In article , A L
wrote:

I am hesitating between buying the iPhone 4 and the iPad (or else?) to
use as a VFR GPS. One of the attractive feature of the iPad is the
larger screen but it is also one of the drawback... Apparently the
iPhone has an internal Gyroscope which the iPad does not have (might be
added on the iPad 2..) but the iPad has apparently better GPS reception.

I will use this primarily for web browsing, in-flight GPS and reading
plates. I would not use this for phone, mp3, etc,.

what is the best purchase?? thanks.

My general thought is that if the iPad will fit comfortably in your
cockpit then you should go for that choice. (It certainly would not fit
in mine, but I understand these things come in different sizes.)

I would not worry about GPS reception. You'll get excellent reception at
altitude with even a poor receiver. Modern receivers are so good that
the difference between good and bad is whether accuracy is measured in
tens of feet or twenties of feet, performance indoors, in urban canyons,
etc.

Pros for the iPad:

- Much larger screen will be significantly easier to read, especially in
bright sunlight which will hurt contrast a great deal.

- Considerably better battery life.

- Vastly superior for web browsing etc.

- Data plan is cheaper and completely optional. You can pay $25/month
for 2GB of data, $15/month for 100MB of data, or $0/month for no
cellular data at all. There is no contract. (iPhone will run you around
$75/month at minimum, for at least two years, even if you never use it
to make calls.)

Pros for the iPhone:

- Much smaller, thus potentially more convenient to manipulate in the
cockpit, carry around, etc.

- Internal gyro means you could conceivably use it as a backup HSI,
although I would be *extremely* hesitant to trust it for such a critical
application.

Note that if you do decide to go for the iPad option, be sure that you
get the 3G version even if you aren't interested in cellular data. The
WiFi version does not have GPS.

If you aren't in a hurry, you might wait a few months, as it is widely
expected that iPad 2 will be available this spring.

--
Mike Ash
Radio Free Earth
Broadcasting from our climate-controlled studios deep inside the Moon