This was a long six hour flight from Honolulu to Denver. The airplane was large with three seats on each side and four in the middle. The seats do not recline. who can sleep sitting up straight? This flight left at 9:00 p.m. and flew through the night. It was the longest six hours of my life. Don't plan on sleeping if you take the economy class seats - it is not possible. Just watch and listen to movies if you have a tablet, United lets you stream movies with an appropriate app.