PC-12
Flight Crew Commercial; Flight Crew Instrument
Flight Crew Last 90 Days 123; Flight Crew Total 3800; Flight Crew Type 198
Situational Awareness
Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance; Flight Crew Became Reoriented
Human Factors
While in cruise at [16;000]; approaching LRP on the V39 airway on a heading of 240 I realized the next point along my route was input incorrectly.  MULRR was the correct point and I mistakenly typed MULLR.  Upon realizing my mistake; I engaged the heading hold on the autopilot and quickly made the correction. I was unable to make the correction prior to arriving at LRP and I overflew the point and deviated from the V39 airway approximately 2 NM. I immediately turned back to the MULRR point and was given permission from New York Center to proceed direct to MULRR with no further incident.
PC-12 pilot reported a track deviation when he navigated toward MULLR instead of the proper waypoint MULRR.