I have (unfortunately) landed on LAND with a banner attached.
The technique is to land the airplane before the banner touches (and possibly snags) the ground. Usually this means an idle approach with a 45 degrees nose down (to maintain about 40 kts) until about 5-10' above the runway.

If you snag or drag the banner, it will stop you IMMEDIATELY, this is an uncontrolled situation, the cable fuse could (should) break first but any number of things could happen.

No, you do NOT want the banner attached when making a forced landing. trust me on this one.

You'd be surprised how much detail of the runway there is when looking at it, filling your entire windscreen, at 10'.

CE