Bingo!
"scoring or scribe lines"
Today Show video
Now comes the real question. Why is Southwest still flying these planes if they know about the "scoring or scribe lines"???????????
NTSB field guy says "We're going to be looking for corrosion, .... cracks, ...., scoring or scribe lines". Of course that's what they're going to be looking for, all of the above. Why jump on "scoring or scribe lines"? My opinion is that it is unlikely to be scoring or scribe lines but that's just my opinion.
An aircraft can quite safely fly with with a score or scribe line and most already do. Any score, scribe, crack, dent, ding or corrosion discovered in day to day operation or even maintenance should / will be cleaned up, measured and assessed against published limits (Structural Repair Manual, SB, AD, etc.). If inside these limits an inspection program and "repair by" limit is then set or it may even just be reprotected and recorded.
If it is outside published limits then you carry out the repair specified or you can go to the TC holder and ask if repair can be deferred to a more suitable time or if there is an interim repair with full repair at a later date. The TC holder may come back with some immediate repair actions, an inspection program and final fix date, or they come back with a "repair before next flight".
The AD mentioned, if I am thinking of the same one, is looking for scoring or chafing of the fuselage skin where the (removable) dorsal fin that runs forward of the vertical stab caused by the dorsal fin vibrating where comes into contact with the skin. The location of the hole in this aircraft is forward of the area the AD applies to. Red herring.
The reporter says 11 cracks were found on the aircraft during maintenance last year. A bit of sensationalism going on there. That's no big deal - that's why you have a maintenance program and inspectors. For an aircraft that age and if it is high cycles then 11 is pretty good, perhaps even on the low side. Whoops, set things up now for the "poor maintenance" nay-sayers.