It’s nearly imposable to take off with a loaded down jet if you don’t deploy the flaps, that’s a fact. If I’m sitting over the wings during take off or landing I always watch for flap extension. 37 years ago I was on a United flight and we were landing at Newark I was sitting over the wing again and watching in horror as we made our approach as we flew over the runway landing lights we were really moving and loaded down with passengers about 5 second before landing the flaps deployed, the nose of the jet came up and we hit the end of the runway hard, hard enough to scare the crap out of everyone then the reverse thrusters were deployed at max thrust as we were all pined forward in our seats, it was the hardest landing I’ve ever experienced. I was pissed at the pilots and they stayed in the cockpit till we all got off the jet. I did tell the head stewardess that ether there was a mechanical problem with the flaps or the pilots F’ed up big time. I think they F’ed up. I exited the jet from right behind the cockpit and made sure I was loud enough explaining my observation to the head stewardess so the pilots definitely heard me. I never did read anything in the paper about a hard landing so I guess the pilots never reported it which would put any subsequent flights in jeopardy due to the real possibility of airframe damage.