We note in the sample list of obstructions in Panel 4-1 that the party leader reported an obstruction that was in
addition to the five types which we discussed in Lesson 3.
What was this unusual obstruction?
(underbridge clearance; 4) (4-43)
The first four columns of the body of the bridge reconnaissance report _________________________________
the bridge by serial number,______________________________________ it by grid coordinates, and list both the
_____________________________ and _________________________clearances.