Mr. Bill's are easier to launch with larger aircraft, that can make a world of difference. For instance, luanch one out of a skyvan and you could basically be safely docked to each other, even before stepping out the back.....that would cover otters too, where intercouse can be had with the first to pull facing into the door and the attachee having a secure dock before count off/launch. They are just another fun thing to try in a very inforgiveable sport where safety is always the first and most primary concern. Mr. Bill jums are only as safe as the sum of it's parts; it all depends on the natural combination of the two jumpers involved, skill levels, training, groung prep, communication and mixed in with a heafty dash of the unknown; Murphy's law still applies to Mr. Bill, too! peace and love in all their forms to you and yours, Tiedye Keith