F91720 emergency alert: Santa Ana–Phoenix flight reportedly diverting to Tucson

F91720, a Frontier Airlines flight from Santa Ana, California, to Phoenix, Arizona, was reported transmitting emergency transponder code 7700 and diverting to Tucson, according to the supplied flight-tracking update.

The flight’s scheduled route connects John Wayne Airport with Phoenix Sky Harbor International Airport.

Code 7700 signals a general emergency but does not identify its cause.

The supplied update did not explain the reason for the reported diversion or confirm whether the aircraft had landed in Tucson.

Scheduled route verified against flight records; the emergency alert and diversion are attributed to the supplied update.