So , just today , I was doing a test to try and take off from here:

The plane that I was using weighed 858 pounds and HP/Weight ratio of 0.076,Wing loading of 1.8/ft2,And a wing area of 487.5 ft2.

So by adding and decreasing all of these while keeping everything equal to the ratio of all these combined (i.e : 0.076/858lb/1.8ft2/478.5ft2 , or just dividing all the numbers or multiplying them by the same number) , I was able to do the samething multple times.

The hill had a 45 degree drop at first that in this plane lasted about 3 seconds and then a approximate 80 degree drop.

Theoretically , anything done keeping the ratios correct should allow the plane to take off from that point.