On a recent flight to Romania, the whole flight erupted with applause once we'd landed. This wasn't a "difficult" flight - no turbulence, delays, or hijackings. Just a bog standard flight.
On the return flight to London, no one applauded.
However, when I flew to and from Jamaica lots of people applauded. Again, a fairly routine flight.
Are there traditions in some countries around clapping? Can airline staff predict who is likely to applaud?
A cabin crew member here, and I am from a country where people do not clap after landings and I was very surprised when I experienced this for the first time, so I started asking passengers when this happens on different flights. Basically there are three main reasons:
A sign of appreciation: the smoother the flight/landing, the stronger the clapping. You know, clapping is cheaper and more feasible than sending the crew flowers.
A sign of happiness for safely landing. The harder the flight was, the stronger the clapping will be. There could be other reasons as well behind "happiness", I am sure it happened with me when no one expected it to happen, but in general it happens on certain flights with certain communities on a regular basis.
A sign of excitement for reaching home. Seen this in flights where most of the passengers are expats arriving home after spending a long time away from home.
The three above situations happen more when arriving home, not when going away from home. That also was noticed.
I guess in some communities, this clapping thing became a tradition, Egypt for example. While the applause is mainly a sign of excitement, people from there do not need a reason to do so. You'll see passengers from all classes (even rich people in first class) will usually clap especially older ones regardless of the flight even if it was a one hour flight with no service and a hard landing!
There are also other less common reasons behind that. Sometimes crew announcements initiate that, as mentioned in the comment (the crew announced that this was the last flight before the captain's retirement), another announcement that I personally experienced when the captain announced the result of an important football match (he got the result from the ATC).
To add to Heidels answer: Humans are herd mammals, psychologically speaking. If you pay attention to such applause, usually it starts slowly with 1 or 2 people clapping, then others joining in until eventually everyone is clapping and cheering. You don't have the entire plane bursting into applause at the exact moment the wheels touch down. Sometimes it start, but never quite gets going and quickly fades again.
It takes a certain number of people to clap before everyone joins in. So depending on whether you have enough people that always clap or not, applause may:
As to why some locations do this and others don't, that's usually due to what kind of destination it is. Romania and Jamaica are mostly vacation destinations: people go there to relax, and they're probably happy that they have started their holiday, or happy to have arrived at their destination. On the other hand, the return flight to London is mainly a home destination: people return from vacation, and they're probably a little bit worn from their vacation and not really looking forward to returning to the threadmill, so they're less likely to be happy about that.
The answers above are good, but I'd like to add a few things. People have clapped on flights because of:
All of these things may be the root cause of the clapping but in many cases most people start clapping because their neighbors were clapping. Additionally, there are a few people that always clap all the time (many Americans do this) and it only takes a few of those people to start the whole plane clapping.
Generally, people in business class clap far less.
The accepted answer and the supporting answers are all good, but me living in a country neighboring Romania, and having too many flights between the UK and my country, the explanation is much simpler.
We're generally poor. We don't get to fly that often, half these flights are filled with older relatives visiting their migrant children. So a flight is generally an exciting, new and most of all scary thing for these people.
What the applause means is "Great job, on landing and not killing us, bravo" It's comparable to the "thank you" on your way out of the UK bus.
I personally hate this, as I've already payed my ticket, showing my trust with the company and by proxy, the pilot, and moreover he's much more concentrated on finishing the landing to hear me clapping at the back ... As mentioned in the Question, much more extraordinary things need to happen, for the pilot to earn my "Thank you for doing your job"
In Israel, it is very common for people to clap their hands and applaud after landing, especially when flying with the national airline El Al.
While it might sound silly - a lot of Israelis are very proud of the fact they do in fact have a nice airline with good pilots. Add that to the fact that pilots in El-Al often have ex-airforce backgrounds (and are considered heros) and you get part of the motivation.
So, it's part motivated by that pride and part by the fact the airplane made it.
Some Israelis also burst into song, especially when making Aliyah (moving to Israel from another country) or returning to Israel. Typically "Hevenu Shalom Aleichm" (We have brought peace upon you).
It's a weird national quirk - but it has been pretty consistent until recently and has become slightly less (but still very) common over the past few years.
Years ago, there were a series of dc-10 crashes. In my experience, passengers started applauding safe landings in that time period -- particularly on dc-10s. It was a bit of gallows humor ... "We made it!"
At the risk of making broad over-generalizations, I'd say people are likely to clap on an ordinary landing if
From my experience in the United States it is more a tradition with specific airlines to help stand out from the crowd to say thank you and express gratitude for the pilot after a good landing, or any landing at all. Specifically in the US Southwest airlines do this, along with many other things including jokes from the flight staff to stand out from other airlines, and help the passengers relax and have more fun. It has happened on every Southwest flight I have been on (15+ flights) and none of the other airlines in the US.
I would say that some cultures are more emotional and playful to the event of something that could go wrong and this is a way to cope/reliefing with that back of the head stress. Less travel time leads to more excitement. This wears down once flying becomes more frequent in life and you become experienced with its procedures. But once in awhile, why not cope with the enjoyment :)...
