Definition
In aeronautical decision-making, the realistic options a pilot has available to handle a developing situation safely — such as diverting, delaying, turning back, landing early, or choosing a different route or altitude. An alternative is considered viable only if it is practical, achievable with the aircraft and conditions at hand, and likely to produce a safe outcome.
Plain English
The real, workable choices a pilot has when something changes in flight or before takeoff. Not every option counts — only the ones that can actually be carried out safely.
Context Anchor
Seen in preflight and in-flight risk assessment when deciding what you will do if conditions change, a problem appears, or the original plan stops being a good choice.
Derivation
‘Viable’ comes from the French vie meaning ‘life,’ originally meaning ‘able to live’ or ‘capable of working out.’ In aviation, a viable alternative is one that can actually succeed — not just one that exists on paper.
Why Pilots Care
Recognizing viable alternatives prevents get-there-itis and supports safer go/no-go or en-route decisions.
Analogy
Like checking whether your backup route home actually has open gas stations before you take it.
Intuition Check
Do not read viable alternatives as meaning every possible option. In aviation, it means the options that are actually safe and practical under the conditions you have right now.
Example Sentence 1
When the ceiling began to drop, the pilot reviewed the viable alternatives and chose to divert to a nearby airport with better weather.
Example Sentence 2
When weather deteriorated en route, the pilot selected a viable alternative by diverting to a nearby airport with better conditions.