There was some discussion about ten years ago that a contributing
factor in the early '20 accidents might have been the type of sealing
tape used on the flaps and ailerons. Specifically, before the
wholesale adoption of Mylar seals, many of the older ships had white
cloth tape on the lower surface that could bulge out at the hinge line
under certain airflow conditions, presumably triggering some sort of
undesirable behavior.

Anyone recall this or know if it was true?

Chip Bearden