Flying is not a normal job it's a lifestyle espeacially if you are operating as long haul crew. Flying means eating, resting and exercising at irregular hours.
My suggestion to you is to find a good personal trainer in your area, ask some friends etc for references or just go down to your nearest gym, Im sure you are bound to get put in the right direction. Explain your lifestyle to your trainer and he can put you onto a nutritionist who can suggest a proper diet plan specifically for you.
I assure you that with the right exercise and diet plans you will look and feel a whole lot better. The sooner you get the right advice the sooner you will save time, energy and money. Most of all it will give you the safest and most effecient way to lose weight and keep it off. There are many crash diets around that may not necessarily transition you into feeling better with less kilos!