Hi Englishal, Tory boy,
Whilst I don't believe that it is alway necessary to do full checks before fuelling, the car type switch on and go routine can have its problems. As you said tow bars also prop covers, intake covers, tie Down's and chocks. Whilst not needing external control locks out for fuel, chances are they may fall out and be a hazard for the subsequent aircraft (not to mention loosing the bloody things). Also engine oil are you going to start your aircraft without checking that. Where do you have most time, ac on the line/hangar door, or on the pumps?
Finally the human factors element. If you have a standard systems for checks and you vary this; you leave the potential for omission later on. Example, quickly start ac, taxi to pumps, do some bits whilst fuelling and due to big ques get hassled to leave. In a rush and get airborne suddenly realising you have not completed your walk round. I know I have done it myself!!!
Obviously it will Never happen to you because you are always so thorough. However the jump in and go approach is just another piece of swiss cheese removed from the accident loop.
Safe flying to all
Wide
