Compliance & Modifications - Q & A's

I am opening this as another intended sticky where Compliance and modification questions and answers may be aired - leaving the main compliance post more as a standing notice.

However, we can edit into it anything worthwhile that comes out of discussion here.

So ask away.

Tony

To get this thread underway I have copied over some questions from Thruster Bob in another thread – to show how the flow can go.

Bob posted:

“Yep I like the idea of a "sticky" post with approved modifications, (possibly as a table?) potential buyers can skim through this to see what kind of lemon they are buying.

You need to indicate for which model number each modification applies to, there are probably many T600 "approved" parts that obviously won't work on a T300.

Make some mention about the wing bracket AD as well.

What about some of the variations that have come straight out of the factory, are these classed as approved because they came from the factory or what?

Post should also have links to relevant TOSG website pages and RA-AUST pages.

On a similar topic, what about fuel tanks, I have the rectangular type, rather than the beer barrel. The visual fuel gauge works brilliantly, but it is more difficult to refuel; are there any other fuel tank variants out there?â€Â

ANSWERS.

1 MODS & MODELS. This is not much of an issue – other than in practical terms. ALL the items listed in the compliance listing in the main ‘sticky’ may be applied/retrofitted to any model of 95.25 Thruster as they (Gemini A&B, TST, TST L, TST E, T300 & T500) are being classed as the same airframe that has just been progressively strengthened but not changed in basic design or flight loading capabilities.

The main practical issues are as follows:

(a) The roof panel and main rear bulkhead components of the full cockpit enclosure will not fit the Gemini and TST pods because of the side shaping. So a T300/T500 pod has to be fitted to take these. That is of little consequence as the later pods fit the Gemini & TST and they are anyway the only ones you can buy now. In fact the only new pods you can buy now are Swift pods from TOSG but they also fit the Gemini & TST as they are basically a 1988 factory original used as the main mould but with additional services added to it.

(b) Full rear fuselage enclosures are a bit more of a hassle. You cannot fit a T500 rear enclosure to the open models for weight and balance reasons. Aerodynamically there is no problem with them on the open models but the key point is the stringer structure. As part of the ‘Swift Project’ TOSG is having a suitable framework certified under an Engineering Order for the TSTs and T300 and I intend to extend this to include the Gemini as well.

• T600 & VISION 600. The main compliance thread probably covers this adequately via a couple of warnings. There are very few ‘600 components that can be used on the earlier types. One very useful one is the fork for the pneumatic tailwheel that are no longer available. TOSG will have one certified and made available for the earlier models but if/when the Vision 600 goes back into production then the manufacturer source will also be available.
   
  

• LIFT STRUT/WING SPAR ATTACHEMENT BRACKETS. This is more of a parts situation as applies to a correction to a faulty batch of brackets produced by the factory. TOSG has certified replacement brackets available under an Engineering Order. The procedure is a trifle messy as each set is hand made using the faulty brackets as a model. This is because the mounting holes varied slightly between batches of brackets made and the consequent holes in the wing spares varied as a result. The new brackets are made so that they will fit the aircraft the old brackets came off.
   
  

• FACTORY PRODUCED RETROFITS. This is a curly one Bob that I do not wish to delve into publicly too much. With the lack of record keeping by the various authorities and the fact that the factory retained its authority to manufacture – then an assumption has to be made that nothing they produced and sold had not been prior approved and certified by their CAR35 Design Engineer (Newton Hodgkiss who is now dead).
   
  

I personally believe that is a load of bollocks but that is a personal opinion and carries no weight in this magnificently regulated industry of ours! The best that I have been able to do is attempt to keep to the ethic and intent of 95.25 compliance for the flight safety of owners. Successive AUF & RAAus Tech Managers have been of considerable assistance in doing that.

However, a good look has been taken at what did come out of the factory – hence the somewhat veiled warning on the compliance thread about the crap plastic stream-lined wing strut shrouds that they flogged. Equally, in the past I went through a bad session of convincing Thruster owners that the Thruster Vne had NOT been magically increased to 120 knots as the factory was (verbally) informing people – mainly because they did not understand the significance of various engine proving requirements when the R912 was being attempted to be introduced and they became totally confused!

• CROSS REFERENCE LINKS TO WEB SITES. That may happen Bob but both Ian and I are frantically busy at the moment and it would be an involved job. The main aim at the moment is to get the information out in view where it is of direct use to users.
   
  

• FUEL TANKS. The basic evolution of these is as follows:
   
  

The first 95.25 tanks were 40 ltr plastic barrels (and some larger versions of these appeared up to 45 ltrs). These changed to increasing size spun alloy barrels which maxed out at 75 ltrs (and great care has to be taken with overall aircraft weight and balance of these things as a full one can easily push you out of the aft C of G limit).

In 1988 the vertical oblong 60 litre stainless steel tank was introduced for the TST E and T500 primarily so they were high enough that you could refuel through the centre section shroud. When the factory began using the large barrel tanks they introduced a Velcro sealed side flap in the rear enclosure and extended filler tubes so that you could still get at the tank.

Of note is that a lot of tanks fitted to the Thruster (from whatever sources?) do not have either sumps or total drain taps in them. That should be corrected such that responsible pre-flight fuel contamination checks can be made and the hygiene of the fuel system maintained.

I think that covers the questions.

Aye

Tony

The main compliance sticky thread has now been edited to include compliant engines, propellers, some notes to counter popular misconceptions and a brief warning on how easy it is for compliance to come off the rails.

Tony