Al R is correct. Maximum commutation works for most but sometimes you may be better off preserving a bit more pension income. If I were you, I would be talking to a financial advisor (trust me there are some good ones out there!) and formulating a long term plan.
One last point - spend wisely. When I was in the RAF I thought I would go and blow a significant chunk on a fast car/boat/round the world holiday but, when the time came, I invested wisely (not stocks and shares). Right now I get £500+/month interest payment on the lump sum. Not exactly massive money, but at least it is working for me.