CAA Certification on the UFO Gyro

[mak]

Well done Pierre on your perseverance, hope to see you both at Alldays

[Jean Crous]

Hoe vlieg die UFO met die "nuwe" stert

[MPL Pilot]

Hi Jeantree

Johan is happy with the progress, he says the UFO does 90mph with no effort. No funny behaviour like the submarine rudder it had on previously.

During a flight test on Wednesday afternoon, Johan did a power off landing, and had to use all left rudder to keep the gyro in a straight line, which
prove that we have some more work to do on the tail position.

Heat under the cowling is still a problem, we will give it some attention this week. The oil cooler will be moved to a position with more
airflow. The oil temp in cruise is 90 deg at current conditions, might be a problem in summer.

Pierre

[MPL Pilot]

We are back in bussiness again!
Johan, back from holiday and some of the other projects that has been eating time, we will sort the last of
the heat issues under the cowling and then we can start the conversion
It has been a year since we started with this project, I have learned a lot (patience and then, a little more patience)
I take my hat of for Johan, he has a plate full of test flights (some of them not worthy to be tested) they are scary.
Presure from all sides with Braam and his gunship, Danie at Bethlehem, Jaco in the Cape, Jaco at Harties, Roux from where ever, Mark from ??? and all the guys flying in from Tedderfield needing TLC! and then the earocopter want it's share as well!!
Not to mention the commersial endevours Johan has his fingers into.
We could have done this in 2 weeks max, but then I would not have met all the other great fellow pilots like Garreth, Jan, Riaan, Jadri, Josef, Heu, Richard, Francois
and all the others that I can not think of now.

We are almost there, the UFO missed some of the fly ins, but rather safe than sorry. Johan is very safety concious and I appreciated that, when he was under pressure with commitment, made the right decision and stuck with it, it was the right decision both times.

Once we have this last little things sorted the UFO will be seen often.

Fly Safe

[Low Level]

Nice perseverance Pierre. It pays off - ask Frans. He really enjoys the Sycamore after almost giving up.

[MPL Pilot]

For everyone wanting to attempt what we have been up to with the UFO, here is a lesson to be learnt concerning heat
on the exhaust when a turbo is fitted.
I suppose JVL will be able to give the technical speech on what happens when you change from normaly aspirated to turbo charged on a
engine, to me it was a great learning curve. Now I have a better understanding why aircraft is very expensive... its called "DEVELOPMENT"

Long story short, new stainless steel pipes (ceramic coated) will be fitted at the end of this week, if all comes together as planned.
The two previous exhausts had a lifespan of 5-7 hours each, if the stainless steel exhaust fail, we will test inconell and afer that
titanuim and then heyns.
At least we have some options open for development

With all the trouble shooting we had, there is less trouble to discover

Watch this space, almost done

[MPL Pilot]

Everything came together on Saturday.
New exhaust fitted, made from stainless steel, ceramic coated to preserve the stainless and keep the heat where it
works best. We added heat deflectors, which is not on the photo below, all the cables, water and oil pipes stay
at a touchable temp. We are moving forward, I trust that anyone doing the same type conversion will learn
from our experience.

Next step would be a UFO conversion for Jan Ludolf who will give me a conversion shortly after he recieved his.

JvL is satisfied with the preformance of the UFO in flight, has flown 13 hours now. We will keep an eye on the
stainless exhaust, the working temp is between 800 and 850 deg celsuis, depending on the power setting.

Till next time

Fly safe

[OzGyro]

Hi Pierre

Just out of curiosity, what sort of HP and Torque figures is the current engine configuration producing?

Cheers
Darren

[MPL Pilot]

what sort of HP and Torque figures is the current engine configuration producing?

I can not give a simple answer for you question, but will try to explain.
Torque and hp does not give a clear indication of power output, since we use thrust as propulsion.
Depending on the reduction drive and prop configuration with power available = thrust.

The UFO need nothing less than 260kg static thrust with the 33ft rotor blades and all up weight at 5000 ft
above sea level for safe flight.
This 2L Subaru fitted with the turbo produce enough hp/torque for static
thrust of 320kg without effort.


Cheers

[OzGyro]

Hi Pierre

I am a little lost in your answer, do you really believe knowing the Hp and Torque figures does not give a clear indication of the thrust output one would expect to achieve? I beg to differ. True there are many other variables that will affect the final thrust achieved, prop pitch, prop diameter, blade configuration, reduction ratios etc. However the fact still remains you need a certain amount of HP and Torque in order to even attempt achieve the final thrust you will require. I firmly believe its adventageous to know where in the rev range the engine produces the most power and at what revs it produces the most torque. However if I am wrong I will stand corrected.
The standard version of the EJ25 puts out approximately 165Hp, the newer version of the EJ25 with variable timing puts out approximately 180Hp (Both non turbo). I have owned several homebuilt gyros all exclusively Subaru powered, Single seater with an EA81 (80Hp), Single seater with an EA81 Turbo(125Hp approx) and a two seater with an EJ20 (110/115Hp approx). I was just curious to how the motor you are using compares thats all

Cheers
Darren

[MPL Pilot]

I am a little lost in your answer

Darren, that's understandable

This particular engin can deliver anything from 208hp to 280hp and 300Nm torque and up, depending on the application.

We do not need that much power on the UFO. Our aim 260-280kg static thrust and low engin rpm in cruise.

[OzGyro]

Hi Pierre

In the never ending quest for knowledge, just wondering if you can explain to me as to some of the possible reasons/causes as to why the exhaust system on your gyro glows cherry red and if memory serves me correctly even the turbo housing itself. But please remember to keep the answers SIMPLE

Cheers
Darren

[Magnifan]

Hi Darren, I'm going to try and keep this very simple, they get, like hot hey?

Of course, the more complicated answer is that the electrons in the outer valence positions of the metal are excited into a higher quantum energy state. When they fall back to a lower quantum energy state they emit a discrete amount of energy in the form of a light photon. The the frequency of the photon released is dependant on the energy gap from the one quantum energy state to the other and determines the colour of the material as witnessed by the human eye and is dependant on the temperture of the material.

[Gyronaut]

bliksem Magnifan.
... and you get all modest when I tell people you ARE a rocket scientist!

[MPL Pilot]

Magnifan, where were you when I needed you?
How would you explain torque and hp, then convert it to useable thrust?

Never mind, I am confused already

explain to me as to some of the possible reasons/causes as to why the exhaust system on your gyro glows cherry red

EGT at 5000rmp is 820 deg celcuis.