Definition
A free smartphone app provided by the FAA that helps drone (Unmanned Aircraft System) operators determine whether there are airspace restrictions or other flight limitations at their planned location before they fly.
Plain English
A phone app that tells a drone pilot whether it is okay to fly at a particular spot, and warns them about nearby airspace rules or restrictions.
Context Anchor
Seen in FAA drone guidance and in discussions about checking whether a drone flight area is allowed before launch.
Derivation
The name is a stylised spelling of 'Before You Fly' -- 'B4' is text-message shorthand for 'before' and 'U' for 'you'. The name reflects its purpose: check the app before you launch the drone.
Why Pilots Care
It helps operators avoid restricted airspace and regulatory violations that could lead to fines or safety incidents.
Intuition Check
B4UFLY is not a clearance or approval by itself. It is a planning and awareness tool that helps show what rules may apply before a drone flight.
Example Sentence 1
Before launching her drone at the park, she opened B4UFLY to check whether the location was inside controlled airspace.
Example Sentence 2
Using B4UFLY before takeoff confirmed the area was clear of airport proximity zones.