Chinook CH-47
Sea Stallion CH-53
Better watch that video again. If you're having trouble identifying the helicopter you're having trouble identifying other things as well.
But, having earlier enjoyed watching three aircraft, in echelon (very, rare), flying west from L.A. county this afternoon, and having noted that their three twin contrails were very short and hardly as copious as the one on video; I still have one question:
Why is there a Chinook (CH53), which is also very rare in or near L.A., in the foreground of the video and pointed directly at the contrail/exhaust trail shown on the video?
Chinook CH-47
Sea Stallion CH-53
Better watch that video again. If you're having trouble identifying the helicopter you're having trouble identifying other things as well.