GPS 296 operating tips

[flyme273]

GPS 296 operating tips

BATTERY life: other posters have mentioned this item. I would urge a conservative approach; in my unit, I usually get a blank screen at around 2:00 hrs battery life remaining, without any warning. (I carry a spare battery). This is with EGNOS enabled. However, in ground simulation mode the normal warning messages appear and it continues to operate until around 15 minutes.

ROUTE: I start with the departure airfield. This will allow INVERT if one has to make an unscheduled early return, and thereby re-trace the outbound route.

ALTERNATE(s): How to enter a Planned Alternate? The Manual is silent on this and there is no menu provision. It seems to me one possibility is to add the alternate after the Destination Airfield, however it will then be interpreted as the actual destination. The problem here is that once past the field in the circuit area, the unit rolls over to the next WPT – just at the time one may need some confirmation guidance to the destination (e.g. low sun).

Another possibility is to insert it above the Destination and then if not required, skip over it during the flight; at least the entry would be available for ready use in preference to searching NRST or having to search under GOTO/ DIRECT.

TRACK feature, I turn this on to allow download to PC of my actual route for information purposes and if accused of entering Control Airspace/ low flying I have a defence.

Any opinions or further tips?

[sternone]

Thanks for this post, i'm gonna aquire a 496 (or 596 if it comes out at aopa) in a few weeks, do you know if above problems/battery life also counts for the 496 ?

[flyme273]

Sternone

No experience of the 496/596. Probably a similar situation. Battery performance is very individual and does of course change with age, usage, temperature, the backlight settings, tracking on and if EGNOS is enabled. My post was intended to draw attention to the possibility of the forecast battery life remaining being over-stated. In a previous post an airtraffic controller sited two occasions when navigation assistance had to be given to ‘flat battery’ pilots. (of course the Portable GPS should not be the primary nav - there have been enough warnings about this)

I would suggest ground testing your unit to avoid unpleasant surprises. Also to know the remaining life when the 'low battery' warning appears so that if in-flight one has the option to reduce battery loads.

[Kyprianos Biris]

Diy Ils

There is nothing you can do regarding alternate if you want to have a realistic vertical profile computation (descent to destination) and trip estimates on time/distance to go etc.

Something I have never used but was discussing with another friend who has a 296 was how to set up a virtual ILS for a specific runway.

You set a final waypoint at the aiming point of the runway (where the glideslope antena would be).

Then you set another waypoint (initial) in the point where you should start your descent. Account for 330ft per nm of track to find out how far you want it.

Make sure you have no terrain below.
Roll laterally the initial point so that that the track connecting is the track of the runway.

Set the Vertical navigation profile of the 296 to be 0ft at 0nm of the destination.

When you taxi onto the runway at the touchdown area record the GPS altitude at that point. and also move precisely the waypoint to the exact location you are, provided you are on the runway centereline.

Then go back and edit the final (touchdown) waypoint's AMSL altitude to the one you see at the GPS.

Save the above two connected points as a flight plan that you can call up in the future.

With this you can simulate an ILS via loading up the FPL and following it via the page showing the miniature aircraft panel and the two bars in the HSI.

Things you must not do with the above :

Never rely on it for actual ILS simulation in IMC.
GPS and units like the the 296 specifically are inacurate both laterally and vertically for guidance towards such a precise 3D point in space.

Just do it for fun some day with nice weather out of curiosity to see how reliable it could be and how far down the virtual ILS you can keep the needles centered. Do not do it without someone else looking outside the window for traffic and terrain !

Also remember : the mini panel instruments show you groundspeed in the ASI , track being flown in the HSI and GPS altitude in the Altimeter, not Indicated Air Speed, Heading and barometric altitude.

You'll find that AMSL baro. altitude may deviate as far 200~400 ft from the GPS one.

[flyme273]

thanks for that tip.

A possibly easier way is to use the Project the Waypoint to give an IAF say 4 to 6 mls from the threshold. Then as you say set the VNAV to zero at the airfield. I'll report after test.

I note your comments on the panel page - seems a bit of a gimmick - I use 1 column to show the HSI.

[High Wing Drifter]

GPS and units like the the 296 specifically are inacurate both laterally and vertically for guidance towards such a precise 3D point in space

That is something I used think before I got my 496. It correlates to within a few feet of my altimeter. I suspect most of the error is in the dial. Not an assumption I would rely on, but interesting non the less.

[flyme273]

quote:
GPS and units like the the 296 specifically are inacurate both laterally and vertically for guidance towards such a precise 3D point in space
unquote

. . . if you have EGNOS enabled, the GPS should be within a few metres.

more than sufficient for guidance assuming a typical ILS cat A decision height of circa 200 ft.

[Kyprianos Biris]

A possibly easier way is to use the Project the Waypoint to give an IAF say 4 to 6 mls from the threshold.

Negative, this method will guide you down to touch down at the runway end (e.g. perimeter fence at touch down side end) and not the touch down zone which will be a descent of a glide slope of some 50~100 ft lower approach than the proper one.

[KatanaDV20]

Problem encounters when editing routes on map

Hi anyone,
i'm having a problem using the GPSMAP 296:
In normal map mode, putting the cursor on a city results in the city's name displayed on the cursors hint box and in the displays top line.

If creating a route in "edit on map" mode, cities with road crossings (most of the bigger ones) are shown with their road numbers instead of their names.
Cities w/o roads are shown with their names.

So using bigger cities as route waypoints is inconvenient, because the road numbers are not very useful.

What can i do to get the name of the bigger cities instead of the road numbers to be used as waypoints?
The unit is in aviation mode, map and firmware are up to date.

Thanks in advance for help.

Regards, Katana-DV20 flyer

[drambuster]

Garmin lawyers beat you to it !

Kyprianos - a nice idea about the quaisi ILS but the clever lawyers at Garmin have already worked out that a few crazy guys like you (and me ! ) would give this a go. So they have deleted the function of the vertical profile bar once you get below 1,000 ft !! It simply disappears.

So, if you did pile in using your 296 for a 100 ft cloud break then your partner wouldn't be able to ask those kind souls at Garmin to top up your pension fund

[drambuster]

Finding land points

Katana DV20. I agree it is annoying that the cursor picks up roads etc when you're trying to get it to lock onto a city or town in 'Edit on Map' mode. The best thing to do is to insert a waypoint in normal list mode. When faced with the list of Aviation and User waypoints etc then press 'Menu' and it will show an option for selecting 'Land Points'. then select cities. They should be listed in order nearest to the cursor, so you should see the relevant location.

Under 'Menu' again (when looking at Cities) you can either have them listed as 'Nearest Cursor' or 'Alphabetical Order'.

An alternative is to go to the town on your normal 'Map' page and go 'Enter' and then 'Save'. This saves the city/town so that it becomes a user waypoint as well as being in the map database. I think you will find that under 'Edit on Map' it will then be more dominant than the background roads and so you should be able to pick it up !

let me know how you get on.

[KatanaDV20]

Editing routes on map

Hi Drambuster,
thanks very much for the quick answer.
The alternative method works fine. All i have to do is to convert all big cities on the route to user waypoints, then edit the route on map as usual.

But i'm not sure if i understand "When faced with the list of aviation and user waypoints etc"...
What menu item are you spreaking of?
In the POINTS main menu there is the list of user points and a "Proximity" tag...

Anyway, what is the reason for this behavior of the software (it was the same on my old 196).
On the normal map page the unit shows the cities name, in "edit on map" mode it doesn't. Why???

Thanks again
Always happy landings
Katana-flyer

[flyme273]

drambuster,

Thanks for your post - I've been trying everything to get the VNAV to work for approaches.

Katana,

I wasn’t able to reproduce this problem.

To make a route (if not using airports and nav aids) I first start with inputting the User waypoints. Start with the main menu “Points” then User and “Create Waypoint”; move to Map page, using pointer to highland city press “Enter” and “Save”. It works on my 296.

Not sure about the wisdom of using large cities as waypoints, sounds more like “Target for Tonight”. I prefer nav aids, identified reporting points (e.g. from IFR chart) – makes it easier for position reporting, or terrain features such as bridges, river, railway, motorway, etc. Of course, one could Project a user waypoint say 5 miles west from a city then report e.g. “Passing west abeam [city]”.

[flyme273]

ILS approaches with 296.

As "Drambuster" reports the VNAV terminates 500 ft above the target altitude (page 40 of manual).

Seems to me the fix is to copy the airfield co-ordinates into a User waypoint. Then subtract 500 ft from the airfield elevation.

In the VNAV setup page insert 500 ft above the target waypoint and the desired descend gradient e.g. for 80 knots approach 400 ft/min (approach groundspeed multiple by 5). Remember on the Panel page "Options" VNAV indicator ON.

Project the runway centre line (page 75 of manual) to give User waypoint say 6 mls IAF. Now take your observer along and practise ILS's.

4 ml height 1275 ft
3 ml height 950 ft
2 ml height 640 ft
1 ml height 320 ft and DH 200 ft

[as mentioned by other posts above, the airfield reference point can be fine tuned for the landing threshold, but with almost one mile to go there is room for correction]

[drambuster]

KatanaDV20.

The first alternative I suggested was to edit the route in 'Text Mode' rather than 'Edit on Map'. If you go to the position in the route where you want to insert a town then select 'Insert Waypoint'. This will give you the Waypoint 'Find' box of Aviation, Recent and User waypoints. At this point press the 'Menu' button where you will find an extra option for 'Find Land Points'. From here select 'Cities' and find the City/Town that you want.

When looking at the list of cities they are shown by default as the nearest to the aircraft location. If you press 'menu' again then you can switch to either 'Find by Name' or 'Near other'. If you play around you will get the idea !


Drambuster

[KatanaDV20]

Originally Posted by flyme273

Not sure about the wisdom of using large cities as waypoints, sounds more like “Target for Tonight”. I prefer nav aids, identified reporting points (e.g. from IFR chart) – makes it easier for position reporting, or terrain features such as bridges, river, railway, motorway, etc. Of course, one could Project a user waypoint say 5 miles west from a city then report e.g. “Passing west abeam [city]”.

What i had in mind was not NY or LA, but cities on road crosses, which are "bigger" then cities w/o roads on the map. They are causing the mentioned effect. Small cities w/o road crossings appear with their names.
I agree 100% that it is not wise - or even prohibited - to fly over cities, were they big or not.

Regards
KatanaDV20

[KatanaDV20]

Hi everyone,

is there a way to use the gpsmap286 devices's aviation map data in the mapsource.exe program on the pc as a background?

Uploading the map data fails because of "missing data cartridge..."

Any ideas?

Regards
KatanaDV20