The Arrow antenna I have is for 2m amateur radio (~144 MHz, ~19.5 in.) so is actually a little short for aviation frequencies (~125 MHz, ~22.5 in.) but seems to work fine for the scanner.
I'm about 9 miles from the airport, so with the homemade antenna in the attic I don't get great reception. I've hooked up the Arrow j-pole in the attic and it seems to work better, even though it's a few inches short. I hope to get it up on a mast soon, but I have a few house repairs that my wife feels are more important.