Over the years I have rode quite a few United Air on my trips from US to China. Amid the most recent incident on the UA (warning: the video may not be suitable for little kids), I am thinking of a few UA trips I took, such as this one on March 2007, which worked out ok. Another trip (Summer 2002), which is also my first UA flight, was also eventful. The UA857 (from SFO to PVG) was spotted some fire (presumably under the wing, per some passenger) during the take-off. The plane had to drop most of the fuel above the sea, and turn back to SFO. And we had to reboard another plan to PVG. Here are some of the pictures of the plane releasing the fuel. I recall one flight attendant specially mentioned how much weight was the fuel, and the unit price of fuel, I calculated it was about $350,000 worth of the fuel.
Fast forward, the industry had another meltdown during the financial crisis, and has since come back. The regional carriers, such as the one had the incident on Sunday night, was never the money maker. In fact, I recall in year 2009 (Colgan 3407) there was an fatal accident on a flight from NYC to Buffalo NY. And I learned from that accident that those regional carrier’s pilots are not really well paid or trained. This combined with my observations of over the years, when the airlines tries to charge the baggage fees, and on those regional flights, people would just check in the baggages at the gate (to save the money). Then at the destination, esp. when during winter time, you will see a long line of people picking up the luggages. It just feels America is a 3rd world country at that time.
Last but not the least, my friend Wang Jianshuo wrote on similar topic almost 10 years ago.