kasper

2 hours ago, Geoff_H said:

Not limited to one engine but just try to get a two engine light aircraft registered with RAA, eg Cri Cri, just can't happen!

Twin engine is only within 95.10.  For that you need the wing area limit to be met so you are correct - a cri cri will never fit within 95.10 due to inadequate area for the more. and twin engines means it’s outside 95.55. 
 

nothing to stop twin engines in 95.10 … I recall a lovely little flying boat with push/pull engines in the 90’s. 

3 hours ago, Mike Borgelt said:

Interesting. No good for RAAus as not a recip. Also Basic Med does not allow turbines in Australia.

The cao 95.10 and 95.55 do not exclude turbines. They refer to engines. 
 

95.10 does not limit to 1 engine and does not require a propeller so they can be jet. 
 

95.55 experimental/Jone built/kit requires 1 engine and 1 prop so turbine like this is ok. 
 

Cost to buy and LPH might not be raaus friendly but they are possible. 

12 hours ago, spacesailor said:

Hirth 3202 motor goes well. McCulloch 4 cylider 2 stroke is a little over powered, and very thirsty.

The two cylinder HALF VW, is just powerfull enough, & Super thrifty on fuel.

The Rotax 503 had to have ' lead weights ' put in the nose for C B.

Remember that tail draggers are ' tail heavy ' 

While, nose draggers have the .motor pushed forward to accommodate the nosegear. Meaning heavier pilot accommodation.

( pilot weight goes to rear CB ).

spacesailor

 

Sorry spacey - you are 95% wrong on your description of tail heavy and engines pushed forward.  Tailwheel airfraft are never 'tail heavy' and the engine on a nosewheel is rarely moved for balance reasons. 

The CofG range that is safe in relation to the wings centre of lift is exactly the same regardless of undercarriage configuration on an airframe.

The issue on ballasting (or mass relocation) dependent on undercarriage design is in relation to the distribution of the undercarriage mass around the CofG.

In all cases the main legs and wheels are the greater mass with the tailwheel/noseleg being a less mass.

When you move the heavy main legs from in front of the CofG to the rear of it when changing an airframe from tail to nose landing you need to offset this by moving mass from behind to the front ... and you do that by taking a tailwheel mass and replacing it by the noseleg.  It is quite often the case that the nose leg mass on a short moment arm is around the same total moment as the lighter tailwheel mass on a longer arm and you end up with no net balance adjustment required.

Some designs are not so lucky - and the lighter and smaller the design the more likely it is that the landing gear changes will require reballast or other mass adjustments.  In some cases this is by choice done with an engine move as it stops the empty weight growing as much but thats a choice.

Engine placement on really small and light airframes is more of an engine mass issue - the Hummelbird has a design engine mass with the half vw  of 29% of empty being enigine and that engine is a long way forward of a very small CofG range

the 4 engines you mention for the Hummebird vary the engine mass by up 25% either side of the half VW ... if you are comparing those configs of Hummelbird you looking at are moving the location of the engine on the Hummelbird not due to landing gear config but due to engine choice.

36 minutes ago, turboplanner said:

  I wouldn't expend too much effort thinking about it. It was gossip in 2006, so old man's talk. It didn't sound too bad for RAA then, but today RAA has shrunk into a single company with an office in Canberra, and as you've pointed out, important sectors of RAA are not receiving the focus they deserve. The people who are operating unregistered are not doing themselves any favours because when the inevitable collision or crash into a town occurs they will be taken out of the skies. Their efforts would be better applied reshaping RAA to represent its roots and separating it from GA at the dividing line of LAME maintenance.

GA has operated as an autonomous group since the inception of aviation and fly much more closely together in GA airspace than RA. The top end of RA is already knocking at the door of GA airspace with less rules and compliance and that can only lead to difficult times ahead when things go wrong.

However, whilst this is the object of that company bunkered down in Canberra:

"6 Object

The Company’s object is to pursue the following purposes:

(a) the advancement of aviation in Australia including to take all actions howsoever connected with the design manufacture of all and any machine object device and/or concept that relates directly or indirectly to the advancement of flight whether powered or otherwise whereby such flight is under the control, supervision or participation in any degree by human activity, and

(b) to encourage training in the art and science of aviation, piloting, operation, design, manufacture of aviation and/or space craft of whatsoever design and capability."

We have bugger all hope of refocusing the direction of travel.

It includes unlimited weight, unlimited classes, covers powered and unpowerd flight and explicitly includes spacecraft - this is the core problem - we have a company with an unlimited scope - if it is not directly attached to the earth its within their possibility and they want it all.

Add to that the rusted on instructors/agents for aircraft sales that are involved in the company and you have, from an old school ultralight perspective no viable ability to have any voice heard at all.  Ever.

I'm a compliance minded person so I am still within the playpit of RAAus BUT there is only so long you have have the sand kicked in your face and any toys you like taken away before you walk away and decide there is no longer a passtime (not a sport) of ultralight/recreational flying that has any attraction.

And if they want to hand over up to 1500kg that means then the four seat GA come after 2 seat GA ... wonder how much leveled up will apply to training and maintenance on that one within RAAus ...

4 hours ago, Geoff_H said:

Howuch is a Hirth F23?

 

I can’t say now.  Contact them in Germany as there is no OZ agent

http://hirthengines.com/2-stroke-engines/

mine was second hand NOS and I built an aftermarket ignition and carb setup.

Mine was a bare spare core from an abandoned drone program I was involved in many years ago … its a lovely engine as are the KFM107s. 

47 minutes ago, Kenlsa said:

I have just completed the above survey to get rid of the stall speed limitation so I can fly my Colt under the RAoz banner.

 If I may urge all owners and potential owners to respond positively to it.

For those who have articulated a reluctance to increase the stall speed, remember, it is NOT COMPULSORY that you alter your aircraft in any way, all will stay ‘as is’ for you.

Ken

It may not be compulsory ... but the evidence from the past two releases of the tech and ops manuals from RAAus shows that everything is leveled UP to the highest degree that they have coverage of ... as soon as type cert airframes over 45knts are in the pool what the hell hope is there for the few of us left tinkering around with self designed self built single seat aircraft? 

Already I find it ridiculous that RAAus completely 'forgot' about a whole control type and now not only do I have no biennial or medical reqs for one group of airframes but the CAO was modified without care and now that control group is not covered by the CAO at all throwing several airframes reg into question and one of my half built projects parked up due to no registration path at all.

By all means be positive about something that will help a few more people and airframes get lower cost flying but be aware you are getting this at the cost of others on the other end.

And I'll be open and frank - I do not fly RAAus coverage airframes outside by RAAus reg and cert ... BUT I know of several beautifully maintained airframes that continue to fly outside of reg and cert of pilots simply because the whole CASA/RAAus admin and control became far too much for their fun flying and I can completely understand where they are coming from - its just I have not taken the step outside the system that they have.   

Edit - this is not an attack on you Ken - its the system and progression on control that is getting worse in my opinion.

5 hours ago, Geoff_H said:

One of the problems that I have in converting to a single engine is "which engine".  The original idea of this design was to build an aircraft that could be built for under $10k using tools and equipment that could be easily borrowed or used by 'friends'.  The two two stroke engines cost $4k.  They put out around 30hp together, each weighs just under 10kg.  They have 600mm props and operate up to 6000RPM.  So to keep the weight down, to maintain less than 45kts stall speed I need a light 30hp engine that is reasonably light including and drive speed reduction for a single prop that will have to turn at a slower speed ( still have to do the calcs on this)

Your options are limited.

Second hand out of production engines that fit your need:

Rotax 277 single pot two stroke = 27hp (in my experience ponies not horses)

KFM 107ER or ERMaxi = horizontal twin two stroke - electric start and 25-30hp (in my experience horses not ponies) - 24-25kg installed (I have 3 of these engines)

Current production

Hirth F23 = horizontal twin two stroke - electric start and 50hp (in my experience horses not ponies) - 26kg installed (I have 1 of these engines - best engine BUT expensive)

Beyond that you are looking direct drive high prop RPM with model engines or if you can get hold of them military drone engines ... I have 5 former drone engines putting out 26hp and are only 15kg including prop - but they are sinning the prop at near 6000rpm

I cannot think of any viable 4 strokes ... but given you are looking to replace 2 x 2strokes with a single staying 2 stroke should be OK for you.

Cheers.

5 hours ago, Geoff_H said:

Ok you have me.  What is category A?

Spacey is once bitten VERY shy ... he built what was supposed to be a 95.10 registered airframe back in the early 1990's and when he was finished they had changed 95.10 to introduce the wing load restriction and he was caught out.

The easiest thing with RAAus it to understand single seat has two possible paths limited by either wing load or 45kts stall in landing config.  Work out your MTOW wing load and either eliminate or consider 95.10.

All of the procedural steps are then within the Tech Manual and given you mihgt have a half built airframe call RAAus and talk to tech as they can accomodate their processes to suit the case in hand eg moving from GA/SAAA build to RAAus build part way through. 

RAAus tech  are very approachable and talk plain english.

Cheers

If you go RAAus then with a single seat aircraft you have two paths with 3 end points:

1. engine = two options for rego:

    a. Stall speed 45kts or less wing area unimportant => CAO95.55 covers you and you get 19- rego

    b. Wing loading at MTOW 30kg/m^2 or less and you can alternate to a. => CAO 95.10  can cover you and you get 10- rego

2. 2xengines = 1 option for rego => Wing loading at MTOW 30kg/m^2 or less => CAO 95.10  can cover you and you get 10- rego

95.10 is the only current RAAus rego class that allow multi engine/multi prop/jet propulsion BUT you are limited to single seat and 30kg/m^2 at MTOW

95.10 does not work for efficient little single seaters because it gets caught with the MTOW wing load => not enough wing

95.55 does not allow jets or multi engine or even 2 propellers from 1 engine - but allows any wing area so long as stall speed is lower than 45knts at MTOW

14 hours ago, Arron25 said:

I did an hour in a Thruster with my instructor..to learn tail down, before I bought Soni. After doing my certificate in an LSA55, the shock of going from a trigear with an acceptable glide to a high drag with brick tendencies without power was frightening..

Needless to say only did the power reduction ONCE... 

Did the rest of my tail training in a 582 Lightwing, and Soni

Awwww.

The fun of learning in a two seat thruster is the power off performance - its the reason there used to be a need to have an AUF training for pilots from GA ... no inertia, all the drag and minimal airspeed between cruise and stalled brick was and remains a very different set of demands on pilots.

Still, if you go back to the thruster now that you can handle a tailwheel you might find it a lot of fun ... and a T500 engine out at MTOW can be handled quite safely in full power off safely into a unexpected paddock outlanding.  Plus there is less to worry about in a thruster outlanding - you know where you are arriving - its underneath you 😀

Instructing on thrusters, drifters and LSA55 Jabs back in the day was always fun and meant you got a wide range of experience, throw in weightshift and skydiving and my 20's were a lot of fun.

I think I’ll go for kph for my single seater … it’s not fast and every little helps 😛 it does nearly 80k/h in cruise. 

On 7/2/2022 at 8:22 PM, FlyBoy1960 said:

You wont fit the Sapphire

Leave the lid off and 6’2” fits in the sapphire … but 105 is a tad high for them … 

a 95.10 sapphire legally can carry 105kg but you’ll need to ballast the tail and accept curve of the earth climb 😛

8 hours ago, kasper said:

Brief be12

 

Bloody spell check!

Brief be12

Cost of training ... for me in the mid '90's training on Jab LSA55s I paid $105/hr when training and $90/hr wet hire after license.

I did my AUF certificate in 10 months Jan-Dec of weekends and had the pax and cross country for around $5,775.  With inflation that would be $10k today.

The flying school still exists today (Dave at the Oaks) and is even using the same airframes (plus new ones) but the hour training/hire rates for the LSA55 today are lower in real terms than in 1999 - $170 training and $140 wet hire.

9 minutes ago, skippydiesel said:

Agree!

 

Foreign/heavily accented english of any origin (even the UK) must be discouraged when communicating to/from an aircraft. Aviation english is the international standard that we should all aspire to (including Stralans).

Yep, Stralan English was always fun with my calls in the UK ... particularly as my plane was G-CCZR ... that "Charrrrleeee Charrrleee" (as the English heard it) was always getting me a smile.

But the most fun was the French lady who came over the radio after by inbound call to Abbeville with a correction ... "French Language only please" ... she probably regretted that because my French position calls after that were in even more mangled French than my English ones 😀

You can supercharge a two stroke if its using a second pumping piston of greater volume than the firing piston.

For my dream list on supercharged spark ignition two stroke engines that have actually flown I would take the Bernard Hooper stepped piston engine ... 580cc v4 = 30kw/40hp in a flying engine water cooled at 18.9kg.

Give me two of those on a slippery two seater ultralight with a belt redrive and I will be happy ... a LongEzi with these as a set of twins would be really nice or one of them on a sapphire ... 27hp cruise on 7LPH of avtur sounds nice 

They are spark initiated two stroke diesels with wet sump.

If they work out reliable then good'ish news but at US$25k not looking to compete with Rotax but instead the Lyc-a-Conta-saurus

Doors of size “x” when you need “x+” is not a design fault.  It’s a procurement failure on the part of the Australian military and/or govt. 

if the manufacturer said they could/would redesign to “x+” and they didn’t then that’s also a procurement contracting failure - we failed to make sure it is +
 

general serviceability is always an issue for military hardware.  It’s expensive to buy.  Expensive to maintain. But has to be available.  If the airframe was unable to meet serviceability levels with specified usage AND that was in the procurement process then manufacturer might be responsible.  But if it’s not it’s on us. 
 

now if the real reason is that a slightly smaller capacity more robustly built machine that our military has decades of experience with is easier to change to and achieve the serviceability and availablity requirements then continue with them then the decision to scrap early and replace is probably the right decision

Wing radiators/surface radiators were used on the Supermarine S5 with the lion engine from napier

From memory

Corrugated upper surface radiators for the engine coolant were built onto the wooden wing

Corrugated surface radiators for the oil were on the rear fuselage sides aft of the cockpit

Fuel tankage was in one of the floats - and that float was offset from the centreline by a different distance than the non-fuel filled float

The S6/6B used Rolls Royce R engines (the basis for the merlin) and added more surface radiators for engine cooling on the floats as well as the wings ... also think they extended the oil radiators on the sides forward of the cockpit

A quick google will probably prove my memory faulty but that wat I 'member

7 hours ago, Methusala said:

Earlier Drifters (Maxair I think) Had a weakness below the engine support strut. Casper could know more.

If that's me I can only add a little as I only looked after 1 drifter and spoke to Wayne F on what to look for and care for when he delivered it remanufactured/overhauled to this back in the 90s

The maxair and austflight drifters do not have a weakness as such at the engine mount to fuse tube BUT that is a stress point AND a corrosion point.  

The folded metal floor is rivetted to the fuse tube along the tube length and Wayne was clear that the thing to watch was any streaking from a fretting rivet from stressing in that area.  That was the point where you needed to unrivet the sides to inspect the tube for stress cracking which you couldn't see with the sides on.  From Wayne the issue was that once a rivet started fretting it was a moisture trap for corrosion in an are where cracks from rivet holes were at a high stress point along the tube. 

Never had to strip one down because there was never a need whilst I was working on the maintenance or instructing in it. 

I’ll just stick with cruise at 55% power on a fixed pitch prop that at sea level is properly set up to absorb that power at that throttle setting and has WOT that is exactly per the graph.  
 

and anyone who thinks the minimum/proper cruise power setting is well over 75% can have the fun of finding out all the bits of the engine that need work when run at high power.

I’ll just keep plodding along on a half hours engine that exceeded its years life nearly twice but issued bugger all oil and has compressions that are unchanged in the last 200hrs and 10 yrs.  

I can’t say thousands as I’m only a weekend flyer.  The engines in all the raven 912 eclipsR trikes have performed perfectly for the past 20 years and there is no history of issues.  Only know that because I worked at the factory building them for years and flying them as an owner.  
 

we set that engine / prop combo up and it works. 
 

As for overpower I’ll agree.  But you tell me what 50hp 4 stroke engine was available 20 years ago that would sell to the market?   There wasn’t and the market was anti-2 stroke so there was and remains no option except the 912. 

1 hour ago, skippydiesel said:

That RPM setting for continues cruise would concern me - Rotax 9's should be run at about 5200 + rpm

I would BUT for the fact it’s a trike and it’s been propped to that power setting. 4300 by the book burns 11lph when the power is fully absorbed.  The aircraft burns 11lph when cruising at 4300.  The prop is correctly set for the rpm.  
 

thw result is that it’s burning the correct mix and it’s ok.  The 912 in this airframe goes for hundreds of hours and never misses a beat.   The only failure I’ve had on the engine was a failure of 1 ignition unit - and that was found with ign check at 3000 😛

if your engine is burning the correct fuel for the rpm your prop is set to the correct cruise.  
 

on the raven you simply can’t run 5200+ because the airframe is coming out of the top side of the drag bucket above 4300 … all it does is make you exhausted holding the bar or make you climb at many hundreds of fpm.  Cruise climb at 4600 gives over 500fpm at mtow … I’m not going to run it any where near 5200