AN ACR FLC EXPERIENCED A DELAY IN BEING ABLE TO COMPLY WITH ATC CLRNC DUE TO A LOSS OF THE IRS SYS ON THE DEP PROC. NIGHT OP.

Narrative

AFTER LIFTING OFF OF RWY 26L PHOENIX SKY HARBOR THE ACFT ENCOUNTERED A DUAL IRS FAILURE. ALL PRIMARY ATTITUDE AND DIRECTIONAL INDICATIONS WERE LOST. THE DEP REQUIRED A TURN OF 20 DEGS L OR L TO THE HDG OF 240 DEGS. DEALING WITH THE LOSS OF INSTRUMENTATION AND DEP DUTIES ON THE ACFT; WE WERE UNABLE TO IMMEDIATELY COMPLY WITH ATC'S REQUEST TO FLY DIRECTLY TO THE BXY VOR. AFTER REPOSITIONING THE MAGNETIC COMPASS (OUR ONLY DIRECTIONAL SOURCE) AND STABILIZING THE ATTITUDE OF THE ACFT WE BEGAN OUR TURN TOWARDS BXY VOR. ATC THEN REQUESTED THAT WE LEVEL OFF AT AN INTERMEDIATE ALT SO THERE WOULD NOT BE A CONFLICT OF TFC. ONCE WE WERE HDG TOWARD BXY; PHOENIX DEP HANDED US TO ZAB WHERE WE ASKED FOR A SAFE ALT AND HDG TO FAMILIARIZE OURSELVES WITH THIS SIT. THE SOLUTION TO THE ATC PROB COULD EASILY HAVE BEEN PREVENTED IF WE WOULD HAVE INFORMED THE CTLR RIGHT AWAY OF OUR SIT. THE LOSS OF ALL DIRECTIONAL INFO ON TKOF DREW ALL OF OUR AVAILABLE RESOURCES TO CTLING THE ACFT AND ANALYZE THE UNFAMILIAR SIT.