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PDA's, PNA's and Flight Nav Programs

PDAs (Personal Digital Assistants), or Pocket PCs have become very popular for use in gliders as they are reasonably priced and have a high degree of computing ability.   The first generation of PDAs included the Compaq Aero Series (1520, 1550, 2100) and some Casio models.   The second generation are predominantly IPAQs with faster processors and full colour displays.

At the current time, programmers have only written gliding software that can be used with the Windows CE operating system (OS), which means that those PDAs which use a different OS are unable to run gliding software.   While early PDAs with monochrome screens worked tolerably well in gliders, the visibility of early colour models such as the Compaq Aero 2100 was unacceptable in a cockpit environment.   However, later models of the IPAQ range now have reasonably bright colour displays that are useable in the cockpit.   While the PDA remains a cost effective method of displaying a graphical, map based display showing the task, navigational information and airspace, it has many inherent dis-advantages that limit its use in gliders.  These include:

  • Manufacturers bring out a new PDA model each year which may have different mounting arrangements from its predecessor meaning that it will no longer fit into the same mount.   At the same time, support for 'last year's model' is withdrawn.   A good example is that replacement batteries for the 1520 and 1550 Compaq models are no longer freely available.

  • When PDAs are used in gliders, they are invariably fed with GPS data via a COM port.   When this port is active, the current consumption from the internal battery is considerably increased resulting in a short battery life before charging becomes necessary.   For this reason it is not practicable to operate from the internal battery and arrangements have to be  made to provide a 5 volt power supply in the glider.

  • The lead feeding the GPS data into the COM port invariably plugs into the bottom of the PDA.   This plug and socket is complex and fragile and as the PDA is usually mounted somewhere on the upper instrument panel coaming, the lead can easily knocked by the pilot's knee or thigh, stressing the PDA plug/socket.   Mounts are available which have a plug that provides for the cable exit at the rear but they are relatively expensive.

  • The displays are generally small while the amount of information that it is possible to display is considerable.   This means that a significant amount of time may be spent looking at and interpreting the display to the detriment of lookout.
  • Some PDA models have a USB port and no COM port.   A COM port is essential if current gliding navigation software is to be used.  

A useful summary of the various PDA models and their suitability for use in gliders can be seen on Paul Remde's web site at Cumulus Soaring.