Hi Alan
You may need a certain post count to be able to attach pics.
I use Imgur.com which means I can copy/paste the BB code directly to the thread page (other photo hosting sites also work such as Flickr etc)
I am not sure if the photo hosting site method works with a low post count but might be worth a try.
I am also an old Chipmunk hand - my last tour was at Abingdon where we looked after 7 Chipmunks for 6AEF + 14 Bulldogs for the 2 UAS's.
I did loads of flying on both - much to my Flt Sgts displeasure