Nosegear failed to extend
My pupil's C177 had just had a large service & everything looked fine. However during a session of circuits & landings, on the final landing ( despite a green down light) the nosegear retracted.
Obviously the system had not pushed the nosegear into the locked position!
This was the enthusiastic owner's 1st ever problem.
Have a look at the Cessna Flyers website-it's huge & very useful.