new side flairs fitted

[Guest terry]

hi guys, Thought I'd let you know I've fitted new side flairs I got from tony on my t500.

 

Man what a different. I also fitted wheel spats at the same time and I can't believe the different in cruise speed even at lower revs. and the glide rate at ldle is fantasic.

 

You got to see it to believe it. I'd post a picture if I new how too.

 

Terry

 

 

[Guest TOSGcentral]

I am pleased you liked them Terry.

 

As some general information on reducing drag on a Thruster:

 

I have spent some considerable time getting the newer gear legal so you can put it on safely without risking colliding with liability issues by being outside 95.25 conditons.

 

The side flares Terry has will fit any Thruster pod (including single seaters) and are not difficult to fit.

 

I do not recommend spats for training aircraft as they inhibit good quality pre flight inspections for students – particularly if the aircraft is fitted with brakes. For private owners they are great, but do take the time to keep them clean inside as accumulation of mud etc can give you a braking effect that can inhibit take off run performance and even cause asymmetric braking on landing, even if you do not have brakes fitted – which can be exciting!

 

Very soon (I hope) there will be anti-interference drag fairings to fill the gap between the top of the cockpit and the wing undersurface. These also improve appearance. There will be two models – one for standard two seaters and another for those that fit the reduced angle of incidence bracket. They will have air intakes for head level ventilation on enclosed cockpit types (that get quite hot in the summer).

 

The reduced angle of incidence bracket will reduce profile drag at cruise by aligning the fuselage more with the relative airflow.

 

The most impact you can make on drag reduction on a Thruster is fitting aerofoil section lift struts. These will give you an instant 6 knots on your cruise and a much better glide – but they have to be the correct ones and fitted the correct way (by an L2 or an L2 sign-off if on a school aircraft).

 

Top of the line is the new replacement ‘Swift Pods’ that have the side fairings built in, a large forward inspection hatch for servicing of the rudder pedals and pitot head and the next model of these pods will also have air intakes moulded in for leg level additional ventilation on enclosed cockpit models.

 

Aye

 

Tony

 

 

[vk3auu]

Tony, I wonder if some of John Gilpin's vortex generators in strategic positions around the side of the pod would help to reduce drag.

 

I once calculated that there was about 3 HP required to pull the lift struts through the air at 45 knots.

 

 

[Guest terry]

Ga da tony and others interested. I've also fitted aerofoil lift struts and I wonder how much better it can get

 

Regards Terry

 

 

[Thruster87]

Where the heck do you get the areofoil lift struts from? I've tried a few places without luck. How much for the side flairs? Cheers

 

 

[Guest terry]

Hi Allan The side flairs I think were $112.00 each through Tony and the aerofoils

 

were dare I say it bought off Tony about 7 years ago but never fitted by the previous owner. I bet Tony's kicking himself now for selling them they were brand new still wrapped. At the time they were surplus to his requirements. So with tight skins. new aerofoils, wheel spats and side flairs, a shine on the skins and highly polished pod, window etc She's like a different plane altogether. Ah ye I've also fitted new doors that came through tony as well. Sorry to go on but I think Thrusters are the bees knees plane and with all the extras Tony's working on we can continue to improve them. Thrusters will always require Competent pilots to fly them because their not for the faint hearted as I discovered yesterday after a brilliant fly, on returning home found aproximately 20 knots of gusty turbulent wind to land in. It brings a smile to your face but only after your rolling along the runway throttle set to idle and the wheels firmly on the ground. Ah side tracked again sorry Allan. I have seen the aerofoils advertised in mags in America and I'm sure would be easy to source. Regards Terry

 

 

[Guest ozzie]

Hi Terry, I was involved with the Thruster during it's birth. so to read your comment that it is the 'bees knees' after all these years puts a smile on my face.

 

Thanks.

 

I did some wicked and nasty things to some of the early models and other than the gemini nose in not once did they try to kill me.

 

ozzie

 

 

[Thruster87]

I wonder [i know I'm dreaming] if Tony has anymore of those lift struts left. The trouble with getting them from the USA is you need a container as they are so long. Looking like I might need to make some foils around the tubes. Cheers

 

 

[Guest TOSGcentral]

Hi, Just hold onto your knickers for a bit mate, I am working on a rather large post going into Thruster drag a bit more but I suddenly find that I no longer have my mother in intensive care but also her twin sister - and there is a family feud going on concurrently!

 

So I am a trifle preoccupied but trying to live my normal life! I will explain the current situation on the lift struts - in detail.

 

Hopefully I will be back later this evening, or tomorrow morning. I have stack of sabre toothed females on my back as well with their own anxiety so the shotgun is beginning to look the favourable option :)

 

Aye

 

Tony

 

 

[Guest TOSGcentral]

MORE ON DRAG REDUCTION & THRUSTER DRAG GENERALLY.

 

VORTEX GENERATORS.

 

VK3 – The challenge is where would you put them and why? After my involved session or resolving the Gemini Pitch Instability issue I am very cagey about disturbing the airflow aft of the Centre of Pressure on a Thruster.

 

This is an area that I am still trying to research and a central key could well be the Thruster having the Thrust Line, Wing Drag and tailplane all in a straight line while on most aircraft they are usually at different levels.

 

Having said that Vortex Generators have been fitted but these were for specific purposes and only on aircraft with glass fibre mouldings immediately behind the cockpit (and then only on one of these).

 

There were only three such aircraft – Rusty Jenkins T83EHF with quite a large, slim glass fibre mould from the cockpit to the wing trailing edge, doors etc. When this was first flown in that configuration a considerable amount of elevator authority was lost while you would reasonably expect that a better airflow would have made improvement.

 

A vertical row of VGs down each side of the moulding fixed that very well and the aircraft returned to normal handling but better performance.

 

Other aircraft were the Flying Fox that has a large aft moulding and I suspect would have required VGs but I did not do enough testing before it was moved to WA. Other casts were made from the master mould but not fitted to my knowledge. I acquired the master mould to get it out of circulation as the castings only fitted the two seaters and are very much illegal under 95.25! The Flying Fox is legal with the moulding as it is registered in 19 series and a helluva lot of changes have been done to that machine.

 

The Flash also had a similar moulding and had elevator trouble as a result. That was resolved by simply taking the mould off and not using it again while VGs may have fixed it.

 

Note: We are talking about potentially deadly stuff here sportsfans and I seriously suggest that you do not mess about and go into this kind of area unless you are highly experienced, have good nerves and a reasonable grasp of what you are doing (and what the implications could be)!

 

It is very sobering to be doing 60 knots in a Thruster, find the elevators have TOTALLY stopped working, the machine is pitching down towards the ground and you have no apparent means of stopping it doing so. If this is happening at just a few hundred feet on approach you have precious little time to find a solution!

 

I have been there three times now and do not recommend the experience!

 

What is of more interest to me is partially enclosed two seaters. This is quite legal and we have Lois’ T300 (which we are using to develop the Swift from) fitted with T500 cockpit roof and rear panels. Drag is currently noticeably high on this aircraft resulting in a reduced climb rate and rapid deceleration on throttle reductionb. I fixed some of that by three coats of Armour All but there is still a lot of extra drag left.

 

What appears to be happening here is airflow ‘double curl in’. On any open Thruster you get curl in (which will produce drag) around the broad windscreen. You may have noticed that there is a pronounced forward movement of air inside the cockpit – especially on a T500 or TST E which does not have doors fitted.

 

If you then add just the rear panel to a T300, TST or Gemini you will get curl-in around that as well as the windscreen. Fitting doors then removes the windscreen curl in and leaves you with the curl in around the back of the now enclosed pod. Something definitely happens as the 912 engined T300s (which all had enclosed cockpits) has to be operated 5 knots faster – but that could be just from the extra engine weight.

 

What is of great interest to me is what this is doing to the airflow going to the tail! I will have the chance to find out as is progressively entirely enclosed and I can get some valid performance measurements plus handling comparisons.

 

SIDE FLARE PRICES. A pair of these still costs $112 plus postage and packing. I send them parcel post as they are not too big and are very light.

 

AEROFOIL LIFT STRUTS. Common supply of the aerofoil section material dried up several years ago. However this is exactly the same as is used on the Jabiru lift struts so you should be able to source raw material from the Jabiru factory. It used to be surprisingly cheap and you could get a new set of struts made up at an attractive price.

 

I will be re-examining this area myself when we get to that stage with the Swift development. Making and fitting instructions are available free from myself/TOSG.

 

Aye

 

Tony

 

 

[Thruster87]

I made some recent inquiries to Jabiru and their stock from what I recall was too short.Wadair may put into production the approved end fittings plus the struts in the near future? That's where I left it. Cheers

 

 

[vk3auu]

I would expect that a row of VG's down the outside of the windscreen on each side and the side of the pod would reduce the "curl in" quite considerably without causing too much angst to the tail feathers as well as reducing total drag.