747 engine takeoff power

I have a question for anyone familiar with flying the 747-200.

According to news stories in the media reporting the crash of a
MK Airlines 747-200 freighter at Halifax Canada awhile ago, the
investigators found that the airspeed was some 55 kph low. It was
noted that the engines had been operated at a power 'inconsistent
with the a/c weight' (as if the engines are normally operated at
a power governed by the a/c weight during takeoff).

Is this true for this a/c?

I've never heard of this. Any a/c that I'm familiar with
certainly don't modulate takeoff power according to their weight.

Is it done on the 747?
--

-Gord.
(use gordon in email)