JoAnn, you did not fail at all.. I see the little eyes.. if you touch the bark of the trunk you will feel the different of the crusty skin where it started pushing for roots... if i were you and you want that airlayer you should score  just below the area where the little white callous formed, the scoring, need not be bigger than a 1/2" of removed bark all the way around, and put that soil or moss back in place.  did you see the video I posted? the plastic around needs to be very tight, pushing the matter (moss or soil) against the trunk...but not too tight...take a fork and make a few holes in the plastic on the under portion of if water from rain gets in, it has a place to run off rather than sogg up the area.   and whoola, you will have a new tree in the spring... you can do now. I have some out there.. it works... try again, the callous are formed. I see them.  if you touch, you should feel the difference...the tree already put some work into the callous, so, just help it put out the rest of the way!  Good luck there.