Author Topic: Request - Possible Loss of Separation, July 5, SY105  (Read 7419 times)

Offline adanto6840

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Request - Possible Loss of Separation, July 5, SY105
« on: July 11, 2014, 12:45:56 PM »
This is probably a long shot but...

I was a passenger on SY105 on July 5th, KMSP to KLAS -- during the flight, at approximately 5:21PM CT (plus/minus 2 minutes), while at or near cruise altitude there was another jet aircraft visible out of the left side of the cabin window.   I was unable to identify the other aircraft as it was traveling in the opposite direction and moving fast, so this happened quite quickly. 

I would estimate that the other aircraft was approximately 1/4 mile away, and certainly less than 1 mile away.  The other aircraft appeared to be flying at an altitude approximately 500 to 1,000 feet less than the altitude of us / SY105.

I'm not sure if this violates rules of separation or not, which is one of the reasons I'm posting (I'm just an aviation nerd & student pilot who should have had his PPL several years ago).  I'm also curious if anyone can find the ATC recordings that may have contained related dialog.

FWIW, I have searched a decent bit but I suspect we may have been under control of a center which is not yet covered by a feed -- I wasn't able to find anything so far though, but if anyone finds it I'd certainly appreciate it.

On July 5th at approximately 5:21PM CT, while traveling KMSP to KLAS on Sun Country Flight 105, an aircraft going in the opposite direction to us appeared awfully close.  Any insight or related audio would be appreciated!  :-)

Offline bbrasmussen

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Re: Request - Possible Loss of Separation, July 5, SY105
« Reply #1 on: July 11, 2014, 01:03:16 PM »
Probably traffic 1000 feet below you. Happens many times during a flight. The separation requirements are 1000' so there was no loss of separation.

If there was any audio it would have been the controller issuing mutual traffic to your flight and the other flight - an extremely common occurrence.

Offline Rick108

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Re: Request - Possible Loss of Separation, July 5, SY105
« Reply #2 on: July 11, 2014, 01:06:10 PM »
The other aircraft was most certainly 1000' below you.  Since you were west-bound, you would have been at some even altitude (32,000' or 34,000', etc.) and the more-easterly-bound aircraft would have been at an odd altitude (31K, 33K, etc.).  At 1000' vertical separation, you could have passed directly over the other aircraft without violating any rules.  That's how the system works.  ATC would have notified your pilot of "traffic at your 12 o'clock, opposite direction, 1000' below" and also notified the other pilot, so they wouldn't be surprised by the oncoming plane.   :-o

Offline JetScan1

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Re: Request - Possible Loss of Separation, July 5, SY105
« Reply #3 on: July 12, 2014, 03:12:53 PM »

The flightradar24 website has a playback option where you can watch traffic from a given date/time in the past.

Watching SCX105 on July 5th between 22:10 UTC (17:10 CDT) and 22:30 UTC (17:30 CDT) cruising at FL400, it appears the most likely traffic you saw was DAL820, A319, SAN-MSP, level at FL390 (or possibly SWA4524, B737, SJC-MDW, also at FL390).  

At 06:06 (min:sec) on the 2230Z ZDV High North archive you can hear SCX105 get the handoff to Denver Center on 133.95 (given the route presumably from 120.57), then at 12:29 you can hear the handoff to 132.85. Prior to this on the 2200Z archive I did not hear any transmissions from the flight, which wouldn't be unusual as the radio is scanning so many frequencies that chances are they would have been blocked anyway.

« Last Edit: July 12, 2014, 03:14:46 PM by JetScan1 »

Offline martyj19

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Re: Request - Possible Loss of Separation, July 5, SY105
« Reply #4 on: July 12, 2014, 06:48:41 PM »
As everyone else has said, 1000 vertical satisfies the separation requirement.  Years ago before RVSM we had 2000 vertical in the higher flight levels to compensate for the accuracy of altimeters.

Remember that there is TCAS in both aircraft that will almost certainly have indicated the opposite direction aircraft to both, in addition to any ATC traffic point out.  If "dangerously close", the TCAS will issue a Resolution Advisory that if followed will prevent a possible collision.

The same thing happened to me many years ago, I happened to be flying commercial and looking out the window and saw an opposite direction aircraft shoot past.  As pilots, we strive never to be surprised by nearby traffic and it did cause me a shot of adrenaline.  I asked the crew what it was after the flight and if I remember correctly they said an F-14.