Superpup/Aeropup

[Brett]

Well the wings are going ok and have also just received the engine from Sonex. Came in a nice packed box with excellent instructions and a really good dvd. All I need now is a fuselage kit to bolt the motor onto and life will be sweet ;)

 

 

[Mark]

Good work Brett. I have just about done all I can do on my wings until I get the fuselage in July. I have my Aerovee motor half built with the crank case together. This weekend I plan to have the barrels and heads on and and the flywheel and electrics together and it will be all done.

 

Mark

 

 

[Guest Curandero]

Ducky, after putting on a 42 to my 2200 jab I cannot get more than 2800rpm on take off blowing black smoke.I get 90kts at 2600 which would be OK except that I hear that the engine should take off at 3000 and cruise at 2800. So... have ordered a 38 and hope it doesn't turn out to be carby problems because the carby has been inspected and seems quite OK. Any advice anyone? The engine is still under 100 hours.

 

Curandero

 

 

[ducksrus]

Curtandero, I currently have a 42" fitted which gives me 2650 max static rpm (full power ground run up) and about 2800 max rpm flat out in level flight. This is fine with just me in the aircraft, but recently when I had a 95kg passenger as well and near max weight, it used alot of strip to get off the ground. I have purchased a 38" prop from jabiru which I get next week, so this should give me much better rpm and thus more HP produced, for a slight sacrifice in cruise speed, so takeoff and climb should be much better at higher weights and hot / high days.

 

Having talked to jabiru, they say that the engine should be run fairly hard anyway, so will let you know how my figures and performance come in.

 

I recently fitted the latest jabiru carby needle & jet kit so the engine is running more rich but no black smoke though. i think that kit will also be more suited to higher rpm with the 38 " prop.

 

I have just ticked over 50 hours on my aircraft now and all is going well so far (still got a few radio problems though).

 

Will let you know

 

regards

 

Ducky

 

 

[Guest Curandero]

Thanks Ducky, seems a similar story. Don at Jab said my prop was 'skidding' (does he mean cavitating?),and the lack of revs with hard work was causing the richness and smoke. Still the 2.2 should be cruising at 2800 for the sake of the engine. I'm offering my 42 for sale in the next magazine.

 

Curandero

 

 

[Guest Curandero]

And Ducky, I had a stbd tank leak which I tried to fix with a 3M sealant but guess what.....yesterday16/6/08 it was leaking again. I can only assume that, since the tank was leaking at a baffle weld, that the weld was so bad that it has over come the very expensive goo that has held seal for a few months now. Some times I get verrrrry frustrated.

 

Curandero

 

 

[ducksrus]

Hi Curandero,

 

I was a bit worried about the aluminium welds craking over time with fatigue and vibration, so I put on a coating PR 1422 B2 aircraft tank sealant externally over all welded areas prior to installing the tanks, so far no leaks. You may want to look at using a tank sloshing compound which coats the internal surface of the tank. This would require wing removal (not too hard to do) and turn the wing all over to allow the compound to coat the entire inner surfaces. Spruce & specialty sell the stuff but you may be able to get it within Aust also. may be worth a try. How did you get access to the tank to apply the 3M sealant ?

 

JC has now added the external sealant idea to the revised manual since I told him what I did.

 

On a different note, my 38" prop arrived the other day so I fitted it and went for a fly.

 

I'm not totally satisfied as am still only getting 2700 rpm max static ground run which is only 50 rpm more than the 42" prop. But I am now getting 3000 rpm flat out straight & level and I can cruise at 2750 - 2800 rpm which gives me about 85 kts. Overall performance is a little better but I guess I was expecting a bit more.

 

All the best

 

Ducky

 

 

[Guest Curandero]

HI Ducky, couple of things. 1 Already did the wing off slosh the 3M inside (which was slow like honey),and it held for about 3 months. JC recommended Senkit from Aviaquip which would be a 2 part mix cement to plaster outside /over offending weld. CRC have a 2pak product for aluminium repair and I have asked JC if he knows of any objection to that as I expect the Aviaquip product to be more expensive since it is for aviation. Am currently flying on the port tank.

 

2. Been getting 95kts with the 42 but to gain the 13litre/hr economy have to go back to 2550/2600 which is not ideal for the engine. Malcom Millard at Kadina says I should put solid lifters in place of the hydraulic ones and that would fix the valve problems which he assumes will be the cause of the performance probs. Well that's abridge too far at the moment. If the cement doesn't fix things this time I am going to ask JC for a replacement tank that was not made by the guy who assembledWelded the present one

 

Curander

 

 

[Brett]

,

On a different note, my 38" prop arrived the other day so I fitted it and went for a fly.

 

I'm not totally satisfied as am still only getting 2700 rpm max static ground run which is only 50 rpm more than the 42" prop. But I am now getting 3000 rpm flat out straight & level and I can cruise at 2750 - 2800 rpm which gives me about 85 kts. Overall performance is a little better but I guess I was expecting a bit more.

Ducky do you thing perhaps something like a 54 x 44 prop from Sensenich may give better performance in cruise????

 

 

[Guest Curandero]

Brett, Kevin Frost took my Aeropup for a performance test when it had the first 38 and got: climb out 70kts @2800, Cruise2800 94kts Max 3000kts @12.3L/hr plus some stall figures.

 

Also there is a shock absorber effect said to exist in the wooden Jab sourced props. Is the Sensenich wood or something else

 

Curandero

 

 

[Brett]

From what I can gather from their web site they make them out of wood,carbon and metal but I was thinking wood when I posted that last message.

 

http://www.sensenichprop.com/sen_html/propeller/jabiru-adv-4.pdf

 

,, this was just a bit of a chart about what props they have supplied for the jab motor on different airframes. Worth a read I thought.

 

 

[Guest Curandero]

ok.. finally have the 38 prop in place, crc'd the tear in the tank and did a 3.5 hr trip from Balaklava to Hawker (SA) and back. At2750rpm I got fairly constant 94kts with14.7 Litres per hour and it (the engine) sounded happy. I will need to find a way to test the carby as the engine runs rough when the throttle is pushed to the max on climbout.

 

Curandero

 

 

[ducksrus]

Curandero, I may be able to help with the rough running problem as I experienced the same thing after I fitted my 38", which I thought was an out of balance prop. An owner from Mallacoota also experienced this. Previously, I had fitted the richer carby needle, needle jet & main jet as per the latest Jabiru SB. After climb out when I retarded the throttle I would get what appeared to be an out of balance just as I would retard the throttle. He suggested going back to the original (leaner) main jet, which I did and it fixed the vibration, so I am not sure why but must have had something to do with the mixture (this problem only happened with the 38", not the 42").

 

I have since experimented with a combination of both props and both main jets (225 & 245) and at the moment I have gone back to the 42" prop and the 225 (leaner) main jet. I also did thrust force checks with all above mentioned combinations and there was hardly any difference (124 kgs of thrust) between the 38" and 42" props full throttle static. Thats why I am a bit disappointed in the 38" prop as I was expecting more, although flat out in flight I am able to get 3100 rpm with the 38" vs about 2900 rpm with the 42".

 

On another note, I am interested that you can get 94 kts with the 38" prop at 2750 rpm. Do you have your wheel spats fitted ? I don't. 85 kts seems to be about all I can get (thats at cruise power).

 

Ducky

 

 

[Guest Curandero]

Hi Ducky

 

1 what is a Jabiru SB?

 

2Regarding the carby, It had the same needle as before when I had a previous 38 and behaved quite well giving litres per hour in the 13+ range. When we put the 42 on the revs were poor and so we pulled the carby to pieces and rebuilt it without any changes. You know, it may be something as simple as too much reach on the cable. Any way the plane is due for a big hourly and oil change etc so we may address the problem then.

 

3 No I don't have the spats on at the moment but am considering doing so now that I have some airspeed statistic with which to compare. do you have a fuel management system to tell you what litre/hr your engine is pulling? I now cruise at 2750rpms to keep economy under14. this is my problem.... I used to get 13.5 with the previous 38. Sometimes I wonder if the props are not exactly what they say they are i.e. how do we know they are what they say? they may vary from prop to prop. we can't know.

 

I will make enquiries prices re a leaner needle and then experiment. But as I said, the same carby used to deliver 13.5

 

Thanks

 

Curandero

 

 

[ducksrus]

Hi Curandero,

 

Go to the Jabiru aircraft web site, click on Service Bulletins, then engine SB's. Have a look at JSB018-1, it has all the information about engine tuning and some history of carby jetting etc. My engine came new with the "economy tuning" jets and needle (the main jet was a # 225), but I then bought and fitted the recomended richer jet and needle kit (the richer main jet is a 245).

 

Yes I do have a Mizer fuel flow guage fitted so I can easily see what my FF is. When I had the economy jets fitted, my FF was also about 13.5 lph with the 42" prop. I then fitted the richer jet kit and it went up to about 15 - 16 lph at cruise. I then fitted the 38" prop (with the richer jet & needle kit), thats when I had the vibration. so as I mentioned I then refitted the 225 main jet and it went away.

 

The reason jabiru introduced the richer needle & jet kit was in an effort to stop some of the burning valve problems owners were experiencing, so be carefull not to run it too lean, if you do, I would suggest you do a cylinder leak down check every 50 hours as an indicator of any potential valve problems, that's what I plan to do.

 

Jabiru recomend that their engines be run hard i.e cruise rpm 2800 or above.

 

Anyway, I hope all of the above makes sense.

 

Regards

 

Ducky

 

 

[Guest Curandero]

Thanks Ducky. I'll be putting the spats on next week to see if there is any difference. and... when I get some time I will look at the SB you recommended. I am having a good time at last with my Aeropup. Next major adventure will be flying into controlled airspace to travel coastal to a town south of Adelaide as I live north of . I also had my first bad weather confrontation recently and went through the should I's shouldn't I's and eventually turned back, lost a day but kept my life. so these things help mature one.

 

Curandero

 

 

[ducksrus]

Curandero, great to hear you are enjoying the Aeropup, as I am. Iv'e got 60 hours up now and the furtherest I have been so far is Orchid beach on Frazer Island (I fly out of Caboolture). I plan to soon start spreading my wings further within Qld & Nsw. What strip do you fly out of ?

 

Ducky

 

 

[Guest Curandero]

Hi Ducky, well I joined the Balaklava Gliding Club -a half hour's drive from my home in the Clare Valley. It hastwo 1.1 km runways and I get to land on the grass which is good for props and helping increase my ability to land at the speeds which keep me out of trouble ie 60kts.

 

Apart from nav skills, I imagine that long trips could become quite boring solo. One thing I really like is having another aircraft alongside. Also I am fortunate to have met some great people like Frosty, Malcom , Graham and James of Bushman fame. These fellows have helped me so much and I feel much in their debt though they would tell me to get real because they help because they enjoy doing so.

 

I'm up to 75 hors in the Aeropup now.

 

Hasta la vista

 

Curandero

 

 

[Brett]

hey guys,,, just butting in here but was wondering what did you use to debur the inside of the wing spars tubing?

 

 

[ducksrus]

Hey Brett,

 

I didn't deburr the holes on the inside of the spar tubes. i don't know of any easy method of doing so. Out of interest, does the manual say to do that ? I can't remember.

 

regards

 

Ducky

 

 

[Brett]

nope but Lew mentioned it to me the other day while i was on the phone ,,,he just said he uses a deburring tool of some sort and didnt think to ask what one ..

 

 

[ducksrus]

Yeah, I did deburr every other accesable hole but the ones on the inside of the spar tubes are inaccesable. I you find out an easy way to do it, let me know !

 

 

[Mark]

Hi Ducks, and other Aeropup builders,

 

I wanted to ask is there any good reason for making the port side panel hinged rather than being fixed like the starboard side? I guess it is intended for access to the back of the firewall and the rudder pedals but I question is this needed once the plane is built? My concern is that it may take a bit more work to make and I thought a good chance that it might become a bit untidy over time for little advantage. Any thoughts?

 

And if you are looking for a destination in NSW you can drop in here at Inverell. I have plenty of room in the hangar at Warialda (YWRL)if you want to stay over.

 

Regards,

 

Mark

 

 

[Guest Curandero]

Hi Mark. Due to my 5':6" height and the long travel of the factory rudder pedal I needed to modify. Side entry a must. I needed to relocate my throttle and choke - side access a bonus. Everything from repairs, modifications even cleaning is done better with a side entry.

 

Curandero

 

 

[Guest Curandero]

Mark, I had a property called "Glenelg" near Bundarra. I have great memories of Inverell, and our band did a big gig at Warialda Rail pub in the 80's. I also have a friend at Gilgai so I will keep your invitation in mind as my 'pup is a goer now

 

Curandero