I cannot believe that BA's defined contribution scheme would pay only 12% including the employee's 5% contribution - I would suggest that there has either been a misprint or a misunderstanding.
For comparison purposes, in Virgin's DC pension scheme the company pays 15% of pensionable salary (all of basic plus all of flight pay) as long as the employee contributes 6% - making a total of 21% contributed. By law, the maximum employee contribution is 15% (to a Group rather than a Personal pension plan), making a theoretical maximum pension contribution of 30% of pensionable pay.