youngmic

Brentc, Sorry no cigar, check the ASI and it was about -5c.

Thanks for that. Have read your dummies guide in the past but thanks anyway. Comant 121 is a non starter for this aircraft, that is why I sold it. Similarly you won't ever see a 121 on a sailplane but the Xcom is marketed specifically at this group. What are they using and what are the typical mixed results you mentioned Can you offer any specifics on the matter of antennas. Regards Mick

G'day Michael C., I am not sure of the orgins of the techs concerns but will be speaking with him again soon. I suspect it maybe a carry over impression from the earlier models of which both Microair and Xcom had some issues. At this stage your product is looking very good and the confidence of a 3 year warranty is worth noting. It appears antennas are a sore point with radios and I have had some issues in this area in the past as well. At present I am using a S/S whip clipped to length under the belly of the eze, it has not been SWR'd but seems to work fine, reception across the Nullabor is quiet good. I have seen an example of a dipole on an eze in the states where the chap used the thick (2mm ish) single strand copper house wire stripped of its sheath and fixed to the trailing edge of the main landing gear bow which is fibreglass. Apparently reports say that it works exceedingly well but I do not know what radio was installed. I would like to try this type of installation to gauge its merits as I would suspect that it would be an improvement on the S/S whip and a drag reduction to boot. I physically cannot bring myself to install a Comant 121 and I even bought and sold one at a loss unused simply because of its weight penalty. What are your thoughts on the matter, can you recommend a low drag, low weight effective antenna compatible with the Xcom 760. Regards Mick

Jabiru owners, We've all met one or more of them, they hang around airports smiling like they have just one the lottery and the penthouse girls are on the way with the cheque, you rarely see them working on their aircraft they usually don't need to, they rarely go wrong. If you’re lucky you might catch someone building one, but you gotta be quick it's usually all over and painted in the time it takes a proper kit to clear customs. Most of us at one time or another have been held up at the runway hold point with climbing CHT's while we wait for half a dozen or more Jabiru's to finish their formation arrival from some Trans Continental excursion of the Australian outback, all bearing the same silly grin. They've even managed to foul the airways of foreign countries with there unnatural grins, Africa, Malta, India they're everywhere, they're like bloody airborne Model T Fords. They rarely complain much about matters of aviation, as is the time honoured custom of aviators, all is good in their world it would seem. And you would be more likely to hear a lawn mower owner complain about the price of fuel than a Jabiru owner. In fact they even discuss ways of richening up their engines as their fuel usage just seems so unnaturally low they don't believe it themselves, 13.2 L/hr at 100kts indeed. Well here is a new bit of Jabiru light sport, the photos below were taken a week ago on flight from Perth to Cowra, feel free to send it to as many Jab owners as you like. The aircraft is a 1970's design and the engine a 1930's design. The top R/H corner of the Garmin 100 (no not a 496) is displaying 217 kts GS and the Dynon is showing 16.5 L/hr this was at FL135 Maybe that'll quieten them down a bit for awhile

Hi All, I have recently had my old Collins 251 VHF's expire, both inside a week. So time to upgrade, unfortunately I don't have the panel space for a flat type (icom A 200) so I am looking at filling the existing space from the Collins with one of the following: Xcom, Microair, Becker, or Flightline. The aircraft in question is a composite construction Vari-eze and has all the associated issues of radios in composite airframes. Zulu's and Altronics headsets will be used and either PTT intercom or true adjustable VOX capability is preffered. I have heard one unit claims VOX but is open mike all the time? I have been advised to steer clear of the Xcom from a tech but must admit it was/is my first choice at this stage. Any advice on the following would be greatly received: Company after sales support and what they are like to deal with, warranty issues and effectiveness, unit performance, clarity, range etc. Reliability and parts back up. If anyone has a servicable Collins 251 for sale I could be interested. Please feel free to PM me if you wish to maintain anonymity. Regards Mick

Classic Lancair accident by the sound of it, low and slow with flaps in reflex, very light stick forces, then throw in 300 hrs TT and marginal VMC into an unfamiliar destination. Unfortunatley any other outcome would've only been based on luck. Didn't know the fellow but I bet he was doing the best he could under the circumstances. And under those conditions in that type of aircraft it would be a big test of metal for even highly experienced drivers. Was it not the case that the ATSB are simply looking into the safety margins of this and some other high performance homebuilts. And not a case of CASA pulling type certificates.

And on Radium dials, from Rick Durden, Avweb contributor. http://www.avweb.com/news/pilotlounge/191377-1.html I promise you that you will feel infuriated with bureaucracy after this, and I hope you all do. Never give up the fight.

I heard a lovely story when all these security issues came to pass. Apparently a concerned aircraft owner contacted CASA or DOTARS and inquired about various agreeable methods of securing his aircraft. After a some amicable discussion the aircraft owner asked whether it would be considered suitable if his aircraft was imobilised by the removal of the starter motor. The response was that it would be considered secured in such a case. The gentleman thanked him for his time and bid him good day, I think he still owns his Tiger Moth.:thumb_up:

Rocko, I for one think your onto something here with the current crop of jet ski engines, and have wondered for a long time why no one has had a serious look at outboard engines as well. These engines are light and designed to operate with a flat torque curve and run a horsepower absorbing load at WOT for extended periods. Clearly there would still be a mountain of R&D to make them suitable but the core engine does look like a promising start point. As a professional pilot for 20 years who makes his crust flying low level aircraft I'm keenly tuned to engine reliability, I also own a Vari-eze powered by a Continental 0-200 100hp engine. It is largely agreed by those that fly the Vari-eze's that engine reliability is of the highest importance, these aircraft are not designed to survive an off field landing. Nothing I have seen to date compels me to change my engine to either Rotax or Jabiru, (and certainly not an auto engine derivative) they're good but not good enough. Maybe in time, I'm certainly watching the development of the 3.3 Jab. I commend both Jabiru and Rotax for their considerable efforts achieved to date. One of the beauties of this (O-200) little engine is its simplicity. I would not consider that an electronic managed fuel injection system would give me substantial benefits in either reliability, economy or increased power. Certainly some benefits in economy but only small due to the fact that not much fuel is being used anyway. Similarly air cooling doesn't fail, I like that. Increasing volumetric efficiency with a multi valve design tends to compromise cylinder head strength whilst increasing the amount of stressed moving parts. Modern ignition systems are one area where significant improvements can be made, and are. Many home builders are enjoying improved efficiency and reliability from retro fitted variable timing solid state systems. At some point in their operational life nearly all aero engines will be asked to be the sole factor in deciding whether the occupants live or die. Within the company I work for not a single pilot is yet to state they feel safer between the Thielerts than they do between a pair of IO-540's One of the greatest attributes of the current certified aero engines is that they have manual mixture control, and those in the know curse Jab and Rotax for the lack of this feature. I often feel that a lot of the pro auto engine camp are really pilots that haven't learned the benefits and real economies that can be achieved by manual mixture control. And in disgust with perceived inefficiencies go searching for alternatives. I am not an anti auto engine proponent but wise to the benefits of a rugged simple purpose built design. In fact Thielert who are the only company to have a serious go at a modern piston design have found that out, as have our pilots who fly between their engines, the level of electronic dependency has turned out to be their Achilles heel. We have suffered many aborted flights due to partial power losses caused by the electronic fuel injection system. In time these problems will be solved but there is a way to go yet. The fundamental laws of chemistry dictate that to achieve the most efficient use of fuel you need to run your engine at 35 degrees lean of peak EGT, cars can't do this because of there mission role but Lycoming and Continentals can and do. My 0-200 Continental produces 75 hp (75% MCP) for a fuel burn of 19 liters/hr about the same as a Rotax 912S. It is slightly heavier than a Jab or Rotax but the new D model 0-200 for the C162 Skycatcher has apparently shed some weight so the difference is small. And the O-200 Continental is one of the most dated aero engines in service, literaly back to the 30's On the matter of warranty, in the business of making money as aero engine manufactures are why would you put the company in the line of litigant lawyers with extended engine warranties and the prospect of an unfortunate failure and death, one strike and your out. Still at the end of the day sensible development in the RIGHT aircraft of potentially beneficial design advances should be heralded. Just another opinion.

I suspect the best starting point is to talk/meet with all the flying schools within an achievable radius of where you live to determine if there is a need or interest in such a proposal. As for an off the shelf business/economic model this would be something you would need to do yourself as each scenario will be different. Suffice to say that a very simple rule off thumb for machinery operating costs is cost of fuel and then double it, and add bank cost to that. Aviation businesses can be fickle, you need to develop a nose for what is a good or bad thing, RAaus offers a much less risky opportunity than it's GA equivalent. Good luck

A mate does the same thing hear in Oz with a RAAus type and after 2 years it is doing very well. The secret appears to be in the ability to find a very good school who can generate the use and look after it.

Motzartmerv, From time to time I rock on up to the local ** bowser at the countries busiest GAAP airport swipe my ** carnet card and in full view of the tower, numerous flying schools, and the Air ** compound I gleefully fill the odd plastic Jerry can. No one gives a rats, and I have spoken to the refueler on the matter. However if I was to call the Avgas tanker over or ask the refueler to fill my Jerries from the bowser...no way. At this point the Air ** OH&S policy steps in. One way to test the fogginess of the "rules" is if you are ever asked to stop fueling your own container, ask the person requesting you to stop if he/she has the power of arrest, if they don't ask that they summon a police officer and charge you with an offense.

i know that in GA you aren't allowed to put fuel back into the plane after you've drained it..because the container isn't autherised.... Not sure this is correct either, I have heard plenty of engineers regurgitate this one over the years and my understanding is that if an authorized aircraft maintenance facility has a dedicated and controlled vessel they may defuel and then refuel from it. But I may be wrong. As for a private pilot I am not aware that you can not defuel into a clean container and then refuel again from it. During the 90's I operated an aviation business that sole fuel supply was from re-used drums, CASA had no problem with this. Today there exist a major airfield that operates many aircraft fueled solely from re-used drums. Follow Ozzie's sound recommendations and you'll be right. Visit a Mcnaught stockist for a good rotary pump and filter, there are also small electric and engine powered pumps on the market as well. Fueling from drums should be no more risky than any other method if you bone up on the guidelines and use common sense. Having said that I have witnessed a 1/2 inch long spark jumping from the fuel hose off a 1 litre stroke Mcnaught fuel pump back to the drum due to poor bonding. And an old boss reports the same with Jet A throwing a spark from the hose back to the wing when refueling an Ag machine. Both cases, poor bonding.

Jandakot airport has a security fence all the way around it (a good thing) but aside from 2 gates which maybe a looong way from where you have parked, all other gates require a unique and specific (to JT) E gate card. You need only pay a one off $20.00 deposit for this card, you must of course present proof of ID, either actual or forged when applying. The deposit will be refunded upon your death when you present yourself again with proof of ID at the relevant controlling authorities counter. I don't think Jandakot airport is a security controlled airport as it was deemed impossible for any terrorists or others to infiltrate airside via the general public open gate under the cover of darkness and remove a $20.00 padlock from the approved security device fitted to all the lighties. But in the extremely rare event that a terrorist or other could negotiate their way through an open gate under the cover of darkness and remove a whole padlock it was then considered highly unlikely for them to inflict their dastardly act upon a sleeping city CBD or suburbia as the distance of 15nm from JT to the CBD is considered outside the capability of a typical lighty. Even in the event that an extremely highly trained terroist could overcome these obstacles probably the worst he/she could do is perhaps steal one of the parked Dromaders and fill its 3000L hopper with a diesel/ammonium nitrate brew, the detonation of which would barely wake the local dogs in a quiet suburban neighborhood, let alone say a heavy sleeper. Now the country airport in Newman, in WA's remote Pilbara region, well that's another story.... a veritable seething cesspit of fundamentalists eager to launch them selves at the occasional overnighting R22 left waiting and unsupervised and ready to strike out at any number of our capital cities on its mission of evil. Hence this airports security controlled designation and the pin coded 3m high barbed wired gate, supported by the 1m high 4 strand sheep fence. In keeping with DOTAR's legislation for security controlled airports the gate pin code will only be handed out to those that request the code by phone or other means from the airport manager and are prepared to give their full name and aircraft registration, such as for example Achmed Bin Liner capt. of VH-ABC. M

An interesting article on Bio-mechanics in a recent National Geographic appears to be paving the way forward on stall enhancement. Turns out the the protrudences on the leading edge of the Humpback back whales pectoral fins, called Tubercles result in a stall AoA increase of around 8% resulting in a 16% increase in the CL and remarkably a drag reduction of 33%. for the same NACA 0015 section (ie. a whale fluke). Seems this was first discovered in 2003 and is now showing efficiency improvements in wind generator blade design. Just for a bit of interesting info. On pusher engine power on power off stall IAS differences, unless the designer has intentionally limited the elevator effectiveness the difference is attributed to the vertical inclination of the thrust vector, ie. the donks carrying a bit of the weight. M

I didn't realise the Ultrabat was one of his designs. If I remember correctly it was a bold venture to build an ultralight design to compete in the unlimited aerobatic class. Amazing! he certainly was out there, such a huge loss. If he'd been born in the US he could have well become another Jim Bede or Burt Rutan. M

Scott Winton (?) was another local cutting edge designer around the same time. A young bloke who died prematurely in one of his own designs. Set some remarkable records for endurance and altitude if I remember rightly. M

I think it is: Experienced aircraft designer + compotent aircraft builder + Certified test pilot + 250,000 X $1 USD/annum. + 1 pen and note pad = Vd speed. Or: 1 + owner/builder + 1 borrowed parachute + new undies = terminal poo speed. M

There seems to be a lot of confusion here. Readers responding with the confirmation that flutter is related to TAS are quite correct. However it's not a simple as been given in this forum. Sailplane designers are acutely aware of this issue and you will see published in the POH a graph for calculating the corrected Vne as an IAS for altitudes, generally above 10,000' Many will also have several Vne's placarded on the ASI face given for various altitudes, again generally over 10,000' Sailplanes have a somewhat unique difficulty in that there large wing span versus chord, (high aspect ratio) makes them very prone to torsional and elastic issues. Whilst the same principals do apply to all aircraft the short broader wing section is far more tolerant and the frequency response to flexure different. Such that for the sort of speeds mentioned and the relatively low altitude of 9500' it is probably not of a great concern. Unless it is a poorly designed wing (structurally) and proper consideration to mass balancing not followed. In the example scenario given the aircraft is operating in the yellow arc of it's flight envelope, and this means it is in smooth air, or there's a test pilot at the controls. What is of more concern perhaps, might be that you could extrapolate the scenario to a situation where it's about to leave the smooth air and pass through the inversion layer into the layer of convective activity and perhaps into a strong thermal shortly after that may exceed your Va gust envelope, which by looking at the relationship of the Vs to present IAS it will. M

Oops. Thought about this a little more and realised the 582 is water cooled. So I spoke to my dad about this, he's an outboard mechanic and he pretty much ruled out cold seizure factors. And when I think about it in all the years of abusing 2 strokes from outboards to motocross bikes I've never really seen cold seizure, and the small outboards are a classic for this sought of treatment, start to flat out in 2.8 seconds and it never seems to worry them. Even the big ones used to get little respect, think water skiing and motor off drifting in the middle of the river swapping skiers, refreshing beers, laughing at the last crash, then it's motor on take up slack and flat out till you bend the throttle lever, and under a huge load. What he did point out is mixture and timing, some how I doubt timing was the issue in light of the other factors outlined. As the old man pointed out 2 strokes are critical on mixture as the cooling issues are different to that of a 4 stroke. On a 4 stroke the heat path for piston cooling is via the rings to the bore but on a 2 stroke this is tricky as the bore has much less surface area due to the ports, so the fuel takes over to assist in cooling particularly the swirling cool fuel on the underside of the piston crown. Reduce the amount of cooling fuel and the issue can compound quickly. So perhaps the principal issues as in my previous post but with out the issue of piston bore clearance due cold temps may still be a likely scenario. I can see that the question arises of why just one cylinder failing and not the other, but it's not that unusual, rarely do both cylinders experience the same combustion parameters. And looking over the old mans shoulder over the years as he'd pull down another big bore 2 stroke it was rarely the case that all pistons were damaged, usually just one and perhaps another on it's way. And thinking about it given this whole piston failure event happens quite quickly it's not hard to see that perhaps the other one was suffering but still before the point of visible damage and the failure of the first brought the whole proceedings to a close. Good to see you pulled off the forced landing without to injury. M

2c worth. The scuff marks: You stated that they are on equal quarters of the piston skirt, in the world of Lycomings and similar this is an indication of poor differential cooling. What you may be looking at is that the scuff marks correspond with the cylinder base nuts/bolts, and or head bolts this is an area in the circumference of the bore which exhibits more rigidity than the areas between. As the bore dimensions increase with increasing temperature this area is slower to grow and hence represents a closer cylinder bore piston skirt clearance. The hole in the piston: Lean or timing could either or both be a culprit. But essentially what you have is a break down of the cool boundary layer (relatively) of air on the piston crown. The temperatures that occur during the combustion event are of a magnitude much greater than the melting temperature of piston alloy. The only thing that protects and stops melting is the pistons average temperature and that thin but important boundary layer of cool(er) air. What can and does typically break through that layer is a sonic pressure front (flame front) ie. detonation or pre-ignition. Pre-ignition ie. an incandescent spot on the cylinder head or grossly advanced timing will result in very rapid failure < 1min. Detonation is much much slower to destroy an engine and needs to be reasonable severe. Perhaps looking at both your issues in conjunction and history we might see some idea of what happened. You down size the main jet and thus increase the temperature of the combustion event. Now the front cylinder perhaps slightly and inherently leaner now has a reduced detonation margin. I don't know your installation layout but if your front cylinder is cooled by the free stream as opposed to fan cooling perhaps it's possible that the cylinder temps weren't quite there yet and with the application of take off power your pistons are now rapidly heating and thus growing yet the front cylinder being free stream cooled by rather cold temperatures of the day (9'c) doesn't expand as quick as the rear and starts to scuff skirt to cylinder. But so far so good it's still running but now its generating a lot of heat back into to piston (and the cylinder, but piston alloy expands quicker) with the metal to metal contact and that cooler air protecting the piston crown that isn't quite as cool and the mixture that is leaner due to a jet down size, and also the air density which is high due cold OAT thus leaner and the horsepower capability is up due to a leaner mixture and the air density being high and so therefore the heat being produced is up also. Detonation might well be now occurring. If your piston wasn't scuffing you could have perhaps got away with the detonation, or if you had scuffing but no detonation again you might have got away with it, but together it might all just be to much and self compounding. Perhaps the guru's and regular users of these engine might shed some light on whether detonation is an audible event on these engines, it's not on Lycomings and the like. So maybe you don't hear the cry's from your engine. But don't discount a partially bloked jet either. Maybe food for thought. M

No guarantee's and like many have stated wind and temp are usually the key to it. A TAF is useful guide with a FM XXXX (From time) prefix indicating an increase in wind speed or direction. The other is the dew point temperature and reference against this the bottom line of temp's and QNH given for typically 3 hourly intervals from the period of validity of the TAF. If the temperature is forecast to increases significantly above the dew point then this time is a likely indicator. Follow this up with the AWIS if available (number in the ERSA) and it usually includes dry bulb/wet bulb temp's, track this for an increase in the split and it's also a guide. Similarly you can use this in reverse, ie, en-route to a destination regular checks of the actual temp v the dew point can give an indication of lowering cloud base in the late afternoon on an overcast low cloud day. A phone call to Met briefing and speak to the on duty Met officer is often a good way to get a good picture, these guys are usually very helpful. Having said all that even QANTAS and the like get caught out a couple of times a year coming east to west.

The wisest of old gliding instructors said of this same question, "the worst thing you can do to your hobby is make it your career". I ignored him, in the most respectful manner of course, and 20 years in I still feel sorry for those who have to work for a living. From a small Mustering business to Aerial Ag, Float planes, Charter, and now international Survey flying, I wouldn't change a thing. Resolve to never be broken no matter how hard they try, and they will!! Develop a passion for learning, be polite, and if your starting at 35 then work like you've never worked before, and then it will happen. As to how much it will cost, that's easy. All of it! It helps if you have already been to the school of hard knocks. As it will make it easier to smile in the face of adversity. The boom will see you right if you don't dither about. Good luck M

Tie down cables on the GA apron at Maroochy and good terminal facilities, (food coffee). Try the Heli opertors, one offered me short term hangarage (sorry can't remember the name as didn't use it in the end) usual fee, good SA wine. Security is a pain though. Pre organise to aviod delays. TWR guys seem pretty good. Or the golf course at Coolum if that's the venue, aviod the sand trap. M

Yeah right, :big_grin: