Nathan Young wrote:
In Garmin's defense, the airways take up a lot of memory

Feh. The FAA distributes the airway database in an extremely verbose text
format which is about 10 meg in raw format, but compresses down (with gzip)
to a little under a meg. The only data in the file which doesn't already
need to be stored anyway (i.e. fix coordinates) is a list of which fixes
make up each airway. There's 42k records in the file. If you used a
32-bit pointer for each fix, plus some per-airway information (I count 2240
airways), the whole thing fits into under 200k. This is nothing.