Narrative:

I was the pilot in command of a C208. This is a scheduled cargo-only flight from ZZZ1 to ZZZ2. I was operating IFR; on an IFR clearance. I was assigned 13;000 ft. I was cruising above a wet; unstable cloud deck. As I neared zzzzz intersection; ATC gave me a descent; and a heading to intercept vxxx. Almost immediately; ATC then gave me a turn direct to ZZZZ1 intersection. At the instant I turned toward ZZZZ1; I entered the clouds at 10;000 ft; and experienced severe; then extreme turbulence. I was unable to control the aircraft's heading; altitude; or navigation. The autopilot disconnected; and I was temporarily disoriented; and unable to navigate the aircraft on course. ATC queried me about my status and my heading. I told them I was in 'severe turbulence;' and needed a climb back to 12;000 ft. ATC asked me if I was tracking the airway; and I told them the autopilot was 'slow to intercept; but I was working it.' ATC told me I was about 90 degrees off course; and asked me if I needed 'no gyro vectors on course.' I said affirmative; and requested a climb to clear the clouds. ATC immediately issued me no gyro vectoring instructions. While I was still struggling to maintain aircraft control; I also picked up a significant amount of moderate mixed ice. Upon reaching 12;000 ft; I exited out of the clouds. I was then able to successfully utilize the autopilot to fly a basic heading and hold an altitude. I told ATC I was back in control. ATC advised me to let them know if I needed any additional assistance. I told them I wanted vectors to the ILS at ZZZ1. ATC acknowledged this request; and gave me headings and altitudes to intercept the ILS. While descending from 10;000 ft to approximately 7;500 ft; I experienced very tenacious moderate mixed icing. At approximately 7;500 ft; I broke out of the clouds; and advised ATC I had the airport in sight. I was cleared for and executed a visual approach to runway xxl at ZZZ. I landed at approximately XA20Z. Observations: the loss of situational awareness; aircraft control; and navigation all occurred simultaneously. This was induced by the severe turbulence that I encountered; and the disorientation I experienced. I was unable to successfully navigate to the airway. I believe this was due to a GPS 'programming' error I made while under extreme stress; and as a single pilot. I also feel that fatigue was a factor in this event. The weather locally has been poor for about 2 months; and has affected most of our line pilots on a daily basis. We are just not getting enough rest between critical events! Personally; the day before this event; I was on duty continuously for 15 hours; without the rest we normally get at our outstation. I did not eat a regular meal; or get a nap for that entire period. Someone needs to really look at the duty day of single-pilot operations. The decision of ATC to immediately intervene and render me assistance was paramount to the successful outcome of this event. ATC did a wonderful job.

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Original NASA ASRS Text

Title: A C208 pilot lost control of his aircraft when he experienced severe turbulence and icing enroute to his destination. He cited fatigue issues as contributing to the severity of the incident.

Narrative: I was the pilot in command of a C208. This is a scheduled cargo-only flight from ZZZ1 to ZZZ2. I was operating IFR; on an IFR clearance. I was assigned 13;000 FT. I was cruising above a wet; unstable cloud deck. As I neared ZZZZZ Intersection; ATC gave me a descent; and a heading to intercept VXXX. Almost immediately; ATC then gave me a turn direct to ZZZZ1 Intersection. At the instant I turned toward ZZZZ1; I entered the clouds at 10;000 FT; and experienced severe; then extreme turbulence. I was unable to control the aircraft's heading; altitude; or navigation. The autopilot disconnected; and I was temporarily disoriented; and unable to navigate the aircraft on course. ATC queried me about my status and my heading. I told them I was in 'severe turbulence;' and needed a climb back to 12;000 FT. ATC asked me if I was tracking the airway; and I told them the autopilot was 'slow to intercept; but I was working it.' ATC told me I was about 90 degrees off course; and asked me if I needed 'no gyro vectors on course.' I said affirmative; and requested a climb to clear the clouds. ATC immediately issued me no gyro vectoring instructions. While I was still struggling to maintain aircraft control; I also picked up a significant amount of moderate mixed ice. Upon reaching 12;000 FT; I exited out of the clouds. I was then able to successfully utilize the autopilot to fly a basic heading and hold an altitude. I told ATC I was back in control. ATC advised me to let them know if I needed any additional assistance. I told them I wanted vectors to the ILS at ZZZ1. ATC acknowledged this request; and gave me headings and altitudes to intercept the ILS. While descending from 10;000 FT to approximately 7;500 FT; I experienced very tenacious moderate mixed icing. At approximately 7;500 FT; I broke out of the clouds; and advised ATC I had the airport in sight. I was cleared for and executed a visual approach to Runway XXL at ZZZ. I landed at approximately XA20Z. Observations: The loss of situational awareness; aircraft control; and navigation all occurred simultaneously. This was induced by the severe turbulence that I encountered; and the disorientation I experienced. I was unable to successfully navigate to the airway. I believe this was due to a GPS 'programming' error I made while under extreme stress; and as a single pilot. I also feel that fatigue was a factor in this event. The weather locally has been poor for about 2 months; and has affected most of our line pilots on a daily basis. We are just not getting enough rest between critical events! Personally; the day before this event; I was on duty continuously for 15 hours; without the rest we normally get at our outstation. I did not eat a regular meal; or get a nap for that entire period. Someone needs to really look at the duty day of single-pilot operations. The decision of ATC to immediately intervene and render me assistance was paramount to the successful outcome of this event. ATC did a wonderful job.

Data retrieved from NASA's ASRS site as of April 2012 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.