plane type schedule

Just wondering how accurate the pre-booking plane is, etc.
I can see that VS11 is currently mostly served by the Dreamliner, however my booking next month says it will be a A340-600.
This is backed up by http://info.flightmapper.net/flight/Vir ... ways_VS_11
Where it shows the service change starting 23rd of June
Tue-Thu 13:05 Heathrow, London (LHR) 3 15:25 Logan, Boston (BOS) E
VS 11 Non-stop Airbus A340-600 (346) 7:20
Effective 2015-06-23 through 2015-08-13
Mon,Fri-Sun 13:05 Heathrow, London (LHR) 3 15:25 Logan, Boston (BOS) E
VS 11 Non-stop Boeing 747-400 (744) 7:20
Effective 2015-06-26 through 2015-08-17
Just wondering does flightmapper scrape its data from.
I guess I can check on the 23rd to see which plane left heathrow.
I can see that VS11 is currently mostly served by the Dreamliner, however my booking next month says it will be a A340-600.
This is backed up by http://info.flightmapper.net/flight/Vir ... ways_VS_11
Where it shows the service change starting 23rd of June
Tue-Thu 13:05 Heathrow, London (LHR) 3 15:25 Logan, Boston (BOS) E
VS 11 Non-stop Airbus A340-600 (346) 7:20
Effective 2015-06-23 through 2015-08-13
Mon,Fri-Sun 13:05 Heathrow, London (LHR) 3 15:25 Logan, Boston (BOS) E
VS 11 Non-stop Boeing 747-400 (744) 7:20
Effective 2015-06-26 through 2015-08-17
Just wondering does flightmapper scrape its data from.
I guess I can check on the 23rd to see which plane left heathrow.