VFR GPS

Towards the end of my training I decided that I wanted to get a handheld GPS to assist with my VFR navigation.

I spent endless hours reading reviews and opinions on the internet, and decided that I wanted:

• Moving map with airspace boundarys
  
• Route creation and navigation
• Large easy to read screen

This didn't really narrow the options down much, but my budget of $NZ500 definitely did.

Creating a GPS system for VFR

Luckily, in my keyboard travels I ran across some software called OziExplorer which looked perfect for the job. It worked on any PocketPC device, allowed me to import my own maps, and cost just $US30. I also purchased the PC version for another $US85.

I then bought a new HP iPaq h1930 for $NZ250. It had a 3.5" LCD screen, 64Mb RAM, SDIO Slot. There were other models of iPaq with built in GPS, but they were much more expensive.

To add GPS capability to my iPaq, I purchased a GlobalSat SD501 GPS receiver from EFrontier for $NZ180 which plugs into the SDIO slot on the top of the iPaq.

The worst part of this system was that it didnt actually include any maps or aviation data. However, I own a full set of New Zealand VNC charts, so after several hours with a scanner and Photoshop, I had scanned all my maps, and joined the images together to create one image file for each map. Then I simply had to load each map into OziExplorer, tell it a few known points on the map, and copy the data to the iPaq.

Although not as accurate as 'official' aviation data like that included in the Garmin GPS units, I found that my maps were always accurate within 50 meters, and this was more than accurate enough for VFR navigation. The GPS and OziExplorer software were much more accurate, I just wasn't very accurate with some of my known points.

In flight use

My first few flights with the handheld GPS went well, I found that I normally kept the GPS zoomed to display approx 10Nm around me, and then I also had my paper charts open to show me the 'big picture'. The GPS is great for knowing exactly where you are, and also for showing you the track to your next waypoint.

I quickly realised that having the handheld GPS floating around the cockpit was sometimes annoying, as it was easy to drop it between seats etc. So I bought a clipboard and some velcro, and attached the GPS to the left side of the clipboard, with enough room left on the clipboard to also keep my flight plan / notes attached with bulldog clips.

One problem with using GPS for VFR flight is that it causes pilots to keep their eyes inside the aircraft too much, and not out the window watching for traffic. I generally dont look at the GPS until I am 5 miles away from my departure aerodrome, and then I only glance at it every minute or so to make sure I am still on track.

Problems / notes

• The battery life is only about 3 hours, which is normally not a problem because very few of my flights are more than 2 hours, and this is just because the model iPaq I chose only has a small battery.
• In high-wing planes the GPS can have problems receiving signal when the kneeboard is on my lap, which means I have to attach the external antenna (luckily it has a 3 meter cord) and sit it on top of the glareshield. This cord can get in the way, and if I was to buy the system again, I would get an iPaq with bluetooth support, and a bluetooth GPS receiver to avoid this problem.
• The maps take up a large amount of storage (~5mb each), so I can only keep about 5 maps on the iPaq at once. Luckily this hasn't been a problem for me yet, as 5 maps covers the whole North Island and I haven't flown to the South Island yet.