Additionally , skydivers use a variety of altitude - sensing devices in order to know when to deploy their parachutes .
This is prescribed by law in the U.S. Federal Aviation Regulations and in the aviation regulations of many other countries as well .
Skydivers use a variety of altitude - sensing devices in order to know when to deploy their parachutes .
This is prescribed by law in the U.S. Federal Aviation Regulations and in the aviation regulations of many other countries as well .