Navex's

[hihosland]

Thanks for the reference Mike.

 

The "yez getz wotz yez pays for" rule remains valid.

 

Davidh

 

 

[facthunter]

Magnetic compasses.

 

Hihosland, the horrible conventional magnetic compass has these errors because the magnet in the instrument is pendulous. and is not sitting flat due to the fact that the earth's magnetic lines of force are only horizontal at a point we could call the magnetic equator (for want of a better name), where all works well.

 

The tilt of the compass card system makes the centre of gravity of it move away from the nearest magnetic pole, causing the turning and acceleration errors we are supposed to know all about As you get closer to the magnetic pole the horizontal component of the mag. lines of force reduce as they eventually become almost vertical and the instrument becomes pretty useless .The only good thing about a magnetic compass is its simplicity and the fact that it does not need power to work. It is worth remembering that the earths magnetic field is very weak and the compass is affected by ferrous metal objects near it, including parts of the aircraft & probably electronic gadgets as well. A bit of heavy metal I was involved with a lot of years ago had a device called a gyrosyn compass, with a flux gate out near the wing tip, well away from these influences. If a flux gate is part of these modern electronic systems, hopefully it can be located remotely as well, with advantage.. N......

 

 

[facthunter]

Direction.

 

Pelorus, do those dynon gizmo's really have accelerometers in them? That's incredibly high tech. To the people who like a DG. & artificial horizon, these items, being mechanical (either vacuum,or electrically driven) with a gyro for stabilisation, are expensive,& subject to a relatively high failure rate. the electric ones are the more expensive. Invariably, the gyro direction indicator, because of precession (friction in the bearings) drifts off the set heading & has to be reset to the correct heading, about every 15 minutes, however without the stability of the DG, heading keeping by reference to the magnetic compass only, in rough air, requires a fair amount of attention, to say the least,& in the circuit, you are better to time your turns & correct by looking back at the runway.

 

If you want more precise information, the obvious way today is to go digital, as while it looks expensive, if you do your sums ,it is cheaper (& lighter) than the mechanical alternative. Remember that despite all this data,as impressive as it may be, give consideration to what would be left if the power had to be switched off due to some smoke coming out from under the dash, and keep a good lookout outside as well as on your panel ...N...

 

 

[Guest pelorus32]

Hi Nev,

 

the text below comes from one of the Dynon user manuals:

 

"Attitude information is obtained from 3 solid-state gyrometers, 3 solid-state accelerometers, and the airspeed pressure sensor. Heading information is obtained from 3 solid-state magnetometers housed in the EDC-D10A. Airspeed, altitude and angle of attack are obtained from three separate pressure transducers."

 

Regards

 

Mike

 

 

[facthunter]

accelerometers etc

 

Thanks Mike, To me that sort of thing is close to unbelievable.The way to get that sort of information is by measuring the distance an electron beam misses a target, when you accelerate the whole contraption at right angles to the beam, is that the idea? Can you get an angle of attack readout?..N..

 

 

[Guest pelorus32]

Now Nev, settle down. I might be able to tell you what...but as for how....it's all magic to me.

 

However as for AOA - that's measured by what looks like a glorified pitot probe. It has the main pitot inlet and then underneath on a beveled surface a series of other tubes. As the AOA increases the relative airflow strikes the subsidiary tubes more directly and so AOA is "measured".

 

Regards

 

Mike

 

 

[Admin]

Like this one although it is upside down and you can't see the little holes in the angles part of the tube

 

 

 

[jcamp]

The way to get that sort of information is by measuring the distance an electron beam misses a target, when you accelerate the whole contraption at right angles to the beam, is that the idea?.

The accelerometers are (somehat simplified) basically a weight on a beam with the deflection being measured by a strain guage. The whole thing is etched from silicon using the same process as is used for IC's (often the same piece as used for associated temperature measurement and signal processing) and they are packaged as IC's

 

The gyros have tuning forks rather than spinning wheels and are made the same way

 

All this stuff is widely used in cars hence are quite cheap - Putting a system together can be a bit tricky. For more info:

 

http://www.analog.com/en/cat/0,2878,764,00.html

 

 

[facthunter]

Dynon.

 

Thanks Jcamp, Ian,& Pelorus 32. I got active and found & registered on, the Dynon forum. Dead easy & you can ask anything and you get company people to respond almost straight away. The thing that bothers me somewhat is the terminology used to describe course /heading, track etc. There is no standard set of names and this leads to confusion, Particularly when abreviations are used. Pretty hard on the instructors when you have several names for the same thing. The last thing that you need. We even have multiple names, within australia Then we make it worse by using systems that apply american terminology. Applies to some of these little calculators that are used also, which almost rules them out as far as I'm concerned. As far as the DYNON set of products is concerned, I get the feeling that a modification by an appropriate download might be possible to organise, We would have to agree on a national standard first ( we should do that anyhow ) Nev...

 

 

[timshel]

GPS Failure over east gippsland about three weeks ago. Garmin 196 was tracking 12 sattelites then six then 3 then 1 and they were all gone...... Lasted for about half an hour. Then came back online without a word of apology. Am told it happened to others but don't really know why. I am committed to inflight use of map and whiz wheel, I will purchase two GPS, and I have flight planning software on my PC and PDA. I believe in redundancy. The cockpit is no place for regrets.

 

 

[vk3auu]

Sometimes you just need to get your head out of the cockpit for a while to see where you are at; I'm serious.

 

David

 

 

[Ross]

Hi Paul

 

I have no experience of flying in the high country. I think the highest thing around here is the MTN 9 aerial at Griffith.

 

 

 

Were you above all the surrounding terrain when your GPS failed?

 

 

 

Regards

 

 

[PaulN]

Well above it Ross ... as always ;). Some may frown but when over alpine areas and nearby terrain I like to be up around 9500' or so.

 

Paul

 

 

[timshel]

I have alot of hills around here: Mt Hotham and Koziosko to name a few (each well over 2000m AMSL, I would love to learn more about mountain and rough terrain overflying - any good courses or books or websites or any other resources you can recommend?

 

 

[Guest pelorus32]

Hi Tim,

 

try these:

 

http://www.mountainflying.com/

 

And for a course:

 

http://www.flywanaka.co.nz/mountainflying.html

 

You want Ruth.

 

Regards

 

Mike

 

 

[Admin]

Hi Tim

 

I am not sure here in Aus and I hope someone else can offer a suggestion but I do know of a great one in New Zealand. Apparently after you have done the course over there you will know everything there is to know about flying around and between mountains. Let me know if you want some info on it and I will look it up for you!

 

EDIT: Mike thanks - you beat me to it!

 

 

[PaulN]

Funny this should come up now, I've been talking with Ruth just last week about the possibility of hiring a Tecnam for a fly-your-own scenic around the Sth Island of NZ next month. Here's her comments ...

 

Dear Paul,

 

Thank you for your email. I have been flying the 206 today..hence my late in the day reply!

 

Yes you are able to transfer your licences to a 'holiday' Microlight (Or ultralight ) certificate with us, to an eqiviliant level of the rec licence you currently hold. This is valid for 4 weeks and all you need to do is fly with myself or my CFI for a check out. Similar to a BFR and we have a chat about airspace and airlaw as well. If you wanted to transfer your rec licence to a NZ eqiviliant then you would need to sit airlaw with us. However this is not necessary if you choose the 'holiday' licence.

 

Once we check you out, we may fly with you again in moderate wind if we have not had the opportunity to do so, as the wind here can creep up without warning. How long the check out takes is dependant on your skill level, however if you fly the CT I would imagine it would be a straight forward type conversion.

 

The cost for administration to join our afflilated national club is NZ$65.00, regardless if you do the four week visitor licence or join for 12 months. The airlaw exam is NZ$10.00 and our hourly rate is NZ$179.00 dual or solo.

 

Once you are signed out you can private hire our machines for the same hourly rate. All rates exclude landing fees and airways charges.. E.g. landing fees at Wanaka is NZ$7.50 and Queenstown is one of the expensive ones at NZ$30.00.

 

At the moment we have Tecnam Sierra and Echo Supers online. Our national club is called Sports Aviation Corporation.

 

We are recreational only, in regards to Instruction towards your NZ PPL. However we do have have access to GA machines that we can take the both of you for flights in or there is another operator in our building that has a cherokee and provides GA instruction. I can also recommend various accommodations.

 

Best regards,

 

Ruth Presland

 

I also made enquiries about hiring and flying a 172 and whether my PPL would be valid there. Not so easy for this one. The NZ CAA requires an o/seas PPL holder to sit a BFR and Flight Law exam before being issued with a NZ licence, and at least one operator I enquired from required that I do 10 hrs of mountain flying under an instructor before they'd hire one of their Cessnas.

 

We've settled on hiring a 4-5 hour training flight in a 172 out of Christchurch with Canterbury Aviation (NZ$225/hr). This way we both get to fly with another pilot who is familiar with the region and will act as tour guide ... and I get to do the flying for more experience and logged hours. We plan to track over the Canterbury Plains, over the alps, around Mt Cook, over several glaciers, the Fiordlands, down the west cst and along Milford Sound where we land. Then off again for Queenstown, more of the alps across to the east cst and back up to Christchurch. Of course, all subject to weather . Doing the tour this way works out around $500-$600 cheaper than taking one of their full day commercial tours in a 206 and we don't need to share with other tour pax. Methinks this might be the highlight of our NZ trip :big_grin:.

 

If anyone reading this has tips to offer re flying conditions and/or places to see ... please step forward and let's hear from you.

 

Paul

 

 

 

PS Sorry to digress from the original thread topic, guess I got a bit excited .

 

 

[Guest pelorus32]

G'day Paul,

 

my flying experience in NZ is nearly 30 years old!! However I did fly quite a lot in Canterbury/Otago in gliders and as non-flying crew in rotary wing in Fiordland and Otago.

 

The three things that I think are important in understanding NZ flying are:

 

1. The prevailing winds in the SI are westerly and the Alps run rougly perpendicular to them. So the westerlies come across the Tasman/Southern Ocean and pick up moisture. They then hit the Alps and dump all their moisture on the West Coast - hence the 365 inches of rain a year in some places on the west coast. This also seriously affects your ability to fly VMC at times;
    
    
   
2. Having crossed the Alps the winds, if strongish, create mechanical and rotor within and to the lee of the alps and also create standing waves of substantial proportion to the lee of the Alps. The NW airstream that causes this is very dry and sometimes hot in the lee of the Alps - having dumped it's moisture on the West Coast;
    
    
   
3. NZ is a maritime climate. It's hard to get more than 50nm from the coast anywhere. In addition it's in the higher latitudes - I think that almost the whole of the SI is 40 degrees south or more. So the weather is highly changeable and there's moisture aplenty - albeit in the SI it's drier on the eastern side and in places like Central Otago - less than 20 inches rainfall in Central from memory.
    
   

 

The summary is that it's great flying country but NOT the country for the unfamiliar or faint hearted. Conditions change quickly and there are traps aplenty for young fellows like you and me

 

I remember in 1978 taking part in an aerial search from a RC priest who took off from Big Bay on the West Coast and tried to scud run up various river valleys. He was the chaplain of the Southland Regiment and wanted to get back for a regimental dinner that night. He, his pax and his a/c have never been found. I still remember the feelings of hopelessness that all of us experienced on that search.

 

Have fun, it's absolutely superb but make sure that you don't get palmed off with the newest instructor for that trip.

 

Regards

 

Mike

 

 

[PaulN]

Thanks for the tips Mike. It's always helpful to hear from someone with experience and local knowledge. I've done a bit of reading and am now aware of their F'ohn (spelling?) winds and have been cautioned about turbulence and rotors of the mountains and in the valleys. This has influenced our decision to tag along with an instructor, better to use his previously gained experience/knowledge than gain mine the hard way.

 

Paul

 

 

[Guest Crezzi]

Apparently after you have done the course over there you will know everything there is to know about flying around and between mountains.

Sorry Ian but it's more of a introduction than a course - you wouldn't learn everything about mountain flying in 15 years never miind 15 hours.

 

Cheers

 

John

 

 

[Admin]

Point taken John - we are always learning :big_grin:

 

 

[Mazda]

On the original question, I know what everyone is trying to say, but I personally swear by flight planning software. I've used the Jeppesen FliteMap (buggy), Champagne PC (great, accurate, powerful, but no real terrain picture) and AirNav VFR (very good visual picture, map based, simple).

 

These programs are awesome. You'll know your distance and track with no mental calculation errors. They take into account variation (and will adjust wind if that is put in) and will warn you if you are not hemispherical. They will give you ETA and calcualte fuel (as long as they are set up properly). They'll automatically slot in airwork, most will put in IFR routes if required and will automatically put the ZZZZ details on your plan. Some will do weight and balance calcuations instantly and they will work out PNR and CP. They are a great way of avoiding human errors in basic planning.

 

Of course you need to check it (the Jeppesen one has come up with weird speed errors, the others have been very accurate).

 

The AirNav VFR actually prints the track on current Airservices charts and will put in notes (like tune the CTAF 126.7, or anything you want to put in). You input the route and can print out that route on IFR or VFR charts, eliminating the need to plot lat and long of visual waypoints on ERCs.

 

As far as I'm concerned, using any resource available is a type of CRM!

 

Having said all that, yes, of course it is imperative to know how to draw lines on charts and do your own plans!

 

Same with GPS. Why not use it as a resource?

 

 

[Sky Gazer]

OK Guys ,

 

I am enjoying this thread but being a newbie I am a little confused with all the terminology and features of each system so can some one tell me which one will allow me to print of WAC charts and possibly with way points,track with 10 NM increments etc.:;)5:

 

Peter

 

 

[Mazda]

AirNav VFR!

 

 

[Sky Gazer]

Mazda,

 

Thanks, I had been looking at their website without much success.

 

Does AirNav VFR lock you out if you don't subscribe to the 6 monthly updates?

 

Apparently they are no longer offering Demos for $20 since they have just released their latest version- Seems a bit Stupid to me that they used to charge for a demo and now won't even supply one all. Talk about a lucky dip.

 

Peter