JG3

I used Solaguard on old perished skins and the result was really good. Looked like new and now protected somewhat from UV.

The good quality exterior water based house paintss work well on Dacron fabric. Stick well and are very flexible. Clean the fabric first with spraying thinners. Sounds vicious but doesnt hurt the Dacron at all.

I use the vertical compass already in my Garmin GPS when displaying the HSI page. Works really well and easy to read and not influenced by magnetic effects. Another benefit is that it shows actual track made good, compensating for drift. I use it nearly all the time.

Could I please get some more info from you JG? Any recommended brand / type, mixing ratio etc. I want to paint the plane hopefully this summer. Probably white with blue trim. I don't have details about brands and ratio of hardener. I just go to a good paint shop that supplies the automotive respray market, and tell them what I need to do, and they should know the best combo. They tend to be experienced professionals as distinct from those that supply the domestic market.

Automotive enamel with hardener added. Sticks well, covers well, light weight, good gloss with hardener, easy to touchup, low cost. Fairly impervious to fuel with hardener added.

1800hrs over 16 years. All recreational, no commercial training.

That's not static; it's 5800rpm wide open throttle straight and level, just as Rotax recommended and their charts are based on. That puts me at 5200rpm at 60kts best climb, and 5100rpm for best cruise right at the top of the Rotax torque curve between 5000 and 5200rpm. Not pitched fine at all, just correct by Rotax recommendation. I found static to be not a consistent base line for props comparison due to cavitation and whatever effects at no airspeed, straight and level far more consistent. Fuel consumption at WOT straight and level is 26 litres/hr.

JG3 you have a few errors ! TECHNICAL DATA FROM THE ROTAX BOOK max continuous performance : 69kW at 5500 RPM. fuel consumption at max continuous performance : 25 litres per hour. **** specific consumption at max continuous performance is 286g/kW/hour **** premium ULP caloric value ~ 46 MJ/kg, so translates to 13.15MJ/kW/hour, efficiency about 3600/13150 = ~ 27% probably +/- 7 % depending on how you value the weight of the fuel, the calorific value of that specific fuel etc Yes, I realize that Rotax publishes 25 litres/hr, but I do not get anywhere near that consumption in real life. I get 20 litres/hr at max continuous of 5500rpm when pitched at 5800rpm WOT. Tested and retested many times and calibrated and rechecked my fuel flow gauge many times. Long ago I did fuel flow calibration using a calibrated container and stopwatch at various power settings and airspeeds and t/o weights, several times over. These results were very consistent and matched the gauge readings. Those results were very interesting and I'll post those them on another thread presently. Then several times on Xcountry trips I checked that calibration on three hours legs and refilling from a metered bowser. A couple of months ago I did a 30.5hr trip and carefully logged all fuel used. Flying all the time at my usual leisure cruise at 5100rpm with prop pitched at 5800rpm WOT, which gives a speed of 80-83kts at 2500 QNH carrying my usual load, and fuel flow indicating 17 litres/hr. Total fuel used was 520 litres so that gives an average for the whole trip of 17 litres/hr. Can't get much better check than that..... It's the real life results that I seek in all my testing. I take testing and analysis very seriously. I've studied the factors involved and tried to make all comparisons as valid as possible. As for the thermodynamic efficiency, I concede that my estimate may have been overly optimistic.... That efficiency for car use on the road with varying speeds is usually estimated at 25% so I upped it for continuous operation and good Rotax design.... Maybe too optimistic.... So that means that even more waste heat has to be dissipated......

I do need to step in here and try once again to clear up some misunderstandings that are being tossed around. First of all, if an aircraft is pitched to 5500rpm wide open throttle (WOT) straight and level, then 5500 is no longer max continuous, not at all, it's now wide open throttle full power and is limited to 5 minutes! I guess I need to try to explain that.... The max continuous specification for an engine is not governed by the revs but rather by the amount of power being generated. That max continuous power is limited by the ability of the internals of the engine to dissipate heat away from such items as exhaust valves and pistons. The thermal efficiency of a Rotax at constant rpm will be better than a car on the road, but still only about 35% for the carbureted version. That means that only 35% of the energy in the fuel being burned goes to driving the propeller while 65% of that energy needs to be dissipated as heat. About half goes out in the hot exhaust gas and the rest through air cooled cylinder walls and liquid cooled heads. But the critical part is getting that heat away from the internals exposed to the fire and out into the cooling medium. Imagine a poor little exhaust valve with all that super hot gas going by and only the little valve stem to carry away the heat and through a layer of oil into the valve guide. That contact can only carry away heat at a limited rate, and the recommended max continuous is based on that conducting ability. At the Rotax recommended max continuous of 5500 when pitched to 5800 WOT, I measured fuel consumption to be about 20 litres/hr. That's as much fuel burn and thus heat as Rotax recommends for continuous operation. When pitched to 5500 WOT and then flown at 5500 I measured the fuel consumption to be 26 litres/hr. That extra 6 litres/hr is a lot of extra heat to be dissipated, and why Rotax recommends only 5 minutes at that power rate. The torque curve published by Rotax is based on WOT 5800rpm, and the top of the torque curve is between 5000 and 5200rpm. That's what they have determined by dyno testing to be the most efficient operating speed for this engine. If pitched to 5500 WOT then that curve will probably be very different. I measured the fuel burn at Rotax's recommended max continuous to be 20 litres/hr when pitched at 5800 WOT. When I pitched to 5500 WOT that 20 litre/hr showed to be at 5200rpm so 5200 should be the max continuous in that case. Fuel burn is a very dependable indication of power generated so I am very confident in these results. No doubt Rotax's recommendations are conservative, but are you comfortable exceeding those recommendations in your engine??

Wandoan, Qld airstrip 17 Aug 21.

I sure wish that I could delete those old ads that have sold months ago. Surely it's not that hard to make it that clicking 'Complete' could delete the ad. I won't be adding more ads until I can delete when I want to.

It's easy enough to post the ads. Surely we should be able to delete when we wish to. Could be made possible under the 'Edit' function.

I have found the Classified section to be very useful for selling items and has potential for much more. Is there any way to delete those items that have long since been sold and now labelled 'Completed' or 'Expired'?? They clutter up the list and make scrolling tedious......

Please do let us know what works the best, if anything.....

Try WD40, that works for doubles-sided tape residue.

I have two sets of unused plans myself, 701 and Affordaplane. No way I'll build either and no way I'll pass the plans on.

I wonder how many plans that were purchased never end up as a completed aircraft??

Warm water means active crocs, lots of them......

Sunset 21 June 2021, shortest day of the year, as seen from the Sunset Tavern, Karumba N Qld. Great place to be this time of year. JG

Have a look at the new map now. Much more useful this way I think.....

I've had a look thro the old map and most is already duplicated and updated on the new one. I'll go right thro the old map and add any info that's not already on the new one. I'll also mark airfields with a different colour where fuel is an easy? carry of a jerrycan.

Don't know how I mussed Dunmarra, I've fueled there a couple of times. On the map now. Sandfire also now on the map.

Leongatha no longer supplies mogas on field.

I've now updated that map with the new suggestions and highlighted the airfields with PULP on field by orange markers to make it easier to find them. https://www.google.com/maps/d/u/0/edit?mid=1HDxCTbbdJ7DiSSakAVEBsIzGCrg&ll=-27.40189582364664%2C133.53847499999998&z=4 Check to see if I've missed anything. Sure would be good to make this map easier to access. OZRunways did ask for a copy and I sent it to them but don't see it used... That would be the best site for a link to be displayed for easy access when you would most need it.