EMB ERJ 145 ER/LR
Flight Crew Air Transport Pilot (ATP)
Fatigue
Aircraft Equipment Problem Critical
General Declared Emergency
Aircraft; Human Factors
While being vectored for a visual approach our flaps failed in the 0 degree position. We notified Approach Control that we would like box vectors while we troubleshoot the malfunction. The First Officer ran the QRH and handled the radios while I flew the plane; with automation; and notified Dispatch via ACARS. We notified ATC of our situation; declared an emergency; requested emergency vehicles; and requested to land on [the longest runway]. After completing the QRH; I contacted the Flight Attendant; made an announcement to the passengers; and the First Officer notified ATC we were ready for the approach. We landed without any abnormalities aside from the high speed. The rest of the flight was uneventful.  Threats included a tired crew; odd hours; aircraft malfunction; night; high density altitude; high speed landing. I don't believe we made any errors that I was aware of. Fortunately I had started 5 hours or so after my First Officer and Flight Atendant; so I was well rested and not affected by fatigue. Due to delays; this event occurred at [very early morning hours]; which is what our bodies were operating on. Although my crew had expressed their fatigue; the F/O in particular showed no signs of it while dealing with this malfunction. I'm not sure what can be done to prevent this type of situation from happening. Our fleet is aging; and I'm flying with more MEL's then I did 5 years ago; but this type of malfunction could happen with a brand new plane. My First Officer and I both felt we were trained well for this situation; and we were thankful to have a 12;000 foot runway available!
EMB-145LR Captain reported flaps failed in 0 degree position on approach. Crew declared an emergency and landed on the longest available runway.