Ahh... I see your problem.
That program is in HD, but it is also only 664x336 or so in size. So it has the amount of pixels required for a crisp and clear picture if you only watch the framed version on their web page. When you grow it to by full screen you are stretching it and it will look like crap compared to a video shot in HD and with a frame size of 1900x1080.
Look at this video.
https://youtube.com/watch?v=Ou6_MkIvKOo
Make sure to set it to 1080. It will start in 480. Once the aircraft lines are perfect pin stripes, move it to the middle of the movie where there are more cutaways. Do those look good? Did the airplanes lines become crisp in 1080? (you will click the little gear/cog icon on lower right of video).
If so then you have what you need. It is just the source sucks.
It may take a few seconds for the stream to catch up and actually go HD. Wait 10 seconds before judging the plane.