be lost and
the same purpose would still be achieved.

Time is lost because full power is not being applied in the direction of the
takeoff roll.

No, it takes a certain amount of time for a plane to reach takeoff
speed after the application of full throttle. Whether the first few
seconds of that acceleration are spent going straight down the runway
or starting out at an angle and then straightening out will have no
significant effect on the time to accelerate to the critical speed.

Consider this from an energy standpoint. The engines need to provide
enough power for a long enough time to give the plane enough kinetic
energy for takeoff. The only effect of starting out at an angle and
then straightening will be a miniscule increase in rolling resistance
of the nose wheel due to slight scrubbing forces. The energy lost to
that slight extra rolling resistance is negligible compared to the
total takeoff energy.