Solo Patrol near Loos: Over the lines , I spotted and chased a Recon machine ( a Blue color ) I made 2 passes getting off 1 full drum then I took 4 hits abut the tail found the machine would barely go up and down. ,but turned ok. looking around, it appeared that ripped fabric had twisted around the cable ( elevator ). I arrived over our field and cut power to see what glide angle to use for landing. after try # 4 I went dead stick on the aerodrome touching the wheels in the center of the field and stopped just in front of the end Fence.