skippydiesel

I agree that this is a an unfair pole and unlikley to result in a genuine unbiased documentation of members opinions. - only being able to vote for one topic out of three diverse options is just rubbish.

Take myself access to CTA would be my No.1 priority - I fly out of the Sydney Basin, which means, due to CTA North & East, I am pretty well forced, if I stay within RAA regulations, to fly over very extensive & dangerous Tiger Country, if I want to go anywhere other than South. The ability to access CTA would allow a significant increase in my flight safety margins to say nothing of more direct routes & lower costs . For someone based in a country area this the inability to access CTA is at worst an infrequent minor inconvenience barely worth discussing.

The higher stall speeds and increased TOW are, in my case, academic - I fly a European aircraft that is limited by the manufactures to 540 kg ,(although their latest offering is certified in Au to 600 kg). So the increase in RAA TOW is unlikely to benefit those who have aircraft that will remain at lower weights. A higher TOW may benefit RAA itself, as it makes more aircraft, from the GA world, eligible to be registered under RAA - so more members more $$$$.

Well said - Thank you Thomas

Sorry Skippy, if a preflight doesn't include inspection at the cap, you need to 'change your installation'. If not, one day you WILL be looking for somewhere to land with a cooked goose! Experience talkin'.

I have not disagreed with the principal of your argument just its practicality in real life operations where cowling considerations preclude easy access.

I would also make the point that a correctly fitted safe cap stays that way until someone does not complete the locking turn or forgets to lock it down altogether. Cooling system problems are better diagnosed by observing leaking coolant, empty or contaminated overflow reservoir than repeatedly opening & closing the cap which lets air into what is supposed to be an air bubble free system.

In the scheme of priorities you might do better to checking that the radiator fins are free of chaff/insects etc that may cause your cooling system to overheat.

As I said my installation is not ideal from a cooling system cap inspection point of view but after 700+ hrs of trouble free operation and many more hours of trouble free operation of similar systems in land based vehicles, I feel confident that my maintenance regime, preflight checks and instrument scan give me almost all the information I can hope for.

Do you inspect the radiator cap on your land based vehicle before each journey? No! nor do I. I do glance at the translucent overflow tank about once per week - coolant level normal, system good to go.

Cooling system rarely give problems, if correctly maintained. Usually give plenty of notice of things like seal or cap leakage. Using proper/appropriate cooling system hoses/pipes, coolant mix and observing the Rotax service interval/time limits on hose and coolant life, is far more important than obsessively checking an already correctly installed cap.

Any change in cooling system "normal" performance should be responded to as you would an imminent engine failure - if in the air LAND - if on the ground do NOT TAKE OFF.

My aircraft along, with all its Rotax 912 powered siblings, has an exemplary safety record.To my knowledge, in about 20 years of operation across hundreds of aircraft, there has yet to be a catastrophic cooling system malfunction reported.

There are no grantees an apparently normal engine may fail on take off or in cruise. Usually there are warning signs that were ignored or just not observed/understood.

I put a lot of faith in my gauges, after start up which is when I picked up the initial problem, and climb out ,not all,but most of these problems seem to occur when the engine is running.

Yes most failures will occurs during an operation and probably during high power/climb situations. This is when all systems are under the most stress/demand, so stands to reason if there is a weakness, this is when it will show up and failure occur. Other flight situations may have their own challenges (icing at low power, nose wheel failure on dodgy landing, etc)

Pre-flight checks are in large part reading the history of the aircraft, that is what anomalies are evident, that may indicate a future problem. This is why knowing the normal level for the coolant in an overflow bottle is a vital piece of information, if you are to make informed judgements about the condition of the cooling system.

A serious leak of coolant on the ground should be obvious. (As Rotax recommend Castrol coolant, which is green, I will stick to this colour.) Green steaks down fuselage/belly, pooling of coolant around the engine cowling, green drops from under the cowling, green liquid on the ground (earth or concrete) - all a bit of a "give away".

Unexplained drop or rise in temperature, while in flight, is a concern that should have you looking for the nearest airfield or decent paddock. Luckily a Rotax 912/914 will run for a long time without coolant, especially at reduced power.

The condition of the coolant in the overflow container is just one of many indicators of engine health.

If your aircraft is stabled on an earth/grass or gravel floor consider placing an impervious membrane/tray under it, to catch any liquid (fuel/oil/coolant/hydraulic fluid) that me be escaping from its lawful container.

Just suppose a hose, a fitting or even the radiator was leaking and not the lid. If a hose was leaking it could drain the coolant on the ground while sitting for a few hours and you'd never know.

Any liquid on your aircraft belly/cowling, on ground under aircraft is cause for serious concern this could be oil, fuel or coolant (or I suppose rainwater or pee). Corrective action before further flight might just be in order.

Yes you can have a "catastrophic" failure of the radiator and still potentially have coolant in the overflow bottle.

If your installation allows easy access to the "radiator cap" over the top of the engine, go ahead check it in your pre-flight inspection.

I still stand by my earlier statement

"I agree that periodic inspection of coolant level at the "cap" is a good practice but doing this, at other than service intervals (cowl removal time), is impractical in my installation.

In short, I must rely on the coolant in the overflow bottle as an indicator of the condition of the entire cooling system."

After an embarrassing number of years mucking about with all sorts of internal combustion engines, I am convinced that the by monitoring the coolant surge/overflow you haves a good indication of the integrity of the entire liquid cooling system. This is not perfect but then what is.

You would think if the cold level in the overflow bottle dropped away there would be a problem

It would seem you do not know how this sort of radiator works.

First of all you need to understand that the coolant will boil at approximately 100 degrees centigrade at sea level pressure. (I say approximately because of the glycol & other inhibitors present.)

Water boils at lower temperatures at altitude. The higher the altitude the lower the boiling point.

Boiling water turns to steam and steam is not a good cooling medium.

Early liquid cooled engines had cooling systems open to atmosphere & required frequent "topping up" as the water boiled off.

From about he early 1940's or so, liquid cooled engines use a sealed cooling system, keeping the coolant under pressure to prevent boiling.

Water (coolant) expands as it is heated.

The expanding fluid must be allowed to go somewhere or the cooling system will rupture or if fitted with a spring loaded pressure cap "blow off" .

In the old days the radiator was only filled to just above the internal core/fins. This left a space, in what was called the upper radiator tank, for the expanded fluid to fill. On cooling the old system went into negative pressure often collapsing (non reinforced) coolant hoses in the process (usually the lower radiator hose). The cap was often hard to remove, due to the negative pressure and many people on seeing the coolant well below the top of the radiator, topped up the system, only to have the excess blow off.

The Rotax 912/914 range of engines (in common with most modern liquid cooled engines) has a serge/overflow tank & a two way pressure cap.

As the coolant heats up so it expands. The expanded fluid is released by the two way cap, into the serge/overflow tank.

As the coolant cools, after shut down (or as the engine cools when in cruise flight) the coolant is drawn back, past the two way cap, into the cooling system/radiator.

Modern engine cooling systems require that they be filled to the very top (preferably leaving no or very little air gap) and a small amount added to the serge/overflow tank.

For the overflow tank to work properly, there must be no air gap between it and the radiator coolant. (any small amount of air present will be blown through on your first engine start/warm up after refilling the system, leaving no air gap/bubble)

The overflow tank must be open to atmosphere to work correctly (usually a small 3mm hole in the cap will suffice)

If you fill the overflow tank to the top, it will overflow, to waste, when the engine starts to warm up.

This system allows for a relatively small (light weight) cooling system in which pressures both positive and negative are better controlled and very little coolant is lost over the service interval of the system.

SO!! if the Rotax cooling system has been correctly installed and serviced, the level of the fluid in the serge/overflow tank will indicate the general health of the system.

If there is a:

• Leak the cool level will slowly get lower (depending on leak rate)
   
   
  
• A blown head gasket the level will drop very fast and there may be bubbles rising in the overflow tank.
   
   
  
• Oil contamination, a seal has gone somewhere.
   
   
  
• The coolant level does nor rise on engine warm up you are low on coolant for a range of possible reasons headed up by a major leak or failure to correctly fill the system & purge air.
   
   
  

The above "off the cuff" explanation is I hope close to correct.

NOTE: Any variation from normal levels of coolant must be cause for immediate investigation failure to do so may cause loss of engine/aircraft/life

Simple things indeed....coolant in the overflow bottle is not an indicator of coolant in the system. Your choice.

The bottle is translucent, so the green coolant level can be seen without removing the lid.

I have marked the cold coolant lower level on the bottle, so a quick check with the metric eyeball tells me if levels are normal - system full of coolant.

The lower level also allows me to keep a check on coolant loss which, in a well maintained engine, should be very slight/negligible.

I usually open the hatch after an "opp" and again a quick check will show the hot, upper, expanded, level of the coolant. The upper level may vary slightly with cooling system temperature.

The observed coolant at or very near the cool/low level mark and the rise to the upper hot levels and back down as the engine cools, strongly indicates situation normal.

I agree that periodic inspection of coolant level at the "cap" is a good practice but doing this, at other than service intervals (cowl removal time), is impractical in my installation.

In short, I must rely on the coolant in the overflow bottle as an indicator of the condition of the entire cooling system.

HI Skippy Diesel,Yes, I agree - my mistake - I meant to say that I mix ordinary unleaded with Avgas when premium ( 95or 98) is not available.

 

As for the Declin scavenger - I adopted that practice after flying the US where it is widely used with Avgas and rotax engines. I also change oil at 25 hrs irrespective.

 

chers

 

r

I use 98 RON almost all the time. In seven years of flying, necessity once dictated using 95 RON and also once used AVGAS to fill my tanks for the next leg of the trip.

Would it be too impertinent to suggest that a 25 hr oil change for a Rotax 912 is, to some extent, negating one of its main advantages over the air cooled mob.

OZJohn - "Rotax recommends maximum of 30% Avgas. Oil changes and gearbox service requirements as above. Lead affects the gearbox clutch."

I think you will find that you may use 100% AVGAS in the 912 range (and a few people do) and that the lead build up is pretty much throughout the internals of the engine/gearbox, not just the clutch. Clearly the lead may only have a negative impact in certain areas, clutch mechanisms, valve seats & stems, oil galleries, etc etc.

Hi Rossyehart,

My understanding is; Rotax specifications allow for fuel from 95 RON or higher, including AVGAS. I effect this means you can run on straight 95 or 98 RON and AVGAS or blend of any two or three..

There is no need to be concerned about ratios/blends.

In real situations, you will have a blend of varying ratios, depending on the amount of fuel remaining in the aircraft tank and the RON standard and amount of fuel added.

The Rotax 912's ability to generate take-off and cruise power will be unaffected.

In theory there may be a small performance benefit from using higher RON fuels however few pilots report any noticeable change.

There are opinions "out there" that suggest that the lower volatility of AVGAS will improve the hot starting of the engine, due to reduced incidence of "vapour lock" .

The tendency of 912's to develop vapour lock on hot days, can be "managed" by various strategies.

It is well documented that the regular use of AVGAS will result in the build up of lead deposits on internal components of the engine & gear box, necessitating more frequent oil changes and an early gear box strip, inspection & clean.

I would not be relying on any additive to "scavenge the lead" much better to keep the use of AVGAS to the barest minimum or adopt the Rotax service regime for using AVGAS.

I suspect all fuel. from whatever source.

Contamination is unavoidable:

• Condensation - water
   
   
  
• Corrosion - rust
   
   
  
• Algi
   
   
  
• Brake down of "rubber" hoses, "o"rings, seals & pump diaphragms etc
   
   
  
• Paint flakes
   
   
  
• Metal swarf
   
   
  
• Plastic chips, fibres, etc
   
   
  
• Windblown chaff, dust
   
   
  
• Insects
   
   
  
• Other hydrocarbons
   
   
  
• Etc.
   
   
  

The best way to minimise (note I did not say total removal) these contaminants is to filter the fuel into the aircraft.

Aviation bowser's have a filter on the delivery side. Unfortunately it is "up stream" from a long rubber hose and an uncapped delivery gun/nozzle.

The more times fuel is decanted the more chance of contamination.

It is probably completely "anal" but it gives me "piece of mind" to filter the fuel into the aircraft tanks.

I would rather the on board fuel filtration be underutilised than relied on as the last line of defence.

Check your aircraft fuel filters every 50 hrs without fail.

One last thing you can easily make your own version of a Mr Funnel for a lot less $$$$

Zodiac - The risk would seem to be exceeding small. No one seem to care

DSM - As vertically challenged person, I sympathise with the difficulties in refuelling your high wing aircraft. Believe me even my low wing has problems (design fixed in later models) resulting in occasional spilt/wasted fuel (spoiling my careful measuring) steaks down wing/fuselage and aromatic trousers/shoes.

I only filter once - into the aircraft (not counting the on board filtration).

I agree with your logic, in your circumstances, regarding the dedicated collapsible jerrycans and your compromise system due to high wing fuelling points.

I have modified, by adding an internal filter (diesel mesh type) & a hook, to an off the shelf funnel that boasts a top & bottom screw cap. My mods include a way of holding the funnel secure & vertical. Unfortunately the speed at which the funnel drains is slightly reduced by the addition of the filter.

The added time to fill, causes muscle fatigue, which conspires with the "floppiness" of the collapsing jerrycan, to sometimes induce the shakes, leading to spillage.

I am continually amazed by the very small but consistent amount of material (gratifyingly) caught by the filter.

At home (base) I have a 12 volt pump to do the "heavy" lifting, so no spillage. I could carry a small electric fuel pump but the added weight and drain on my battery may not be such a good idea. Something to consider in my dotage.

Despite the problems, I have piece of mind knowing that the fuel going into the tank is as clean as I can, practically, get it.

I still inspect my filters at 50 hrs & replace at 200 hrs (even if they look clean)

DSAM's policy is almost identical to mine.

I have run my 912 ULS on 95 RON (Rotax min spec) without any apparent change in performance. I hope that by using 98 RON I am accommodating any loss of RON during storage (fuel station/home). I rarely use AVGAS but again have done so without any apparent change in performance.

I would council against only filtering (Mr Funnel) into your transport container (jerrycan or bladder). I always filter into the aircraft as the penultimate contamination catch point (the ultimate being the in aircraft filters). Containers may potentially have condensation, breakdown in the container material, paint, rust, etc that will be transferred with the fuel . So best to filter into the aircraft.

Like DSAM I find out, ahead of time, where I can get 98 RON along my track. You can use BP/Shell/Caltex apps , local aeroclub, etc for rout planning/fuel supply So fare have had no problems.

The lead in AVGAS contaminates/builds up on all internal all parts of the 912 engine and gear box not just the gearbox/sprag clutch. Not only due you have to halve the oil change interval but also reduce the service life of the gearbox/clutch (from memory 600hrs a disassembly, clean, inspection is required)

Cruel Nuts

• Dogs hearing is many times more sensitive than ours. No animal should be deliberately exposed to a high noise environment. Unless there is a very good reason to do so.
   
   
  
• Dogs will do almost anything to stay close to their human. This should not be misinterpreted as enjoyment, willingness or other anthropomorphic BS
   
   
  
• What happens when dogs inner ear is blocked, just like us,extreme discomfort /pain how will dog react ? I have seen a dog in pain try & bite just about anything in the vicinity-humans, cables, chair legs etc GOOD LOOK IN THE AIR.
   
   
  
• All loose items within an an aircraft should be properly restrained/secured
   
   
  

Cat video showed cat in extreme fear & poor pref-flight checks. I am amazed that cat did not leap onto pilot/passenger & then into thin air.

Agreed ! even the in depth extended perusal in the Throne Room.

Rarely a cutting edge magazine, but a conduit to the comings & goings in RAA .

Hi Jerry,

Glad you didn't agree with me completely, whee would be the fun if we all agreed.

In post war Australia, with its vast open spaces, poor roads and limited rail infrastructure, flying was seen as the natural & efficient way to get around the country. In short the public supported and even idolised aviation/aviators. Flying is now mainstream, mundane, no romance - A to B cheap & fast .( Oh! were we talking about little planes and amateur pilots - way to dangerous.) Unfortunately that is ancient history and i fear no amount of education is going to change it in our lifetimes. (We all know/speculate at the reasons for this 180 degree change - suffice to say they are multiple). Without significant community support, something more immediate & direct is the only way to get the attention of the pollies. Other single issues groups have stood up/closed the gates/ picketed the factory/chained themselves to the railings/etc/etc & achieved significant even complete change in policy/law - why cant we?

In this context I would see our group

Strengths as -

• An unusually wide range of talented persons from diverse backgrounds - much knowledge and ability to draw on
   
   
  
• The ability to make dramatic displays - massed aircraft movement
   
   
  
• Highly mobile - quickly move from location to location
   
   
  
• Goal oriented - can do attitude
   
   
  
• Logical - planners
   
   
  
• Age - largest segment near or in retirement time to devote to a cause
   
   
  

Weakness as -

• Independent movers & thinkers - hard to get consistent coordinated action
   
   
  
• Middle class conservative - complacent inertia
   
   
  
• Relatively small - numerically insignificant
   
   
  
• Dreamers - lot of talk, little action
   
   
  
• Conformists - a bit to much faith in the authorities/law to act appropriately
   
   
  
• Age - lacking in the mental energy to make a stand
   
   
  
• Thin on the ground - geographically widely dispersed making communication and coordinated action difficult
   
   
  

You can probably add more & subtract some

DSAM / bunyips -" I tips my lid" to you two gents but please lets not agree to much, takes all the fun out of having a good (truthful) rant. On that note;

I am a firm believer in attempting the conventional communication routes. When this has been done and done and done, with little to show for it ACTION is required. People must stand up and shout, go on a march, boycott an event or three. It must be public, in their faces and attention grabbing and all parties must be prepared to do IT as often as is strategically required. The media (including on line stuff) love nothing better, the polliess love/hate the media . They key is to attract media attention - then watch the pollies jump on the bandwagon

I despair -

• FIRST - Flexible hose & all other fuel delivery/metering components must be compatible with the fuel being used nothing else will do!
   
   
  

• SECOND - All rubbery component that come into contact with fuel are subject to deterioration and must be replaced at intervals specified by the engine, aircraft or component manufacture nothing else will do !
   
   
  

Your welfare and that of passengers and innocents on the ground, depends on you wholeheartedly adopting the above.

Nuff said ! I will make no further contributions to this conversation.

A few things to respond to here - Hope I can make some sense of it all;

Yenn - "How can we hold the servants to a higher standard ?"

Well the first answer has got to be at the ballot box (all three ridiculous levels of government). Stop voting for the people you have been habitually voting for since ,"whenever". Do a bit of policy research, ask some awkward questions of those standing for election, vote for the person who will come closest to upholding YOUR values. DO NOT MINDLESSLY VOTE ALONG PARTY LINES just because you have always loyally done so. In other words make your vote count. Make the buggers work for you & your vote and if they don't, VOTE FOR SOMEONE ELSE NEXT TIME.

It is big party propaganda that a vote for an independent/or micro party is a lost vote - Independents have to work very hard, on "shoes string budgets" to win and keep your vote. They must listen and act or loose out . They are far more likely to vigorously pursue their electorate/electors concerns and once in power, keep their colleagues to some semblance of ethical conduct.

Start to discuss issues that concern you, with family, friends & colleagues (never mind the social embargo on polite conversation - no sex, politicos or religion) be VOCAL. This is how you get ideas, start groups of people with common cause(s).

Be prepared to take considered action - PROTEST !! when/where necessary. Do something mildly outrageous / discomforting to get public & media attention. In today's world, groups of like minded protesters get whats called MEDIA COVERAGE - absolutely essential in generating change in the political world. Above all be fearless and indefatigable (it will take time).

Use the internet. Forums like this one.

Jerry - "the public service (Victorian) is actually not that much different to large corporations" TRUE ! These groupings are collectively known as bureaucracy's (B). I would suggest a B is a, common, irrational, inefficient self serving, natural spontaneous phenomena of large human groupings (not confined to governments).

• Common - they happen everywhere in the world where large numbers of people group together under an administration (the dreaded ADMIN is essential in a B)
   
   
  
• Irrational - little real thought/ planning goes into their formation an structure
   
   
  
• Inefficient - inevitably
   
   
  
• Self serving - B's become organic, that is much like a living organism in they will defend their existence & sustenance ($$$$) against all comers and often at all cost with little concern as to the consequence(s).
   
   
  
• Natural - every group from a small club, through government bodies, to transnational corporations seem to "crystallise" into very similar formations and internal functionary's.
   
   
  
• Spontaneous - result of a sudden impulse or inclination and without premeditation
   
   
  
• Phenomena - an extraordinary naturally occurring event
   
   
  

I could blather on but in short B's are inevitable, a bit like death & taxes. Not good, just necessary & inevitable. Just like death & taxes, we as a society/individuals should strive to contain and minimise the growth and negative impacts of B's.

Unfortunate another naturally occurring set of social phenomena are: COMPLACENCY and INERTIA (She'll be right mate, no worries)

Good Rant - I feel so much better

There must have been something in the 2 stroke oil which reacted, gosh there are a lot of pitfalls in this plastics/hoses/chemicals business. My older Jabiru has something in the fuel-tank which would react with ethanol.There is also another trap. A Jabiru was flying up the Stuart Highway when it ran rough. Turning on the electric pump fixed things for awhile but the problem returned and they made a safe landing on the road.

 

The answer was eventually found to be that the newly-replaced fuel line was vibrating its way up the wedge under the fuel tank and pinching itself off.

Not sure if 2/ is chemically much different, compared with strait ULP - just a slightly different blend of hydrocarbons. I think the type of fuel hose you use has more to do with durability than the fuel type. Gates for instance make fuel hose for several different applications, so don't just purchase the cheapest or the one behind the counter at Repco/Super Cheap. Always check on the codes (words, letter & numbers printed on the hose) and understand what they mean. I have always used the highest rated fuel injection hose - could be overkill but then I am still alive to tell this story.

Ethanol in fuel will react with fuel systems not rated to use it. This is the whole system we are talking about, from the tank filler to the carby needle valve rubber. As a lay person I think of it as the ethanol "eating" the rubber, fibreglass plastic components. Rotax now supply their 912/4 range as ethanol acceptable - this does not include the aircraft manufactures tank , auxiliary pumps or delivery hoses, unless specified as ethanol resistant.

I suggest you still might not want to use ethanol blend fuel for other than compatibility reasons.

Jab hose pinching off in flight - poor installation practice. This can happen to even the best hose.

This is called a "make work scheme" - all to common in that welfare agency called the government.

They call themselves public servants, suggesting they are all about the welfare/interest of the public. In reality they are public parasites (my apologies to those very few that take the title seriously and act accordingly).

They are only to happy to spin out an issue, consult here/there & wherever, appoint committees, advisers, consultants and travel oversea's, interstate (wherever there is a good restaurant and comfy accommodation?) ALL AT OUR EXPENSE to change what almost any class of 12 year old's could do as a morning exercise.

The way ASIC has been implemented & maintained is a case study in government ineptitude,verging criminal misappropriation of public funds - an all to common scenario.

When will the great Australian public start to hold our SERVANTS to a higher standard? (She'll be right mate, no worries)

Thank you for the reply's. There is no "Quibble" with safety, the reluctance to fit one is purely practical. The aircraft is a Cri Cri. This thing is tiny, the panel is no bigger then a shoe box.

I elected to replace my old transponder (dud) with the same size (fits in the same tray) ADS -B. While I was researching the replacement, I found several panel space saver small units and several , I think they were called remote head units, that is the small control head on your panel is remote from the actual gizmo, which can be installed almost where ever you want. I imagine the latter may be applicable to a Cri Cri

From Little Things Big Things Grow

I am suggesting boycotting major aviation events - no pilots - no planes (flying). Not talking about your local fly-in's. The serious big industry events. Any risk that they might be negatively impacted would get a whole lot of attention.

It is just not good enough that anyone should have to pay a cent towards an unjustifiable law or feel guilty/uneasy about flouting it.

In truth our representatives, bureaucrats & lawmakers have let us down badly on the ASIC matter. Something so asinine should have been fixed as soon as it became apparent it was achieving so very little. Yet it remains. Why? I would suggest shear bloody minded inertia.

The polite within the system, (representation, lobbying, rational argument, etc) clearly has had no discernible impact.

Hell will freeze over before any of our pollies take up this matter with genuine interest.

Sometimes people power is the only alternative to a disinterested body politic.

Bad law must be removed or changed, not just ignored

Never had a problem with Gates fuel injection hose (changed every 5 years as per Rotax 912 maintenance). Very low permeability, high burst strength and ethanol resistant. Flexibility defiantly deteriorates a little over the 5 years. Still good enough to used as "pre loved" on all those "terra firma" transports, mowers, etc.