A couple weeks ago my electric pump gave up the ghost on me. I knew it just needed to be opened and cleaned but why bother, I had a magnum hand crank in my flight box too. After the second day of flying I came home and cleaned out my electric. I have bigger tanks in most of my planes and I have a lot better things to be doing then turning that crank!! Those cranks are way more work then I want to be doing on a nice day. My electric pump is over 20 years old so if it quits on me again a replacement may be in my future.