Transponders would have allowed air traffic controllers to see the fire truck’s location on their instruments.

A jet crashed into the fire truck at LaGuardia Airport on Sunday, killing two and injuring dozens.

NTSB says LaGuardia’s surface warning system was "unable to alert."

Firefighters confirm their units at Phoenix Sky Harbor Airport are not equipped with transponders, even as federal officials push airports to add them.

BIGFORK, Mont.--(BUSINESS WIRE)--Today, uAvionix Corporation announced it has filed a Technical Standard Order (TSO) application with the FAA Aircraft Certification Office (ACO) for its flagship Mode S ADS-B OUT transponder for Unmanned Aircraft Systems (UAS).