Gulfstream G100/G150 (IAI 1125 Astra)
Air Traffic Control Fully Certified
Other / Unknown
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Aircraft; Procedure; Human Factors
Gulfstream 150 was issued the normal departure procedure: 'RNAV to HISOR; Runway 18L cleared for takeoff.' Pilot flew towards HISOR; but then started a right turn towards the southwest just prior to HISOR instead of continuing on the RNAV Southbound. The G150 was issued RADAR vectors away from traffic that departed Runway 18C. Charlotte is forced to depart Southbound departures on parallel headings for 1.6 miles due to an outdated noise abatement procedure. The last noise abatement study was done over 40 years ago during a time with a completely different mix of aircraft and a drastically different volume of traffic. Traffic departing Runway 18L should either be turned to a 160 or 150 degree heading; and the RNAV should be modified to match this new heading to allow for instant divergence from traffic departing Runway 18C. This has been brought up on numerous occasions from different individuals; but no noise study has ever come about to correct this problem. Any such submission just gets referred to the last noise abatement study.
This was a training flight. I was in the right seat. I was the PIC. We were departing CLT Runway 18L conditions were VFR. Our clearance for takeoff included 'RNAV to HISOR.' We experienced a failure of the number 2 FMS. While correcting this problem we drifted right of a course that would have taken us to HISOR. I asked for a turn toward HISOR. I am not sure that the Controller got that request. He did however give us a left turn toward the fix. Which made a second request not necessary. In talking with ATC after the occurrence they advised there was 'no' conflict of traffic and no loss of separation between other aircraft. This was not an intentional deviation and a was a result of the failure of the number 2 FMS and the few seconds that it took to transfer systems.
CLT Controller expressed concern regarding the noise abatement procedures governing Runway 18L/R departures; noting these procedures need to be re-evaluated and updated.