Building the new Bushbaby SAFARI

[Oupa-G]

This work on the gear fittings was done by my son Vliegvark he can transfer computer drawings onto the CnC machine.The parts are at the anodisers and when you see them next time they will be gold-yellow to fit in with the colour scheme. His standards are very high, the way it should be. As I always say we are Non type certified so we can make it better then the store built aero-planes. My paperwork is finished and the manual is of to the CAA. I have incorporated a DVD with all the relevant reading material that an aircraft owner would like to read which will make him a better pilot and operator of his aircraft. The NET is such a wonderful source finding the data is sometimes difficult if you do not have the correct search phrase. The manual must contain all the required paperwork for a safe and legal flight. Incorporating modern electronic logbook keeping without adding mistakes. The testing overall went well and I hope the CAA fundis are positioned towards this "Bosvarkie" I see that the site has reached more then 93000 hits. FIFA is still cramping our flying but that will also pass. The future design will incorporate the new bigger SD cards that can be read by most netbooks . All small computers cannot always read DVD's. We now have lekker SD cards that can hold all the data and it also fits into the Voyager to do the flightlog transfer etc. Then on the topic of carrying certified copies,I believe it should not be necessary to carry certified copies. We are honest people and if an inspector feels that the documents are not real then he is in the ideal position to check and nail the fraudster. We are just honest aviators.

The production of handbooks and the contents of the handbook will evolve. We are going to improve on this as the critical eye moves on and works with the document. If we are critical with judging weather and all other aspects of aviation then our safety will also improve. IT is internal discipline that improves safety and the safety culture. The rules guide us and they must be such that it becomes easier rather then more difficult. If the microchip can help us and we print hard copies, we can move away from old tippexed logbooks full of mistakes. It must be fun.


Cheers Oupa-G

[Oupa-G]

I feel ashamed not writing for almost two weeeks . One must not make excuses but I'm allowed to explain. I was busy making radiators exhaust do the final paperwork for the Bosvark, had new saddles made for the under carriage to bring the center of the axle another 17mm forward I will explain this in more detail, meanwhile the new exhaust in the jig was screaming in my ears please weld me and meanwhile I still do a 9to 5 job. My trike has been standing in my workshop for the last 6 months with no attention and then via the grape-vine I hear that other potential Safari owners are blowing their tops because nothing is happening, people must just realize I'm doing this for fun I have only put money into this project , and it is all I can do no more. But all the paperwork is done I have written a handbook that will be open source and people building and doing their thing will be able to use this as a framework. Diesel-Dog you are welcome to use it and the Safari with the Rotax engine will also slide into its format. The handbook was written in easy to read format and the data in it is what a potential pilot can use. We must remember that not all aspiring pilots have many hrs and are sometimes also not very current. The hand book fills this niche in the back there is a DVD disc with data on lots of subjects as well as the Excel file to do the weight and balance. Just fill in the moment arms and weight an with the press of a button its done. I hope this will help I'm awaiting the comments from CAA and then its all yours. I have to do a bit more moaning to get it of my chest, for months I have been cropping photo's writing it all takes time the only thing that console me that the biggest moaners do nothing so they are not open to to any dangers of criticism. That's all I love writing I love sharing my knowledge and I will continue to do so and if you disagree lets discuss it.

So here comes the reason for bringing the axle centers further forward. Lets compare the taildragger with the tricycle gear, lets imagine the extremes. The taildragger with its wheels so far forward that the elevator cannot lift the tail, if the angle of attack is 12degrees the aircraft will run along the runway and as speed builds up the wings start lifting and she will fly, when you come in to land and the lift diminishes you end up with a tail heavy aircraft, of course the CoG must be right. With the nose wheel aerie if the wheels are so fare back that the elevator cannot rotate the aircraft she will happily go through the fence at the end of the runway. So the design is always a balance. The taildragger must not nose over when it strikes softer soil (beach). The nose wheel aircraft must be able to rotate without having to yank it of the ground at to high a speed. Some of the earlier Zenairs 601 had this tendency but that has been corrected. Most of the Executive jets run with a negative angle of attack and need positive rotation the Piper Chieftain also liked its positive rotation. That is enough for this evening I'm still suffering from a bout of flue I was in bed for 4 days the longest I have been ill, I'm still spluttering along, my hip replacement was easier. I'm going to bed and will then edit this page and add the Photo's in a warm bed on my little netbook. Later in the week I will talk on the aerial tuning but to-morrow evening I will have to watch the Dutch playing, I did not know I had so much orange blood in my veins.


Cheers Oupa-G

[JACO]

I am impressed !
Some of us "want to" an some of us "CAN"

[Tailspin]

Now this is really Cool
Nice finished off Fittings and some really good welding

Yes i concur

I am impressed !
Some of us "want to" an some of us "CAN"

[Oupa-G]

Things are moving all the stagnation measuring giving orders chasing things are now all getting together. The first exhaust out of the jig is stunning , to-day received and fetched the radiators with all the changes that I wanted they have done a superb job. The paint is now black and is to beautiful not to build into an aeroplane. Enclosed some photies on the trimming of the aerial and eventually cut of 5 cm and have perfect tuning for 124.8. Today visited a workshop with wonderful rolling benches and discussed the rolling of the spring gear I'm making another gear with a slightly different geometry reducing stress points. On the Whisper they had some stress point problems. Got some fuel consumption figures from the Whisper 5000rpm 80 mph 7litres/h My net is very slow I've been told some cable is broken.



Cheers Oupa-G

[Oupa-G]

I have had some questions on the springsteel gear. Here is my honest opinion, the answer is no . The Bushbaby is a draggy aircraft she is a 100mph aeroplane and definitely not a Reno racer. But for the average weekend pilot with low hours and not always current, may only fly 30 hrs a year what a wonderful machine. I enjoyed making the gear and the challenges. Our final product is stunning the brackets turned out very nice. For the average builder the conventional gear is doing a fine job. If I had the Titanium available as the Russians have I would still go for the rolled gear. If I had to build another aircraft it will be the Safari fuselage a wing more conventional with flaps and ailerons to reduce drag , a rolled gear for aesthetics. a BMW motor and I would cut weight drill holes and leave out anything not helping. But the MGL Voyager definitely stays.

I will revisit these thoughts would also like to hear from other builders


Cheers Oupa-G

[Boet]

Lyk Beeeeaudifull!! Oupa moet bietjie Borstol of Olino vat vir die hoes en die stem. Smaak vreeslik kak, mar dit help!! Lekker dag.

[Tailspin]

Oupa-G

How much would you charge me for one of those exhausts ?

[Oupa-G]

Tailspin of course I can make an exhaust. What do you want to use it on and the position of the silencer box etc.

Cheers Oupa-G

[Tailspin]

Hi Oupa-G

Want to use it on my BMW motor on the Sunbird.
once the Sunbird is Flying i will fly over and have you make one up for me.
going to be making a new Cowling and all that too so a few changes to go.

[Oupa-G]

The weather has descended on the fairest and is busy filling the water reservoirs. Was privileged to do an ILS in George and in Cape Town in the early mornings of Saturday. I had a young co-pilot who remarked that it was so beautiful to come out of the cloud and see the runway at George, the lights are then even more beautiful. I was getting ready to execute the missed approach when the lights appeared. My co-pilot's comments were that that was the lowest approach he had flown. We broke cloud at 400ft and the limit on runway 11 is 300ft so there was a full 100ft grace. To day I'm going to make the audio link between the MGL Voyager and the Icom 210. That is all for today.


Cheers Oupa-G

[Oupa-G]

Sunday treated the day with rest had a afternoon nap and I'm much better for it. Got some other paperwork up to date watched the telly saw my favourite team being beaten by better play by the Spaniards, and if somebody plays better they deserve to win. Today was hectic at work our flying ban was lifted and Ystervark flew in the cold post frontal weather. I have to wait again for the final paperwork from CAA. Keeping my fingers crossed. Thats all for tonight


Cheers Oupa-G

[KFA]

Hi Oupa, I am glad you brought up the subject of the spring gear versus the conventional bungee gear. I for the life of me could and never will understand the argument about the spring gear types being better than the standard system. The spring gear might look better and is slightly more aerodynamic but the weight penalty is huge, and like you piont out, these aircraft are not reno racers. The Grove gear weigh's in the region of 13-14kg if I remember correctly and the standard gear weigh's 6kg and on top of that the spring gear systems need supports welded to the fuse and that weigh's another 3kg.

Between me and Rick we have done over 1000hr's in Bushbabies of which 300 of those are in training aircraft and we have never even bent an axle. We had worn bushes and bearings but nothing ever bent. The secret lies in the bungee tension. You should be able to rock the wings without the wheels lifting of the ground and you will see the bungee's flexing and working under the plane. If this is done correctly you will never bend anything.

One thing that is absolutely worth the time and money is fairings. We have proved it time and again that cleaning the aiframe up has a lot of advantages. The plane if faster and burns much less fuel for a given airspeed. DZI is case in point. She used to burn 17l/hr at 85mph now she burns 13l/hr at the same speed. That is a huge saving and I think worth the effort. So spend your time on making the frame more efficient at the normal speeds rather than trying to build that reno racer.

Fly safe guys and thanks Oupa-G for sharing all your knowledge.

[Oupa-G]

I promised to do accurate reporting, if you don't do that this site is not worth looking at. So far we have had 96000 hits and we may even touch the 100,000 I'm awaiting the paperwork from CAA and then I will report on longer flights and fuel consumption etc and places that I will visit. The only thing I will say pro my spring gear the aerie looks sexy. But not worth it.

I will still put on wheel spats and further cleaning up and then lots of flying.


Cheers Oupa-G

[ZAZU]

Oupa, KFA and others....

The issue around fairings on these aircraft should never be to increase the speed. You can never make a F1 racer from a 1970 Beetle by putting on more fins.

But, having said that, the aerodynamic boffins will tell you that the drag from a round tube, say 25mm in diameter, is equal to drag of an aerofoil with SEVEN to EIGHT times that diameter
My knowledge about Aero D is limited, but common sense tells me that, by putting fairings on the lift struts and landing gear, the amount of overall drag is hugely reduced. Drag roughly increases with the square of speed, a small increase in speed results in a large increase in drag.
Remember, any decrease in drag will always come with a penalty (weight), but on this aircraft the benefits FAR outweigh the penalty. I believe when fairings were first introduced to the Bushbaby, the guys gained between 8-10 mph on there cruise speed. For an aerrie only doing 80-90 mph, that is a gain of roughly 10%. . In Aero D terms, that is light years

I know, I said you don't put fairings on to gain speed. a 10% increase in speed is huge, but the difference between 85 and 95 mph is not earth shattering. THE BIG GAIN IS IN EFFICIENCY AND ECONOMY OF THE WHOLE OPERATION. Hope this make sense....