133.900 ORD Class B

[Premises2972]

I got a close call hit on this frequency near the lakefront a bit ago. It seems to be one of the Class B frequencies. It isn't added in the DB, can anyone confirm what this freq is used for?

 

[RichardKramer]

Goshen Municipal​

Frequency	Input	License	Type	Tone	Alpha Tag	Description	Mode	Tag
123.050			CSQ	GoshenAirpr	CTAF & UNICOM	AM	Aircraft
127.550			CSQ	GoshenAirp	Chicago Center - Low Altitude	AM	Aircraft
133.900			CSQ	GoshenAirp	Chicago Center - Backup	AM	Aircraft
133.950			CSQ	GoshenAirp	Chicago Center - Low Altitude	AM	Aircraft

 

[Premises2972]

So should it be added to the ZAU page?

 

[kevino]

So should it be added to the ZAU page?

Where on the lakefront were you when you got the close call hit? If you were along the Chicago lakefront, I'd think it would seem to be a bit of a distance for you to be getting a close call hit on a low altitude ATC freq active in the Goshen, IN area...but then again who knows? VHF air freq assignments have been known to change from time to time, and not being close to Goshen, IN, I don't know if 133.900 is currently used there. Maybe give it a listen and/or record it to see if it's currently active in the Chicago area?

 

[Premises2972]

Where on the lakefront were you when you got the close call hit? If you were along the Chicago lakefront, I'd think it would seem to be a bit of a distance for you to be getting a close call hit on a low altitude ATC freq active in the Goshen, IN area...but then again who knows? VHF air freq assignments have been known to change from time to time, and not being close to Goshen, IN, I don't know if 133.900 is currently used there. Maybe give it a listen and/or record it to see if it's currently active in the Chicago area?

I was on the north end of the city
I can still hear that frequency active in the chicago area. but its only active sometimes, its not consistently active like a normal ZAU or Tower freq

 

[kevino]

I was on the north end of the city
I can still hear that frequency active in the chicago area. but its only active sometimes, its not consistently active like a normal ZAU or Tower freq

Are you hearing aircraft, Chicago Center or both? Have you tried locating tail numbers you're hearing (using adsbexchange, etc.) to determine what sector the aircraft are in?

 

[Premises2972]

Are you hearing aircraft, Chicago Center or both? Have you tried locating tail numbers you're hearing (using adsbexchange, etc.) to determine what sector the aircraft are in?

I mostly hear aircraft and not the other side of the conversation. Next time I hear them Ill locate the aircraft, since i have heard tail numbers on there.

 

[kevino]

Just heard Southwest 3324 talking to an unheard user (ATC, I'm assuming) on 133.900 just after departing Midway Airport on runway 31C and making a hard right "turn" to an E/SE heading. Sounds like they were given a different freq to switch to and they said "OK, see ya'". Definite Chicago area use, now to determine what that use is and add it to the Radio Reference database.

 

[kevino]

133.900 Update - In reviewing recordings from a few weeks ago, I'm hearing various aircraft (only) working "Chicago Approach" while enroute to landing at Midway Airport runway 22 Left. From this freq, it appears that aircraft are handed off to 135.200 (MDW Tower).

Current RNAV XRAY, YANKEE and ZULU approach plates found online show the VHF Chicago Approach freq as 128.200. I have not yet had the chance to listen to 128.200 and 133.900 at the same time to see if one freq might be connected with the other.

Anyone have further information about how the Chicago TRACON uses 133.900?

 

[Premises2972]

Just heard Southwest 3324 talking to an unheard user (ATC, I'm assuming) on 133.900 just after departing Midway Airport on runway 31C and making a hard right "turn" to an E/SE heading. Sounds like they were given a different freq to switch to and they said "OK, see ya'". Definite Chicago area use, now to determine what that use is and add it to the Radio Reference database.

Hey, its been a while since this freq has been sitting in my scanner's bank without any traffic. Today I was able to confirm this is being used as MDW App/Dep, multiple planes going to and from MDW were on this frequency getting standard app/dep instructions. I'd say we can add this as an alternate freq for MDW App/Dep in the DB, right?

 

[kevino]

Hey, its been a while since this freq has been sitting in my scanner's bank without any traffic. Today I was able to confirm this is being used as MDW App/Dep, multiple planes going to and from MDW were on this frequency getting standard app/dep instructions. I'd say we can add this as an alternate freq for MDW App/Dep in the DB, right?

Since it has been observed as what appears to be a MDW App/Dep freq in the limited times that it has been monitored, that's how I've added it to the database. Thanks for the report.