We think so.
So long as endurance is not your prerogative then with an electric motor of 200kW+ and modifications to the control surfaces - specifically the Ailerons - larger and with a horn balance to increase their 'throw' - and a larger elevator, again with horn balance (these act as 'power assistance' to the controls in place of spades) then it's quite possible a Twister could compete at Unlimited level.
Below are three pics.
The first is a 'mild' upgrade with no new molds or major changes to existing layout needed. The flaps are gone and have been replaced with full span Ailerons.
These ailerons also have a horn balance on the outboard section, which is where the mass-balancing weight would now be so that 'throw' is not limited as it currently is by being inside the wing. The outboard hinge is in the same location but on the inboard section of the tip rather than outboard as is normal on a Twister.
The elevators are a little larger in area, also with a horn balance.
The rudder remains unchanged. The standard rudder in a Twister is already very powerful and overly sensitive compared to the other controls - due to it's too large horn balance - but ideally suited to this more extreme version.
'Mild' version of an Unlimited Twister. |
The second version, below, is a more extreme version with a larger aileron surface area - particularly on the outboard area (where it has the most effect). The inboard section of the wing has been left without a control surface (as per the Extra 300SC).
The roll rate for this version would be 400 degrees per second. Roll rate being a function of aileron area and 'throw', coupled to wingspan (wing area ultimately).
The elevators are also larger for more rapid 'Flick rolls' and more control at lower speeds.
More Extreme version with 400 degree per second roll rate and greater speed of flicks. |
The final image shows this extreme version overlaid with an Extra 330SC (currently considered to be the ultimate Unlimited aircraft, and with identical wingspan to a Twister at 7.5m). As you can see the ailerons are now of similar size. The elevators don't need to be as big because the Twister is considerably lighter than the Extra (approx half the weight).
Extreme version with Extra 330SC overlay. |
Overall the Twister would need to be strengthened considerably so that it could deal with the increased G forces but also the expected higher Va and Vne needed to compete at this level of competition. This will add weight of course but I still don't think it would be as heavy as the steel framed Extra with it's heavy Lycoming 580. The power to weight ratio would be comparable or better than the Extra.
No comments:
Post a Comment