Building the new Bushbaby SAFARI

[grostek]

Hi Papa G

I hope you are soon out and about and pain free.

Thank you for a very well written description of your method of finding a suitable engine.

Lookng foreward to more of the same.

Kind regards,

Gunter Rostek.

[Boet]

Ja, ek kan sommer hoor dit gaan al klaar stukke beter met hom! Namiddag met Oom gepraat.........en hy was besig om sy kieries se handvatsels te modify We had a helluva busy day. The cold front moving thru, left us shivering in the cold. At least we had some rain, but we could only start on the glueing once the temperature started getting a bit higher.While it was too cold to start glueing, I used my time productively, and sold another BB-kit. Both leading edges on the wings are now on, and after some minor finishing will be ready for covering. Meanwhile we made a start on covering the fuselage. See pics. She is now really starting to LOOK the part.

[Oupa-G]

Boet hoe gaan ek slaap. To all of you I have had zero pain I came out of Hospital Sunday morning . For six weeks I will have to take care of the hip. Meanwhile I'm writing and also working on the website for what is to follow tomorrow night . There is a small competition on with Boet Esteban and Willem's covering and my writing. As soon as the fuselage and wings are covered I will come to Loeries with the scales to get final figures so that the CoG can be 100%

See you Pappa-G

[Oupa-G]

Choosing an engine:
The first requirement is mass production. After a serious search all pointers showed in the direction of the new OIL COOLED BMW engines. The older generation BMW engines were also purely air-cooled as the air-cooled engines mentioned earlier in the project column.

Here are some basic differences in what we now shall call the OIL HEAD.
The engine heat dissipation is 70% oil 30% air.

The 30% air-cooling is over the cylinder barrels and sump fins. This is easily managed with conventional baffling in a puller configuration. This will be perfected in the Safari and should be adaptable on other aircraft. In the open engine like a trike it suffices to just have the open-air approach.

The 70% oil cooling is achieved by a separate oil system. This means this engine has a separate oil pump that circulates the oil through suitably placed oil cooler, the pressure in the system is only the internal resistance of the oil cooler and pipes so essentially an open system with the return to the sump. This oil pump serves the same purpose as the waterpump on water cooled engines. Now we know that water and oil do not mix well. So using just oil sort of makes sense. The calorific values of these fluids is a matter of engineering. Oil will function very well for long periods at 120C

The circulation capacity under normal operating condition is 20L yes twenty litres through the cyl heads. This is the big difference with what I call JUST AIR COOLED. The engine still has a normal lubrication high-pressure oil pump for the bearing lubrication etc. In the air-cooled engines this oil circulation is also pumped through relatively small oil cooler.

So with the 1200GS engine we have an oil-cooled engine thermostat regulated Formula One type of engineering. Well balanced with balancing shafts and at a reasonable weight. Everybody has been asking for the weight and here it is:
Engine complete with Gearbox throttle bodies and oil cooler
70.5 kgs
This does not include the exhaust it does not have an extra oil tank or extra water radiator fittings if we are comparing apples with apples of a well known brand X

Practically this means you start your engine by the time you get to the end of the runway for take-off your engine is at operating temp of 50C.

In the next session I will discuss the fuelling and ignition control of the turbine smooth
Power plant. Please keep questions till later as I will be covering most topics in this little mini soap opera for aircraft Junkies. Lekker flying Pappa-G
Ps. my undercarriage is doing well I’m looking forward to the final drop test.

[Boet]

This makes a lot of sense. Using this engine in the place of "brand X" will make flying affordable again!! Today was once more bloody freezing cold. NOT good weather for glueing fabric on. Afternoon saw a bit higher temps, so we could then cover the other side of the fus and the fin. Starting to look more like an airplane. Meanwhile Esteban was very busy making all the re-inforcing patches and finishing tapes. Hopefully tomorrow will play the game weather wise.

[Oupa-G]

The engine management system;

Here we broke away for the BMW controlled system for the following reasons.
The generic bike system is excellent but designed for the road and the modern parking and stealing environment. The original system has a transponder key, no proper transponder key no running of engine. Actually the system is designed to stop the engine, side stand out stop engine etc. Now every pilot I know is allergic to stopping engines in the air even a slight cough running a fuel tank dry has the ability to change the shape of your throat.
So the bold step was taken to make our own EMS engine management system.
Fortunately my household is littered with electronic engineers and not sommer such lightweights. My daughter married an electronic engineer sommer nogal a heavy one with a PhD in electronic engineering and he has this wonderful attribute he is crazy about flying. He fathered the EMS and then also went through the labour pains to eventually produce what is now known officially as the E-Boxi.

His name is Otto Strydom. He wrote the software, designed the hardware, the circuit board is made in Cape Town and we do not have to go on our knees to BMW or some imported black boxes. It is 100% South African made by a critical thinking high powered South African brain his name is Otto, no relation to the Otto cycle in the Four stroke engine. There are a lot of programmable EMS’s but their quality and running stability equal primitive doorbell electronics. I tried them and when the timing light stops your engine and the system needs a reboot you know you are on the wrong track. When transmitting on the radio stops your box is also not a good start.

All the test flying was down as actual airtime in my trike it has done 230hrs and in Jan’s trike (vliegvark) 100hrs. Enough for tonight I hope you enjoyed reading this. Tomorrow night it will be on the redundancy philosophy strongly influenced by successful aircraft like the Cessna Citation on which I have close to 2000hrs in command and the wonderful PC12 which is a single engine with severe redundancy built in. This cross-pollination had a very strong influence in the development of the E-Boxi and the whole E-Boxi redundancy. The E-Boxi was designed to keep on running, and in case Mr Murphy had some other ideas we decided to have two of everything. 100% redundancy. This has not been done in light aviation.

Greetings Pappa-G

[grostek]

Hi Pappa G,

What a wonderfull effort.

First of all I want to congratulate you and your team on an outstanding contribution to the local aviation scene.

Not knowing any better I thought from reading Vliegvark's previous posts about the building of his trike and then the using of the BMW motor that there were a couple of real "boer maak n plan" type pf blokes making do with limited resources.

From reading your articles I see that you have put a think tank in place , a development plan in place, a testing department in place, a design review departmet in place, chosen your component suppliers and sub contractors with care.

These departments may not have doors as yet but the systems are in place.

Having worked in the Auto Industry in Europe and having been in charge of setting up a satellite component production facility in Portugal I can only applaud your efforts and professionalism displayed.

Any of the big 3 motor manufacturers in Europe would have similar systems in place for any new developments.

I can see that a well designed ,well researched, well tested product is soon going to be available to local aviation enthusiasts and further I predict it is going to be a world class leading product.

Kind regards,

Gunter Rostek..

[Massimo]

More Pappa -G,

Please keep the information flowing, the faster the better. I have been seriously bothering Jan lately asking many questions about the BMW as i now need to make a final call on a motor, so the more info the better.

Thanks once again for your soap stories, as its gives great comfort to hear the thinking and processes behind the develpopment of a new application.

And i want to join you guys up in the swamps when you go tiger fishing so i need to get the skyjeep finished soon....

Ps: I want to say that i visited the Vleigvark family at their home earlier this year to look at the whole BMW issue and the work they have done is impressive, the quality is good and i love that gearbox, im getting very excited....

Cheers
Massimo

[Oupa-G]

Dear Gunter
Thanks for the compliments the design philosophy is reliability reliability and again reliability. You know I've had an operation and I'm recovering well. So now I've started writing on what we've done . My aim is similar reliability as the Prat and Whitney in the PC12. We are working on a slick website for the Eboxi with instalation hints tips on crimping. I have been in research for 30 years with the University the result is only the correct way backed by documentation so that if something out of the ordinary happens you know why . For the second pickup we created a additional 60-2 pickup on the flywheel. In the two seperate Eboxi's we even try for the vital processers to be from different origine. We are very serious I have funded everything sofar from my private funds part of the reason building the Safari was to have a good platform for testing. We had a lot of input in the developement of the Safari. Most of the details will be covered in my articles. The main ingrediant is Otto's Brain he has worked on satelites intel chips and lekker high powered electronics. He is a very practical man with no arty-farty ideas . Every signal is recorded on the scope documented etc. It was all done in our own worshop in the evening and weekends The most powerful ingredient sofar was no pay fired by enthusiasm. Difficult to beat even by big companies. Boet is working hard to finish our Bosott (Safari) As soon as th cover is on the final CoG will follow and then the Engine Mount.

Keep well Pappa-G

[Oupa-G]

100% Redundancy:

How was this achieved? Very easy of all the critical items have two.
Two plugs per cyl standard on the 1200GS
Two injectors per cylinder
Two fuel pumps electrical 4 Bar (the diesels have 1500 bar one pump)
Two separate fuel filters and pre filter and main filter
One battery optional two batteries
One alternator
For around the world non-stop one would have to apply a slightly different redundancy capacity
How does it all work?
You start up on the backup system, which is energised by the battery
So the battery is tested and the filters and the pump and the injectors and the spark plugs.
The alternator is brought on line and then you switch to the primary system.
Under normal running conditions the alternator keeps the battery full the 1200GS has a 600w alternator that is 50A compared to brand X, which is very limited.

Should there be a problem in the primary system you lift a gangbar this will switch off all unnecessary equipment like recognition lights and any other useless systems that homebuilders so love to clutter there aeroplanes with forgetting all non-functional items must still be carried aloft.
Once the gangbar is lifted the engine runs on E-Boxi #2 on the battery. B
After your scan you can check the status of the alternator and if OK bring back the alternator and fly home to check the primary system. If the alternator has failed the capacity of the battery will decide how long you stay aloft. If any major trans-oceanic flight are planned brush up on your PET (point of equal time) and PNR (point of no return) and this will be the deciding factor. Remember the system uses 5amps so a normal 17amp bat that is commonly used will give you a safe 1.5hrs .

Something to think about

Cheers Pappa-G
My name is going to change to Oupa-G with respect to the late Geof Cronje who passed away he was an engine Boffin and his name was Papa-G. At least we are in good company. If anybody was upset it was totally unintensional Greetings Oupa-G

[Boet]

Todays progress.

[Boet]

Nog n paar.

[grostek]

Very, very neat,

Great covering job.

Kind regards,

Gunter Rostek

[Tailspin]

Hey Boet

Your covering is looking almost as good as mine

Very nice sir.

[Guest]

Does the system use 5 amps including the fuel pumps ?

Would one mechanical and one electrical fuel pump not be better alternative ?

How does the torque on the BMW compare to the 912/914 brand X?