It’s simple: If the aircraft goes down in a harsh environment, or if there are injuries, the best way to survive is to be found by search and rescue personnel. One of the easiest ways to make this happen is to file (and activate) a flight plan: It guarantees that someone will eventually be looking for you.
In most cases, it’s wise to stay near the aircraft if the area is unfamiliar or remote, or if the weather is bad. First, it’s easier for search parties to find a downed aircraft than a person. Second, the aircraft will probably provide at least some shelter against the elements.
If the planned flight takes you over inhospitable/remote areas, bring a survival kit and rations customized for the terrain, season, and climate. Pre-made kits can also be purchased from various outdoor retailers. Dress appropriately—or at least bring suitable clothes—for the weather/temperature in the area over which you’ll be flying.
Unfortunately, the 121.5 MHz emergency locator transmitter (ELT) installed in most general aviation aircraft perform poorly. Many signals are false alarms, and it can be several hours before a real signal is even received. Even then, an ELT search area may be quite large.
In most cases, it’s wise to stay near the aircraft if the area is unfamiliar or remote, or if the weather is bad.A better alternative is a 406 MHz ELT, which defines a more precise search area, and does it much faster. Some are GPS enabled, and can provide a pinpoint location. Another alternative is a personal locator beacon (PLB). Although they have certain limitations as compared to 406 MHz ELTs, they work in much the same way. Bear in mind that PLBs must be manually activated.
A little knowledge on what to do once you’re on the ground can go a long way. This video discusses some items you should pack in your survival kit and what actions you can take to help reduce the time it takes to get found.