ianboag

And a few months ago, a 230 owned by the NZ Jab agent blew its bolts. It was about a year old. Engine had the new starfish thingo. That was not long after his 120 broke a through bolt, threw a pot and trashed the engine. These little things are sent to try us ......

Hasn't Don retired? Higher cruise revs are a given of course - one doesn't want to be too slow. Vev tells me with is fined-off-leap-off-the-ground prop he cruises at 105 knots/3150 rpm. Every bit of folklore one reads about the Jab engines says that is good for it. Only drawback I suppose is that it tends to be a bit noisy in the cockpit.

Ralph? The 2" was where I started here and a Brent Thompson prop. Brent thinks 60x40 is good for Jabs. I am tempted to push this a little further 64x38 (more diam - = more thrust - and less pitch). It will fly I'm sure and if it ends up over the bar so be it :-) Just curious to know if anyone has tried this before on a J160 ...... IB

So - be a dev Nev - what would you do? Yes 42->38 would be a huge drop if one was not increasing the diameter ..... That's why I have a 60x40 on order with Brent. In your money it costs a whole $A700 which is not a lot compared to the cost of a Jab plank or a Sensenich or anything composite .... I'm curious to know if anyone has gone the slightly-more-diameter-less-pitch route or would I be a pioneer? IB

Man in Christchurch is Brent Thompson. Here at Feilding we have good experiences with his product. There's a man with a 3300 in a Zenith who says his BT prop blows the Jab one into the weeds. Ditto with a Pioneer 300 here where the GT prop was taken off his 3300 and replaced by a BT one. I have a 60x40 on order with Brent. There is about a two month lead time. You know you're at the front of the queue when he sends a bill. I'm wondering about a 64x38 instead. The static thrust is quite a strong function of the diameter ..... One has heard the term "plank" used about the Jab prop :-) Just curious if anyone has already done any of this ...... Warp drive even? The Sensenich ground adjustable is a bit more money than I feel like spending. IB

I like the idea of getting my J160C off the ground in a bit less runway. The obvious (?) way would be a finer pitch prop. I am OK with the resulting drop in cruise speed. Say going from the standard 60x42 to a 60x40. Not that a J160 will ever be a Zenith 701 or Savannah or any of those football-field planes, It also wouldn't seem off the planet to go to a larger diameter prop - say 64x38 even. 4" on the diameter is 2" on the radius etc, so one would have to jack the nosewheel up a couple of inches which should be reasonably doable. Has anyone been there and done any of this? IB

If you fish around on the Net about this one, opinion seems divided. I have heard opinions that hot leakdowns are likely to give better numbers than cold ones (expansion and all that). On that basis, if cold numbers are OK, hot ones are likely to be better .....

They are from ARP in the US - http://www.arp-bolts.com

Don't get me wrong. I'm not trying to bag the Jab. I fly a 160 that had a valve grind at about 800 hours which isn't too excessive IMO. There's something about all this that we don't understand.

We have a one-year-old 160 hr J230 on the field here that just burned an exhaust valve. The (fine finned) heads also show signs of crush. It has been maintained properly. Go figure.

Dunno. The waypoints are sorted by distance, so assuming you don't point at anything much more than 100 nm away, the list to scroll down can't be that long. A search function would require firing up the KB which would be real hard work in flight ....

File>Configuration>MovingMap>Pointer .......

Spot uses GlobalSat - I gather there are significant holes in the coverage from time to time. Google it .... Spidertrack uses Iridium which costs more and has much better coverage. I've had one for 12 months or so. Total peace of mind flying anywhere. Reinforced by the calls from Search and Rescue when I was at the home airfield and had forgotten to log the unit off so it came up in the monitoring system as a sudden stoppage :-) They have a stepped tariff structure - I'm on "up to 8 hrs/month" for about $A16. Overage costs about $4/hour. I use the "auto-on/manual-off" variant that they call Spiderwatch.

Spider Tracks blows EPIRBS into the weeds ....

On the other hand You are using Airservices Maps! They show terrain and CTA. The GPS's can show waypoints/airfields. Otherwise would have to look at a book or read the T&B All there on the el cheapo The el cheapos use maps from Airservices ... at least as good a Jeppesen? What's on screen is what's on the paper! No contest .... get Slarti to help you out. Spend the savings on a weekend away somewhere nice with the wife

So where would one find out how to do the conversion?

Ian. I take it you are suggesting that the best thing I could do for aviation safety is to take my site down and leave folk back grumbling about gobbledygook. Wot? Noone is compelled to use it .... BOM could try the Canadian approach - http://www.flightplanning.navcanada.ca/ - choice of plain English or jibberish In NZ CAA beat MetService round the head a bit and now our MetFlight (Kiwi NAIPS) has an (optional) PLM link with the following disclaimer >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> DISCLAIMER You are leaving the MetService MetFlight Homepage and will be redirected to an external translation service. The user assumes the entire risk related to its use of this translation service. MetService is providing the link only and disclaims any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will MetService be liable to you or to any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profit resulting from any use or misuse of this data. MetService is not responsible for the contents of any "off-site" web pages referenced from its servers. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> IB

I think Os is right - it's a trend METAR and I had stripped off the TTF. Guilty as charged. My bad. Apologies all round. This is the sort of thing that can happen when a non-meteorologist makes a met site and the "authorities" (BOM in Aus, Metservice in NZ) offer zero help, have zero interest in doing it themselves and pretend it's all not there. Backed up of course by CASA/CAA. The latest "Vector" (NZ CAA magazine) had an article about weather - how vital it is to get an official briefing, how useful the TV/press can be, what a good idea it is to look up webcams, how you should think about phoning people on your planned route to ask them about the sky etc etc. Everything but PLM. Go figure. As far as TTFs are concerned, the basic problem with my translator is that when it gets to the <RMK> bit it is pretty much expecting plain (or abbreviated) English (aside from the rain/QNH stuff). So I was not sure what to do with gibberish and just left it "as written". At some stage I will get around to letting the gibberish translator loose on trend METARs and we'll all be happy :-) I assume one of the reasons this has never cropped up is that the kind of rec pilots who use the site don't fly into the big international airports very often. Cheers IB

Drat - my mistake - it was so long ago that I wrote this thing .... Now that my memory has been prodded I do remember something about "Trend Metars". We tend not to see them in NZ, so I had forgotten about it. Thanks for putting me straight Mr Ossie. Cheers Mr Boag

Fair enough. One is always ready to learn. It says "METAR" but it's a TTF. Got it. We try :-)

Here's an example of some non standard stuff from BOM (today) This is a METAR, but the forecaster has packed a TAF into the "Remarks" bit. My translator doesn't really expect the "remarks" section of a METAR to be a TAF written in gibberish. IB

I actually think the gibberish is a good idea. It is a very restrictive language and means very standard things. That means it is easy to (accurately) translate into English via a computer. I have to say BOM are a bit naughty with ARFORs though - they tend to be a higgledy mix of English and gibberish. That's because there are no ICAO standards for ARFORs. BOM could happily do them in plain English and not break any rules ... I think the ideal situation is to preserve the gibberish, but provide an optional (yeah right) PLM translation. That should make everyone happy. Now where I have I seen someone doing that .... ? :-)

Airmaster VP prop They now make a 2-bladed one using the Sensenich ground-adjustable blades http://www.airmasterpropellers.com/Products/ProductDescription/tabid/97/agentType/View/PropertyTypeId/30/PropertyID/19/Default.aspx

The prop thing Jaba Chat August 2010 ... And yes, Sensenich have issued an SB about paint cracks at the blade roots. There were prop extension problems on at least one Pioneer 300 which lost its flywheel bolts on our field back in 2006. The (non true) 4" prop extension was from Pioneer - the prop was a wooden two blader from GT. The plane now has a 4" prop extension supplied by Jabiru.

Perhaps this should be in another thread about props. There have been a moderate number of Jabs fitted with Airmaster VP props over the years. None of them (that Airmaster know of) ever broke the engine. The Airmaster weighs about 12 kg, but of course it's the rotational inertia that matters - the actual weight of the hub is not really an issue as it's in the middle and makes little contribution to the rotational inertia. Airmaster have been working (for years now) on a 2-blade VP prop using the blades from the Sensenich ground adjustable. The Sensenich ground adjustable prop is approved by Jabiru because Sensenich did a heap of testing on it and they are a big prop manufacturer. I don't know about the inertia of the ground adjustable prop, but a VP one using the same blades would not be very different inertia-wise although it would weigh a whole lot more. I know someone who ran a Woodcomp 3-blade VP on a J200 for a while - I think he took it off when he smacked a blade against something on the ground and broke it off. I never found anyone who run an IvoProp on a Jab engine. They would not be too bad inertia-wise either. IB