skippydiesel

Latest news.,Bert Flood inspected the oil pump housing and found a discrepancy in the seat of the pressure relief valve as compared to a new one so they sent me a new one to try and glad to report a 90-95% improvement.instead of large fluctuations of between 20 and 60 psi i now have a small vibration type fluctuation of 2-4 psi which could be caused by an air bubble somewhere.

That's great news, however you should not have a "small vibration type fluctuation of 2-4 psi" - damping by the sender/gauge should take care of any tendency for this sort of low level oscillation.

 

 

You will only "blow off" at 1.2 bar if it reaches that pressure/temperature.If the engine runs perfectly well and not hot, then I don't think you will see much difference.

Rotax probably upped the pressure to prevent very hot engines "dumping" the coolant.

I like your logic/reassuranc

 

 

If your cooling system is working fine and the old cap is holding pressure, why change it? You probably know, the reason for pressurizing the cooling system is to raise the boiling point of the coolant. Take a look at this article Things you should know about coolant | hellafunctional As long as you have the correct mixture of "antifreeze" and water your .9 BAR cap should be fine. So why did Rotax recommend the change? You'd have to ask Rotax. Good luck in getting any info out of them."If it aint broke don't fix it"

Yeah! that's kind of the way I feel. Due (about 30 hrs) for its 5 year rubber (carbi, hoses etc) replacement might try the new radiator cap after all the new stuff has been fitted.

 

 

Hi Peter,

 

My prop is a compost, 2 blade, ground adjust. Static balance & pitch adjustments fairly easy to do (with the right equipment).

 

"......new prop,.................... my static balance proved good enough so that I didn't have to change any weights."

 

This seems counter intuitive. Would have thought a new prop would have needed a fresh Dynamic Balance.

 

 

Hi Peter - very interesting & informative.

 

I started from a different perspective - I was pretty happy with my static balance and perceived vibration but as a self confessed obsessive, I wanted more/better.

 

Did a bit of research - service providers/ cost / accessibility and availability and ended up wit SuperAir, Armidale ( I just happened to me visiting friends in Moree, NSW, so a small diversion to Armidale, worked in very well.

 

The results were very pleasing but hardly as dramatic as your problem vibration at a certain RPM.

 

 

Thanks Rick - By chance, I checked out Kingoonya on Google last night and saw that the airfield is right on the edge of the settlement - don't think there was mention of a fuel station, so your info is great news.

 

 

Hi Peter,

 

I agree with "... it is not necessary to run the engine at cruise revs...," If the revs you choose are the ones (range) you want the balancing to be most effective in.

 

However most pilots will be looking for a smooth cruise.

 

Static Balancing & accurate prop pitch adjustment (for CS & ground adjustable props) will give benefits throughout the RPM range. This is a prerequisite, if you are to get any benefit from Dynamic balancing.

 

Dynamic Balancing does not claim to remove all anomalous vibration, at all RPM's. It is all about reducing vibration within a chosen RPM range, hence my choice to go with my cruise RPM range. There may be benefits higher & lower (as was the effect in my case) but this is not particularly looked for.

 

I have difficulty with "....takes just 3 runs of about 30 seconds: one run to get the base data, one run with a trial weight attached and a check run with the final balance weight."

 

True this would be the minimum runs required, but I suggest not typical of a well done dynamic balance service.

 

In my case, from suspect memory, a total of five runs were done certainly more than three. After the base data run - 4 more, each refining the last, until an acceptable reading was achieved.

 

The aim to achieve an acceptable reading under .14 IPS (inches per second) and usually to less than .07 IPS. at your chosen engine/prop speed with the MINIMUM of additional weight added.

 

 

Hi Rick - have checked out the location of Mt Ive Station. Thank for the info/recommendation, looks good. Bit south of what I am trying to investigate. All good "grist to the mill".

 

At this stage can afford and must keep an open mind as to my eastbound track.

 

The track I have provisional made is:

 

WA - Serpentine / Kalgoorlie / Forrest. SA - Oodea / Glendambo / Rawnsley Station NSW - Broken Hill / Ivanhoe / Forbes / Camden

 

The bit that I am finding it difficult to research is the Forrest / Oodea / Glendambo / Rawnsley Station / Broken Hill section.

 

Oodea would be just a bladder relieving & leg stretching stop, with the possibility of transferring fuel carried in bladders.

 

Alternate to Oodea, would be Maralinga, if allowed to land, or one of the other bush strips along the railway line, such as Kingoonya

 

Glendambo has the potential to provide ULP and accommodation - if I can make contact .

 

I would plan to leave the railway line in the vicinity of Woomera then direct to Rawnsley

 

Rawnsley Station has the potential to provide ULP and accommodation and possibly an extended stay to check out Wilpena Pound.

 

Broken Hill, I think its fair to assume good and plentiful supply of ULP

 

The rest is the home Utrecht and back on familiar territory

 

Narrowing this down, what I real need is some comment on fuel availability between Oodea & Rawnsley Station. If I can find a usable airstrip close to ULP that secures the "leg" in question then I can hope for a safe flight.

 

In the absence of some other intrepid flyer having flown/willing to comment on this rout, I will start from scratch and check out each possible location for a landing & ULP.

 

 

......... I am considering a permanent small "vibration" meter for the panel............" It would be interesting to know what meter/cost you manage to find.

 

".......... I am capable of imagining things and would find a meter .reassuring when flying over tiger country. ......."

I think you probably echo the thoughts of many a pilot, while over the dreaded "tiger country".

 

 

My two bob's worth. The track Forrest, Ceduna, Broken Hill is almost the same, within a mile, of the Forrest, Glendambo, Broken Hill track. The track via Ceduna puts you much closer to active airstrips like Nullabour, Ceduna, Whyalla, Port Augusta, Port Pirie and Peterborough. If you track via these points you will only add 19 nmiles to the track and be closer to road and population.

Good advise Col - my plane was to make my outward bound trip E-W

 

NSW - Camden / Griffith / Mildura, SA - Port Pirie / Ceduna / Nullarbor, WA - Caiguna / Kalgoorlie / Serpentine.

 

Originally going to return W-E same way but the desire to see different country and Poteroo's advice:

 

"........The small amount of 'frontal' wx is usually moderate intensity, fast moving, not extending far north from the coast, and gone in a few hours ...."

 

Plus a few other comments regarding the slightly more northerly/inland rout/hospitality at Forrest, etc, has got me interested.

 

I am not in the "game" to be particularly efficient but to have fun/ be challenged and above all to be SAFE.

 

Further the lack of information coming in regarding Forrest - Broken Hill has me intrigued. There are some interesting places on this track eg Rawnsley Park / Wilpena Pound possibly a bit of a longer stop over.

 

 

Overheating while ground running...

WOW!! when I had mine done (912 ULS) it was quite quick. (I am assuming you had prolonged ground runs) They started very soon after I landed, so no need to warm engine. I helped with cowl removal and "tying down" the aircraft. One person fitted the various instruments to the engine/prop, another did a quick check on prop pitch and asked me my preference for best RPM range for balancing (4800 - 5200 engine 1975-2134 prop RPM). I sat in the cockpit and made throttle adjustments on their signals. Each run up was followed by a brief shut down for analysis of readings and weight adjustments. Don't think the whole process took much more than 20-30 minutes. From landing at Armidale to departure - max 45 mins. Take off brought an immediate smile to my face, which only got wider in cruise - turbine smooth.

 

 

..........................I had a bad experience with dynamically balancing my jabiru 2.2 when I lost an exhaust valve-seat due to overheating.

In the end,it was all worthwhile because it led to instrumenting all the cylinders for cht and egt and evening them up.

 

But next time I'm going to do the prop balance in the air even though it will be more work to set up.

Hi Bruce,

 

Can't get my head around your suggestion of a dynamic prop balance somehow being involved with a subsequent malfunction of an exhaust valve seat and the need for CHT & EGT.

 

In those immortal words - "Please Explain" ??

 

You are absolutely correct in saying that an attempt to do a dynamic prop balance in the air will be "more work". A correctly done dynamic prop balance at or within the nominated RPM range (usually cruise RPM) will require several readings after each weight adjustment. I presume you will land for each weight adjustment??

 

 

........... E to W.....fly low, and inland winds are usually lighter than near the coast. ..............Unsealed strips can become very slippery after rain, and it pays to call the roadhouses - but speak to whoever does the refuelling there.............

Hi Poteroo - invaluable advise . Much appreciated

 

Still hoping that someone has advise / information regarding fuel/rest stops due east of Forrest (further down the railway line). The one place I have found on the, almost direct, rout Forrest - Broken Hill is GLENDAMBO Shell station near to bush strip - has yet to respond to my enquiry regarding ULP/accommodation/transport to/from airfield (3 km).

 

 

I think you are worrying about nothing - I fitted the later cap to my old 2000 hr Rotax without any problems and, worst case scenario, the increased pressure might show up a problem somewhere in the system that otherwise mightn't have been noticed. If you have done the hose replacement requirement as per the maintenance manual cant see that you would have a problem.

Thanks Microman - that's the sort of reassurance I am looking for - 2000 hr's without a problem "way to go!"

 

Got to say though - its the "showing up a problem" that concerns me a little. There may be no problem at 0.9 BAT with the coolant pump seal, but 1.2 BAR may be too much for it. Same goes for the radiator. Suddenly life becomes expensive (as always with aircraft).

 

 

Here's a conundrum -

 

Commissioned 2000, 912 ULS 750+ hrs, Third Owner (done most of the hours).

 

Another thread prompted me to check out my Radiator Cap next time I had my cowl off (today).

 

Cooling system has always worked very well. No complaints. All required rubber (hoses etc) replacement done on time.

 

Existing radiator cap 0.9 BAR (13 psi) - possibly never changed (certainly not by me). Cap appears to be in good functioning condition.

 

Rotax manual (and other thread referred to above) recommend replacement cap 1.2 BAR (17.4 psi).

 

I have the new cap but if I fit it, the internal /operating pressure of my cooling system will increase by 0.3 BAR (4.4 psi).

 

I fear the increased pressure in my now quite old system.

 

What would you do??

 

 

HummelBirdFour litres per hour = three litres reserve!, easy out of 18 ltr small tank fill, over-fill is 25 litres.

In the states they say 61 mpg.

 

The more fuel you carry, the faster the HummelBird flies, as the fuel-tank is ahead of the CG/pilot.

 

spacesailor

That's is truly extraordinarily - This is a major "thread drift" but the temptation is too much - I have always loved the look of the Hummel aircraft - real pocket fighters but as in life and most other things, including aircraft, you have to make compromises. I have no doubt you will correct me but I imagine a Hummel is good around the training area and may be the occasional short away trip, supported by ground trans/other larger aircraft and/or accommodation close to the airfield. You can not have much more then toothbrush/change of underpants baggage space. The better 1/2, tent, sleeping gear, cooking equipment/food etc etc must be totally out of the question ????

 

To me the Hummel must be something like a stripped down motorcycle - exhilarating performance on the smell of the oil rag but unfortunately non to practical.

 

 

That's for sure. I'm not sure how many planes have anything over the 45 min fuel reserve with just 15L of fuel.

Hi - I plan at 14L/hr @ 100 knot econo cruise. With "one up" my actual is under 13 L/hr. So my 45 min reserve is 10.5 L (I use 11 L to be sure) without a power reduction. My main + reserve tanks will hold 87 L usable. Duration 6 hrs or 5.25 with reserve. I also carry two 20 L bladders on away trips.

 

The bladders are usually used for transporting ULP from the servo to my aircraft but at a pinch can be filled & strapped into my passenger seat for a total of 127 L (got to land to transfer) for a potential total duration of 9 hrs.

 

 

Hi Mick & Phil -

 

Mick - Quite the adventure. You were very "game" to persist with the journey in the face of headwinds , rain and potentially boggy runways. Thank you for your story. What was your planned air speed/fuel consumption?

 

I take from your comments (without you actually saying it) that continuing east along rail line the from Forrest is a little to far between drinks (fuel). You both divert south to the coast.

 

This may be the way I am forced to go, but as I intend flying the coast on my way west, I would like to pursue the idea of the inland rout for a little longer.

 

So are there any intrepid flyers out there who have continued east from Forest along the rail line ?

 

If so where can I refuel (preferably ULP but will go for the stronger stuff if I must) & stay the night(s)?

 

 

For me & my Zephyr it seems to me that on the return (W-E) inland/railway rout the fuel question becomes quite interesting from Forrest onward.

 

Like Berni, I will be carrying 2 X 20 L fuel bladders - Perhaps fill all my tanks (inc the bladders) at Forrest - land somewhere like Maralinga (if allowed) or Ooldea, empty first bladder - then on to Tarcoola, second bladder.

 

Next available fuel seems to be filling station at Glendambo (would need to check ) Anyhow it all looks a bit (fuel) dry across to Broken Hill, so may have to divert to somewhere like Leigh Creek to get enough fuel for a safe transit to YBHI.

 

My Z is good for about 5hrs @ 100 knts + 1 hr reserve ( 9 hrs if include fuel bladders). This is well past bladder endurance so take off 30 mins for comfort stops.

 

To those who have been here before - what were your fuel stops on the Forrest - Broken Hill leg?

 

 

In planning my, yet to be realised, Nullarbor trip, from the east to west, I checked out ULP & accommodation (will also take a tent) availability and planned legs that I hope would be no more than 2-3 hrs and came up with:

 

NSW - Camden / Griffith / Mildura, SA - Port Pirie / Ceduna / Nullarbor, WA - Caiguna / Kalgoorlie / Serpentine

 

To be honest it never occurred to me to fly a bit further north along the railway line SA/WA. This conversation has highlighted other options.

 

I had sort of assumed that I might take a number of side trips, as the mood/weather/interest dictated, before returning to my main rout .

 

May be the west to east, return trip, could be made further north along the rail line from Kalgoorlie to Woomera and on into NSW . Would need to check out the fuel and accommodation stops along the way

 

Any comments from you much travelled people??

 

 

Hi All,I have just fitted another engine in the Sporty and I found this vibration around 3000 rpm when coming back to idle, you don't seem to feel it as you take off and all the other the other rev rages it is smooth, it is just around the 3000 rpm, the old engine never had this vibration that I have now which seems so strange to me, same prop.

Dieter the L2 has checked everything else and now it seems to be this balance issue, so to eliminate this and hopefully fix it who is the best person to get this prop balance done and how much does it cost approx?

 

David

Hi David,

For best results

 

Static balance your prop as best as you possibly can

 

Same goes for pitch adjustment.

 

(You need to be obsessive about the above - I use small increment digital scales for weighing & digital protractor for pitch, double check the protractor with a Warp Drive bubble unit)

 

Then get your dynamic balance done.

 

I used Superair @ Armidale Airport, NSW Ph (02) 67725055 - they are aircraft engineers, servicing all classes (inc turboprops) of smaller aircraft including choppers. Their prop balancing equipment is independently calibrated & certified and they are very thorough when using it. They are not cheap but you know you are getting a professional job - call them for a + GST quote.

 

You will find that the "focus" of the calibration is on cruise rpm. The power setting/prop speed experienced over the longest time (cruise) is where most pilots want the smoothest running. This may mean you still experience vibration at other power settings. In my case the dynamic balance seems to have benefited the whole rpm range.

 

 

Correct me if I am wrong but isn't it already a way to access CTA and CTR in a RAA AUS aircraft (equipped appropriately) ?Just get a RPL with CTA and CTR endorsements.

 

It seem to me that you make my point. That is: - we all fly (with the exception of jumpers, who drop) the standards and rules should be uniform across all types. If you have a CTA endorsement and your aircraft is appropriately equipped, why should you not be able to access CTA. It should not matter from what segment of the sport aviation flying fraternity you hail from or that you have a RAA Cert, RPL or PPL - Do the training get the endorsement, when the need arise's or the whim takes you enter CTA legally.

Hi Poteroo - Wow! terrific answer. Many thanks

 

 

Not very often does a "change" become, for the better!spacesailor

Ooooh! are we just a tad cynical?

 

 

SkippydieselYes weather and fuel supply are obviously the most important planing points.

Not addressing my question - which related to the time of year, as in why March/April? or alternatively just the time you want to go.