SMA IN THE TRAFFIC PATTERN SHOOTING TOUCH AND GO LNDGS AT NIGHT ENCOUNTERS SMA ENTERING NON STANDARD TRAFFIC PATTERN; NMAC.

Narrative

I WAS FLYING IN THE TFC PATTERN AT N LAS VEGAS ARPT WITH A STUDENT. IT WAS A NIGHT FLT AND THE CTL TWR WAS CLOSED. THE TIME WAS APPROX XA 45 PDT. WE WERE L DOWNWIND FOR RWY 25 ABEAM THE NUMBERS WHEN I SAW THE NAV LIGHTS OF AN AIRPLANE APCHING NEARLY HEAD ON FROM MY 2 0'CLOCK POS. BY THE ANGLE OF THE OTHER ACFT'S NAV LIGHTS; IT WAS INDICATING A L BANKED TURN BUT DIRECTLY INTO MY FLT PATH. MY EVASIVE ACTION WAS A STEEP BANKED DIVING L TURN; USING EXTREME CONTROL FORCE IN ORDER TO AVOID A COLLISION WITH THE OTHER ACFT. IT APPEARS THAT THE OTHER ACFT WAS APCHING FROM THE SE; MAKING THE L TURN FOR AN ENTRY TO A R DOWNWIND TFC PATTERN FOR RWY 7; THE NEAR MISS OCCURRED JUST AS HE WAS ENTERING R DOWNWIND. WE HAD BEEN IN L TFC FOR RWY 25 MAKING MULTIPLE TOUCH AND GO'S AND BROADCASTING OUR POS AND INTENTIONS DURING EACH LEG ON THIS CTAF; 125.7. THE OTHER ACFT GAVE NO BROADCAST ON THIS FREQ UNTIL AFTER THE NEAR MISS. I HEARD HIM CALL OUT HIS BASE LEG. THE WINDS WERE RPTED BY MCCARRAN ATIS TO BE 230 AT 09 KTS AND THERE IS NO R TFC AT N LAS VEGAS ARPT AFTER THE TWR IS CLOSED. APPARENTLY THE PLT OF THE OTHER ACFT DID NOT AVAIL HIMSELF OF THIS INFO. THE INCIDENT COULD HAVE BEEN AVOIDED IF THE PLT OF THE OTHER ACFT HAD BROADCAST HIS POS EARLIER OR AT LEAST MAINTAINED A LISTENING WATCH ON 125.7. IF NOT CERTAIN OF THE TFC PATTERN PROC HE COULD HAVE OVERFLOWN THE ARPT ABOVE TFC PATTERN ALT AND THEN MADE A PROPER ENTRY INTO THE PATTERN. ADDITIONALLY; IF HE HAD USED HIS LNDG LIGHT (IT WAS OFF) I COULD HAVE SEEN HIM EASIER. CALLBACK CONVERSATION WITH RPTR REVEALED FOLLOWING. ACFT WAS A SMA AND THE TRNEE HEARD HIM ANNOUNCE HIS INTENTIONS AS THE INSTR WAS DOING THE EVASIVE MANEUVER. DID NOT TALK TO THE PLT BUT HAS FILED A RPT WITH THE LCL FSDO. THEY ARE STILL INVESTIGATING THE INCIDENT. NO SPECIAL NOTAM HAS BEEN ISSUED REFERENCE THE TFC PATTERN WHEN THE TWR IS NOT OPERATING.