blue eagle

No delay when extending the gear. Also there is almost always no delay retracting at the first take off of the day. We checked the relay by measuring at the solenoid, when the solenoid gets power the gear retracts immediately. This shows that the relay is functioning. The solenoid of the relay gets no power when we replicate the problem with the jacked up aircraft . If you wait some time the solenoid does get power and the gear retract immediately.

Dear All, I have intermittent delayed gear retraction on my M20J (1998). When selecting gear up sometimes it will retract immediately and sometimes it retracts delayed (30s~120s). Pushing the overriding switch (airspeed) does not help. Checked function of speed sensing membrane (connected to pitot static system, this aircraft has no squat switch), all OK. Then changed the Gear switch with no effect, so old switch was OK. Jacked up the plane and did some checks and electrical measurements, gear relays are OK. So we concluded that it must be the gear limit switches. Because these are very difficult to get, I wondered why. Checked the schematics and the data sheets of the limit switch manufacturers. These switches are very robust and derated tremendously, so it is unlikely that these switches are bad. My Questions: - Is it possible that after 25 years the limit switches drifted? - What is the procedure for (re-)adjusting? In the Mooney service and maintenance manual on page 32-30-02 a procedure is mentioned to adjust the striker arms on the bellcrank when performing rigging of the landing gear. No mentioning of fine adjustment of the gear limit switches.

Let me react on 2 items : - Corrosion of aluminum is caused by destruction of the oxide layer. This is because of contaminant solved in water making the water acidic or alkaline. If we control the water content these contaminants cannot perform their destructive work. If you take the water away the chemical reaction stops. Mentioned already earlier that the water percentage should be as low as possible when the ethanol is being produced, stored or transported as the percentage of contaminants. Water vapor in your tank also will be absorbed by ethanol in the tank, this is very clean water and will not cause any problems if the ethanol is also pure. - Phase separation is not an issue because it is not there. We are talking about pure ethanol with possible a very small amount of water (caused by water vapor absorption inside the fuel tank), this will never ever separate as with fuel/ethanol mixtures due to water content. Or did somebody see a bottle of whiskey separate into water(mixed with some other stuff) and ethanol (= alcohol), or sugar getting separated from your coffee. The only way out is to cook is out (distillate) or with some very special nano filters to block distinct larger molecules and letting only water thru. So with ethanol you will never have suddenly only water as mentioned before it will remain a homogeneous mixture. I know there are issues with pure ethanol as a fuel but all these issues can be solved without complex technical solutions. And therefore I would like the engine companies to change some seal and diaphragm materials to ethanol compatible materials. What is stopping them? Regards, Blue Eagle

You are right for the same amount of energy you will need 31.6 % more ethanol if measured volumetric. Your number of Avgas is not correct it should be 31.59. Having only a range of 68.5% besides replacing some o-rings and seals it would be still interesting because 80% of my trips are shorter than 60 % of the maximum range of my aircraft. If I really require a longer range then i would have the option of selecting another fuel without having any problem, or planning an extra stop which is often preferred by passengers. There is a team called vanguard squadron and they fly many years on pure ethanol, and proving that it is possible. I have no relation with them but come to the same conclusion after thinking about it. They managed solve all issues and replaced the Lycoming engine fuel pump by an ethanol approved electric fuel pump. Regards, BA

We have to clearly distinct items from each other. Ethanol in Avgas is bad for the not compatible materials were seals are made from (e.g natural based rubber). Ethanol will cause swelling of these materials and causing fuel flow problems or leaks. That is main reason why ethanol should not be in your Avgas fuel for now. Because petroleum based fuels with ethanol cannot be checked on water content easily now, the EASA warns for it because there are no procedures yet to check. That's is why I do suggest to implement a daily batch release with a water content measurement by measuring the specific gravity. Like mentioned earlier if you have a homogenous mixed fuel ethanol saturated water content with a E15 fuel you will hardly notice the difference in power, but you have at least always power. regards,

In the experimental class there are examples of running a Lycoming IO360 on pure ethanol for many years. Because they were able to replace the engine fuel pump by an electrical pump approved for ethanol. We are not able to do this with our certified airplanes. Otherwise I would have converted my plane a long time ago. It is just getting this from the experimental world into the certified world. Blue Eagle

Dear Mooniacs, Would it not be nice to sit in the cockpit and flying on bio Ethanol knowing that only carbon dioxide and water is leaving the exhaust. Also that your Lycoming or Continental engine is running cooler, giving more horses and never ever fouling your spark plugs again. Your engine is running with a full synthetic engine oil making it last longer and you are able to fly for many years with your same current engine. Let's go over some topics to make this dream come thru: - Octane number of ethanol is around 105 MON, this is much higher than that of 100LL making it a perfect replacement (this is also why top fuel (drag)racers are using ethanol as fuel). - Energy density is slightly lower compared with Avgas, so the mixture needs to be adjusted to a higher value. This can be done exact the same way as we do it today by leaning and using the EGT as parameter. Our Lycoming and Continental engines are a perfectly designed for this and we can use the same procedure as always. - Ethanol can be solved in water, so it is not (easy) to detect if there is water in your fuel. I hear you saying that is a risk and therefor don't use Ethanol as a aviation fuel. I disagree, let me explain : If water is soluble in Ethanol it makes it a homogeneous mixture. So If I would use it I would always have the same fuel and no pockets of water that could kill my engine if I switch tanks. When I perform a run up prior to releasing the brakes, I actually execute a performance test. With pitch fully fine and throttle fully forward I know what MAP and RPM I have to expect. If these values are off I would abort the take off and go check what is wrong. Now if I would take of with ethanol after a good performance check I know that I will get the same power because the fuel is exactly the same. With Avgas this is a different story, I know I have now good fuel and power but if there is a pocket of water because I failed to drain all the fuel point in my pre-check, I could loose my engine. The Question is what is safer? There were many accidents were engine power was lost just after take off caused by water in the fuel. I would prefer ethanol. There are some other things you should know, tests have revealed that there needs to be a considerable amount of water in the ethanol fuel to have a noticeable drop in power. We are talking more than 20 percent water content. Water content can be determined by measuring the specific gravity (talking a sample of 1 pint and weighing it precisely (like battery acid). This could be performed every morning by the Ethanol Supplier as some kind of batch release that day. So there are solutions to mitigate risk concerning the use of Ethanol as a aviation fuel. It is a small effort to execute a more precise power check prior to the take off and perform a daily ethanol batch release with tight specifications (e.g. less than 1 % water content). - Pure Ethanol burns with less visible flames compared to Avgas (because it is cleaner). Top Fuel racers know this problem and act accordingly. With some additives the flames could be made visible if that is what some would like. - Compatibility with materials is different between Avgas and Ethanol. Ethanol can cause swelling of some hydrocarbon materials. I did some internet study on the materials in my 1998 Mooney M20J turbo-normalized (M20-turbos) with following interesting results: + fuel cap o-rings need to be replaced by viton o-rings + polysulfide kit used to deal the wet fuel tanks is approved for ethanol + 303 aeroquip hoses made from synthetic rubber are approved for ethanol + fuel selector seals and o-rings need to by replaced by piton o-rings + electrical fuel pump can be replaced by ethanol approved item + Lycoming engine fuel pump is not approved and there are no efforts to do so + Injection throttle body seals are not approved for ethanol + fuel divider seals are not approved for Ethanol + injectors (with pressure lines from intercooler) o-rings need to be replaced by viton o-rings. - Ethanol price is now around (€ 1.55 per liter) U$ 7.90/ Gal. For the US this is expensive but for Europe it would be cheap if only sales taxes would be applied. Bio ethanol is as green as a hydrogen cell engine and even greener than an electrical propulsion because there are no batteries with all kinds of toxic materials. On top of that ethanol is providing a environmental solution for all the existing engines out there and freeing the world from leaded fuel.This would be good arguments in Europe to only apply sales taxes on the bio ethanol. If bio ethanol would be produces in large quantities from bio waste materials, there would be no competition with crops. Also it will make us less and less dependent on foreign oil. The ethanol price also will go down due to the scale of economics. Now the Question is why are we taking so long solve the above mentions items, and instead spending a lot of money in finding petroleum based alternatives for 100LL. The next question that comes to my mind is why are the main engine manufactures not active in finding, certifying and offering ethanol approved fuel system components and let the end Customer decide if he or she will use a petroleum based 100LL lead free alternative or green Bio ethanol. Oil companies had their fair share in finding solutions for alternative fuels. They have chosen to pursue petroleum based road and were blocking green alternatives (Shell killed a solar panel activity and Mobil killed a algae project to grow bio diesel/kerosine). My final Question to you is how can we get together and form a front in forcing the aircraft industry and the governments of many countries to get ethanol in as a perfect green alternative, by approving and offering aircraft owners components to convert our existing aircrafts in an easy and cheep way (it is just a bunch of seals, o-rings and diaphragms). Looking forward to your reaction. Regards, Bue Eagle

Dear Mooniacs, Would it not be nice to sit in the cockpit and flying on bio Ethanol knowing that only carbon dioxide and water is leaving the exhaust. Also that your Lycoming or Continental engine is running cooler, giving more horses and never ever fouling your spark plugs again. Your engine is running with a full synthetic engine oil making it last longer and you are able to fly for many years with your same current engine. Let's go over some topics: - Octane number of ethanol is higher than that of 100LL making it a perfect replacement. - Energy density is slightly lower compared with Avgas, so the mixture needs to adjusted to a higher value. This can be doen exact the same way as we do it today by leaning and using the EGT as parameter. Our Lycoming and Continental engines are a perfectly designed for this. - Ethanol can be solved in water, so it is not (easy) to detect if there is water in your fuel. I hear you saying that is a risk and therefor don't use Ethanol as a aviation fuel. I disagree, let me explain : If water is soluble in Ethanol it makes a homogeneous mixture. So If I would use it I would always have the same fuel and no pockets of water that could kill my engine if I switch tanks. When I perform a run up prior to releasing the brakes, I actually execute a performance test. With pitch fully fine and throttle fully forward I know what MAP and RPM I have to expect. If these values are off I would abort the take off and go check what is wrong. Now if I would take of with ethanol after a good performance check I know that I will get the same power because the fuel is exactly the same. With Avgas this is a different story, I know I have now good fuel and power but if there is a pocket of water because I failed to drain all the fuel point in my pre-check, I could loose my engine. The Question is what is safer? There are some other things you should know, tests have revealed that there needs to be a considerable amount of water to have a noticeable drop in power. We are talking more than 20 percent water content. Water content can be determined by measuring the specific gravity (talking a sample of 1 pint and weighing it precisely (like battery acid). This could be performed every morning by the Supplier as some kind of batch release that day. There are solutions to control this risk, but then the ethanol would be safer on the risks caused by water. - Pure Ethanol burns with less visible flames compared to Avgas (because it is cleaner). Top Fuel racers know this problem and act accordingly. With some additives the flames could be made visible if that is what some would like. - Compatibility with materials is different between Avgas and Ethanol. Ethanol can cause swelling of some hydrocarbon materials. I did some internet study on the materials in my 1998 Mooney M20J turbo-normalized (M20-turbos) with following interesting results:

Now the real story about lubrication of valves: - Old engines (before the 70's) used stellite valve seats, this is a high carbon steel. This steel has a ferritic crystal structure is magnetic and sensitive to decarbonization by high temperatures, this is making this material softer. - Lead (TEL) does suppress this tendency at higher temperatures, so protecting the valve seats from becoming softer and causing negative valve clearance in engines without hydraulic valve clearance adjusters. This causes burnt valves (remember running an old beetle on unleaded gas will cause burnt valves). - When unleaded fuel was introduced in the 70's, the problem of the valve seats was solved by using an steel alloy with an austenitic crystal structure. This material is not magnetic and has very good high temperature properties, but it is more expensive. All automotive engines have this valve material as of the end of the 70's and as far is my knowledge is all certified aircraft engines have it even earlier, because it makes the engines much more reliable. - Valves were already earlier made from better materials because of the high mechanical load at high temperatures, especially the exhaust valves. You don't want a valve to break ever. So before improving the stellite crystal structured steel valve seats the valves were already made from a steel alloy with chromium, vanadium, tungsten to make them strong at high temperatures and resistant to softening by high temperature decarbonization. - Aviation engines don't need TEL for valve lubrication or valve seat scavenging. The only reason for TEL is Motor Octane Number (MON) period. So if there is a fuel with a sufficient MON leaded or unleaded it is suited for aircraft engines. Unfortunately at this moment TEL is the one of the most effective octane boosters. Otherwise we would have had already an alternative for the Leaded 100LL. I tried to run my turbo normalized IO360 engine on premium unleaded but saw after only a minute with a leaned engine that nr 2 CHT went up dramatically. Switching to the other tank with 100LL solved the nr 2 high CHT immediately. This process could be repeated by switching from one tank to the other. I did not test blends because this is for my a risk of not getting the ratio when filling the tanks. So I decided to stick to 100LL , proving that Lycoming is right about the statement that the angled valve head engines like the 200 HP IO360 are not suitable for unleaded Mogas. regards, Blue Eagle