define penalised?
BA pilots who joined before 2003? are on a final salary pension scheme. In that scheme you gain a proportion of your final salary for each year of service. The proportion you get depends on your choice (ie how much you pay).
Pre 2007, you would typically get 1/52 of final 'pensionable' salary per year of service.
For post 2007 service, it is more likely to be 1/60th for post 2007 service.
For me, the changes meant I would have to work about an extra 8 months to get the same pension.
I'm sorry, but the system is very complex and not possible to give a simple answer to.