PA-46 Malibu/Malibu Mirage/Malibu Matrix
Flight Crew Private; Flight Crew Instrument
Flight Crew Last 90 Days 41; Flight Crew Total 2714; Flight Crew Type 429
Confusion; Distraction; Human-Machine Interface; Situational Awareness; Troubleshooting
Aircraft Equipment Problem Less Severe; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Became Reoriented; Flight Crew Overcame Equipment Problem; Flight Crew FLC Overrode Automation
Aircraft; ATC Equipment / Nav Facility / Buildings
In route to MYF on an IFR flight plan in VMC; I saw a DOD drone (inverted V tail) pass overhead approximately 1;000 [feet] above. At the same time; my Garmin G3000 PFD indicated that I had a large magnetic variation error; and in turn the PFD indicated that I was now flying to a new way point (TCH VOR) located in Utah; well off my flight plan between Northern and Southern California. Later and second way point in Montana was introduced. The MFD still showed the original flight plan; but the PFD was in conflict; which resulted in a loss of ability to fly an instrument approach of any kind; and loss of synthetic vision within the PFD. Had it not been a VMC day allowing me to fly a visual approach; I would have had to [advise ATC] - and find a way to land without any reliable approach capability.The system has since been checked and is operating correctly; but it seems pretty clear this was some type of interference / jamming arising from the DOD drone. Clearly; this is a significant risk to all aircraft; and because if occurred within the LA airspace it is a serious threat to safe flights
PA46 pilot reported after a UAV encounter the PFD in the aircraft produced a large navigational error. The reporter suspects GPS jamming.