PA51184391 is an audio clip.
In the clip there is static and Morse code going through it.
The Morse code message is:
"CQ CQ OTPST $ GRNLND UF FA2 E NVSCOT Unidentified aircraft spotted. Headed eastbound approximate speed estimated at mach 5 size indeterminate. Could be up to 20 fleets. Immediate response required. Initiate last resort defense protocol. There is no other way."