The word 'virtually' does not mean definitely. I know you can crash and break just about anything. The reason I asked is because I know a lot of balsa trainers out there and Ive looked into just about every one of them. I just want to know if anyone knows of any trainers not made of balsa. Call it personal preference. The duraplane is made of PVC I believe and its very durable, hince the name. There is nothing wrong with wanting the strongest plane you can get.