Flight Drama Over San Francisco: United’s Mid-Air Communication Breakdown

United flight 35 from San Francisco to Osaka returned to San Francisco on Friday after dumping fuel. The aircraft was unable to make two way voice communication with air traffic control or with the airline’s dispatch.

The pilots of the aircraft communicated via text message – first with ACARS messages and then Controller Pilot Data Link Communications for air traffic control clearance to return to San Francisco.

The exchange between the cockpit and United dispatch is fascinating.

First, two way communications failed. One way they could be heard, but couldn’t hear responses. Another way they could hear but couldn’t be heard.

C=Cockpit. L=Dispatch

C=UNABLE TO CONTACT SFO
ON HF11282 WE HEAR TRANSMISSIONS BUT UNABLE TO REACH THEM IT SEEMS
L=UA35-02 KSFO RJBB TEST
L=UA35-02 KSFO RJBB LOST COMM. WILL CALL YOU BACK VIA SATCOM.
L= CAN HEAR YOU JUST FINE, BUT APPEARS YOU ARE UNABLE TO HEAR ME. PLZ ACK.
C= CORRECT. DID NOT HEAR YOU. UNABLE TO TRNSMT ON HF

United dispatch recommended returning to San Francisco, since the pilots were only able to communicate in writing with the company via ACARS.

NOT SURE ITS A GOOD IDEA TO CONTINUE. LONG WAY TO GO WITHOUT ABILITY TO TALK TO YOU OUTSIDE ACARS. TOMC SAYS NO SATCOM FAULTS.

They had to dump fuel so they wouldn’t land too heavy. They couldn’t communicate, but were required by EPA rules to communicate.

C= YES WE INTEND TO DUMP TO MAX LWT
L= UNDERSTOOD. WILL ADVISE OAK OCEANIC.
L= DUE TO EPA CONSTRAINTS. COMPANY NEEDS TO KEEP RECORDS FOR EPA. AMOUNT OF DUMP FL OF DUMP LOCATION OF DUMP START TIME AND END TIME OF THE DUMP
L= SPOKE WITH OCEANIC. WHEN CLOSE TO SHENU ATC WILL DIRECT YOU TO SPOT WHERE TO DUMP. NEED TO BE IN RADAR ENVIROMENT FOR OTHER FLTS SAFTEY.


United Airlines Boeing 787

Fortunately Oakland Center is set up with Controller Pilot Data Link Communications, which is mandatory in Europe and still rolling out within the United States, and this allows text communication with air traffic control.

The Boeing 787 made a four hour roundtrip, and then after four hours back on the ground got underway again to Osaka Kansai airport.

The most striking thing about the whole exchange? The ‘recovery flight’ that flew to Osaka didn’t serve dinner. They were having an emergency, they couldn’t communicate, but United dispatch made sure that the flight completed its first meal service… so they wouldn’t have to fully cater the second plane.

L=IF YOU HAVE A FREE MOMENT CAN YOU CONFIRM 1ST SERVICE HAS BEEN INITIATED AND OR COMPLETED? A/C SWAP IN SFO TO CONTINUE. HOPING TO AVOID HAVING CATERING PROVIDE FULL SERVICE ON RECOVERY LEG.

Passengers would never have known that there was an issue, until they were told they were returning to San Francisco. And a meal is a good thing to keep everyone occupied.

About Gary Leff

Gary Leff is one of the foremost experts in the field of miles, points, and frequent business travel - a topic he has covered since 2002. Co-founder of frequent flyer community InsideFlyer.com, emcee of the Freddie Awards, and named one of the "World's Top Travel Experts" by Conde' Nast Traveler (2010-Present) Gary has been a guest on most major news media, profiled in several top print publications, and published broadly on the topic of consumer loyalty. More About Gary »

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Comments

  1. What happens if there is a mid-air communication link issue with ATC and the aircraft…drone pilot cannot connect. SHOOT sucks. Given how bad all the new products coming out of aviation manufacturers have been… (NEO engines..Max everything) I cannot wait to see what the have planned to remove pilots in what Gary says would be as soon as 2025!

  2. If there was no food served on the flight that made it (just about there), that is a long flight to go without eating.

  3. wow. Just wow.
    the recovery flight was 8 hours late… a whole nother meal window but we’re not catering for it cuz we checked the box already.
    nothing like putting it all in black and white for all to see.

  4. The issue was with transmitting over HF, which is only used for long distance communication. VHF was available when within 200 miles of the coast. And contact was never lost, but they didn’t have the redundancy they needed. With 8 hours, they should have fully catered the airplane.

  5. It is not Dispatch’s fault they did not have catering. That decision would have come from higher up (Network Directors, Station Operations, etc). Dispatch is not responsible for that function, they would have been relaying information or instructions from other departments.

  6. @Alert

    AI would have easily continued to Japan.

    People need to stop thinking of AI acting as human. The whole point is to not be human.

  7. @Gary. I just read into the actual issue. Once again. You can’t post anything accurate

    There was no communication breakdown. The issue was a loss of HF … radio used when out of VHF/Radar. It’s common to do an HF check before entering Oceanic airspace… there was no actual loss of communications between the aircraft and ATC.

    Just an example readers of how to take everything you read from the media and understand very little of it is real.

  8. novrev
    nobody is trying to find fault w/ dispatch
    The point is that UA – IN ANY DEPARTMENT – would think that not catering a 12 hour flight would be ok because the meal was served hours earlier.
    Even if they thought they could get the replacement flight out 2 hours after the flight returned, the new flight leave would still be leave in a different meal window. Given that the replacement flight left 8 hours later, this just confirms what Gary posts all the time that UA looks for every opportunity cut catering costs – even under IROP situations.
    If UA can’t get its caterer to prepare up to 240 new meals – even boxed meals – on as little as 2 hours notice – they need another caterer.

  9. We are all turning into “armchair aviation investigators” and there are many incidents that we don’t ever hear about.

  10. Typical hyperbole in the comments – Nowhere does it says it wasn’t catered altogether

    The question was asked by dispatch re: the *first* service so they wouldn’t have to do a *full* catering of the recovery leg. The simplest outcome is they planned to do a partial catering: the midflight and arrival service for the recovery leg.

    This was not a 12 hour flight with no food.

    “CAN YOU CONFIRM 1ST SERVICE HAS BEEN INITIATED AND OR COMPLETED? A/C SWAP IN SFO TO CONTINUE. HOPING TO AVOID HAVING CATERING PROVIDE FULL SERVICE ON RECOVERY LEG”

    With that delay I’d rather get more time to sleep on the recovery flight given the time zone changes and wake up for the remaining service.

  11. Because the flight left 8 hours later doesn’t mean the caterers had 8 hours to prepare a new set of meals, also keep in mind the meals for the day are made in massive batching during the overnight, to make another flights work of meals and put them in the galleys takes hours, so the goal is to get people moving as quickly as possible, so they likely substitute for something ready made to get the catering done as quickly as possible for the rescue flight.

  12. SMR is 100% right. This was not a loss of typical (VHF) ATC (Civilian) communication. This was a loss of shortwave (HF) communication used for long distance comms. The particular frequence mentioned is 11282 which is NOT 112.82MHz (VHF) (108-137MHz) but rather 11.282MHz (AM, HF, shortwave).

    The chart of pacific frequencies for CA departures over the Pacific is at:
    https://radio.arinc.net/pacific/ and yes it does show 11282KHz (11.282MHz).

    Each aircraft has a radio station license, in the US tied to the registration. So N123UA has a VHF station license to transmit in the airband frequencies using that callsign. Outside the country they’re supposed to stick to the HF range until in touch with another country’s ATC where they’re allowed by treaty/convention to use their callsign again.

  13. Steven Wolf tripled the size of United’s flight kitchen then sold it to his buddy!United management outsourced most of United’s maintenance. This trend is also reflected in Boeing’s current troubles. Point fingers at contractors when problems arise.United moved its headquarters to Chicago and thats where they hide! United got rid of 13,000 mechanics. Screwed them and the pilots and anybody they could out of their pensions, pay, and their job. This is American corporate in action.

  14. Perhaps they were listening to Led Zeppelin song “communication breakdown” and they got dazed and confused .

  15. Leroy,
    and an air return means another meal.
    Whatever plans UA or their cater had went up in smoke.
    not hard to comprehend.

  16. All meals were provided on the replacement flight. The question was to clarify if whole new galleys would need to be prepared or what from original galleys could be used.

  17. Hello all!

    – Gary – I am a long time subscriber – thank you for your good work
    – I was on the flight – and am in the final steps of completing my 45 hour trip from Park City to Niseko due to the delay
    – United Airlines did a very professional job in managing this tough situation. I am a million miler – lifetime gold and thankful for UAL performance over many decades of travel
    – I had a chicken entree on the way out and chose the pasta entree on our second flight out – both delicious
    – I have a very cool video (11 sec) of fuel dump – if you tell me how to get it to you – I am happy to share!

    Mark

  18. Catering….all y’all are worried about is food!?!? For the love of everything good and holy on this work, grow the F up!!!!!

  19. @Tim Dunn Almost certainly catering another meal means that the airline has to take an even longer delay to wait for new catering to arrive. Much better for pax and the airline to get everyone going as quickly as possible by handing out some meal vouchers on the ground while waiting for the spare plane to be towed to the gate. I’d be mad if my flight were already delayed 6 hours and they told me I had to wait another 2 hours on top for them to re-cater some crappy economy meal.

  20. Used to work at KIX; expensive taxi ride off the island. I hope UA organized a bus or offered taxi vouchers to get people at least into Osaka. (Last train off the island is literally at landing time)

  21. Andrew M,
    why can’t you accept that a cater at a major global airport should be capable of coming up w/ at least a cold, boxed meal on 2 hours notice for 250 passengers?
    An air return isn’t the only reason to need to re-cater. A lengthy ground delay or any number of other reasons could cause meals “to expire” requiring a need to re-cater.
    No one expects that the same menu would be offered twice but another service should be served and a caterer should be capable of having the flexibility and speed to deliver it in two hours – as soon as UA dispatch made the decision that there would be an equipment change and a 2nd attempt.

  22. @Tim Do you work in catering? You are speaking as if you have some insider contacts at catering to know that what you propose is possible. As a pax, I would much rather have a meal voucher to go get some sushi rather than a shelf-stable box of crappy carbs even if what you propose is possible.

  23. AI sucks and is a real threat to humanity. As far as convincing the flying public they don’t need pilots–good luck with that! And what are people to aspire to? Sit around and watch robots and quanta do all the work? What a world. I guess we’ll just get bored and start striking matches for fun.

  24. OMG there was an issue and it was handled safely. Such riveting “journalism” these days. #clickbait

  25. How about 8843 or 6640 if 11282. They must have tried other frequencys. Plus they had sat com.and 121.5. Emergency frequency. United needs change in flight regulations. Both hf inop minimum equipment list on ground would prevent takeoff but in the air carry on.

  26. The dispatcher and crew did a good job coordinating a plan to adjust for the unexpected loss of communications.

    The catering comment isn’t about being cheap, it’s about recovering the flight in a reasonable amount of time. The passengers will still eat – meal vouchers at the airport and a partial meal service on the flight. It can take 4+ hours to prepare a whole new set of meals for a for an international flight, and aside from subjecting the passengers to an extended delay (after an air return) there are often operational factors that prevent the ability to take any more delay than necessary (crew legality, airport curfews, handling hours of operation, etc).

  27. How on earth did they get the ACARS? I am a dispatcher at AA and I’m not sure those are public. Maybe I’m wrong.

  28. Hundreds of incidents happen like this and even more interesting ones and are documented in the Website “Aeroinside” but they make you buy a subscription.

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