On Saturday, as our AA 767 was beginning its descent into JFK, I witnessed 3 rapid, succesive flames accompanied by popping sounds coming from the engine right outside my window. The flames seemed quite pronounced.
I was alarmed (scared actually) but seemed to be the only person looking outside at the time. I was sure it was a "flame-out" or foreign object ingestion and that they'd have to shut down the engine.
As my anxiety increased the crew did absolutely nothing. As time passed I realized that it was actually a non-event.

My question is; Is this a common occurence??