I read something about a woman making the first flight of a human powered helicopter the other day, and I wondered a bit, but then Oh, look! Shiny! and it slid off my pate. Then today Dustbury is rambling on about someone singing a song about Gamera, and I wonder what the heck is a Gamera, which leads me to Alfred's webpage at the University of Maryland where I found this video.
This was a year ago and the flight only lasted a few seconds. It looks like it ended when it ran into the wall (or bumped into a spectator, hard to tell). They didn't give it much flying room. They tried again this year with a guy. He managed almost a minute. I think his flight ended when he ran out of steam.
I'm thinking the sitting position they are using might be good for long term endurance, but maybe not so good for short term, peak output. I remember seeing an old movie about guys fishing from dories out on the Grand Banks. Guy would stand up in the center of the boat and row facing forward. He was using his whole body to propel the boat, arms, legs, torso. Bicyclists climbing hills often stand up on the pedals and the bicycle frame will swing side to side as they pedal. Same sort of thing. But maybe I'm all wet. Maybe sitting down on the job and having a seat back to push against does allow you to deliver more power.