tcr2
There could be a number of reasons for the apparent difference between BA & SIA744 take-off rolls at LHR.
Some have been stated in previous posts. Others include:
i) different routes
ii) different levels of take-off derate/reduced thrust
iii) optimum vs fixed flaps. I believe that some airlines operate optimum flaps where others tend to use a single flap setting (for simplicity) at the expense of a longer take-off roll (or less derate)
iv) Possibly improved climb or not
On the PIA subject you may fancy a look at the attached link (remembering there are also many pictures on this website showing many other PIA take-offs from MAN that look fine)
http://www.!!!!!!!!!!!!!!/open.file?i...tic=yes&size=L