jetboy

Ulpower issued a SB 3 wks ago about ECU connections corroding, whether this has anything to do with the 3 Bantams currently inoperative and the other one's electrical failures I havent heard. Otherwise its been a good engine in NZ so far. Ralph

Not to say they are a gimmick but thats the only category you left for me to apply; In summary, and having used one, I cannot think of an RaAus type plane suitable to use them on, especially STOL style with slats/VGs. The reasons I guess for ineffectiveness: No indication compensation for different weights carried No indication compensation for amount of flap deployed In the context of the type of planes we fly, I think it does not adequately address the relationships of low inertia vs. airspeed and power settings, in gusty conditions where outcomes change quickly. Dont be put off by my opinion, it costs so little to try one the plans are readily on the net and the indicator gauge is an off the shelf HVAC device, and calibration is easy to do. Ralph

I tried one, useless in CH701, Easy to build but just not meaningful enough (things unravel fast in a 701, no time to watch what the clocks are doing) I could install it again but it is a waste of panel space Ralph seeing your poll has got ages to run I reserve my decision

4 x EGT because you have 2 carbs and float levels to keep out of balance, far more interesting than CHT Ralph

Hi Andrew, Quite a few topics here I'll start from my experiences with the O-200 over a 12 year period where the maintenance manual expects it to be flown daily if not weekly, any longer than about 4 weeks is considered requiring storage treatment, of course we all can't meet those desires and I frequently felt and heard the rust scrape off the bores on first pullthrough, after as little as 3 weeks tiedown, this also happens to my 2200 and is just one of those indications that I'm not flying enough to make taxicab mileage out of the engine. Looking at the 4 logbooks of the O-200 showed those 1800 hr cylinders typically pack up in 6-700 hrs although some did go longer. The ones that got repaired the most got repaired again the most. My new cylinder kits had to be reworked twice in 200 hrs possibly because the LAMEs neglected to use the correct oil - nothings perfect. My 2200 did 300 hrs in 6 years when I replaced the exhaust valves because of minor leakage - very small pitting on the seats and valves - it appears the problem here was insufficient regular running. I thought, in reading up on the website, Jaba Chat etc. that the valves are one piece construction, certainly my new ones look to be, and all the AAIB recent investigations point to lean mixture causing valve stem failures in UK, very lean low octane fuels in my opinion, as I know my engine did 50 hrs at the leanest and meanest tuning kit and a further 200 hrs without anything like the look of problems to the stems. I really don't think theres anything worth spending time on changing, once you have the revised cylinder - piston clearances, revised basenuts, cooling and oilflows & valveguides OK the factors affecting its longevity are more in the way its operated. I have since only done the basenuts mod - if I had known about the honing and ring work that would have been done at the time too. It was worth 200rpm more in flight which is a substantial increase. There is nowdays a huge amount of info in the manuals, Jaba Chat, etc. that needs consideration before 'making it better', especially the facts that they've gone thru 2 or 3 valve suppliers and seat types in the search for the holy grail....and still searching. Half my friend's 912s have delivered heaps more failures, so I don't see them as better, just different. Yes I'd put a 912 in my plane, except I can buy 2 new 2200s for the same cost of changing over, so in my case it would be a nicer to fit a UlPower, if they ever get a track record, because of the mounting arrangements. For cost and reliability I'd go with their carb option, or consider the aussie TBI. I'm really hoping my 2200 will just wear out slowly, say over the next 6 years, with the normal maintenance work, and plan to replace it because overall it will be marginal to refurbish some areas. A case of "the whole amounting to less than the sum of its parts", to misquote an old Greek saying. Ralph

4aplat, If you are removing the heads etc. to work on this, then you should carry out the machining required to the cylinder base nuts at this time. Jabiru issued a bulletin last year, and it is described in some issues of Jaba Chat, on the website, and you will also discover the service bulletins and details of leakdown testing there. Looking at your plugs, I think its an oil problem, either valveguides or more likely stuck oil rings in 2 of those cylinders. Jabiru has acknowledged the original cylinder basenuts can distort the barrels and cause other problems. It would be good if you can get the help from another Jabiru owner who has aready done this type of work. Ralph

Com refers to the usual VHF radio Navcom refers to a unit with the same radio plus a VOR navigation decoder included and a VOR display instrument. Fairly obsolete now especially in rec. flying not much VOR coverage at the levels we fly. i tried one in a Bantam once had to get hypoxic before it would start to work. ADF not much good either, too much crab angle in a Bantam with a crosswind! Usually they had a nav side and a com side, the nav part having its own antenna and separate receiver so both functions could be used simultaneously. Some particularly crude types like the Narco Escort shared the reciever and had to be switched manually between functions. Ralph

Reply to Bascheffers: Yes you can combine antennas, fit diversity receivers, its just not going to help when the problem is occuring in the circuit, My old job at an HF radio station we routinely used triple diversity systems to haul in signals, the problem on a mobile situation is any phasing of antennas will result in main beams and deep nulls in certain directions, so its not the go for Tony "Can you explain I wont recommend any of the antennas pictured they wont be secure or approved for airbourne use" . Those antennas just have a coarse thread mounting boss and can come loose and depart an aircraft. If the aircraft is a pusher or a helicopter the effects on safety are more than trivial. If you are already using one, I'd suggest drilling and using lockwire. My VHF antenna is mounted with a doubler plate running aft of the baggage space in the centre of the roof (the doubler was already there courtesy of CZAW) The antenna I used was ACS part 11-04516 and cost about $25 however they are a bit heavy for the 701- I ended up welding a smaller diameter SS whip section into it and If I was doing it again would probably use the much better D&M C63-1/A part 11-02764 (ouch- the price seems to have gone up since I last got one). These properly compensated broadband antennas are more likely to work first time and have connections suitable for the correct cabling which generally saves installation time and rework. Ralph

If people cant hear you in the circuit its more likely a headset / radio problem Some headsets overload the mic input to radios, this can be adjusted on the Microair by someone with a modulation meter. This was the problem on the Savannah + Microair I fixed here, local club wouldn't allow it to fly, gave readability 2 reports, radio adjusted lower gain (much lower, like 50% modulation on strong voice as in riding behind a Rotax at full noise), readability now 5 and cleared to fly. Also these radios do not discriminate between pilot and pax mic sockets, flying solo best disconnect the pax headset, this has caused many "radio faults" around here. I wont recommend any of the antennas pictured they wont be secure or approved for airbourne use and the Aircraft Spruce agents can get you much better antennas for the job. If your present antenna is "good" for SWR then there is no need to change it (but make sure it wont fall off) Ralph

Hi Tony, Your'e not telling enough of the story; like exactly what plane this is, why it sometimes does OK and other times not. What is the SWR for 118.0, 128.0 and 136.0 frequencies? I ask this because one reading is not enough to meet the spec and normal whip antennas seldom meet it first time. I'll start by stating that attempting multiple antennas is not the way to go, and rubber duck antennas are unsuitable if you are looking to have any sort of range. A bent whip (when the bend is at least further out than half its length) is OK. I have a CH701, bent whip on top, 5 watt radio and it works to over 50 NM from 1500' in all directions. I am a radio tech and have field strength tested some aircraft (not this one) by walking around them with a meter to confirm the radiation pattern. With the aircraft you described I can't imagine any problem, assume the top whip is a metre away from anything else - other antenna - ELT - rudder ? If the problem is reception in certain directions, there could be issue with interference from engine - strobes - HID or LED lamps ? Ralph

prop vibration would not be an issue if we could get a 3 cyl inline 2 stroke diesel; there are some nice sized 4 strokes about for running cars, fire sprinklers, gensets etc. often run around 3,000 rpm. At my work the smoothest powerplant we had was a V16 Detroit (essentially 2x V8 in tandem) they do require a turbo to operate, and use conventional valvegear, most diesels use a turbo anyway. Is it just a green thing that prevents having a small 2 stroke diesel? I've also been considering Avtur (Jet-A) as a kerosine fuel for spark ignition engines, small gensets and the old Fordson major tractors used to do this, at the moment the only likely engine for this is 75hp Austro rotary Error Ralph

not sure what the type of heads has to do with the Jabiru in question, but do jabs in Oz have the same AD requiring fuel sight gauge verification since the 2 forced landings in NZ attributed to wrong labels being supplied with the particular model tanks here? Ralph

I have 2 friends with these in aircraft (that don't post here) so will summarise what i was told. One has the MRX in a GA aircraft and likes its operation One has the XRX after first getting the MRX which didnt work well and the last report was the XRX was generally useless but better than the other. If I was buying one myself, based on the specs and reports, I'd be using the MRX in my microlight. They only work if the other aircraft has its transponder on and within the ground secondary radar coverage area. (unless a TCAS equipped airliner is within range) If you fly in areas where your transponder does not get interrogated continuously the Zaon wont be working either. Ralph

Thanks, good detailed report. There was a comparison here last week, The Powered Sport Flying Radio Show seemed to have same conclusions, with addition that the Aera has no compass safe distance, pretty bad for use in anything that uses a compass as primary navigation..... I'm having enough trouble upgrading to a pilotIII from my failing GPS90; there are some things the 90 does better and I had to reinstall it by the time the display is completely unreadable I'll have learnt how to sort the replacement Ralph

2 carbs no good for redundancy on the 912 when one carb falls off the engine wont run too good I saw this happen and the plane had to be pushed off the runway couldnt even mange a taxi back to the pits Ralph

None of this has anything to do with "cold seizure" that commonly happens to 2 strokes when they blast off at full noise and then are throttled back too quickly at the top of the climb. It happens to air cooled and water cooled but the most reliably performing hand grenade engine in this regard is the Rotax 618. It is thought to be a case of piston / bore expansion rates when the EGT suddenly goes up, and the engines normally run 'OK' after the forced landing event, but the scuffing has started the galling process in the bore and its only a matter of time things get worse. Enjoy your thermostats, they just work better when there is water in the system. Ralph

Look for antennas spec'd as broadband (usually 108-136 MHz with a VSWR of 2.0:1 or less). D&M C63-1/A is a good example and the way they achieve this is a 12 ohm carbon resistor encapsulated in the base in series with the cable connector. As Dieselten says a small loss of power or signal is not a factor in operation of the radio, these radios and headsets are quite susceptible to bad match of the antenna, problems also may knock off your GPS reception too. Straight wire whip antennas are cheaper but limitations above make them more troublesome with multi avionics installations. Just use RG58c cable NOT foam low loss from the TV installer, you need the loss to control the SWR at the radio with a whip antenna. Ralph

I've got a couple different of 35W HID systems and they both are auckward (bulky) and put out RFI sufficient to be a concern and I have not found a suitable reflector to give the sort of beam desired. They make good jet engine ignition units though. What I use is a Halogen display lamp, the latest generation of these are near the same efficiency as HID and only available up to 45 watt (replaces regular 75 W halogen) The one specifically I use is Philips Masterline ES 12V 45W 08 deg I had a hangar shootout against a 4509 landing light (100W), a 50W halogen version of the same, a 60 deg Masterline and the 8 deg Masterline which was the best to use. These ones also have a curved front face and the burner assembly is enclosed, making them more suitable for the job Ralph

You get a reasonably accurate reading wedging the collar that contains the junction, after cutting off the ring and removing any plastic sleeving, between the first fins nearest the exhaust flanges. It might read 75 deg F higher than the plug ring system, just do dual check on same cylinder probes first. to be sure, use heatsink paste and cover the crevice where the junction is with silicone RTV then you know you are only reading the heads, not the surrounding air or the sparkplug temps. Ralph

The nominal impedance radios and intercoms are made for aircraft is 600 ohms, most will be satisfactory with much lower. If you needed to drive domestic headphones such as 8 ohms then use the speaker output (check required as some spkr outputs must not be grounded). If your volume level is too low with the DCs in series, it may go up with parallel. Some intercoms just parallel all outlets so you can only go so far with the cheap ones. Ralph

well thats funny they seemed to blame humidity for the P versions when they played up too http://www.recreationalflying.com/forum/avionics/16573-my-radio-stopped-working.html any more specific as to what "component"? you need to file a couple of SDRs with the CAA for your failures if anything is going to be done pity it wasnt a Toyota as a minimum theyd send you a couple of floor mats Ralph

You can buy a UFO. I dont see them often around here, they are extremely quiet at flyins because they never get off the trailer....sometimes dont even know theyre there. Most are sold to South Africa I believe. Ralph

its likely that iHUD will also be adaptable to work on the ipad, much better display, should be as good as the cat and duck IFR method Ralph

Andy I covered that in 2nd paragraph, indeed the shorter blade has slightly less thrust so the pich is adjusted accordingly to get the blades in line (coning angle as observed side on to the disc) just mark one blade with white dot for ID I know it sounds all backyard but this is what I was taught from an RC model helicopter guru and similar Bantam owner at the end of the day it worked perfectly well vibration gone and this was on a NEW aircraft with NEW prop so no point in arguing with the suppliers they really didnt know any better just a waste of time and $ Ralph

There is also the method using a plug that fits inside the exact centre of the hub and the prop is suspended by a string so that any out of balance is revealed by both tilt and tist of the blades. Such and adaptor can be purchased or made. I've statically balanced props both methods and prefer the hang way. with Warp drive blades I had to cut 10mm off one blade tip to get the brand new set in proper trim. Just drilling (the prefered fix) into the end of the heavy blade was not enough. The coning angle was then checked on the plane and that blade was repitched a further 0.3 deg to match the thrust. Ralph