Birthday Present -Sat Nav

[benppl]

I've managed to get the family to club together for my 25th birthday! I take my skills in 2 weeks and it's my birthday in 4, so finger crossed if all goes well I may be passed in time for my bday!

I really want a sat nav, problem is Ive never used a areoplane one and I'm not very famiular with the brands? Types (airspace warners etc)

Budget will be around 500-600£

Is that enough for a decent unit or is it worth me putting cash to it and buyi. A better one?

[BackPacker]

Unless you're hard-core IFR and need a specialized unit for that, I'd go for an iPad 2 with Air Nav Pro on it. Make sure to get the 3G model because only those have GPS on-board, or be prepared to spend extra money on a separate (compatible) Bluetooth GPS.

[benppl]

Oh Cool.

I already have Ipad. Are they a not a bit awkward in the cockpit of a PA28/38 with Pax?

[benppl]

I’m doing my IMC course once I've passed and logged enough hours, not sure if that makes a difference to unit cost?

Sorry about my lack of knowledge. I’ve only been learning for 3 months and never really had a interest before then.

[Genghis the Engineer]

I have a Garmin Aera 500 and have been using it through the summer, which will meet your price bracket.

By and large, I'm really happy with it. Good clear navigation, some useful tools such as the E6b, flight log and HSI page, once practiced quite easy to use as a source of reference for various data such as airspace heights, frequencies, approach aids, and so-on.

On net, if somebody nicked it next week, I think I'd buy the same again.

Also with a bit of massaging can help out in getting onto instrument approaches, and whilst not legally cleared as such, does have all the waypoints for published GNSS approaches if you need a "get out of gaol" card one day, as well as GPS guidance onto any ILS.

The extra few quid on a yoke mount is well worth it. Best powered from a lighter socket, but I can get 3+ hours out of it without so long as I'm careful with the screen brightness. Another £30 with a shop in the USA got me a lead that allows me to patch its audio warnings into my headset.

G

[BackPacker]

You can get both suction devices so you can stick them to the windscreen, and kneeboard-like devices so you can strap them to your leg.

Or do as I do - let the passenger hold them. It gives them something to look at and something to do during the flight.

As far as the IMC is concerned, you will learn to fly on whatever *certified* instruments there are in the plane. AFAIK, a portable device can never be certified and thus cannot officially be used for navigation under IFR. (That they can augment your navigation and enhance your situational awareness is just a bonus.)

[StavDav]

Hi all,

As I am new as well, and currently close to the same point as benppl, what would peoples thoughts be on the SkyDemon mobile GPS solution?

Was shown this by a friend, and wanted to see if the community thinks it's any good?

Many thanks,

[benppl]

reading a bit more into the AirNav iPad/iPhone side of things seems to be a decent shout.

Reading though, it seems its just easier to use my 4 (4s) in a few weeks with a suction mount?

[IO540]

As far as the IMC is concerned, you will learn to fly on whatever *certified* instruments there are in the plane. AFAIK, a portable device can never be certified and thus cannot officially be used for navigation under IFR.I am not sure that is quite true.

In general, in private flying, nobody prescribes what navigation method should be used.

Only equipment to be carried is prescribed; this to me implies it should be functional but it cannot possibly imply it should actually be used because e.g. the UK ADF for all IFR in CAS requirement cannot possibly be a requirement to navigate enroute using the ADF...

So a handheld GPS should be 100% legal for navigation in IMC.

Enroute (Eurocontrol flight plan) IFR is a different thing because there you need to carry a BRNAV approved GPS installation, and that can only be panel mounted. But even there there is no law which says what device you actually navigate with.

This stuff has been done to death many years ago; if you google Usenet for "tuna sandwich navigation" you will find long threads there :)

BTW the built in Ipad2 GPS is rubbish. I have flown with mine and it is quite capable of losing the GPS fix anytime during a flight. You need an external GPS.

[BackPacker]

In general, in private flying, nobody prescribes what navigation method should be used.

Although legally you may be right, I'm pretty sure that during IMC *training*, the instructor would not appreciate you pulling out the iPad (or any portable device for that matter) and use that as your primary nagivation device. Or secondary/backup device for that matter.

BTW the built in Ipad2 GPS is rubbish. I have flown with mine and it is quite capable of losing the GPS fix anytime during a flight. You need an external GPS.

Never had a problem with mine so far (Robin DR400 and R2160, both with perspex bubble canopies; no experience with PA28s or other metal-roofed aircraft). But anyway, even the 3G version, AFAIK, can be paired with a separate GPS if necessary.

[Dave Gittins]

Hmmmm ... spent 6 hours in Colorado last month in a 172 and my instructor had his iPad happily working all the time without any loss of signal.

I note "quite capable" but in practise how often does has it happened ?

[flybymike]

Does anyone have any experience of running skydemon or similar on a smartphone? If so any suggestions for best hardware, software, GPS receivers etc?

[Roff]

After the last thread on GPS i rushed out and bought an Ipad, External £80 gps receiver and copy of Air NavPro and hate it.. It all seemed good but getting a signal on the receiver takes the piss! Rather just use my Airbox GPS as iv never had a problem anyway..

[thing]

I have an Airbox Aware 5+ and it does what it says on the tin. Does everything I want, airspace warning and nav, plus it's just like looking at a half mil map ('cos it is a half mil map) so there's no confusion. Look at your map, look at the Airbox and they're exactly the same. I'm only a VFR bimbler, don't know what you would need for instrument approaches etc.

I'm sure the more expensive stuff has more bells and whistles but you have to look at whether you're going to use all the extras. I think mine was about £320.

[SEP Flyer]

After a lot of research I went for the Airbox Clarity. The airspace warning feature is worth the money alone. Planning software, complete with notams is a doddle, and as the map is the usual half mil, it's simples. Prints your plogs too. But like 'thing' I'm happy to buzz around VFR. It works.

[IO540]

Although legally you may be right, I'm pretty sure that during IMC *training*, the instructor would not appreciate you pulling out the iPad (or any portable device for that matter) and use that as your primary nagivation device. Or secondary/backup device for that matter.

That's true but that is nothing to do with the GPS :) It is what you get with an old fart of an instructor. A modern instructor will train you in the use of modern methods, to the maximum extent permitted. Same in the PPL syllabus; only 1 or 2 specific exercises in the whole PPL have to be non-GPS.

[muffin]

I have an Airbox Foresight installed on the instrument cluster and wish I had never bought it. Every time I synch it to the laptop, it crashes when I try to use it, yesterday it could not get a GPS signal whilst my 10 year old Garmin handheld worked faultlessly, you can't read it in bright sunlight and the touch screen is fiddly to use.

My IPAD2 with its built in GPS running AirNav Pro works every time, is easy to use, has never yet lost GPS lock and because it is on my knee strap can be clearly seen as the display is huge compared to anything else. I can also easily switch to uncluttered topo maps in flight if I want to. The ANP suppliers seem to provide excellent support and publish free upgrades almost weekly. Also passengers love to hold it and tell me which way to go!

I know which one I prefer.

[thing]

Odd that, I've never had a prob with the 5+. Never not been able to read it and it's always picked up a signal straight away, plus I like it mounted in my line of sight as an extra 'instrument' if you like.

I wouldn't want to keep looking at my knee or a passengers knee (well depends if she was fit) to see what it was doing. I can keep it in my peripheral vision and still keep my eyes out of the cockpit.

[BobD]

Does anyone have any experience of running skydemon or similar on a smartphone? If so any suggestions for best hardware, software, GPS receivers etc?

I use Skydemon with my HTC HD2 smartphone, and have been very impressed with it.

[flybymike]

Thanks for that Bob. Do you use the inbuilt GPS receiver or external with blue tooth? Any problem with signal dropouts? Perspex canopy or metal roof ? where do you locate the unit?
Does the phone work satisfactorily as a modem for a laptop?

[good finish]

I use an air box aware plus as my primary-cheap and excellent
I then have an iPad 2,air nav pro with Bluetooth gps which I have on my passengers lap as back up -works well.

[Droopystop]

Luddite Warning!!

I'm afraid I can't offer a recommendation for a particular GPS, as I fly with a commercial airliner type Flight Management System. But flying with a GPS is dull in my opinion. I have to use one pretty much all the time but it is nice to be able to do things the old fashioned way from time to time. I still look at the sun, the ADF needle and ground features to confirm the GPS isn't lying (it doesn't lie very often I admit). But navigating by map and compass is so much more satisfying and so much more fulfilling. I definitely think having a GPS is a great idea, particularly if the weather is not looking good, or you need to divert to the nearest airfield, but don't miss out on the fun to be had by using your eyes and brain, and developing a hard won, but immensely satisfying skill.

[CharlieDeltaUK]

"...it doesn't lie very often, I admit..."

Question for you all: apart from hardware failure or problems with GPS reception, daylight viewing etc, does a GPS unit ever give a wrong result? Does it fail safe?

My understanding is that accuracy is defined in terms of % probability of the stated position being within a specified distance of the actual position, but the device will keep refreshing so I'm assuming that it's unlikely to sustain an incorrect reading.

[thing]

I'm afraid I can't offer a recommendation for a particular GPS, as I fly with a commercial airliner type Flight Management System. But flying with a GPS is dull in my opinion. I have to use one pretty much all the time but it is nice to be able to do things the old fashioned way from time to time. I still look at the sun, the ADF needle and ground features to confirm the GPS isn't lying (it doesn't lie very often I admit). But navigating by map and compass is so much more satisfying and so much more fulfilling. I definitely think having a GPS is a great idea, particularly if the weather is not looking good, or you need to divert to the nearest airfield, but don't miss out on the fun to be had by using your eyes and brain, and developing a hard won, but immensely satisfying skill.

You see this is what I can't understand, why is it that GPS users have no other skills and people who use pine cones for weather forecasting and lodestones for navigating are superior?

I use all of the navigational facilities I have all of the time, I don't rely just on GPS, it's there as an AID, like the map and the stopwatch, ADF and VOR. I still draw lines on maps, the lines still have track times on them, I still use a plog, I also use the GPS.

As it happens I did a flight over the Peak District for a friend a couple of weeks ago, which as anyone who flies that area will know is pretty tight for airspace around the top of Derwent/Holmfirth area. I climbed in, looked in my bag for the GPS and remembered it was on charge at home. No problems, I didn't bust any airspace, I didn't get lost and we had a good flight.

[Whirlygig]

You see this is what I can't understand, why is it that GPS users have no other skills and people who use pine cones for weather forecasting and lodestones for navigating are superior?I don't think Droopystop was saying that at all ...

Cheers

Whirls

[thing]

Probably wasn't, I only half read posts at the best of times. Sometimes I just pitch in without reading anything at all, like a pot luck type thing.

[Genghis the Engineer]

"...it doesn't lie very often, I admit..."

Question for you all: apart from hardware failure or problems with GPS reception, daylight viewing etc, does a GPS unit ever give a wrong result? Does it fail safe?

My understanding is that accuracy is defined in terms of % probability of the stated position being within a specified distance of the actual position, but the device will keep refreshing so I'm assuming that it's unlikely to sustain an incorrect reading.

About a week ago I was flying EGPK-EGTC late in the day, having flown up in the morning, using my trusty Aera-500 on the yoke.

About the time I passed Liverpool, I got refused an airspace crossing I'd hoped for and vectored about 15 miles off route, and my GPS lost consistent satellite view - for the next 100 miles.

I *could* if required have sorted myself out using VOR/ADF, but it was a classic case of why we learn to fly accurate VFR/DR diversions, which is exactly what I did.


I have had GPS drop-outs before, and every system I've yet seen is pretty good at telling you it isn't getting a signal. I think it's the longest I've yet seen, and the first from about 6 months / 60 hours use of the Aera.

I've never seen a GPS wrong - they either work or they don't in my experience.

G

[flybymike]

Flying over the Yorkshire dales using an early Skyforce1 GPS which suffered an "engine failure," I twigged something was not right when it showed me somewhere over Germany.
Never had a dropout on my Aera, but my Garmin 96 likes to turn itself off when ever its feeling like a rest, poor thing.

[IO540]

Flying over the Yorkshire dales using an early Skyforce1 GPS which suffered an "engine failure," I twigged something was not right when it showed me somewhere over Germany.

No remotely modern GPS should do that.

A loss of signal should be obvious, with a big message across the screen.

Skyforce have not designed anything (GA) for about 10-15 years.

I fly 100% on GPS. I can navigate using VOR/DME/ADF but such a fallback is extremely rare. I lost a signal (on all 3 GPSs) for some minutes flying down the middle of the Adriatic in 2004 at about 1000ft, and that was obviously jamming. On another occassion I could not get the KLN94 (the main GPS I have, panel mounted) to get a fix for about half an hour after departure from Padova, Italy, back to the UK. It picked it up somewhere over the Alps. This was an IFR flight and ATC gave me a VOR-based route, albeit at a higher MEA (FL160 instead of FL140 as filed). That is about all that I recall. The Ipad2 GPS has proved to be very unreliable and moreover (running Memory Map) the app does not show when it has lost a fix; you just get a map which is no longer moving. I read something on the net suggesting that the IOS GPS API does not return satellite status (which is why the IOS version of MM does not give a clue about the sats) which if true is totally outrageous but I can imagine the arrogant Church of Jobs politburo making such a decision "for the simplest [dumb] user experience"...

[stevelup]

I read something on the net suggesting that the IOS GPS API does not return satellite status (which is why the IOS version of MM does not give a clue about the sats) which if true is totally outrageous

It's kind of true but it's by design and there is some real logic there. It's also utterly trivial to work around.

The reason it does this is that the device caches the last location. On a phone, when you open a location based service, you are more interested in roughly where you are. You're going to want Google Maps to open in approximately the right place, and you're going to want your 'house hunting' app to show you houses near where you are. It is after all what a smartphone is used for 99% of the time.

The first thing that any developer making a navigation application should do is set the desired accuracy filter to two kilometres or so. This will by definition block the cell tower / WiFi location stuff and force the device to use GPS.

The workaround to the caching feature is so stupidly simple that anyone who didn't figure it out shouldn't be working as a programmer.

When you retrieve a location event, one of the members is 'timestamp' which shows when the location data was last valid. All the humble programmer needs to do is check the timestamps. If they aren't changing, then it isn't working.

In summary, iOS does give you the horizontal and vertical accuracy figures, and it also tells you how old they are. It's up to the programmer to decide if he wants to use figures that are 'old'.

[IO540]

Can you get the satellite constellation "picture" from the API?

[stevelup]

Nope, just horizontal and vertical precision in metres.

[IO540]

I wonder why Apple crippled it like that.

OK; it's a "phone" but if it has a GPS then it can be reasonably expected to be used for "serious" GPS apps, whose pre-existence Apple cannot possibly be unaware of.

[stevelup]

What is crippling about not being able to see the satellite constellation? What practical use is it apart from looking pretty?

Surely all that matters is the precision of the fix?

[rasti121]

Surely all that matters is the precision of the fix?

And the time it has been taken. What is the precision of a fix with 1 m precision taken 1s, 10s,100s ago?

[stevelup]

Quite - which is exactly what I covered in my earlier post. I would question the quality of any data more than a few seconds old in an aviation application.

[IO540]

Does the app gets a precise time?

The only time against which the timestamp of a GPS fix could be judged is the GPS time. The Iphone time could be way off.

Actually the constellation data (or at least the traditional individual satellite signal strength histogram) can be very useful. You can e.g. see if there is interference which knocks the signals down when you do something. This is very important in testing for interference from e.g. VHF (11th and 13th harmonic).

I can see Apple would not be bothered because they know where 99% of their sales are coming from, but here we are talking about fairly critical applications.

[stevelup]

It doesn't matter what the reference for the timestamp is - all it is showing is the time between subsequent GPS fixes. What is important is the delta between the two times. It comes from the system clock.

Fair point about the visibility of the signal strength indications.

[BobD]

I use Skydemon with my HTC HD2 smartphone, and have been very impressed with it.

Thanks for that Bob. Do you use the inbuilt GPS receiver or external with blue tooth? Any problem with signal dropouts? Perspex canopy or metal roof ? where do you locate the unit?
Does the phone work satisfactorily as a modem for a laptop?

I use the inbuilt GPS Receiver. Not had any dropout (so far). Used it in a PA28, C150, C152, and TB10. Originally hand held (as I tend to only use if for heading), but now use a suction mount I bought off e-bay, attached to the side window. Never tried it as a modem for a laptop (but it is supposed to have this capability).