Thruster v Drifter

[seb7701]

G'day all. This feels a bit like crossing over into enemy territory, but as devoted drifter pilot, I'm looking with great interest into the pros and cons of purchasing a Thruster, largely due to the transportation options and excellent support base.

 

My main question lies in the ability of the various Thruster types to recover from low level power failure (ie on take off, etc) due to their larger frontal surface area compared to skinny tandem types such as the Drifter.

 

Aside from the increased drag and more 'taildragger-like' behaviour, what is it that set the Thruster aside from the drifter so much?

 

I realise that mentioning the 'D' word in this forum is akin to a uttering swear word, but think of it as a chance to convert someone from the dark side!!

 

 

[Guest Baphomet]

I'll dirty the water even more, by suggesting you consider the Bantam. Send me a PM and I'll tell you why. (I wouldn't want to offend the Thruster crew) I at least have flown all 3 types, so my subjective opinion is at least based on experience and not conjecture.

 

Cheers

 

Ian

 

 

[facthunter]

comparison.

 

Not setting myself up as an expert here, but some obvious differences are:

 

Thruster. more sturdy undercarriage, you sit side by side, (if that appeals to you). Bits that fall off don't go through the propeller. Local back-up available.

 

..... Drifter. No fumes in cockpit. unparallelled view. Need to be careful how you stow things, has a "classic appeal" (a personal thing.) Fragile in a training situation.

 

As far as glide angle, the thruster is supposed to be more brick-like, but I don't think there is much in it, and it can probably be tweaked a little. If you are going to a 4-stroke engine eventually, the tractor set-up is probably easier. I'm not commenting on legality , just that a pusher jabiru installation might be hard to cool in a slow moving machine.. Nev...

 

 

[seb7701]

Thanks gents - all food for thought. It's that glide angle that has me fascinated, although if it is a relatively close race between the two, then I see less of an issue.

 

 

[Guest TOSGcentral]

Hi Seb,

 

It is a bit more than glide angle. I am constructing a comprehensive reply for you but at the moment I am knackered and going to bed - so you will have to wait for the morning.

 

Aye

 

Tony

 

 

[Guest aircraft1]

What about X-Air ? More modern than all of them, has the best undercarriage and as LSA can be used for training etc.

 

 

[bilby54]

..... Fragile in a training situation... Nev...

Hi Nev,

 

Just wondering how you came to that conclusion??

 

My Drifter has a modest 2500 hrs of mostly training time with not much more than the usual wear and tear. The biggest damage was caused by so called "experienced" pilots who pancacked it which always makes me wonder how they were trained???

 

I know that Seb could land it OK!!

 

Maybe the instructor needs instructing:big_grin:..... Bill, Roma.

 

 

[seb7701]

Thanks Bill, I'd like to think that I had left it the way I found it.....

 

Drifter bias aside, I have never know the drifter undercarriage to be 'fragile', in fact far from it.

 

 

[facthunter]

Damage.

 

I've seen undercarriages bent on drifters. I think it is bad flying, but the landing would not have caused damage to a thruster. The X-air would be stronger than either and is also tricycle, but I'm assuming we are discussing the difference between the two mentioned in the thread starter, and that a taildragger is part of the deal. Nev..

 

 

[Guest TOSGcentral]

Arrghh! Drifters (and now even Bantams and X-Airs) on this pristine forum sub-group! Damn, you will be telling the Vicar to nick off next, or spitting in the custard at formal parties!

 

 

OK formally required rant over – let us get it on. I will be brutally frank. I am not some dip stick that is madly supporting an aircraft type because I am blindly in love with it – or even really like it. With over 150 types in my books I class the Thruster as an aircraft in its own right that has much to offer – but can be an evil, witch of a thing, although easily tamed if you have been taught to fly correctly.

 

 

But as they were churned out of the factory they can really bite in careless and unknowing hands – particularly in instructor hands, or those that get into them thinking that they are just ‘another ultralight, so that will be OK’!

 

 

On the latter point I am currently working on two (by remote control) that have been badly bent by high time instructors (but zero time on Thrusters) who rolled them into a ball, with their owners on board, on the first flight! Have I put you off enough yet?

 

 

DRIFTERS Vs THRUSTERS? I would like to start with a more positive view that sees the situation less a conflict or competition (mine’s bigger and better than yours sort of thing) but more of a ‘what do you want to fly’ situation.

 

 

Together the two types gave the market place choice, effectiveness and affordability – and indeed still do. One (theDrifter) offers tandem seating, a very ‘traditional’ image of nearly totally open cockpit and a pusher engine configuration that fitted in well with 95.10 as so many single seaters were pushers.

 

 

The other type (the Thruster) offers side by side seating, a more enclosed (or could be fully enclosed) cockpit in a tractor engine configuration that fitted in well with the increasing trend towards side by side aircraft. The Thruster also offers a very high level of crew protection and is virtually a roll-over cage with wings. You have a full pod and windscreen, two A frames and a battering ram in front of you on a Thruster while in a Drifter you are definitely going to be the first on the scene of any accident! Put a Drifter through a wire fence and you will come out the other side like a sliced loaf!

 

 

So between them the two types do provide a lot of satisfaction in terms of what people want. As basic trainers the situation begins to tighten up a bit more and the two types become poles apart.

 

 

The Drifter (in my personal opinion) is just too tame and easy to be a really effective basic trainer unless in the hands of very good instructors who put a lot of dimension into their work – but the type lets the poor instructor (or pilot) slip through too easily. It is a ‘conditional taildragger’ in that it has a tailwheel – but it sits too flat on the ground and the rear mounted engine neutralises a lot of engine effect swing.

 

 

I had some serious difficulty converting Drifter pilots to Thrusters for a time. As TOSG came into being and the Thruster started becoming better known once more, it naturally attracted interest. I got a rash of pilots (say around the 150 hour mark) who had been trained in Drifters and wanted to be endorsed on the type. I found that too many had been taught bounce recovery on landing as just hold the stick back and wait – the aircraft would sort itself out.

 

 

Try that stunt on a Thruster and you will cartwheel it down the runway – as you will most ‘real’ taildraggers! So the Drifter probably let too many apparently tailwheel endorsed pilots through who were just not equipped to deal with taildragger types capable of considerable pitch rotation on the ground – and all the excitement that goes with that.

 

 

On the other hand the Thruster is harder, gives you no lee-way at all and lets you get away with virtually no error at all in the landing and take-off phases. You get it right or you get trouble – and maybe more trouble than you can deal with! But getting it right is easy when you have been taught correctly.

 

 

The Thruster probably has the edge in the area of seating with it’s side by side layout. This helps the preparation of students for seating arrangements on types that (these days) they are most likely to be flying. A higher order of basic Airmanship habits can be established due to the poorer views to the aircraft’s starboard side from the left hand seat to the point that by the end of training dealing with this feature has become instinctive. In a Drifter you have to make a conscious effort to see any part of the aircraft at all as you (quite literally) are sitting on the end of a long pole and are well ahead of the main airframe.

 

 

Another facet of side by side seating is the parallax illusion. The Thruster has almost exaggerated parallax which makes the subject easily able to be taught clearly (if instructors actually teach it). On the Drifter there is zero parallax as you are sitting on the fuselage centre line so once more this makes the Drifter easier.

 

 

Drag is another large difference between the Drifter and Thruster. From a flying point of view the Drifter has it all over the Thruster. The Drifter’s handling is more balanced and lighter and it has a better glide performance due to the much lower cross sectional area. While the Thruster is quite docile and satisfactory in general flight and bounces around in turbulence like any aircraft of that weight category, I felt that the Drifter gave me significantly more feeling of being ‘in contact’ with the air. While the Thruster leans a bit more towards a ‘GA’ feel, the Drifter leans a bit more towards a ‘glider’ feel.

 

 

Crew operational comfort and psychology is an important comparison factor – both for general operation or specifically for training. This does demark a significant difference between the two types and once more points up what you personally like, or can tolerate.

 

 

Perhaps crassly, we can point this up by stating that you sit IN a Thruster and you sit ON a Drifter! No matter how good the instructor is you cannot get around a fair proportion of the population that are attracted to flying, as either students or passengers, feeling extremely insecure (perhaps inhibitingly so) to the ‘suspended in space with nothing around you’ that the Drifter conveys so powerfully. That is great if you like that sort of thing but schools have to cater to the maximum cross section expectancy of the available market and a lot of people do not like feeling insecure! In this area I give the Thruster a huge tick over the Drifter.

 

 

Equally, all that exposure in the Drifter leaves you simultaneously being frozen by the airflow and cooked by the sun! The consequence is a lot of expensive flying clothing and helmets that you have to keep getting in and out of. With the Thruster a good flying jacket in winter stages down to a woolly pully between seasons and shirt sleeves in summer suffices very well!

 

 

OK some Drifters are now being enclosed representing a huge step forward to them but I hear early attempts gave serious cooling problems with the rear mounted engine. I do not know what the score is there and how it was overcome.

 

 

That was a fairly superficial skim through in comparing the types and I will wind up in the following manner.

 

 

I personally do not like the Drifter and if I never fly one again I will not notice. That does not mean that I do not accept it as a fine aircraft in it’s own right – it just will not (and cannot) do what I require. The only flying that I do these days is either test flying or specialist remedial work and orientation to Thruster operations. What very little personal pleasure flying I need is catered for by the historical prototypes that I own.

 

 

The situation is certainly not one of conflict between the types it is much more of what YOU want an aircraft to do for you and the two types are so different (yet filling the same overall purpose) that it really invites the concept of Drifter vs Thruster when it really is personal choice rather than which type is ‘better’ than the other.

 

 

We also have to bear in mind that between them the two types became the backbone of AUF that evolved into today’s RAAus – and what a helluva good job they did individually and collectively to cover the demand market!

 

 

The final really significant consideration is future development. The Drifter is essentially frozen in time while the Thruster is not. The work that TOSG and myself are currently doing on the two Thruster Swift Prototypes brings the Thruster up to date and makes it an important, valid and affordable option for the small flying school as well as pure sporting flying.

 

 

The main design flaws in the Thruster (mainly the incorrect wing angle of incidence and appalling trim system) are being resolved plus drag reduction devices and a five stage flapperon system. This will place the Thruster in a valid position where it can do effective training and support for the ‘traditional 95.10/95.55 ultralights’ that will remain in service for many years yet. but also perform totally relevant systems training to equip skilled future pilots for the higher performance range of recreational aircraft that are going to dominate.

 

 

In addition the re-instatement of the Vision 600 (license built version of the UK designed Thruster T600) coming back into production breaks the escalating new aircraft price problem and will bring this back into proportion for small schools in country areas – and backed by over a quarter of a century of proven Thruster reliability.

 

 

But there is yet a little more! When the Vision 600 re-enters production I have a plan to create a ‘Vision 600 Convertible’. This will enable a small school to have two aircraft for little more than the price of one. The ‘600 design lends itself to this and an hour’s work will convert a nosewheel aircraft into a taildragger, or vice versa.

 

 

So, in my view anyway, the question really is not simply Drifter v’s Thruster as a type comparison – but the validity and developmental potential of any type to continue providing valid and affordable training for members of our movement.

 

 

(NB – I am not entering into discussion about Bantams or X-Airs here – take it to the General Discussion forum please! They are nose wheel types and the ‘600 nosewheel versions hammer them both into the ground anyway!)

 

 

Aye

 

 

Tony

 

 

[Deskpilot]

Thanks Tony, a very instructive report, even if a little bit biased. You're forgiven. I was wondering though, how many pages does it take for you to answer a simple yes/no question Have a nice day.

 

 

[seb7701]

Well Tony, perhaps I should firstly apologise for violating of the Thrusters user group, but for the sake of Drifter pilots everywhere....I won't!

 

Many thanks for taking the time to provide your thoughts on the subject, as I must say I was hoping to get a view from the ultimate Thruster authority/devotee in order to get a positive view from the other side if the fence, although you should be pleased to know that my original Drifter instructer is also a Thruster advocate!

 

I appreciate that you have provided a 'warts and all' view of the Thruster, as it enables further comparison with the only other grass-roots type with which I have any great familiarity. I am aware that there are few, if any viceless A/C out there, but an honest view of a Thruster just helps the decision as to which vices I am prepared to live when choosing an aircraft.

 

Finally, I must congratulate you on the most courteous statement of dislike which I have had the pleasure of witnessing re the Drifter. I'll bet you were gritting your teeth when you wrote that!! I'd nick back off to the Drifter user group and leave you all in peace, but I have to go and check out the next post I seem to have caused!

 

 

[drifter_driver]

as they say a picture tells a thousand words......Drifters kick a***

 

enjoy

 

p.s. the aircraft in the video was VH registered with appropriate endorsements

 

 

[bilby54]

Hi Tony,

 

An interesting response to an age old problem.

 

What intrigues me is the reason why the original factory Thruster ended up with the angle of incidence set so high as to cause the aircraft to get a fearsome reputation in the first place. I can appreciate that there was an overwhelming rush to get a two seat training aircraft on line but the type had to be approved by CASA so why did they not send it back for redesign in the early stages?

 

On the other hand, maybe Drifter got that part right but ended up with a reasonably docile machine purely due to the aircraft design as a pusher. I had swamp tyres fitted to my Drifter for a while and the handling became much more challenging so it would be interesting to know what the designers were up to (who was watching who?).

 

I did hear a rumour a few years back that it was a political decision, after the HORSCUT enquiry, to get a training aircraft in the air but it may have also been that there was no one in CASA qualified to test an "ultralight".

 

Would the Thruster have been better accepted by the general flying community if it had been better developed?

 

Cheers,

 

Bill

 

 

[Guest TOSGcentral]

Hi Bill,

 

Re A of I. The basic design is a difficult question that I do not know the answer to - only have some glimpses of.

 

Originally I opined that the ridiculous A of I was involved with fuselage orientation for drag reduction in cruise. The type had enough drag as it was so any was worth getting rid of.

 

As readers will be aware the A of I has a large bearing on cruise drag. As you increase airspeed and reduce A of A the fuselage becomes increasingly nose down so is being pulled through the air at an angle. Hence why the introduction of reflex flaps that effectively change the A of I by changing the wing camber.

 

This was not really applicable to the Thruster and the early two seaters were essentially 'one speed' aircraft. So I assumed that the factory had optimised them for the one speed they generally flew at and stuff the landing habits!

 

A bit later on though I had it from a guy who was around the factory in the early days that the real reason was a lot more banal. It was simply to give the aircraft a bit of a nose down attitude at its normal flying speed and therefore give a very slow aircraft the illusion that it was up there with it and not wallowing around.

 

Bear in mind also that while I personally do a lot of wailing about the A of I the Thruster can be 3 pointed neatly anyway! The problem is that it takes a lot of depressing time to get the knack and a huge amount of aircraft have been badly damaged in the process of learning how to do it. Far better to get the aircraft right in the first place and while the Thruster will always be a full blooded tail dragger it can be tamed more than it currently is.

 

Why the factory did not do this I do not know. But I would guess it was wrapped up with re-design cost. Just saying 'lower the wing front spar mounting bracket' sounds simple when you say it quickly! There is after all plenty of room and the fitting is essentially simple in design.

 

But in fact there may only just enough room and the fitting has had to be hugely beefed up to take the 'lop eared' shape it now has to get the leading edge down as far as possible. It was a sod to design and a nightmare to make - plus you need a full machine shop to make one.

 

I had the prototype in my hands again on Monday and still had to leave it behind due to a last minute snag that came up. I have a T300 pulled apart in my own workshop ready to take the new bracket and was really hoping to be test flying it this weekend.

 

But even when we have got this one right it will still be something of a compromise. To do the job really right the entire front end has to be re-designed as the challenge is not actually in the bracket but in the geometry of splay of the cockpit front A frame. So possibly Bill it was just too much for the factory and the aircraft were selling so well then who really cared?

 

At present I have a feeling in my water that I will meet the design target set and we are going to have a much more practical and easier aircraft out of it - it will certainly be even stronger! But I am still going to carry on and put a reflex flapperon setting on it to help more with cruise as the Swifts are targeted for 70 knots at good economy with a 582 and the T500 BMW powered Swift should be really something!

 

Your last question - acceptability of the Thrusters? I do not think it would have made much difference in the early days - the demand was just too great and both Thruster and Drifter (which came out hot on the heels of the first 95.25 Gemini) were flat out keeping up with that demand.

 

It would have made a huge difference later though! By the time demand was beginning to stabilise the Thruster already was gathering it's reputation of being difficult if not impossible - a situation fuelled by how many had gone in on EFATOs or loss of control on the ground. The factory lost inertia and went to the Receivers.

 

Some efforts were made and it was most disappointing that the two attempts to return to the single seater market (the Sprint in 1988 and the T100 in 1990) as the single seaters are a lot tamer than the two seaters so there would have been a balancing in the overall Thruster reputation.

 

As it turned out - by 1993 when I started TOSG the Thruster was already dying and the Glasshouse already totally gone and forgotten. That situation took a deal of turning around in terms of personal money and time but it has been done.

 

The Swifts, and the parts support base they are already generating, in conjunction with the Vision factory coming on line again and a revitalised UK Thruster factory, plus the operational and maintenance support from TOSG, means that there is still a good further 25 years in the marque.

 

One of my saddnesses in how AUF has developed is the move towards an 'evolutionary' mentality or expectancy when the purpose of ultralighting is essentially static in nature and original obectives. Re-inventing the wheel is today becoming a very expensive exercise and a fruitless one when you already have proven wheels that work well in the form of both the Drifter and Thruster.

 

Aye

 

Tony

 

 

[Yenn]

I have never flown a Drifter, so this may not be a problem, but how do you work out your attitude with nothing in front of you to relate to.

 

Good to see that Tony agrees that it is possible to 3 point a thruster. I tried wheeling mine on once and decided I didn't like it, so all of my landings were 3 point, unless they were 6 point.

 

 

[Guest ozzie]

Can anyone run their Thruster down the strip with just the tail wheel on the ground?

 

If so, can you pick it up without putting the mains on the ground?

 

Ozzie.

 

 

[seb7701]

Ian,

 

simplistic as it may sound, you can judge your attitude in a drifter by using part of the windscreen in relation to the horizon. After a while, however it just becomes a subconscious thing that doesn't really require much thought.

 

 

[bilby54]

Hi Ian,

 

Ask most pilots how they judge the landing approach from their favourite aircraft and most will not be able to do so. Put them in an unfamiliar type and they can usually relate the attitude and visual perception quite well.

 

Seb is right when he says that "it becomes an subconscious thing" so landing a Drifter is no different to getting used to landing any other aircraft type, it just takes a bit of time to get used to the lack of visual attitude clues.

 

Cheers,

 

Bill.

 

 

[Guest coolmango]

Driter

 

This has been an eye opener. I am learning to fly in a drifter.

 

Until I read it here about judging the attitude in a drifter. I am now thinking..

 

Certainly is now just a natural thing. So now in my next lesson, I am going to be aware of it. I wonder if it is going to make a difference .. My subconscious may never be the same...

 

 

[Guest Juliette Lima]

Hi Coolmango,

 

For some thoughts on Attitude flying in a the Drifter, you might care to visit the Drifter thread .

 

Cheers

 

JL

 

 

[Guest ricardo]

Can anyone run their Thruster down the strip with just the tail wheel on the ground?If so, can you pick it up without putting the mains on the ground?

Ozzie.

No Ozzie, I don't think you could do that in a Thruster - if you've got the airspeed to lift the main wing up, at that angle of attack you'll be flying away from the ground - if you try to hold the tailwheel on the ground, you'd be trying to hold it on the wrong side of the drag curve, probably in the middle of a stall, in which case you'll almost certainly come a cropper as you'll lose directional control. The angle required is just too extreme. Are you about to tell us you can do that in a Drifter?