Date: 201308
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Weather elements / visibility: Thunderstorm
Light: Daylight
Aircraft: PC-12
Operator: Air Taxi
Operating under: Part 135
Flight plan: IFR
Mission: Ambulance
Flight phase: Cruise; Parked
Airspace: Class E ZZZ
ATC / advisory: Center ZZZ
Reporter organization: Air Taxi
Reporter function: Single Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine
Human factors: Human-Machine Interface; Situational Awareness; Troubleshooting
Anomaly: Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight; Pre-flight
Result: General None Reported / Taken
Contributing factors: Company Policy; Equipment / Tooling; Aircraft; Human Factors; MEL
Primary problem: Equipment / Tooling

Narrative: Experienced a failure of the number 1 nav/radio; a Garmin 650. Radio was mis-wired by installation facility and company maintenance accepted aircraft without knowing mis-installation. Navigation portion of two-in-one radio was working correctly. A big red cross appeared on and off in the communications section of radio. Checked MEL list in the aircraft's GOM. MEL gave instructions on procedure for separate nav/com radios and not for current unit. Was not sure what to write. I had a patient on board and decided to continue with the flight using the number two radio. EPS in aircraft is installed and is supposed to provide power to stand-by attitude indicator; transponder; clock; nav and com radios. On initial power up; those items powered up as normal. After normal engine start; com radio section showed previously mentioned red cross. Nav portion showed to be working normal. Red cross disappeared and came back several times. While red cross was on screen; I was unable to make any radio transmissions.As I taxied to the runway; the red cross would appear on and off. I used the second radio to make all transmissions. Departed under VFR and remained under VFR conditions until I contacted ARTCC. I was given an IFR clearance to my destination. At that point; I noticed that transponder was not working. I then also noted that clock and stand-by attitude indicator were not working. As I mentioned before; on original power up of EPS; those items worked fine. I was distracted by red cross and never noticed that other items powered by EPS were not working until I was given a transponder code. I could not figure out why other items were not working. I thought EPS could not be the reason since the nav portion of the Garmin 650 was still working. I landed and had maintenance look at the issue. Maintenance found EPS switch to be intermittent; thus the on/off red cross appearing on com section. However; after further investigation; the Garmin 650 was found to be not installed correctly. Apparently; even though both nav and com radios are in one unit; they have separate power sources which should have been connected to the EPS switch. In this case; the communication section was wired to the intermittent EPS switch while the navigation section was connected to another source. I should have contacted maintenance instead of continuing flight with the problem. The Garmin 650 was a new radio unit to us and I was not familiar with the meaning of the red cross. I had had a previous flight in the same aircraft where the red cross had come and off twice in quick succession without any perceivable adverse effects. Communication with TRACON at the time were not in jeopardy. This was mentioned to maintenance and they had no answer to issue either. It was basically a wait and see if it happens again.




Synopsis: An aircraft departed with a known radio/navigation component malfunctioning. In flight the pilot noticed the aircraft's transponder; clock; and standby attitude indicator had failed.