Moving a Flat Piece of Steel

There are a couple of ways to figure this out: the first and probably the most interesting would be to TRY IT! however this is rarely feasible, the second is to calculate it. You have on your hands an unbalanced system i.e. movement will occur. You will need to determine a couple of things, the hardest of which will be the average surface area against the wind, the drag coefficient and the angle of incline; then you can do some calculations on the force exerted by the wind, the effective horizontal push exerted by the air due to falling at a given velocity (thrust), the resistance exerted by the air due to falling at a given velocity (lift). I would set this up as a finite integral problem and experiment with different angles of attack having 6 separate columns 3 for displacement, velocity and acceleration horizontally and 3 for vertically.

Another CR4 subscriber wanted to drop plates this size from a water tank that was being dismantled a few days ago. What an opportunity to compare notes!

You did not notice it is the same one!

It could go a long way if it starts rotating, dunno if a square sheet will do it, but a rectangle can spin on its long axis (in a horzontal plane) and fall relatively slowly and fly a good distance.
You may be able to scale it and test it, if you work out the correct factors for plate thickness.

Post the video, we all want to see
Del

You were given the counsel NOT to do the operation since it seams that you do not have the qualification for it but the problem is interesting and I made a THEORETICAL analysis which leads to following point:

- if the plate falls with an angle "α" with respect to horizontal the maximal deviation occurs (without wind) for 55° and is 1.4m.

- in the case of a side wind and a plate falling with an angle of 90° with horizontal, for a falling time of 3 s the total deviation from vertical can be estimated as:

in meters: 1.7E-3*w²-3e-15*w+1.4 where w= wind speed in km/h

in feet: 5.5E-3*w²-1e-13*w+4.6

I did it since to often the comments to a question asking for quantitative estimations are limited to a qualitative bla-bla.

Even you have now indications i still NOT recommend you to do the job by letting parts simply fall down. On the other side cutting will destroy the load symmetry and the connection between columns so that it should be done a structure analysis if the columns as build can stay on their own without being connected by the reservoir.