QUESTION:
How did you finally manage to deflate the third airbag, and what exactly
went wrong in the normal procedure?

ANSWER from Robert Manning on July 16, 1997:
Actually all four airbags deflated and retracted normally. The reason that
the bags had "pooched" out from under the petals was most likely because I
did not program in the correct number of turns for the retraction winches
into the flight software. We had reduced the number of turns in the software
from around 50 to 42 turns because we made a last minute change in the size
and strength of the kevlar retraction cords that snake around inside the
bags. We needed to reduce the number of turns because the cords were thicker
and hence less turns would pull in the same length. Unfortunately, we ran
out of airbags and time to do a really good regression test with this final
configuration so we probably over estimated the effect that the larger cords
would have on the retraction length. However we felt that it really didn't
matter (and it didn't) if we slightly under retracted because we had
designed into our plan an opportunity to do further retraction on the
surface after we had a chance to see for ourselves the state of the bags and
petals. Once we had the pictures of the bags on the first day on Mars and we
could see that the airbags might be in the way of the rover ramps, we
designed and sent up a small script (sequence) that lifted the rover petal
45 degrees and retracted the bag under that petal a few more turns (until
the winch motor nearly stalled). Just like we had tested in our sandbox a
dozen times before, that operation did the trick and the rover ramps were
then clear to be released. We will probably not retract the other bags
further because so far we have found that there is no reason to; they are
not in the way.