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Thruster Swift - Project News

Guest TOSGcentral

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Guest TOSGcentral

At last I have something positive to report regarding the Swift Project and the new Angle of Incidence front wing bracket that a few of you have been hanging out for.


There will now be TWO Swifts and they will be built side by side and concurrently. I have bitten the bullet and got finance for the project so I can just plough on with it. Part of that is taking a half share in the BMW T500 that will become one of them – the other is the T300, 25-381. While my wife Kay is keen she is also getting a bit tight jawed about me now owning outright, or having substantial interest in, eight Thrusters and she knows that I want another two on top of these! A sense of humour is essential in such situations!


Lois (who is now highly involved in the project) will be back next week from NSW and it will be full steam ahead. Meantime I have commenced a full pull down of the BMW T500 and the final preparatory work has already been done on 381 – so that is just waiting for the BMW to reach the stage where 381 can be taken out of the air and put in the workshop alongside.


I am in fact playing ‘Musical Thrusters’ as I have another T500 coming in for a full overhaul and test flying so need the workshop space initially, so that will change places with 381 in the hangar as 381 comes into the workshop.


The BMW T500 is concurrently undergoing a full benchmark rebuild that 381 already has had – so a devil of a lot of work is involved in this. Having two Thrusters totally pulled apart and concurrently being heavily modified is not something to be taken lightly.


I will put progress reports on this forum from time to time and a more complete account plus pictures in the next TOSG Bulletin (end of March).


The Swift Project is now firming up well as a result of the preparation work already done. One intended major benefit is from including the BMW T500 into a full Swift. This will enable us to be able to offer a reliable and proven four stroke motor installation for the older model Thrusters. While we will be certifying the R100 engine presently in the aircraft the finished product will be the R80 with an enhancement upgrade to R100 power, full installation kit – plus a new design extractor exhaust system to get yet more power out of it and all of this at thousands less than R912 or Jab 2200 motors . Exciting times!




Guys will you PLEASE be careful!!!! There has already been one instance down South of someone getting impatient with my dragging my anchor and had a lash at this, despite being firmly advised by others to wait for TOSG results. The landing characteristics certainly improved but the handling DID NOT! So the aircraft has been (very wisely after a spontaneous outburst of common sense) taken back to normal configuration.


Now, while I have been generally quacking that the Thruster has an incorrect angle of wing incidence the actual problem is inherent in the fuselage design that results in a far too high Relative Angle of Attack in the 3 point attitude. We cannot do anything about that (or certainly not sufficient) so we have to go for the wing incidence itself.


We have ONE degree to work with that will leave a positive declage after the desired four degrees change!!!! This has been measured carefully and is much of the design work that Bob Llewellyn is doing for TOSG. The wing strut length will also change slightly or we will have changed the wing wash out (or wing twist if you like) and if that is not addressed and goes the wrong way it is not going to either pleasant or ‘tame’!


While the A of I bracket will be able to go straight on any existing two seater quite easily, and without costing an arm and leg, it will also have a lot of ‘hidden’ work behind it so you are safe! The situation however has been slightly complicated by the flap system and I will have to do concurrent flight testing for the reflex and three positive flap settings intended. Now we have some finance I am not expecting that to be too long a drawn out process.


What our intention is will result in something that you will be able to fit reasonably simply and cheaply and just go enjoy safely. Let us keep it that way please without rushing off for what seems like a good idea on a simple airframe!







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Hi Tony.


Just thinking about angle of incidence.


In most normal aircraft the tailplane has a negative angle of incidence at normal cruise attitude.


In the thruster the tailplane is aligned with the boom, so at normal cruise, the thruster flys with its tail up, which achieves a negative tailplane incidence angle.


I'm wondering if by attaching your angle of incidence brackets, you now have the tailplane flying with close to zero incidence at cruise, which due to the rag and tube nature of the tailplane would cause it flop around, (you would also have more back stick force on the elevator).


Have you tried your foam inserts in the tail plane? Maybe make a set that is curved one side and flat the other, and put the curved side down?


Ok , That's another desk flying for now!


Good to hear progress on the 4stroke front!


Cheers, BobT.



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Guest TOSGcentral

Thanks for comments Bob.


Believe me there is a helluva lot of talking going on at the moment about incidence and declage - especially as I am the bunny who will test fly them.


Personally I am torn between simply converting it to a biplane or going the who bit and area ruling to see if we can go transonic :devil:





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