Narrative:

Falcon 50 (DA50) flight IFR filed from 40N to ord. Company pilot (type rated) yet limited time in type -- less than 500 hours flying with a supplemental pilot (myself) who was listed as captain on flight plan. I have 1400 hours in falcon-50, 6200+ hours total time. WX across eastern united states -- beautiful VFR, clear, until chicago where WX bases were 1000 ft MSL overcast with tops to 11000 ft MSL in rain. Flight positioned from bdr, ct, to 40N, PA, empty for passenger pickup. Upon arriving 40N, PF advised me to turn off the laser reference navigation system. As I questioned this practice -- should leave system running and should only realign both navs -- pilot again advised to power down system while waiting for passenger. Passenger showed up early and system were not turned on. Upon starting engines, I noticed that both laser navs were still off. We turned them on, however, the aligning process was not correctly completed. A heading flag showed a difference of 20 degrees between the actual aircraft heading and the displayed heading on the EFIS tubes. Some confusion ensued about getting the proper alignment completed. It was determined to depart in 'attitude reference' and contact chief pilot on flight phone to correct problem in climb out. PF handled flying and communication duties, I (PNF) contacted company operations for information. This is not the normal aircraft that I fly and its EFIS interface is different from the aircraft I routinely fly. By the time I contacted operations, the aircraft was in level flight at FL350. We were cleared by ATC to join an airway on the present heading. I suggested that we go direct to ewc VOR to realign the navs overhead the VOR. It became apparent that the navs would not correctly show the actual VOR position. ATC asked where we were going as ewc VOR was about 20 degrees off our course. I advised PF to ask ATC to descend below FL180 whereby we would cancel the IFR flight plan, and proceed VFR to pit, PA. Once at pit and on the ground, I knew we could properly correct the heading error from a known position. In hindsight, both pilots were not totally knowledgeable on the navigation system installed. The flight was cleared out of class a airspace and canceled IFR out of FL180. Flight VFR to pit was routine and once at the GA ramp, problem was corrected in 3 mins -- all system normal. Flight continued to ord without further incident. Flight probably should not have departed with heading error. However, the quick fix which could have taken place airborne could not be completed due to crew workload and ATC heading changes, etc.

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Original NASA ASRS Text

Title: FALCON 50 ON A TRIP FROM 40N TO ORD HAS TO DIVERT TO PIT WHEN THEIR LASER REF NAV SYS PROVES UNUSABLE.

Narrative: FALCON 50 (DA50) FLT IFR FILED FROM 40N TO ORD. COMPANY PLT (TYPE RATED) YET LIMITED TIME IN TYPE -- LESS THAN 500 HRS FLYING WITH A SUPPLEMENTAL PLT (MYSELF) WHO WAS LISTED AS CAPT ON FLT PLAN. I HAVE 1400 HRS IN FALCON-50, 6200+ HRS TOTAL TIME. WX ACROSS EASTERN UNITED STATES -- BEAUTIFUL VFR, CLR, UNTIL CHICAGO WHERE WX BASES WERE 1000 FT MSL OVCST WITH TOPS TO 11000 FT MSL IN RAIN. FLT POSITIONED FROM BDR, CT, TO 40N, PA, EMPTY FOR PAX PICKUP. UPON ARRIVING 40N, PF ADVISED ME TO TURN OFF THE LASER REF NAV SYS. AS I QUESTIONED THIS PRACTICE -- SHOULD LEAVE SYS RUNNING AND SHOULD ONLY REALIGN BOTH NAVS -- PLT AGAIN ADVISED TO PWR DOWN SYS WHILE WAITING FOR PAX. PAX SHOWED UP EARLY AND SYS WERE NOT TURNED ON. UPON STARTING ENGS, I NOTICED THAT BOTH LASER NAVS WERE STILL OFF. WE TURNED THEM ON, HOWEVER, THE ALIGNING PROCESS WAS NOT CORRECTLY COMPLETED. A HDG FLAG SHOWED A DIFFERENCE OF 20 DEGS BTWN THE ACTUAL ACFT HDG AND THE DISPLAYED HDG ON THE EFIS TUBES. SOME CONFUSION ENSUED ABOUT GETTING THE PROPER ALIGNMENT COMPLETED. IT WAS DETERMINED TO DEPART IN 'ATTITUDE REF' AND CONTACT CHIEF PLT ON FLT PHONE TO CORRECT PROB IN CLBOUT. PF HANDLED FLYING AND COM DUTIES, I (PNF) CONTACTED COMPANY OPS FOR INFO. THIS IS NOT THE NORMAL ACFT THAT I FLY AND ITS EFIS INTERFACE IS DIFFERENT FROM THE ACFT I ROUTINELY FLY. BY THE TIME I CONTACTED OPS, THE ACFT WAS IN LEVEL FLT AT FL350. WE WERE CLRED BY ATC TO JOIN AN AIRWAY ON THE PRESENT HDG. I SUGGESTED THAT WE GO DIRECT TO EWC VOR TO REALIGN THE NAVS OVERHEAD THE VOR. IT BECAME APPARENT THAT THE NAVS WOULD NOT CORRECTLY SHOW THE ACTUAL VOR POS. ATC ASKED WHERE WE WERE GOING AS EWC VOR WAS ABOUT 20 DEGS OFF OUR COURSE. I ADVISED PF TO ASK ATC TO DSND BELOW FL180 WHEREBY WE WOULD CANCEL THE IFR FLT PLAN, AND PROCEED VFR TO PIT, PA. ONCE AT PIT AND ON THE GND, I KNEW WE COULD PROPERLY CORRECT THE HDG ERROR FROM A KNOWN POS. IN HINDSIGHT, BOTH PLTS WERE NOT TOTALLY KNOWLEDGEABLE ON THE NAV SYS INSTALLED. THE FLT WAS CLRED OUT OF CLASS A AIRSPACE AND CANCELED IFR OUT OF FL180. FLT VFR TO PIT WAS ROUTINE AND ONCE AT THE GA RAMP, PROB WAS CORRECTED IN 3 MINS -- ALL SYS NORMAL. FLT CONTINUED TO ORD WITHOUT FURTHER INCIDENT. FLT PROBABLY SHOULD NOT HAVE DEPARTED WITH HDG ERROR. HOWEVER, THE QUICK FIX WHICH COULD HAVE TAKEN PLACE AIRBORNE COULD NOT BE COMPLETED DUE TO CREW WORKLOAD AND ATC HDG CHANGES, ETC.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.