Sorry for a late response, you can find the information regarding the file upload on this forum post I just created. This will clearly tell you how 39 steps are computed in that simulation.
For your case, if you are dropping your drone from 500 mm (0.5 m) with a velocity of 5 m/s, than your drone will come in to contact with your floor at around 0.1 s i.e. v = d/t => t = d/v = 0.5/5 = 0.1 s. Therefore, you can make second row of file as 0.09, 0.045 to just compute the fall of your drone in just two steps. Than after that, for a second row you can define more steps in order to capture and easily converge your impact.
I am not sure how long it will take your drone hit the surface and leave it, but you can first try a higher total time with less time steps i.e. something like 1, 0.091. Once you know the total time of real impact you need to capture, you can than modify your .csv according to that and re-upload it for the second case.
On aside note, just a suggestion: Try to coarse your mesh as much as possible, otherwise it will take too long to get the results and also will need more computational power. Take an example of the mentioned case, it contains only 48117 nodes compared to yours which are 118431.
Hope this helps. If you have any question/s, feel free to ask. Happy Simulating!