BOI CTLR DESCRIBED INCIDENT AT 4000 FT WHEN ARR ENTERING DOWNWIND CONFLICTED WITH IFR DEP BECAUSE OF INTRAFAC COORD FAILURE AND PLT NON COMPLIANCE WITH HDG.

Narrative

ACFT #1; BE35; DEPARTED ON IFR PLAN. ACFT #2; DA50; INBOUND FOR LNDG VFR. ACFT #2 WAS ISSUED L TFC FOR RWY 28R BY RADAR CTLR. TWR CTLR CALLED AND SAID 'I HAVE THE FALCON IN SIGHT; APPREQ L TURN ON ACFT #1; WHATEVER YOU CAN GIVE HIM.' RADAR CTLR APPROVED A HDG OF 210 DEGS FOR ACFT #1. COMS WERE XFERRED TO TWR ON ACFT #2 AT 4900 FT MSL. ACFT #1 DEPARTED AND WAS IDENTED BUT WAS NOT FLYING THE COORD HDG AND WAS IN CONFLICT WITH ACFT #2. RADAR CTLR COORD WITH LCL CTLR TO STOP ACFT #2 AT 4500 FT. ACFT #1 WAS ISSUED 4000 FT AND TURNED SEBOUND TO AVOID ACFT #2. ACFT #1 WAS IN AN MVA OF 4200 FT WHEN ISSUED 4000 FT AND LEVELED AT 4000 FT FOR APPROX 2 MI. AREA IS ALSO A DIVERSE VECTORING AREA S OF BOISE. RADAR CTLR HAD NO CHOICE BUT TO ASSIGN 4000 FT TO EFFECT ALT SEPARATION. FACTORS: 1) LCL CTLR SHOULD NEVER SWITCH AN ACFT TO DEP CTL UNLESS ACFT IS DOING EXACTLY AS CLRED. 2) PLT DID NOT FLY HDG AS ISSUED. 3) SUBSEQUENT HDGS ISSUED TO PLT INDICATED THAT ACFT'S DIRECTIONAL GYRO AND COMPASS WERE NOT ALIGNED. CTLR QUESTIONED PLT ABOUT THE DIRECTIONAL GYRO AND COMPASS AND PLT STATED 'SORRY.' 4) RADAR CTLR INITIALLY THOUGHT #1 WAS VFR. ALT ASSIGNMENT WAS OK VFR. 5) NO ACFT SEPARATION WAS LOST BUT ACFT #1 WAS ASSIGNED 4000 FT IN AN MVA OF 4200 FT. RADAR CTLR THOUGHT THIS WAS BETTER THAN 2 ACFT COLLIDING.