ianboag

A couple of years ago I installed the economy tuning kit. Never looked all that hard at anything after that as I figured - Jab plane - Jab engine - Jab kit. Has to be good. Since the latest revision SB018 and the "don't fly lean" stuff in JabaChat I have had a closer look at some of my tuning stuff. I tend to cruise my J200 at 2650-2750 rpm which gives me 100-105 kts and 15-18 lph. The EGT is 700 C which falls in the recommended range of 680-720. BUT when I open the throttle beyond this, the EGT goes UP not down. To about 750 instead of down to about 650. On the face of things it would appear that full throttle operation is a tad lean. I possibly need a bit more main jet (?) I'm reluctant to drill my jet out as I have heard about how one can easily XXXX up all this fine drill small hole stuff. I would probably get another jet and drill that out or just buy a bigger jet. Then there's lifting the needle (I don't know which notch it's on at present)... ? Has anyone been there and done that ..... ? Ian B

Dunno who is interested, but I have been working on the mechanics of AVMET->English translation. You might like to try this .... Go to NAIPS and get an area (or areas) briefing. Copy it to the clipboard (ctl-A, then ctl-C). Browse to http://avmet.msgs.net.nz/ozmet/ (OK OK I know Oz met shouldn't have a .nz address). There's a textbox - put the cursor in it (ie click) then paste your briefing report into it (ctl-V). Then click the 'Translate' button. It's still a work-in-progress but it does TAF/METAR into English with local (for the airfielld) times. I haven't got round to ARFORs or proper decoding of RMKs yet. Cheers IB

I just got a NAIPS login. Oz "area reports" don't look unlike NZ ones. Hacking my code to handle it would be doable (tedious though). But what is RMK T 27 24 21 19 Q 1007 1006 1005 1005 I understand RMK but we don't use ones like this ....

Have a look at http://avmet.msgs.net.nz/TAFMET_info.pdf and follow your nose. Given time and examples, one could add SIGMETS and ARFOR etc. IB

My 2c worth. When you veer hard LEFT on the ground the aircraft tips sharply RIGHT - possibly to the extent of lifting the left wheel off the ground and/or scraping the RIGHT wing on the runway(?). I'm not sure how much steering authority the nosewheel has when things get to this point (tipped sideways). And of course if the aircraft is still "flying" a bit, then hard RIGHT rudder will lift the LEFT side some more. Perhaps it is possible to get to a state where it isn't steerable any more because it's tipped over so far. Why it veered in the first place is a different question IB

It's not reall hard to inspect. Mine cracked at the bottom and up uone side. You can inspect it (cowls off) by lifting the nosewheel off the ground, then trying to flex it fore and aft. FWIW mine had a crack right across the bottom. As noted elsewhere I have repaired it twice but have now given up on it.

My J200 had the original (fibreglass) bracket for the noseleg. It has just cracked for the third time. I probably land too heavy and maybe the repairs weren't all that great. Whatever. Anyway I'm looking to replace it with the ally one used in the new nosegear kits. Jabiru tell me it can be done - I'm just curious to know if anyone else has done it and has any useful comments.

I had an experience a bit like this in a Cessna a week after I purchased it in 1999. I have since had a bit of a think about it and figured what (I think) I did wrong. I was interested to read this one but it sounded a bit different to mine. Until I read the bit "veered left" with "right wing almost hit runway" ie the aircraft veered left and tipped right. Remember that when you are flying and you pile on right rudder the left wing goes up .... I have explained my mishap to a number of people viz x-wind landing, all three wheels on the ground, then right (upwind) wing lifted and aircraft veered sharply and asked for opinions. First question was does the aircraft go straight or veer left or right (it veered strongly right - about half the people get that), next was what to do - half said hard left rudder which is what I did. This of course made the right wing go further in the air etc etc. So I leaned hard on the left toe brake and eventually the plane stood on its nose, banged the prop and left wingtip on the runway, then dropped back on to all three and rolled smoothly forward. Except the prop wasn't turning and had bent ends. The 172A Cessna is one of the most docile aircraft on the planet. The tower observed "that looked like it hurt" ..... I have since decided that my key error was not to immediately whack on max aileron to get the offending wing down. I don't know if this helps as advice in this case .... Jabs don't have the most authoritative ailerons on the planet anyway. The main thing this illustrates for me is that when you move outside the envelope the outcome gets to be quite random. One should work hard to stay inside it. Cheers IB

MET gobbledygook Ask yourself this question. If met info was normally communicated in plain English ..... and BOM/Airways/whoever introduced a set of (international standard) codes to make it more concise ... or safer ... or whatever .... Is there anyone one in this forum who would read codes in preference to plain English because it made flying safer or whatever? On the subject of cost, I need a break to laugh. Here in NZ CAA indulge in all sorts of drawn-out dribble to decide simple things. They just introduced a Recreational Pilot Licence to allow old flyers who can't pass a Class 2 medical to continue flying their GA planes 2-up in VFR conditions not over towns. It took ten years and half a forest. They spent about five years deciding whether the long-established practise of running engines past TBO "on-condition" could continue. CAA staff are well-paid so all their navel-gazing come at a high price. Much of what they do involves dreaming up ways that accidents could happen if a whole lot of unlikely events happen to coincide. If they get bored with that they throw resources into tidying up Rules. They aren't really answerable to anyone and their output of useful deliverables is low. "pilot error" seems to figure prominently in the list of accident causes and they haven't found a way to Rule that out of existence yet. I presume CASA are lean and mean and not like this at all .... Anyway. The Perl for a TAF/METAR translator is freely available on the Net. One would be hard-pressed to spend as much as $10k building it into a MET website. Perhaps the Canadians would donate theirs if someone asked .... there would be some minor tweaks but not a lot. As far as plain-language MET is concerned we have to admit that on both sides of the Tasman the regulator isn't listening and doesn't care.. IB

Confusion reigns. My J200 has the economy kit fitted. I cruise it at 100-105 knots - it's appreciably quieter than 120 knots and I'm comfortable flying like that. I have a fuel flow meter. At 100-105 knots I burn about 15-18 lph. On takeoff the meter says about 33 lph and a 120 kt cruise uses about 25 lph. Both quite believable figures. At the 100-105 cruise the EGT is typically around 275 F (I have an early "thick-fin" engine). The oil temp sits on about 80 C - I have the Aero Classics oil cooler half blanked off with tape. An extended WOT climb takes the CHT to 325 and the oil temp to 100. The EGT looks like low 700's C. There are no problems with oil pressure except for the rather strange (to me) observation that the oil pressure increases as the oil warms up. This is the opposite of what I would expect but since it's comfortably in the green at all times I don't stay awake about it. I did a couple of X-countries last week and in 5 hrs flying (which included six takeoffs) lowered the oil level from midway between the marks to just above the low mark. That didn't seem excessive to me. The engine has done about 250 hrs. At 200 hrs I found excessive blowby in #6 after a leakdown, so I honed the pot and put in new rings then gave it 30-odd hours on running-in oil after that. I haven't done a leakdown since, but the low oil consumption suggests there isn't an obvious problem. I read JSB-018 and ended up confused. Am I running things too lean? All opinions welcomed. Cheers IB

Here's an example of what the Canadians get .... Try this link to see what can be done http://www.flightplanning.navcanada.ca Note the options for "standard format" or "plain language". Obviously navcanada are smarter than BOM (Oz) or Airways Corp (NZ) ...... I know which one I would be reading if I lived there. Pig Latin MET info is not all that hard but it's right up there with Morse code, open cockpits and hand-swung props. IB

Resistor plugs/leads/caps etc I found this link interesting Resistor spark plugs - resistor spark plug caps. Rainier Lamers wrote this in 1999. He's Mr MGL - the Stratomaster instrument people. Seems you can add as much resistance as you like and the plug will still fire, although as you add more the plug becomes more likley to fail if contaminated. He says that the aim of resistance in the circuit is to knock back the spark energy and hence the radiated RFI. If that's how it works, then one would think that it doesn't matter whether the resistance is in the leads, caps or plugs ..... IB

Here at Feilding we have a 2.00m tall person who came for a fly in my J200 and has built himself a J230 ...... Unlike me he doesn't need to sit on a cushion! PM if you want to know more,

It seems that a resistor in the plug circuit is considered a good idea. There are resistor inserts for the plug leads and resistor plug caps and resistor plugs. Resistor plugs seem (to me) to be a good way to do it. The standard NGK D9EA would be replaced by the DR9EA. Has anyone done this? Was it useful?

I have a fairly standard J200 and MicroAir 760. Works OK - quite useable - but there's enough noise to be a pain. It's plug noise as far as I can tell - tickety-tick and not a whine. Squelch deals to it most of the time. What do we know? Who has had this problem and dealt to it? Plug lead resistor inserts? Resistor plugs? Super Cheap noise reduction kits? Snake Oil? All ideas gratefully considered ... IB

Have a look at this ..... METAR Translator

Just one other thought we had been kicking round here - if translator software exists then it would be a bit of a hoot to put it on the Web "for training purposes only" and "never to be used as a met planning tool" and all that. Then one could get the Met from normal Net sources , and cut/paste it into the "training" website as a check that your manual analysis is correct. Perhaps you might even find mistakes in the software. At least the software would probably know which times are local and which are UTC and which directions are true and which are magnetic ..... but I'm probably the only pilot on the planet who doesn't have all that good stuff at his fingertips. :-) IB

Here in NZ we have similar grumps with weather info presented in gobbledygarbage. There's an outfit in Dunedin (Flysafe) who wrote a translator (to English) as part of a nav/planning computer program. Have a look at Redirection if interested. I haven't followed this thread so I don't know if I'm telling my granny how to suck eggs here ... but .... if you log on to the Canadian equivalent of AirServices and get a TAF/METAR you have the choice of ggbge, English or French. So it can't be hard. They have been doing it for years. Go figure. There's a lot of bureacratic stuff about it here on this side of the Tasman. I finally got to talk to the man in charge of avmet in MetServices (our equivalent of BOM). I said that presumably the forecasters make it up in English before turning it into pig-Latin, so if we could just have the English ..... Not so! There people look at a map and the Greek just flows. Amazing. Still - one would imagine they would pick up English pretty quick. As was pointed out to me, they are all uni-qualified! Cheers IB

Airmaster in Auckland are working on a 2-blade VP prop to use the Sensenich blades. Although the hub will be quite heavy (probably 8 kgs or so), that's all along the centre so doesn't make much contribution to the rotational inertia. I would guess that this prop will come in at or close to Jab's rotational inertia stated limit ..... Sooooo easy to keep spending money :-)

So what happened? You dremelled them off? Lack of trim problem all gone? Still need to do springs and things? IB

I have a fuel flow meter and it totalises, so I tend to go off what that says I have left. That's OK so long as I don't have a leak out of the fuel drain I suppose. One of the things that keeps me calm is the breather tube from the underseat header tank. It goes back to the wing tank just beside my left ear and there's a few inches of it visible above the top of the pillar cover. If there is any fuel - in either tank - then this breather is full of fuel almost to the level of the wing tank. So long as I can see fuel there I know that everything is feeding OK. Turning off the left or right tanks (individually) does not affect this level. If I turn off both tanks the fuel vanishes out of the breather tube instantly as the header tank starts to drain. 6 litres though - it would still take a few minutes to cough the engine. I'll try the "ball in the guts" approach ...... IB

I have to say mine (in a J200) appear pretty useless. As soon as I take off something like 15-20 litres seems to disappear from each tank. A tank with 20-25 l in it appears to be empty most of the time. I tried putting one wing low or the other and it doesn't seem to make a lot of difference. Is this just me?

Duct is clamped under four SS strips. I didn't think of the heat thing but it doesn't seem to be a problem.

We all encounter these things and find our way to separate solutions... my solution was to fabricate four stainless strips that go under the top rocker cover capscrews on the front two and rear two cylinders. The ducts are clamped under the strips. It seems to work fine. Can do a photo if anyone is interested. Even after I did that, the ducts were still a bit wobbly at the front, so I put a light ally bar across the top to fix them to each other. For me, this all came about because the floppy duct (with the flogged out hole) wobbled enough one day to loosen two spark plug leads on the back cylinder and the plane went all asthmatic. If this was GA there would have been an AD and a factory-approved fix ..... There was a story about one Jab jockey who was doing a very high speed pass over a field when BOTH ducts let go and suddenly he had no connected plugs (or not enough to matter). As he was over a field I gather it all ended happily enough. IB

True. That said, every Piper and Cessna tricycle aircraft has differential brakes and a non-castoring nosewheel ...... as I recall a Cub does as well (in my youth I managed to ground-loop one). I would guess the simple brake system on a Jab is dictated as much by weight considerations as anything else. Wandering round the field and looking at other microlights - the Pioneer 300 and Zenith 601 also have separate (toe) brakes and a non-castoring nosewheel.