21 Years of Thrusters: part 2
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21 Years of Thrusters: part 2 |
| Thruster Operator Support Group | |
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The Thruster Operator Support Group is celebrating 21 years of Thruster history and the contribution of this remarkable ultralight series as the workhorse of Australian ultralight aviation over so many years.
Tony Hayes is the author and Roy Gilby is responsible for the desktop publishing and layout of the original print publication. The Web document is contained in three html pages:
1. A brief history of the marque's evolution and chronology from 1982 — 1990
2. Thruster chronology — 1991 onwards
3. The Thruster main models [with photographs]
Under new ownership the UK factory continued building the T300 but must have also nearly immediately begun taking the Thruster to its next logical step. Over the following years and up to the present day, the T600 was designed, certified and put into production, and was a winner!
There was considerable redesign work done to the airframe and the incorporation of a new and more streamlined pod. The big advance was an all chromoly cockpit chassis and consequently both nose and tail wheel versions. The T600 totally tamed the Thruster, making it a docile and far more efficient aircraft.
UK Ultralight aviation was also developing apace with increased minimum weights becoming available. This allowed the T600 to be certified for the Jabiru 2200 four stroke motor. Further weight increases saw the introduction of new models which began to copy our T500 style. I thought it was a nice touch that the UK factory delved back into the past for a disused Thruster name and called their new fully enclosed models the ‘Sprint’. The weight increase also allowed for further progression to an amphibious float version which apparently is currently under development.
After purchase from the receivers, the new owners relocated the factory in Sydney and shortly afterwards relocated to Evans Head, where they have since remained.
Little has happened with the main T300 and T500 types in terms of major development. There have been a few minor improvements such as pneumatic tail wheels. Approval was eventually obtained for the fitting of the Rotax 912 four stroke engine and a handful of these were produced. More recently it would appear that building of new aircraft are very few and far between.
There were rumours of kits for T300/T500s being developed but this now seems to have gone nowhere. Equally there were hearsay tales about a nose wheel version being built – but again only stories and nothing tangible.
What the factory did do was cause a hassle that took an incredible amount of sorting out over several years to make any sense from. This involved the so-called ‘T200’ but actually comprised some intricate dealings that involveded six separate Thrusters.
After the factory had changed hands the sole example of the T100 came in from ‘out West’ where it had been living, as a trade-in. The physically large owner of the factory saw this as an opportunity and kept the aircraft as his own private machine.
The pod and cockpit arrangement on the T100 was somewhat ‘open air’ but the partially made parts of the second 1988 Sprint were still there. The large Sprint pod was therefore grafted to the T100 and so was born the legend of the ‘T200’ – a term the factory may well have used. The aircraft was also known as ‘Bill Robinson’s single seat T300’.
After a while this was sold but when the new owner came to get it the T100 part had already been cannibalised to rebuild a TST E (which also took the T100’s TST style wings) and what was left seems to have been the second Sprint pod and the parts of a second hand T85C.
The T100 thus ceased to exist and its component parts were spread all over the country. The ‘remains’ were rebuilt to what TOSG now designate as the Sprint/T85C Hybrid and that is still intact in good condition and flying.
The original T100 pod probably went on what TOSG designate as the T100/T85SG which is also in TOSG member hands.
The original entire Sprint escaped all this but from time to time has been referred to as the ‘T200’ which further added to the confusion. All of that took a great deal of working out and a lot of false leads. Promised photos never turned up etc. But the story given is probably close to the truth of the matter if not the truth.
While a lot of owners retrofitted their aircraft with the later developments, three significant aircraft came out of this period.
One was the ‘Flying Fox’ that started as a T300 and was extensively reworked as an experiment in drag reduction with the Thruster. That aircraft is now used by TOSG as a flying test bed for Thruster research and will be used for certification of the flapperon system in Oz.
The second aircraft was the ‘Flash’ which was basically a T85SG put into partial two seat configuration with a new design pod and fully enclosed cockpit.
The third was the Bilby that took to the skies for the first time in 2003. Starting life as a T300 this aircraft was extensively reworked over a two year period to form something half way between a fully enclosed T500 and a T600T Sprint. This aircraft is fitted with flapperons and will be the flying side of the approval process for flapperons on 95.25 Thrusters. Phase 2 of the Bilby is intended to sort out the wing incidence under CAR 35 Approval.
There are some other oddities. One of these, of which not a great deal is known, is the ‘lozenge aileron’. This is an aileron that tapers outwards to about half span and then inwards as per the conventional aileron. Only two sets are known to exist – one on a T300 and one on the ‘Flash’. It is surprising this was not continued as it did away with a lot of wasted drag near the root and enhanced both the roll and coordination.
The last main one is the ‘T300 Stits’ that was designed and built in the Philippines. This was a basic T300 that had its battens ‘captured’ to form permanent ribs attached to leading and trailing edge wing spars, plus top and bottom sub spars added to stabilise the wing structure. The entire wing was then covered in Stits fabric to give the best possible finish on a Thruster wing. The aircraft is now back in Australia and has been re-built to 95.25 standard with another set of wings.
The heavily modified wing of the T300 'Stits'.
It is also probable that during this time period the single example of the single seat Sprint was modified with a fully enclosed cockpit, doors, a GRP rear fairing and the aerofoil section lift struts were fitted.
Towards the end of the 1990s Wade & Brett Mahlo purchased from the UK Thruster factory the Australasian manufacturing rights of the Thruster T600. With the Australian Thruster factory still being in existence the type was renamed the Vision 600 (this was possible as it was far more than 15% different from its forebears even though the pedigree is obvious).
Over three successive years (’98, ’99 and 2000) an example of a T600N was imported for evaluation purposes by the new factory that established itself at Orange. The first two were T600N/390s and the final one was a T600N/450 with the Jabiru 2200 and Ultralam skins.
From these aircraft very extensive tooling was developed to make the Australian ‘600 a totally jigged aircraft – essential for parts supply in a country of our size! Five T600s were then imported and assembled by the factory (4 x ‘600N and 1 x ‘600T). This was intended to get the type available and allow time for Part 103 of the new regulations to come out so new manufacturing requirements could be seen. This was an essential precaution as obtaining these approvals is very expensive and something you would not wish to do twice!
Then the wheels came off the wagon! A flaw in the writing of the existing legislation deemed that the ‘600 could not be assembled as Thruster UK were not an approved manufacturer under 101.55 legislation and the correction to this had not yet been passed. The factory could also not independently manufacture the aircraft from scratch as that approval was not in place. Basically just another paperwork hassle paralysed yet another Aussie product – leaving a wide open market window which was rapidly filled by fully imported X-Air and B22 Bantams.
At the time of writing that situation is still being sorted out with the intention to get the Vision back into full production – but the lost time has probably cost the movement about 40 of them at least.
By 1995 the Australian Thrusters were just about dead in the water. They had obtained an evil reputation for handling at the hands of alleged, but inadequately trained, taildragger pilots. Parts were becoming more difficult to obtain and even identifying what actual part was required was sometimes almost impossible. The general feeling was that there were maybe a couple of types of two seater and a single seater version – but they were all just ‘Thrusters’.
The pre-95.25 aircraft records had gone and there were no copies of the 95.25 compliance ordinance left at either CASA or AUF. Owners were hassled from time to time on pure ‘opinion’ of what was legal or not as they attempted to keep their aircraft serviceable and flying.
So TOSG formed as a central information source to begin accumulating and sorting information, then redistribute it via the quarterly Bulletins that were started. The record and missing support was going to be re-formed.
Now just commencing our 9th year, a great deal of water has flowed under the bridge since that scrappy little first Bulletin, but from it came so much.
Collation of technical information was the first priority and that has gone apace with all of the Thruster Ads (that are known of) being available and a permanent tech answering source from TOSG by phone, fax, email or bang on the door.
To validate the Tech a Type Identification programme started that has now unearthed and located all the Thruster types – we now think the list is complete and only possibly rare oddities are now left, if anything is left to be rediscovered.
That information has flowed into an increasing spare parts supply and most parts are available for all types or information as to how you may obtain them.
An Historical & Heritage section started in conjunction with Identification. This part has located 7 of the 8 main prototypes and traced all 9 of the Glasshouses known to have been built. In conjunction with the AUF Tech Office the previously illegal Glasshouses and Gemini X’s, plus a few other rarities, can now be made legal under special dispensation. However note that this takes a great deal of TOSG effort in assembling a full pedigree for any individual aircraft so this kindness is not abused.
A web site was also established where increasing amounts of identification, technical and parts sourcing information is on free display.
In the operations area all of the ‘quirks’ of the Thruster have been identified, examined and straight forward training counters constructed to deal with them. The Gemini Pitch Instability problem was uncovered and dealt with – it is no longer a problem!
TOSG membership peaked a couple of years ago at 150 and has stabilised at about 60. The Group is honorary so membership numbers are not terribly important if the information is available. However the Group will ultimately close as a result of declining membership for free availability of information, to a point where the break-even overhead cannot be sustained at an acceptable per-capita annual membership cost. We will have to wait and see when that happens.
TOSG’s latest project is development of the ‘Swift’ which will be a fully enhanced and re-manufactured Thruster two seater. This will ensure that schools and owners have reliable and affordable aircraft for many more years to come.
Who knows? In 2007 the Thruster will be a quarter of a century old – not bad for a little ‘rag and bone’ ultralight when so many exotics have come and gone already. We will have to wait and see, but while the future will always ‘just happen’ you can make it what you want if you apply forethought and some effort!
'Just Flying' — as Thrusters have given to so many for so long.
[Next page: The Thruster main models]
Tony Hayes
thayes@bordernet.com.au.
Copyright © 2003 Tony Hayes