Jan 29, 2026, 2:10 pm
Last edit by: WineCountryUA
Additional information on this:
Overnight technology upgrade and outage on Feb. 4 On February 4, 2026 from 1:30 a.m. - 5:00 a.m. CT (07:30 - 11:00 UTC), United will conduct a technology upgrade which will restart our systems to help us maintain better functionality and reliability. During this time, connecting to Uniteds reservations system will be temporarily unavailable to travelers, distribution partners, travel agents, as well as United representatives.
United systems that will be temporarily unavailable include all United direct channels (United.com, United Mobile app), agency channels, and other airlines:
United has proactively adjusted flight schedules to minimize the number of customers affected and gave customers the opportunity to adjust their travel. United/United Express flights will not depart during the outage, but flights enroute prior to the upgrade time will land at their scheduled destination.
Overnight technology upgrade and outage on Feb. 4 On February 4, 2026 from 1:30 a.m. - 5:00 a.m. CT (07:30 - 11:00 UTC), United will conduct a technology upgrade which will restart our systems to help us maintain better functionality and reliability. During this time, connecting to Uniteds reservations system will be temporarily unavailable to travelers, distribution partners, travel agents, as well as United representatives.
United systems that will be temporarily unavailable include all United direct channels (United.com, United Mobile app), agency channels, and other airlines:
- Reservations access through any system
- Flight check-in through United.com, United mobile app, and/or at the airport
- Creating or modifying a reservation (issuing new ticket/exchange)
- Purchases, including new tickets, seats, pay for checked bags and other purchases
- MileagePlus access
United has proactively adjusted flight schedules to minimize the number of customers affected and gave customers the opportunity to adjust their travel. United/United Express flights will not depart during the outage, but flights enroute prior to the upgrade time will land at their scheduled destination.
February 4 "Systems Update" - No Check in, no res access from 1:30-5am CT
Jan 29, 2026 | 1:56 pm
#31
Join Date: May 2011
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Being the IT realist that I am, unless this upgrade already has a ton of buffer in it (and 1:30-5am seems like and odd duration so I suspect there is at least some buffer) I was thinking on taking how far after 5am CT (6am ET) the first United flight actually departs.
'Cuz if the systems are down and UA can't process passengers (from the communication it seems like even airports will be offline) until 5am there's no way a flight is departing before +/-6:30 CT and that's assuming everything is back up right at 5 AM CT
'Cuz if the systems are down and UA can't process passengers (from the communication it seems like even airports will be offline) until 5am there's no way a flight is departing before +/-6:30 CT and that's assuming everything is back up right at 5 AM CT
Jan 29, 2026 | 1:57 pm
#32
Join Date: Apr 2007
Location: USA
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If I'm putting this all together correctly, this may be the last part of the SHARES to homegrown, cloud-native, PSS that they've been working on for years. These details were revealed in 2 different AWS re:Invent sessions late last year, you can watch them
and
. Before seeing those sessions, I knew lots of customer facing entry points, app and website support, etc. were running on AWS, but it sounds like they truly just wrote their own PSS from scratch starting many years ago and have been cutting over aspects from SHARES ever since. Given UA is an industry leader in technology, I'd expect this to go relatively seamlessly and the time frame they quote is worst case scenario. This isn't your grandpa's Apolo to SHARES transition of 14 years ago.
Jan 29, 2026 | 2:04 pm
#33
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Explains why the 773ER HNL-SFO is departing earlier than normal on the 3rd (9:15pm HST, 1:15am on 4th CT). The a/c sits at HNL for a while after arrival from Guam, so easy to move up SFO departure.
Jan 29, 2026 | 2:31 pm
#34
Join Date: Feb 2005
Location: CLE, DCA, and 30k feet
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I expect that it will be better than the previous PSS cutover but given the trauma inflicted for me -- who existed essentially entirely in the pmCO world and did a fraction of the travel I do today (I think I struggled to hit Silver that year if I am recalling correctly) if it's 1/10th as bad as then it will be bad in an epic way -- I had flights appearing, disappearing, being double credited, being improperly credited, etc. for weeks... and theoretically, at least, I wasn't even changing systems.
Jan 29, 2026 | 2:51 pm
#35
Moderator: United Airlines
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The reference prior change
March 3, 2012 - integration day for SHARES res. system. - FlyerTalk Forums
March 3rd, 2012 System Integration Master Thread (PSS)
March 3, 2012 - integration day for SHARES res. system. - FlyerTalk Forums
March 3rd, 2012 System Integration Master Thread (PSS)
Last edited by WineCountryUA; Jan 29, 2026 at 4:37 pm
Jan 29, 2026 | 3:33 pm
#36
Join Date: Apr 2007
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They're essentially doing open-heart surgery on a real-time machine with thousands of cogs ad millions of gears. Especially if they're actually cutting over the PSS (which seems like a logical conclusion based on how much won't work) the question isn't will anything go wrong it's how many things will go wrong.
I expect that it will be better than the previous PSS cutover but given the trauma inflicted for me -- who existed essentially entirely in the pmCO world and did a fraction of the travel I do today (I think I struggled to hit Silver that year if I am recalling correctly) if it's 1/10th as bad as then it will be bad in an epic way -- I had flights appearing, disappearing, being double credited, being improperly credited, etc. for weeks... and theoretically, at least, I wasn't even changing systems.
I expect that it will be better than the previous PSS cutover but given the trauma inflicted for me -- who existed essentially entirely in the pmCO world and did a fraction of the travel I do today (I think I struggled to hit Silver that year if I am recalling correctly) if it's 1/10th as bad as then it will be bad in an epic way -- I had flights appearing, disappearing, being double credited, being improperly credited, etc. for weeks... and theoretically, at least, I wasn't even changing systems.
I'm not going on the ship of absolutely zero issues, but these transitions have been happening in the background for years and we've never really seen any issues.
The reference prior change
March 3, 2012 - integration day for SHARES res. system. - FlyerTalk Forums
March 3, 2012 - integration day for SHARES res. system. - FlyerTalk Forums
Jan 29, 2026 | 7:44 pm
#37
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They're essentially doing open-heart surgery on a real-time machine with thousands of cogs ad millions of gears. Especially if they're actually cutting over the PSS (which seems like a logical conclusion based on how much won't work) the question isn't will anything go wrong it's how many things will go wrong.
I expect that it will be better than the previous PSS cutover but given the trauma inflicted for me -- who existed essentially entirely in the pmCO world and did a fraction of the travel I do today (I think I struggled to hit Silver that year if I am recalling correctly) if it's 1/10th as bad as then it will be bad in an epic way -- I had flights appearing, disappearing, being double credited, being improperly credited, etc. for weeks... and theoretically, at least, I wasn't even changing systems.
I expect that it will be better than the previous PSS cutover but given the trauma inflicted for me -- who existed essentially entirely in the pmCO world and did a fraction of the travel I do today (I think I struggled to hit Silver that year if I am recalling correctly) if it's 1/10th as bad as then it will be bad in an epic way -- I had flights appearing, disappearing, being double credited, being improperly credited, etc. for weeks... and theoretically, at least, I wasn't even changing systems.
I get being pessimistic on it this time, however, I imagine comparing these two is Lada vs. Bentley. Never mind the completely different approach to how modern infrastructure works, with microservices, isolation, infinite path and UI redundancy. From the talks above, it sounds like they've essentially already transitioned 90% of the PSS, and this is the last hurdle. I'd be willing to bet we've been using all the modern PSS infrastructure for months, and all the functions have been duplicated on both PSS's. AA/US took this route and essentially started it, did it for 345 days and by the end, there was no more new bookings on the old US platform, and everything was in SABRE.
I'm not going on the ship of absolutely zero issues, but these transitions have been happening in the background for years and we've never really seen any issues.
The TRAUMA you have just reinvoked on me with this...
I'm not going on the ship of absolutely zero issues, but these transitions have been happening in the background for years and we've never really seen any issues.
The TRAUMA you have just reinvoked on me with this...
Let the fun and games begin - again!
David
Jan 30, 2026 | 7:36 am
#41
Join Date: Feb 2002
Location: BNA
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Posts: 9,524
Jan 30, 2026 | 3:03 pm
#42
FlyerTalk Evangelist
Join Date: May 2001
Posts: 11,695
Wow, so SHARES is done? Never thought this day would come before 2053. (Yes, SHARES and I think other IBM TPF-based reservation systems have a Y2K problem come 2053.)
I guess anyone in IT will expect problems - the question is how big.
I also wonder what differences we will see? Will we be able to make reservations > 330ish days in advance, will the discrepancies between the "reservation" and the "airport" sides disappear, etc.?
I also wonder if UA will end up making this a profit center - outsourcing to to other airlines, etc. like Apollo / SystemOne all over again?
So many questions...
I guess anyone in IT will expect problems - the question is how big.
I also wonder what differences we will see? Will we be able to make reservations > 330ish days in advance, will the discrepancies between the "reservation" and the "airport" sides disappear, etc.?
I also wonder if UA will end up making this a profit center - outsourcing to to other airlines, etc. like Apollo / SystemOne all over again?
So many questions...
Jan 30, 2026 | 3:59 pm
#43
Join Date: Feb 2005
Location: CLE, DCA, and 30k feet
Programs: Honors LT Diamond; United 1K 1MM; Hertz PC
Posts: 5,677
Wow, so SHARES is done? Never thought this day would come before 2053. (Yes, SHARES and I think other IBM TPF-based reservation systems have a Y2K problem come 2053.)
I guess anyone in IT will expect problems - the question is how big.
I also wonder what differences we will see? Will we be able to make reservations > 330ish days in advance, will the discrepancies between the "reservation" and the "airport" sides disappear, etc.?
I also wonder if UA will end up making this a profit center - outsourcing to to other airlines, etc. like Apollo / SystemOne all over again?
So many questions...
I guess anyone in IT will expect problems - the question is how big.
I also wonder what differences we will see? Will we be able to make reservations > 330ish days in advance, will the discrepancies between the "reservation" and the "airport" sides disappear, etc.?
I also wonder if UA will end up making this a profit center - outsourcing to to other airlines, etc. like Apollo / SystemOne all over again?
So many questions...
The 330 day ticketing likely won't change regardless (and even if that wasn't a technical limitation... would UA really want to sell seats much further out when any number of changes in outside factors could change routes. times, aircraft types, etc. (Heck, for a while Frontier [maybe still?] Frontier wasn't selling anything past April 13...)
