Wait, are you suggesting that other coverings actually stiffen the airframe?Hi Skysigns. I'm no expert on the matter and this is just an observation so take it for what it's worth. A Super Cub came in for a 100 hrly the other day. This Cub was recently recovered in Oratex (it was covered in cotton.....was getting tired!). I am not sure about the figures but speaking with a mechanic that was involved with the recover, he said the empty weigh decreased with Oratex so that's good. However, watching the back end of the aircraft when it is on the ground at idle, my impression is that the entire back end flex's (twist's) allot more than other Cubs covered with either Polyester of Cotton. I think the Oratex is more flexible than the regular coverings. Whether this will translate into structural fatigue later on remains to be seen. Perhaps others have had more experience with this? Apart from that, a friend of mine said it seems fairly puncture resistant and if it gets a dent (stretched), just grab the iron and warm it up again and you are good to go. Anyway, just my 2 cents worth!
Marty, I thought it had fairly recently received STC approval, but I can't seem to find a reference now. Somebody here will know for sure -
Wait, are you suggesting that other coverings actually stiffen the airframe?
Watching the tail shake on a cub, would not be a valid assessment tool for the fabric! The big prop/180hp., especially so.
[h=3]FAA STC Approval![/h]Latest STCs include PIPERS, some AERONCAS and STINSONS. Don't forget our STCs for all Maules and Huskys!! We also have Field Approvals for Cessna 120/140s!
Correct me if I am wrong, but generally speaking, isn't one of the reasons that an older aircraft that was originally designed to be covered with cotton, needs to have approval (STC) prior to being recovered with a 'modern' covering, is because the resulting rigidity of the structure changes due to the difference's in strength/flexibility of the 'modern' covering?
I don't think a stretched fabric covering provides enough tension to be considered semi monocoque.
I think coverings require STCs because there's a big concern for fabric failure when your lifting surface is made of fabric.