Markdun

Pubs are the worst. I go in and ask for a half litre of beer, and get the response ‘ do you mean a pint?’. ‘No, a half litre, 500mls’. ‘How about a schooner?’. And now I’m thinking of a multi-masted sailing vessel where the formast is shorter than the following masts. So I ask, ‘do you sell beer in ‘firkins’ or ‘pins’?, as I now could really do with 1/10 of a pin of beer? And then the barman gets shirty, ‘are you taking the piss?’ No, I say, it seems despite this being a metric country you want to use old British units of measurement. You will find ‘firkins’ and ‘pins’ are real, legitimate, but ancient, measures of beer, like pints. How about some claret instead of beer? ‘OK, a small or large one? ‘WTF does that mean; Do you ever buy petrol by the ‘small or large’? I was more thinking of a hogs head actually.... sometimes it’s just so difficult to buy stuff! BTW my aeroplane has a wing span of 52 cubits and a MTOW of 3009 D cell batteries. For those interested in aeronautical units, it’s quite an interesting story as to why UK (& Australian) aircraft ASI is in knots, but the USA use ‘mph’, whatever that is. The answer is about the number of seats in fighter-bombers (money cost), workload and the value of aircrew (human cost). The US didn’t care about any of the costs.

Agree

I’m sure this set up is reasonably safe. But just to be clear: the logic of a system being ancient and on ‘certified’ aircraft means nothing. It’s the same as the fable of the farmer with the sick cow.

I’m no expert, but: if the isolator is a an electrical controlled solenoid even once turned off, you still have power to the isolator/solenoid control switch. If its a mechanical switch, it means you either have the battery in the cabin or a bunch of large heavy copper wires in there with you that will still be live too, or a mechanical link to the isolator if it’s remote from you. And if your electrical fire is due to a short in the AC side of your charging system and/or the voltage regulator, isolating the battery will not affect this. Finally, assuming an electrical fire is due to a wire overheating and burning the insulation on the wire & then cutting through your wingspar, that would be due to excess current... which would be prevented by an appropriate sized fuse or circuit breaker. There is one scenario I could contemplate, and that is a lightning strike. Andeven then, I’m not sure an isolator would help. I experienced a lightning strike on a yacht...it vaporised the vhf antenna, the current flowed down the antenna coax to the vhf radio, which caught fire, releasing all the magic blue smoke that makes all things electronic work, and there to the ground bus and to the engine to earth in the saltwater through the gearbox and prop. All, and I mean ALL, electrical items connected to the negative bus, switched on or not, was toast. FWIW & that’s not much, I use an old aircraft battery isolator solenoid as a 200A relay on the yacht to power the electrical anchor winch. Finally, that smoke in the cabin might not be electrical, it just might be that your trusty plastic oil catch can decided to spray 50ml of old engine oil onto your exhaust (don’t ask)!

Water? Do you have an espresso machine in the cabin?.... now that would be style, although require more landing stops! I make up my own CHT probes. Just bought some J or K thermocouple wire (can’t remember which),at one end expose the wires and twist together, then crimp into an appropriate, other end plugs into the RDAC. For EGT I buy $12 Chinese probes and mount them in a Jubilee clip with a 5mm stainless pull rivet (remove the pull shank and insert the 3.2mm egt probe into the rivet). Oil pressure & fuel pressure are 5v, 3 wire probes $25 each, as is the Hall effect rpm sensor & the Arduino current sensor. Only fuel flow sensors are expensive, but then I took an old Navman fuel flow out of retirement. I compared it to the Red Cube and could find no performance difference once calibrated.

Actually I have 3 fuses in the engine bay.A 150A for the starter motor, a 50A for the supply to the cabin and everything else, & a 15A on one of the AC wires going to the voltage regulator. I did have a 100A for the starter motor , but it blew, so I upped it to 150. The 150 and 50 amp fuses are mounted on the battery box with one large wire about 12cm long going to the positive terminal of the battery. I copied the set up from a friend’s Tecnam where we had to change one of the fuses which had corroded through (plane left outside in the rain by training school). The fuses in the AC charging wires is the one supplied with the Powermate regulator. It’s just a standard automotive inline blade fuse. BTW don’t use the fuses with a wire in a glass tube; the wire bends and work hardens with vibration, then breaks. Yeh, I know the Jab engines don’t vibrate, but I do have a friend who has an engine failure because of this.... the fuse was to his high pressure fuel pump on an EFI. Only use fuses where the fuseable element is supported.

Actually I have 3 fuses in the engine bay.A 150A for the starter motor

Yes, particularly when warming up the oil on those cold frosty mornings after the fog has lifted. I’ve never had icing in the carb in either with the Jab motor or the VW, both with CV Bing carb’s mounted in similar places at the rear of the motor & just below it. My VW set up had a ‘T’ there on the inlet runners with a flange bolted to the crankcase which kept it warm like the Jab inlet. Still I’ve known of people who have landed on a railway track wrecking their undercarriage, saying it was due to icing. So I’m cautious. Same for vapour in the fuel.... not so much for the Bing carb which has a reasonably large float bowl to separate out the vapour, more for the Rotec TBI carb I have on the Corby.... never experienced it and don’t want to! RF guy, I suppose people use the LM335 because most commercial engine monitoring systems allow for it as a plug and play. And it’s cheap and readily available.

Bruce, Radiant make a cheap fuel gauge with a sender attached to the outside of a fibreglass tank. In my view you can’t have too much fuel remaining info, but if you are down to the last 10litres ie. the dregs, you ought to be finding a place to land rather than looking at a fuel gauge. I was flying a delivery of a Tecnam from WA to the east coast and we had that very long leg from Kalgoorlie to Forest with a forecast of some headwind. It was an unknown aircraft to me so I figured the resistive analogue fuel gauges and the digital fuel flow s as rough guides only, particularly so as I had to have the LAME that ‘fixed’ the fuel tank leak by removing the evidence of the leak by cleaning the fuel stain, re-do the job. On filling the aeroplane for the first time I was rewarded with an avgas shower getting into the left seat. Anyway, on the flight to Forest every 15 minutes I did a quick calculation of estimated fuel burned and fuel remaining from our 100l full tanks at Kal and compared this to the 3 gauges on the panel and my flight plan. All pretty much correlated. It would have been nice if the previous owner had connected the RS232 serial output from the GPS to the fuel flow meter so I could have played a bit with airspeed to find the lowest fuel burn per nm. The owner/passenger in the right seat was a bit amused; there were plenty of airstrips to land at, but having to flag down a train and organise a refuel would take weeks. We arrived at Forest with over 35l remaining, mainly due to true airspeed cancelling out the light headwind.

Bruce, yes. I just used one of the spare ports on the MGL and hooked up an LM335 to it. It is inserted into the boss on the opposite side of the throttle butterfly shaft of the Bing carb. And yes, I use it to assist in determining use of carb heat as a sort of prophylactic against icing, though more often I use carb heat to cool down the EGTs sometimes. Ditto for the coil/ignition unit. My thinking was that as the MGL RDAC has the ports I may as well use them and the LM335 are only a couple of dollars.

Seems like a lot of confusion here. I have lithium batteries in my planes for several years now. No problems. I do have Powermate voltage/current regulators, a 15A fuse in the AC side of the regulator, & 150A fuse at the battery terminal (like a motor vehicle). My lithium batteries are ‘ion’ as opposed to lithium metal, and ‘iron’ as in ferrous. They have their own BMS and are marketed as being drop in replacements for lead anchor batteries for motor bikes and race cars. They weigh nearly nothing. Both are mounted on the firewall on the engine side. My experience is that they deliver exceptional current while maintaining voltage for starting the Jabiru donks. They turn the first few blades through compression very slowly, but then you have the engine whirring at over a 1000rpm. They really spin it up once the battery warms itself up a bit. On colder days it may take a bit more to get the battery warm. The batteries can sit for months and still appear fully charged with over 13.2V. In my set up the batteries charge at the Powermate regulated rate of a bit over 8A after startup and it all settles down in a few minutes to 14.2V and 2A for my EFIS/EMS etc. My only concern is whether the cranking power is a bit too much for the Jabiru flywheel. As to fire risk, firstly, my understanding is that this comes mainly from lithium metal batteries. Dendrites off lithium metal grow across the anode andcathode to give you an internal short circuit. Second, some batteries come in flexible bags and damage to these bags can also cause internal shorts. Third, the BMS should prevent charging or discharging currents in excess of the batteries capacity. Fourthly, I use fuses in both the charging and discharging circuits, & the Power matE prevents the alternator doing a runaway current job... as well as the fuses. Fifthly, my batteries are mounted forward of the firewall. Finally, I have had a Jabiru alternator do a complete meltdown in the air (blue smoke in cockpit) about 10 minutes after takeoff, just following a quick fuel and bladder stop after a 2.5 hour trip (so it’s not like the battery was deeply discharged). That set up had the standard Jabiru/Kubota tractor voltage regulator and a lead-acid battery. On landing we found the copper windings on the alternator had dropped molten copper onto the carb, & the reason the blue smoke cleared was the alternator went open circuit. I have noted that the Jabiru engine installation manual does not recommend a fuse in either the AC circuit from the alternator to the voltage reg. nor a bartery terminal fuse. On my view those fuses, whichcost a couple of dollars, ought to be considered essential. I was lucky; the molten copper could have started a fuel fire from the carb; or instead of the alternator burning out, I could have had an actual in cockpit fire from the battery wiring burning or the regulator which were mounted aft of the firewall and forward of the instrument panel..... and directly above the 67litre fibreglass fuel tank.

I flew today. OAT on the ground 8C. Plenty of humidity & unstable gusty air. Carb temp 2C on warm-up, so precautionary use of carb heat used and carb temp rose to 12C for take-off (with no carb heat). At cloud base 4500’ OAT was 3C and carb temp 8C (no carb heat). Carb heat used on descent to keep carb above 20C. Cabin heat would have been nice, but appropriate clothes were sufficient,

Yep. I have a Rotec TBI carb on my Jabiru powered Corby. At cruise I get a narrower EGT spread than my other Jab powered plane with a Bing carb. At WOT it’s just as bad as the Bing.... the rear cylinders go lean and the front rich unless you back off the throttle a bit and drop 100rpm, It’s nice to be able to adjust the mixture, but the Bing is pretty good & if I had the room firewall forward in the Corby I’d go back to the Bing just for simplicity. In both my planes I run an MGL EMS, monitoring rpm, oil T & P, carb temp, coil temp, fuel pressure and flow, 4x egt & cht, oat, voltage and current. It’d be nice to have a knock and vibration sensor. I had manifold pressure in a VW powered plane and this was useful in setting a nice cruise throttle position but I find I set the throttle just with fuel flow. A friend is developing his own engine monitoring system for his Jab powered Drsgonfly. He intends having a large glass screen display. But it is taking him quite some time to get it all together.... he has just received his printed circuit boards from China.

Thanks for that, I'll check them out.

I have 150Amp slow fuses on my batteries as a main fuse. The only unfused wire in the plane is 5cm of cable from the positive battery terminal to the fuse mounted on the battery box (the AC from the alternator is also fused). It frightens me that people fly with a potential arc welder via the starter cable! The starter motor clearly draws less than this. I started at100A, but this blew on the third start. I also monitor current drain/charge using an Arduino module (not in the starter circuit though) which doesn't use a shunt but an Hall effect sensor. Works for me and just plug and play with my MGL EFIS/EMS. On my home power system (off grid with 13kWh lithium batteries) I monitor power & battery state of charge via a 'Coulomb counter', also Hall effect. Mine goes up to 300A and quite a few kilowatts, but you can get them for smaller currents and power. Only a few grams in mass, and cheap.

Here is an oil analysis on my Jab 2200 by ALS in Australia. I do it every 50 hours. Around $35. I agree you need a baseline. Seems easy enough and not that expensive. I've found filter chops less satisfying; only ever saw a few aluminium millings in the break-in period. A surprising result is that even after hours of running with oil temps less than 70C, still no water in the oil! 1592132544241_Mark Dunst_Unit193393_Petrol Eng_Severe_34971739.pdf

Try a new needle jet instead. The mixture at most power settings is set by the gap between the needle jet and the needle. The needle jet is brass and can wear from the needle. So if you gradually have increasing richness, try a new needle jet. If that is still too rich, try the next size smaller, then if too lean polish the bore of the needle jet with brasso until you get your desired mixture. This avoids fligging around with the float level.

Bruce, I've read a bit about the extremes some of the RV guys go to to get an extra knot or 2 by reducing cowl inlet and outlet. Anyway a common thread is that the outlet, or more precisely just before the outlet, is very important. Stuff like gascolators, airboxes battery and even engine mount tubing can reduce the air flow and in particular affect port and starboard sides differently. It would seem to me that as the inlet pressures are the same it has to be the outlets. I note your EGTs are very close for a Jab. I'm still getting a spread from 640C to 700C. I don't see CHTs up around 150 except on 30+C days with two people in the plane and after a long slow climb out, mostly they are between 120 and 130.

Mark, I do not think it is as simple as many have replied. No matter what you use, the key question is whether it will fail under what load, the number of cycles for failure, & its mass. I'm sure the 10mm 304 1×19 stainless wire with 12.6mm 316 stainless turnbuckles which keep my yacht's mast upright with a breaking strain of around 30kN would work with your rudder cables, but it would be tad heavy. Stainless steel does work harden more than the steel alloy use in AN fittings. Stainless fittings with thread are also more likely to gall. Further, stainless fittings immersed in seawater can also corrode leaving them looking good, but very weak. Nevertheless, many aircraft have wire cables of stainless, some have galvanised (same for yachts, though increasingly yachts have plastic such as dyneema replacing wire rigging. My 11m yacht has 5mm dyneema braid for the rudder circuit & it has loads easily 10 times of what you would get in a light aircraft ). Both my aircraft have stainless cables and a mixture of AN turnbuckles and stainless ones. My scratch built Cygnet has stainless turnbuckles on the rudder circuit (20 years, 1000 hours). Each one has a safe working load of 5kN. The ailerons and elevator circuit has AN cadmium plated steel turnbuckles. All cables are terminated on a thimble with Nicopress sleeves. My Corby Starlet (40 years 300 hours), previously VH registered, also has stainless cables. Turnbuckles are all AN steel ones (no turnbuckles on the rudder circuit). However the cables are all terminated by swaged stainless fittings and were supplied by a certified aircraft cable supplier. Having built several aircraft (successfully) my advice would be to stick with what the aircraft designer specifies. If you want to change it, discuss with the designer. And remember the rule for assessing whether to add something or make it stronger than the designer specified. Hold it in your hand & throw it up in the air. If it stays up, it should be added. if it falls down it was never meant to fly and should be discarded. Cheers, Mark

I agree with all the previous comments to the effect that the quoted claim 'seven times more likely' is most likely hogwash. In any research, raw results, like these, may be nothing more than a random chance event. There are statistical techniques, robust ones, to test whether the results are 'significant', and usually they are not significant unless the probability that the results are merely random chance is less than 5%...the so-called 95% confidence. Why haven't the ATSB used them? Either they haven't engaged a statistician, or they have and they are too embarrassed to publish the outcome. There are lots of dishonest studies, particularly where there are commercial or other vested interests. For example, I have seen low quality studies with very small sample sizes that found no 'significant difference' between the control and the variable which are then used to justify a 'no effect' finding and then used to undermine the credibility of studies with very large samples. There are some good books on this detailing the tactics activities of Big Tobacco and Big Pharma.

Of-course as soon as any organisation says 'we take privacy very seriously', it means they actually don't. But in my view privacy is overblown much of the time, and things like the electoral roll, vehicle registration, & even tax paid & declared income should be publicly available on line. The Privacy Act only applies to certain, large and medium sized businesses and organisations. It doesn't apply to small businesses or individuals. It seems to me that the issue is the liability for aerodrome charges. And the answer to that question is what is the legal contract? In most cases the contract between you and aerodrome operator will be that set out in some public document, such as ERSA. By landing, you have partly performed one part of the contract and a court will decide from this that you have agreed to the published contract. There have been cases litigated for pay carparks where the terms and conditions of the contract are on the other side of the boom gate...the courts sided with the car driver that as they couldn't know the terms & conditions before entering, the act of entering did not constitute part performance, so no contract and no liability. However, ERSA does indicate whether charges apply, so I think it could be argued, that as long as the details are discoverable, then you are contractually obligated to pay, whether or not RAA-AUS passes on contract details or not. I have one proviso: I would expect that the contract and liability attaches to the pilot who chooses to land there, NOT the registered operator of the aeroplane. I don't think the pilot has the power to enter contacts for the aircraft owner. AVDATA. I'm not sure whether the demand payment on behalf of the aerodrome operator, in which case they are agents. If this is the case each payment and the contract remains between you and aerodrome operator, in law anyway. They may also be assigned the contract if the terms of the original contract has a term that provides for this. Lots of companies put this provision in their contracts so they can sell bad debts to dubious debt collectors. But, my point on this is that I think most people have an obligation to pay the aerodrome operator, not necessarily AVDATA. The fact it sends invoices is besides the point. Invoices are not necessarily obligations to pay or a debt. I know of some people who pay aerodrome operators directly and still get demands from AVDATA, with whom they have no contract, so they just ignore them. So called penalties for late payment. Only courts can impose a penalty. Even traffic offence fines do not have to be paid until a court orders it. Generally you voluntarily pay an 'infringement notice' to avoid the court ordered penalty. So, any term in a contract that has a fine or penalty will be struck out by a court as invalid (void actually). If you fail to pay on time, a court will order you pay the outstanding money plus interest, plus the the other party's costs for beach of contact. But parties to a contract can make reasonable estimates of cost for foreseeable events like late payment. ..And most people are aware that the banks recently lost a big group action on late payment charges for credit cards because the stipulated amount bore no relationship to their actual costs. Just sayin.

Nev, my apologies if you took what I said applied to you. It was actually a reference to my age. When my kids were 6 or 7 they used to think that dinosaurs were around when their grandfather was young. Now, my grandkids think the same about me. My point was that the tension between those that rely on more recent technolgy and those that rely on older methods is not new. When i was sailing in the '80s using a sextant a 'fix' was within a 5nm radius or there abouts...you adjusted your navigation accordingly....i didn't try a night passage through a gap in a reef of only 1 to 2 cables wide. ..I hove to 10nm away & waited for daybreak (to be woken by a French navy patrol boat). Others with transit satellite nav & radar went straight through (& didn't have the experience of receiving a rousing cheer & waves from the french sailors when I stumbled naked into the cockpit to investigate the noise of the patrol boat). I would sail straight through now too with GPS. I think you are wrong on GPS unreliability now. ADSB relies on GPS, as do lots of other things. If the GPS system goes down, then there are far bigger problems than a guy in a light aircraft. And even if it did, as an RAa pilot you just have to find a reasonable paddock to land. I rely on GPS for my nav in aircraft, on the sea and bushwalking. I still carry paper maps and an orienteering compass but have not had to use them for ages except to teach others or to re-assure myself that things are tickety-boo. I have two aircraft; both with an MGL Xtreme EFIS/EMS as the main instrument and with a 'steam' ASI 'back-up'. I would be happy to replace the stream ASI for a secondary electronic ASI/ALT but the value is not there to justify it. There are some inflexibilities in the MGL Xtreme, but overall they are fantastic. Cheers, Mark

Ahh, Skip, its called the 'astronaut syndrome'. Back in the mid 1980's, pre-GPS & only a few dinosaurs left, quite a few sailing boat owners sucuumbed to this syndrome, with their chart table/nav desk surrounded by dials, lights and switches and transit satellite navigation, probably with a clip-board and check lists. When I was in Nukalofa I think there was only 4 of us out of 30 cruising sailors that only had a compass, log & sextant (& charts) for navigation. Much discussion then that modern sailors wouldn't know how to use a sextant if the transit satellite receiver failed etc. Seems not much has changed regarding attitudes...but tech certainly has. ....i met a guy at 1770 a couple of years ago on a very fast 50' sailing cat who had sailed from Hawaii via lots of islands with just an ipad with downloaded charts for navigation.

I'm also with Skippy. ..my primary navigation instrument is the right eyeball mounted just below my forehead. After 60++ years of service with just one replacement lens I think that is pretty good. (The left eyeball, being only good for things less than 1m away without the monocle, is reserved for the instrument panel). I'm not that keen on voice alerts and warnings...one of the joys of flying is that my wife doesn't like flying and stays on the ground. ..would seem silly to have an artifical replacement that would detract from the serenity. I was taught that if I ever landed 'wheels up' in a sailplane that once the aircraft stopped, to immediately jump out and pace the distance of the landing roll....vis 'I did it intentionally to see how quickly it would pull up'. We did always fly off lawn though.

I've got a real nice electric vario in my Cygnet. I do miss the lovely beep beep beep of the audio it made in a glider. I can't hear it now over the noise produced by the iron thermal (or my 'too much engine noise hearing').