The survival equipment you carry may be all that stands between you and death. It represents the last best hope you may have of surviving whatever perilous situation in which you may find yourself. Select survival equipment like your life depended upon it, because it might. Not Everlasting Bear in mind that many survival kit contents are perishable or have expiration dates. You cannot just throw a kit in the plane and never take a look at it again unless the need to use it rises.
Survival kits require regular maintenance.
Food, water, pyrotechnics, batteries and medicines are among the items which always have a limited life, whether noted or not. Even some items you might not consider having a limited life and which are not marked as such will not last indefinitely. Extreme temperatures, often found in aircraft on the ground, even inside a hanger in some areas, can also have a detrimental effect on some survival supplies, significantly shortening their useful storage life. Very few commercial kits make note of the expiration dates of the supplies and equipment contained in them. Most don't even mention the subject or identify those contents which have expiration dates or limited useful lives.