A (minor) loss of cabin pressure

The flight was unusually cold. Better than being too hot, in my opinion, but it was definitely colder that I’m used to on board as we headed west from London on a British Airways 747-400 and over the Atlantic Ocean towards JFK. No big deal, really, until about 3 hours into flight when it got REALLY cold. As in the air conditioner blowing full blast for about 15 seconds before cutting out completely. There was a brief, almost incoherent announcement made about crew and the flight deck. And my ears popped unexpectedly. They’re excessively sensitive, but it happened and that’s rare when at cruise.

Anomalies like that are rarely a good thing on airplanes and less so when flying 37,000 feet over the Atlantic off the coast of Greenland (flight BA115/23JUL). But the plane continued on and I didn’t think much of it, other than to wonder about getting a second blanket to keep my toes warm. About 20-30 minutes later the pilot came on the PA to brief us on what happened. Turns out we blew an air conditioning unit which affects the ability of the plane to maintain cabin pressure automatically, at least I’m pretty sure that’s what the pilot said.

This was not a total pressure failure – masks did not deploy – but it was enough that it raised concerns from the crew about the welfare of the passengers. I managed to record most of the briefing and included it below:

We’ve switched over to the manual system and that’s settled the cabin pressure down now. We do apologize for that. You may have noticed a little bit of a pressure change in your ears throughout the time that it was occurring. At the moment we’re cruising at 37,000 feet; with everything settled down we plan to continue to New York. I would ask you though if you’ve had any adverse effects at all from the changes in pressurization please do talk to the cabin crew.

At the moment progress-wise we are cruising at 37,000 feet and UK time we are estimating arrival at 22:45.

In the mean time, as I said, apologies for the pressurization fluctuations in the cabin, everything is now settled down. If you have any concerns or had any adverse effects please do talk to the cabin crew. Thank you.

I was hoping to speak with the pilots about the circumstances of the incident after we landed. The cabin crew explained that wasn’t going to happen due to filling out paperwork and such and after 26 days on the road I was ready to let that go. We were met by BA representatives in the jetbridge on arrival, however. I asked a couple of them to explain what happened and this was where I think things failed the most. Rather than answering my question of what exactly failed on the plane they kept asking me if I was okay and if I wanted to talk to anyone about it. Despite my saying over and over again that I’m fine and that I basically sit on planes for a living.

I was given a letter reminding me that “The Captain was in regular contact with our engineering team and was always in complete control of the aircraft” but zero additional information. I understand that having a completed analysis 4 hours after the incident is never going to happen. But being able to say what part failed or what the indicator was to the pilots would have been useful. I assume that I’ll get an answer from them eventually or that it’ll show up in AVHerald.com. But the handling on arrival was not great.

Also, the return flight, BA176/23JUL, was cancelled and the plane appears to still be in JFK. So clearly more than just a little problem, but also not a big one.

Never miss another post: Sign up for email alerts and get only the content you want direct to your inbox.

Seth Miller

I'm Seth, also known as the Wandering Aramean. I was bit by the travel bug 30 years ago and there's no sign of a cure. I fly ~200,000 miles annually; these are my stories. You can connect with me on Twitter, Facebook, and LinkedIn.


  1. Glad you, and your ears, are OK. Mine are particularly sensitive too, particularly with something I’m going through right now, so I know I would’ve felt it. Fretful old me would’ve been concerned over open water like that, and I would be pulling me in-flight magazine atlas page to look at locations of airports in Greenland and how far we had to go to Bangor, Maine, LOL.

    Sounds like the crew in the Jetbridge was crisis-management-by-lawyers.

    Not at all surprised the return was canceled. I have had returns canceled with incoming anomalies seemingly less serious than yours, which was again to be over water.

    Once again, happy you’re OK and thanks for filling us in. Both thankful and a tad surprised that this doesn’t happen more often.

  2. I would venture to say that most gate agents aren’t that interested in knowing what exactly went wrong or expect that any passenger is going to ask. I love knowing this kind of stuff but I am probably in the minority. Interesting to note how they handled the situation on the ground by offering comfort and asking if you would care to speak to someone else.

    1. These were not regular gate agents who met the flight. More like station manager type folks, and there were a few of them.

      1. Honestly, i think you were expecting way too much to get any sort of relevant information that soon after the flight. Especially if they were manager types, then they’re definitely not going to speculate or say anything that could potentially open the organization up to any kind of litigation or liability. At best, they can make sure they ask multiple times that everyone is okay to take care of their customers and, again, to try to avoid any kind of liability.

        Very useful comments below from Jonathan and JB, by the way. Seems to be pretty good speculation.

    1. I didn’t get up and walk around to pay it much attention. And I was in business class so couldn’t see everyone else on board. While I was talking to the agents after we landed only one other person of about 75-100 also stopped. And then I moved on.

  3. I’d say you lost a pack. Basically just an air conditioning compressor type of thing that sucks air from the engines into the cabin to keep the cabin pressurized. Not serious enough to divert, but it seems to be on the MEL, so they can’t dispatch the aircraft till it is fixed.

  4. Seth, Glad you are OK & remainder of the flight was normal. Good thing you didn’t have a cold, as that +sensitive ears could have = painful earaches. Have to ask: did not the BA kit socks assist in warming freezing toes?

  5. Air conditioning PACKs are responsible for providing the conditioned air in the cabin. There is a valve, called an outflow valve, which regulates how much of that air is allowed to escape the airplane’s pressure vessle. Normally you have two packs, both of which operate at the same time to proivde coniditioned air. It seems one of them on your flight decided it didnt feel like working all of the way to New York. When that happened, there would have been a change in the volume of air being pumped into the cabin. Thus, the position the outflow valve was in to maintain the selected cabin pressure altitude, would have needed to change to compensate for the decreased flow. Thus, your ears felt it! Typically, a loss of a pack is more of an inconvenience. Airlines will routinely dispatch aircraft with one of them inoperative, provided certain conditions can be met, like not cruising as high,etc. The only problem comes in when you lose the second one! Then you have an emergency and need to get to 10,000 ft in short order.

    1. And re-entered service on the 25th as BA177, LHR-JFK. Diverted to BOS because of the storms but eventually made it to New York.

Comments are closed.