To test the idea, Mitre Project Manager Rick Niles (no relation to the author) flew a light plane with a safety pilot while using cellphones to connect to all the major networks and seeing if the cell network positioning would work as a backup. "We can then check that the range is coherent with the position from the [phone's] GPS system and not way out of whack," said Niles.
This is a companion discussion topic for the original entry at https://www.avweb.com/uncategorized/faa-tests-cell-phones-as-safety-feature