IThere have been several accidents resulting from seals coming loose,
and causing a "spoiler" effect on the control surface. One is here

http://www.ntsb.gov/ntsb/brief.asp?e...07X04237&key=1

I think there was at least one Grob crash in Germany. Some manuals
specifically state there has to be tape on the elevator.

So, yes, this is a serious issue. Since hearing of the first crash,
"check condition of mylar and hold-down tape" has been part of my
critical assembly check.

John Cochrane BB