RE: Full scale hovering
Nice video - looks like Ian Groom and he IS NOT hovering. He used inertia in the rolling up line until all the energy is bled off and then the airplane IMMEDIATELY starts falling back while he maintains the roll rate. This is a Full Scale Torque Roll and was first introduced by Charlie Hilliard in 1972. It won him gold in the World Aerobatic Championships (WAC) that year. By the way - that looks remarkable like an SU-31 to me - 360hp+ for the 31 and 400hp for the PF version, neither of which can "hover" in the same sense as that of what we do with R/C. The SU-31 weight is only about 100lbs lighter than that of the SU-29 and they use the same HP (empty weight for the 31 is 1650lbs ad fuel and the pilot and you can see where this is going - down. AvGas weighs approx 6lbs. per gallon. The airplane will hold a total of 76.3 gallons of fuel - though not flown at full tanks for a four minute free. 11 liters of oil at 20lbs., smoke oil at 57lbs, and a pilot. That's a 2000lb airplane not 30-35lbs.
While it is true that you only need better than 1:1 thrust to weight ratio, it is not the only factor in determining if an airplane can hover. Sean Tucker regularly flys his airplanes in a harrier - high alpha configuraion, but he cannot hover. Will full scale airplanes eventually be able to hover - probably. Have guys been trying it for some time - yes. Does gravity affect all objects the same way regarless of their mass - yes. It's not as simple as hanging a bigger engine off the nose of a full scale airplane and the full scale pilot doesn't walk away when he inadvertantly induces fludder or surface lock when the plane slides back in a bad way. You can't put bigger servos in the plane. it's the strength of the plane, it's components and the man/woman holding the stick. As of this time, we don't use pneumatic systems in our aerobatic airplanes. The only "assist" we get is counter balanced surfaces and trim. Have you every slid a full scale airplane backwards in a tail slide?