LOUD SQUEAL in the cockpit. Origin is unknown | Southwest Boeing 737-800 | Phoenix Sky Harbor

THIS VIDEO IS A RECONSTRUCTION OF THE FOLLOWING SITUATION IN FLIGHT:

23-MAR-2021. A Southwest Boeing 737-800 (B738), registration N8306H, performing flight SWA2053 / WN2053 from Phoenix Sky Harbor International Airport, AZ (USA) to Metro Oakland International Airport, CA (USA), after departure from Phoenix requested to level off at 10000, reported about loud squeal in the cockpit (the origin was unknown) and pilots decided to return back to the airport of departure.

PART OF TEXT VERSION OF COMMUNICATIONS THAT I'M ABLE TO INCLUDE HERE. Do you want more? Write in comments and I'll give you remaining part of text communications (Read if subtitles in video were fast):

SWA2053: Departure, Southwest 2053, passing 3000 for 8000.
DEPARTURE: Southwest 2053, Phoenix Departure, radar contact, good morning, climb and maintain FL210.
SWA2053: 210, Southwest 2053.
SWA2053: Approach, Southwest 2053, we’d like to level right here at 10000.
DEPARTURE: Southwest 2053, roger, do you need any assistance at this time?
SWA2053: No at this time, we’ll let you know.
DEPARTURE: Southwest 2053, roger, amend the altitude, maintain 10000. If you’re able, for traffic later on would I maybe be able to climb you to 12000?
SWA2053: We’ll let you know on that, we’ll stay lower at 10000 for now, Southwest 2053.
DEPARTURE: Southwest 2053, roger, and just for my planning purposes, to inform Albuquerque Center. Do you know if you’re gonna be returning to Sky Harbor at this time or not? Are you gonna work some out?
SWA2053: Just gonna work some out and find out.
DEPARTURE: Southwest 2053, roger, just maintain 10000. Keep me advised of the situation, please. Phoenix altimeter is 2975.
SWA2053: Alright, we’ll do and 2975, Southwest 2053.
DEPARTURE: Southwest 2053, do you know the extent of the issue yet?
SWA2053: Negative, Southwest 2053, we’ll be right back with you.
DEPARTURE: Southwest 2053, roger, just… If you could let me know within the next 10 miles or so. I got to figure out if I’m gonna be giving you to Albuquerque Center or not.
SWA2053: Roger that. We'll let you know. We'll probably return to field in a few minutes, thanks.
DEPARTURE: Southwest 2053, roger, just go ahead and fly present heading. I’m just gonna give you vectors for a little bit and just let me know as soon as you know what’s going on.
SWA2053: Alright, present heading, about 265 for now, Southwest 2053.
DEPARTURE: Thank you.
DEPARTURE: Southwest 2053, how's it looking?
SWA2053: 2053, Let's go ahead and get vectors back to Phoenix, please.
DEPARTURE: Southwest 2053, roger, turn right heading 350. It’s gonna be vectors most likely for RW 8. And just to verify, are you declaring an emergency at this time?
SWA2053: 350 and negative, just a precautionary landing.
DEPARTURE: Southwest 2053, roger. And what exactly is the issue? Just… I got to coordinate with the supervisor.
SWA2053: Yeah, we’ve got a loud squeal in the cockpit, unknown origin and… Yeah, not really sure exactly what it is.

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THE VALUE OF THIS VIDEO:
THE MAIN VALUE IS EDUCATION. This reconstruction will be useful for actual or future air traffic controllers and pilots, people who plan to connect life with aviation, who like aviation. With help of this video reconstruction you’ll learn how to use radiotelephony rules, Aviation English language and general English language (for people whose native language is not English) in situation in flight, which was shown. THE MAIN REASON I DO THIS IS TO HELP PEOPLE TO UNDERSTAND EVERY EMERGENCY SITUATION, EVERY WORD AND EVERY MOVE OF AIRCRAFT.

SOURCES OF MATERIAL, LICENSES AND PERMISSIONS:
Source of communications – https://www.liveatc.net/ (I have a permission (Letter) for commercial use of radio communications from LiveATC.net).
Map, aerial pictures (License (ODbL) ©OpenStreetMap -https://www.openstreetmap.org/copyrig...) Permission for commercial use, royalty-free use.
Radar screen (In new versions of videos) – Made by author.
Text version of communication – Made by Author.
Video editing - Made by author.

HOW I DO VIDEOS:
1) I monitor media, airspace, looking for any non-standard, emergency and interesting situation.
2) I find communications of ATC unit for the period of time I need.
3) I take only phrases between air traffic controller and selected flight.
4) I find a flight path of selected aircraft.
5) I make an animation (early couple of videos don’t have animation) of flight path and aircraft, where the aircraft goes on his route.
6) When I edit video I put phrases of communications to specific points in video (in tandem with animation).
7) Together with my comments (voice and text) I edit and make a reconstruction of emergency, non-standard and interesting situation in flight.