Thanks and help!!!!
Given that you are British it may be that it is not called a back somersault. You might mean an actual backflip (known by Americans as a back handspring.) On the other hand since you are wanting to teach yourself using information from the internet that may be way too optimistic on my part.
A backflip isn't a move in trampolining but you can use a trampoline to help learn one. However you would certainly need a spotter and would be best taking a gymnastics or tumbling class.
A back somersault (which in the case of a beginner would be a tucked back somersault sometimes abbreviated to tuck-back or back-tuck) is a trampolining move and you can't reasonably learn a decent one without joining a trampolining class and you will quite probably injure yourself if you try. It also is a long way from being the first thing you would learn if you joined a class. You have to work through a lot of other stuff first in order to build up the technique, control and positional awareness you need to be able to do a back somi safely. This is what Rachel is referring to when she says you have to progress.
P.S. a good back somersault is not remotely like a back handspring without putting your hands down. The take-off and mode of generating rotation is entirely different. You DO NOT jump back into a back somersault, although you do into a backflip/back-handspring. I have seen quite a few people as a trampoline coach who have taught themselves to do "flips" meaning somersault but I haven't seen a single one with a decent somersault ever. However most were very insistent that they could somersault properly and were very self-deluding with regard to their own skill level. So Flummox, arguing with a qualified coach and a national level (this means she has a minimum 9 somersault routine with at least one body landing with a somersault out and containing at least one of full, rudi or double) trampolinist is far from unique in his/her arrogance and ignorance.
I'm a trampoline coach and can do a back somersault if that's what you mean by flip which I'm guessing it is . First you need a back roll so you just get the idea but hopefully you can do that . Then I know this sounds dumb but jump as high as possible on your trampoline ( height give you time to fix things that go wrong ) try doing really high tuck jumps wait as long as possible before tucking so you tuck right at the top of your bounce just before you down make sure you tuck tight. Thats the back somersault with out the rotation . Now you can start with the rotation so hopefully you know what a back drop is or a flat back this is where you land on your back on the trampoline flat so try doing this but land your stomach where your feet took off . This will help you keep your somersault on the spot . A back somersault and a flat back have the same take off make sure you get your chest up and look forwards the whole time in the flat back if you don't know how to do this look on youtube . Once you have completely mastered this and are confident you can try the back somersault I'm not recommending this but you will probably try anyway so you would do it properly I would get a sofa cushion or mat and put it behind you before you try this jump up first before taking off dont tuck right away that's how you land on your head like the tuck jump wait till the top of your bounce then push your hips up fast and tuck tightly then look for your knees so you don't throw your head backwards as yo see the ground kick out and try to land if your going to do it go for it and jump high and do everything I say first and you will be less likely o get. Injury good luck
Rebecca, its called a back-tuck.
Actually just flipping back is basically the idea, Its really hard to land on your head, cause they're really easy. Jump as high as you can, and just go backwards lol. On the floor it gets a lot more complicated, But i can explain that later. thats basically it for the tramp. All these people saying that its hard: It really wasn't for me. And don't go saying that I may have a back-tuck, but I don't have proper form, cause i do.
For a start its called a back somersault and secondly you have to progress, your better off going to a club and learning otherwise you won't be able to do it properly!
U jump backwards
