Vev

Hi Bruce, Just a couple of points if I may: Zinc has been replaced with a new Zinc technology .. Mostly known as HyperZDP, which maintaines cat life and provides all the boundary lubrication protection needed to protect cams, followers and more. There is no Matalic Additives, including Zinc (ZDDP) in aero engine oils ... They use a different technology. Cheers Vev

Ashless really mean non-metallic detergent ... detergents plate out on surfaces and stop particulates sticking to them... it doesn't really clean like you would think of dish washing liquid does. The metallic additives use to leave residues that could cause pre-ignition, I've really got no practical experience with this as they are simply not used these days in aero engines you mentioned and therefore not seen. Dispersants, in simple terms, envelopes particulates to stop them sicking together and holds them in suspension to get caught in the filter. Cheers Vev

Hi Camel, Yes was having a graze... There is lots of complexity in your questions but I'll just try and hit the high points if thats ok? Why not use a synthetic lighter viscosity multi-grade oil in jab engines disregarding legal and manufacturers recommendations ? I really don’t see an advantage in a lower viscosity in relation to its lubrication protection in a Jab engine. 15w is the equivalent to a SAE 15 @ 40 deg c (100 degF) and the “w” stands for winter and has a pour point at -32 deg. The 50 is the equivalent of a SAE 50 @ 100 deg c (212 f). All of this gives excellent start up protection with a lower vis and good film strength (this is hydrodynamic film that separates the surfaces) with the higher (SAE 50) during normal operation temps. Btw, Aeroshell is already a semi-synthetic. If you lower the vis you will get less internal resistance (low viscos drag) but could compromise film strength and potentially rupture the oil film and have metal to metal contact. In this senario you are completely reliant on the additive chemistry to protect the surfaces.. much better to use a physical layer of oil to protect the engine. In terms of Syn lubes ... these are good but I prefere the good old minerals with a blend of semi-syn as these have much better clean properties as well as keep the contaminates in suspension to be caught in the filter. What effect on oil does lead content have on oil and how long does it take to have effect. ? Automotive Lubricants are supposed to have backward compatibility and there are some obscure GM engine test that use to measure lead contamination performance. However these days any lead in the fuel will quickly damage many engine sensors and its not really a consideration. In terms of aero engines and Aeroshell as an example, it will tolerate lead contamination but it will plate out around the engine over time and turn into sludge if left too long. All combustion contaminates (including lead) will cause oxidation, causing the lube to chemically break down. Changing the oil often (ie 25hrs) is a good way to keep things under control. Just as a side issue.. synthetics are less capable (owing to lower solvency or aromatics content) than mineral or, to a lesser extent, semi-syn lubes in terms of managing lead. What effect do additives such as "Moly" have on oil other than friction modification ? Most moly particulates are quite big (1 – 100 um) and will just get caught in the filter. Personally, I’m no fan of MoS2 in engine lubes, I know others will argue differently. A high viscosity oil in an engine that should be using a lower viscosity oil, would this cause heat in the engine trying to compress this oil, eg bypass and close tolerences, ? Using to higher viscosity will potentially cause an increase in temp owing to high shear … it is sort of like the oil having its own internal resistance to flow where stationary molecules and high speed molecules interface at a shear point and generate heat. What’s more, a higher viscosity lubes doesn't transfer heat as well and not as effective as a lower vis. Would excessive wear be likely due to a high viscosity oil unable to freely move into areas of small tolerance to adequately lubricate ? Yes particularly at start up when the oil is thick and slow to get around the engine. However, more often this is seen when viscosity get too high in gear boxes you get “channeling” when the oil is too thick to recover onto the surfaces and runs dry. My motive for asking is related to something I am aware of and want scientific facts from an oil man (industrial chemist) to verify or discredit. I'm a motor mechanic, probably won't change much for me, Hope this helps? Cheers Vev

Correct Nev .... it's called Saybolt Universal Seconds (SUS) ... it was 100 sec @ 210 deg F to flow through a calibrated orifice ... this basically said the viscosity is getting close to the top end of the viscosity range for a SAE 50 grade base oil. Cheers Vev

Fantastic Ian ... great stuff Cheers Vev

What a great headline ... I wish we could say the same for light aircraft. Just one of the lessons here about reducing deaths has come from more transparency, proactivity and cooperation ... may be we could all benefit from more timely release of information regarding RAA accidents, so that, we as individuals, can at least improve awareness and take steps to make our flying safer. Cheers Vev 2012 the safest year for flying since 1945 Flying on a commercial jetliner has never been safer. Yesterday marked four years since the most recent fatal crash in the United States, a span unmatched there since propeller planes gave way to the jet age more than half a century ago. Worldwide, last year was the safest since 1945, with 23 deadly accidents and 475 fatalities, according to the Aviation Safety Network, an accident researcher. That was fewer than half the 1,147 deaths in 42 crashes in the year 2000. In the last five years, the death risk for passengers in the US has been one in 45 million flights, according to professor of statistics Arnold Barnett at the Massachusetts Institute of Technology. There are many reasons for this. Planes and engines have become more reliable. Advanced navigation and warning technology has sharply reduced once-common accidents such as mid-air collisions or crashes into mountains in poor visibility. Regulators, pilots and airlines now share much more information about flying hazards, with the goal of preventing accidents rather than just reacting to them. And when crashes do occur, passengers are now more likely to survive. "The lessons of accidents used to be written in blood, where you had to have an accident, and you had to kill people to change procedures, or policy, or training," said Deborah Hersman, the chairwoman of the National Transportation Safety Board (NTSB). "That's not the case anymore. We have a much more pro-active approach to safety." The grounding of the Boeing 787 fleet last month illustrates this new era of caution. The last time a fleet was grounded was 1979, after a McDonnell Douglas DC-10 crashed shortly after take-off at O'Hare Airport in Chicago, killing 273 people. The 787s, by contrast, were grounded after two episodes involving smoking batteries in which no one was hurt and no planes were lost. [NYT] [The Straits Times] [The Business Times]

Hi Rocketing, Many thanks for reporting your thoughts on the outcome. Whilst I didn't attend the meeting, I have been, like most, very interested in seeing how all of this would end. Over the past months members have had the chance to make their concerns heard and yesterday formally register their disappointment and desires to move our association forward into a better place. I read a President Lincoln speech the other day and he said "a house divided against itself cannot stand" ... whist he was talking about much lofter issues than good governance of the RAA, it still ,never the less, remains truism for all groups, parties and associations. I think the members have now arrived at a fork in the road, that is, we can bring down the house and start again, as some have suggested, or we can rebuild the one we have. I'm in the later camp of rebuilding and working with what we had started 30 years ago and make it better. I think its time to be constructive and do all that we can to help and encourage those that have genuinely steeped up to the plate to rebuild.... it's easy to be critical and find fault but this is of low value input, the enduring value comes from positive input and support. Your reported view of "lets try and work together" is just what we all need now ... lets hope that all, if not most, can work to that ethos for here on out and make OUR association the best it can be. Cheers' Vev

Hey Merv They are fun to fly ... they jump off the ground ... next time you escape Nowra and head South come for a fly with me.

We have a couple of these 0-200D engines in our new Cessna Skycatcher 162's in both RAA and GA ... no problems with these engines so far, albeit they are only 12 months old.... time will tell. Cheers Vev

Hi thirsty, I don't think one needs to pull a head off every time you find a soft pot but you do need to investigate why. In the example you have used about compression going up after a hard run, it could still mean there is a serious problem. I have seen on a number of Jab engines rings stuck in their groves owing to carbon build up, often from burnt oil as opposed to blow by from combustion. The burnt oil can also often be seen on the underside of the piston crown, which is a sure sign of over heating. If a stuck ring is left unchecked it can cause ring breakage, bore scoring and piston ring land break up and of course an engine failure. I still maintain you need to find out what is wrong and simply not take chances. Cheers Vev

Good stuff ave8rr In my experience I have found the pull-thru very useful and a part of my pre-flight safety procedure .. whilst it won't tell you what is wrong it allows you to investigate. 9/10 times pulling the top end off a soft pot will save your wallet heaps.. it will also, in all probability, prevent a catastrophic failure in flight. Cheers Vev

One of the easiest things to do each day before a flight is do a pull-through, it's not a 100% fool prof analysis but it's not a bad pre-flight progamme ... if there is a "soft one" stay on the ground and check out why. Cheers Vev

How long have you waited for your renewal? I'm still grounded, I'm sooo over this! The lack of any transparency or indication of when is very frustrating and even more so when I see others get renewals and in shorter time... I'm just waiting for them to ask for more stuff they already have and lost. Cheers Vev

I watched this video today and thought it worth sharing ... a simple question and answered simply well I thought. http://www.eaavideo.org/video.aspx?v=1772099407 Cheers Vev

Agree ... API GL5 will cover a multitude of sins in terms of loading capability and will leave plenty of safety in the bank in terms of boundary lubrication performance. If the viscosity is too high it will cause drag, it can over heat or may even begin to channel, that is, push away from the working surfaces and not recover back to lubricate no matter how much anti-scuff additive is used. Viscosity selection is an important consideration in gear lubes and the OEM spec should be used. Cheers Vev

It the guys at Brumby in Cowra .. Talk to Phil or Paul. cheers Vev

I saw this on the Jabiru site regarding US accident rates in LSA's... it looks like the old Jab has less accidents than some may suggest according to this data? http://www.jabiru.net.au/images/LSA_AccidentChart.pdf Cheers vev

Hi Phil, I can't comment about your experience in your industry .. however in my industry, being the oil biz, most products and basically all engine lubes are made to meet or exceed an agreed spec and tested to industry agreed test programmes. There are some smaller oil or additive companies that do make some claims that are hard to pin down as they are not measured against recognised test programmes... some work some don't. Whilst I can sense your scepticism ... a formal recommendation by a major oil company (not a sales rep or some good intentioned retailer) is underpinned with millions of dollars and thousands of hours of testing. There may well be better products out there that may work well or even better, however it's a game of Russian Roulette to try something not recommended, approved or tested .. believe me I have seen the other side of the "when things go wrong". If I was given a clean sheet to design a new lube for a specific aircraft engine I suspect it would look a little different, however if you wanted the same lube to be backward compatible with other products and tolerate top ups and work in 85% of all aero engines and also meet the OEM performance requirements, you may not end up with something not a lot different. Often you can improve the performance of a lube very simply but then make it fail in another area when you chemically push it over the edge ... there is a lot of balance to get a lube to meet all the performance requirements.... I often see this happen when people put their own additives into a lube and unwittingly damage another performance characteristic. Whilst the perception that aero lubes have not progressed is not true either ... new additives, better more stable base oil and better manufacturing and test programmes has improved old formulations a long way. As for testing, suggesting an air cooled motorcycle caught in traffic test as a good proof of product performance is not something I would want to use to risk anyones life on for an aero lube. Testing is done by dedicated people following exact recognised processes which gets repeated over and over again before any field tested can be considered ... bwt, this also includes test progrmmes to make sure motorcycles lubes can tolerate traffic jams, albeit we don't park motorcycles in traffic but we do simulate it at first then do the field trials in the real world. However just making a motorcycle lubes not thermally crack in traffic is just one performance issue ... making it shear stable to work in the gearbox, not allow the clutch to slip, clean the engine, hold soot in suspension to get caught in the filter, not turn into foam, provide corrosion protection, absorb acids, maintain viscosity, give proper anti-wear protection etc etc are just a few and all are important. I agree there is always room to improve and develop new technology ... this is evolutionary process and people are always looking at the next new piece of technology, it will come, but it takes many years to get this over the line safely. In terms of aero engine lubes selection for myself ... I only trust what is approved and recommended by major oil companies and the OEMs... however I will select a multigrade over a mono grade if it is approved. Multigrades can do all that a monos can but a monos can't multitask as well. Cheers Vev

Guys, You really need to be careful when comparing Aviation octanes to Mogas ... Mogas measured differently to aviation fuels. You also need to be aware that US Mogas is also reported differently to Aust mogas. A very rough but simple conversion +\- a few octane : US mogas to Aus mogas add 5 octane Avgas to Aust Mogas add 10 octane This is not exact but will give you a feel for the magnitude As for using automotive engine lubes or additive packs ... There is so much complex chemistry behind designing an engine lube, you will be playing Russian roulette by departing from the manufactures spec. .. Just don't do it. If a major oil company recommends a product you can be assured its has been careful designed and tested to do the job and meet all the OEM performance specs. Cheers Vev

Hi Error, May I ask you to turn your question around 180 deg.. can you demonstrate where in the Reg it says you can run on condition in a flying school for reward in RAA?. cheers Vev

Hi Phil, LoL ... No problems mate ... I should have used the right words for the acronym. TBO = Time Before Overhaul = 5hitload of bucks as you put it so well. Cheers Vev

Hey CFI, Rotax engines have a use by date, i.e. 10, 12 years etc this depends on the model. They also have a TBO time before rebuild. Lets say you have an engine that has a TBO of 1500 hours but has only done 800 hours in use ... but it 15 years old and has a 12 year calendar life. The question is can you continue to run this engine past its calendar life or not and is there any limitations, that is, private or airwork? Cheers Vev

Thanks John So you are saying there is no option to run a Rotax engine on condition beyond its calendar life despite how many TBO hours it has in the bank be it private or hire? Cheers Vev

If a 912 is still running very well and inside TBO, say 800 hrs .. what is the importance of TTIS as it reachers its calendar life? Can this engine be used in a hire and reward situation or is it now limited to private use or is it all over and ready for an overhaul? Cheers Vev

Spark Plug Maintenance ... some good info on this video from the EAA on how to service them properly and increase the life of your aviation spark plugs. http://www.eaavideo.org/video.aspx?v=2050031304001 Cheers Vev