Narrative:

The purpose of this submission is to explain the circumstances that lead to some challenges I encountered during an instrument approach into montgomery county airpark (gai). I have also studied my flight track and details on an internet flight tracking website and correlated it to the weather at the time and a dc sectional map. In short; while I was IMC; I was caught unexpectedly by a change in the weather as I began the GPS approach into gai. I became very occupied with controlling the aircraft and deviated both on course and altitude when compared to the approach. I recovered the approach and made a safe and uneventful landing. I believe in all candor that I could have avoided what happened; or responded better; had I used the information I had a bit better. I also want to note that in no time did I feel in danger for my life. I was genuinely hit with a workload; got the most important things right; but I am frustrated that I did not do better. I will explain this because; in my sixteen active years of flying; this will be a flight that gives me a lesson to apply in the future. I'd flown about seven hours in the past two days and several hours the week before; most of this in IMC and high wind conditions. In fact; the prior week I made a good decision to land elsewhere when crosswinds at gai exceeded thirty knots; and a good decision to divert and land the night before this event; during a flight; where I hit a band of thunderstorms that originally had a break I could get through. I did not push it. I was well rested for the flight noted here but the flight was mostly solid IMC with light to moderate rain and light chop; so the approach at dusk came after I'd been concentrating for two hours. Coming from a northeast direction; I was cleared by potomac to the IAF of the GPS 14 approach. I've been going to gai for many years and done IFR/IMC approaches there. I was at 4;000 ft and remained IMC in rain and light to moderate turbulence until well after the event. Winds at this lower altitude and with the turn direct to the IAF had shifted to a tail wind. My GPS showed 'four and a half feathers' for winds aloft at 3;000 ft; or 45 KTS. Once cleared to the IAF; I quickly noted that a 90 degree left turn (into the wind) would be necessary to intercept the approach. I also realized that my ground speed had increased from 120 KTS (when in a quartering headwind enroute) to 160 KTS. I began pulling back power; and then was cleared to 3;000 as I approached the IAF. I'd wished I was descended sooner but I also felt I could safely lose the altitude. ATC also informed me that an aircraft that had just landed at gai reported wind shear that caused more than a 20 KTS loss of air speed on the same approach. Winds got rougher and my groundspeed increased to 175 KTS. I further reduced power to slow ground speed; recognizing I would need to add it back as I hit the altitude and made the turn; both of which would likely happen at the same time (airspeed was 105 to 110 - 100 is the start of white arc). It was too rough for the autopilot (tends to porpoise as it tries to correct in turbulence) and I was hand-flying. I put 2;300 ft in the altitude pre-select as a reminder for the next approach altitude after 3;000 ft. I also did this to avoid looking down at the chart and losing my scan while possibly creating vertigo via the head movement. The step down is 2;200 but I was using a 100 ft buffer given the turbulence. Pausing here; I've got lessons one and two for me; even though nothing had gone wrong yet. First; given the flight conditions; I should have asked for vectoring to minimize the turn necessary for the approach; especially after getting cleared to lose another 1;000 ft that would increase my ground speed at the turn. Ground speeds caused me to slow the plane; which softened the control a bit (I was not too slow but a factor in an unusual attitude). Additionally; the turbulence and rain was going from bad to worse. I was IMC and it was getting dark. I am comfortable with increasing degrees of difficultly but looking back; this was a scenario that I could have asked ATC to help me soften the challenges. Second; I should have further considered how the tail wind would affect my track after I made the turn; meaning to avoid getting blown west of the course; I'd need to make the turn quickly and efficiently. I knew that going in but didn't factor the turbulence I was about to encounter. It was a rough ride already and I should have considered that the maximum thiry degree bank I knew I would do; even as I got my ground speed down; would have to happen without interruption to intercept the approach in a professional manner. The weather trend was getting worse; not better; thus an easy turn was less likely and I should have anticipated that. ATC was also busy and I pride myself on being low maintenance; missing the turn would affect their workload. I didn't make the turn that I wanted. As I began the turn at the IAF; just arriving at 3;000; I encountered severe turbulence and heavy rain. It also got very dark inside the cockpit (I had panel lights on). Flight aware shows a cell of dark green and yellow right at the turn. As I made a thirty degree left turn; the plane was thrown around; violently at times. In all honesty; I hit my head on the left cockpit window on one air pocket. I immediately went to find straight and level and actually ended for a brief moment in a fifty degree right turn with strong winds at my left. I recovered quickly; just working for straight and level. I got level but stopped making the turn to intercept the course. Then; I switched the auto pilot on using heading and altitude mode so I could regroup and assess the approach. ATC called me to ask where I showed myself on the approach. Still getting through the cell; I admitted readily that I was west of the approach. ATC also asked me my altitude; which was 2;400 ft I'd lost a few hundred feet when I first hit the shear and the autopilot was taking me to 2;300 (this was my mistake - the preselect at the nest step down. It didn't occur to me at the moment I switched it on to set a higher altitude - I was just trying to regroup). The controller told me I should advise him immediately about deviations; that I was getting close to his dulles arrivals; that there were mountains ahead (my post flight review shows I never got close to terrain) and to climb immediately. I did not argue (never do) but explained that I was trying to get through a 'very rough ride' in my mind I thought 'thanks for the heads up on that cell'; then said to myself aviate; navigate; communicate is the right order of operations. I was one mile west of course and two or three miles from the if step down; I climbed to 3;000 ft and made a turn to intercept the approach. Lesson three - communicate faster with ATC. I was grateful to have that controller chime in; even if I was not making his day easier. He provided calibration for my situational awareness and instructions that I welcomed; plus a human voice after mother nature hit me; which is always comforting. Lesson four - don't program the autopilot altitude ahead of the approach where it's likely to be needed before that step down. I cleared the rain cell but remained IMC. I intercepted the approach; which remained turbulent. I broke out at 1;500 and made a smooth landing. Winds were 18 gusting 25 but more or less down the runway at gai. I studied this approach incessantly when I got home. I found that I went one mile west of the approach course between the IAF and if and descended below the approach altitude for that segment. I also studied the terrain and I got as low as 1;500 ft AGL when I should have been 2;000 plus. Had I gone and stayed at 2;300; I was never tracking to hit any obstructions. I was directly parallel the course from the IAF. Not a badge of honor but comforting to know the effects of my deviation. It was absolutely inadvertent; and while it frustrates me that I did this; I also feel very good about how I handled the cell and wind shear. It was one of the worse IMC moments in my 500 plus hours of IMC and I was able to get to straight and level quickly and maintain it through the cell. I remained in control and thinking - albeit that I could have performed better. I've been candid and taken responsibility because I did not fly the approach as published. That's my job; period; end of story. What I could have done differently; beyond the above; is ask for a climb and vector immediately upon leaving controlled flight. While I feel that I was too busy; that is a reflection of my limits (aviate; navigate; communicate is not an excuse to bust up an approach just a factor about how I responded to conditions that challenged me to stick at 'aviate'). I will be far more mindful of the fluid environments of IMC precision approaches; especially when I have evidence and experience to tell me that it is going to get worse before it gets better.

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Original NASA ASRS Text

Title: The pilot of a high performance turboprop single detailed events leading to a temporary loss of control in turbulence and IMC.

Narrative: The purpose of this submission is to explain the circumstances that lead to some challenges I encountered during an instrument approach into Montgomery County Airpark (GAI). I have also studied my flight track and details on an internet flight tracking website and correlated it to the weather at the time and a DC sectional map. In short; while I was IMC; I was caught unexpectedly by a change in the weather as I began the GPS approach into GAI. I became very occupied with controlling the aircraft and deviated both on course and altitude when compared to the approach. I recovered the approach and made a safe and uneventful landing. I believe in all candor that I could have avoided what happened; or responded better; had I used the information I had a bit better. I also want to note that in no time did I feel in danger for my life. I was genuinely hit with a workload; got the most important things right; but I am frustrated that I did not do better. I will explain this because; in my sixteen active years of flying; this will be a flight that gives me a lesson to apply in the future. I'd flown about seven hours in the past two days and several hours the week before; most of this in IMC and high wind conditions. In fact; the prior week I made a good decision to land elsewhere when crosswinds at GAI exceeded thirty knots; and a good decision to divert and land the night before this event; during a flight; where I hit a band of thunderstorms that originally had a break I could get through. I did not push it. I was well rested for the flight noted here but the flight was mostly solid IMC with light to moderate rain and light chop; so the approach at dusk came after I'd been concentrating for two hours. Coming from a northeast direction; I was cleared by Potomac to the IAF of the GPS 14 approach. I've been going to GAI for many years and done IFR/IMC approaches there. I was at 4;000 FT and remained IMC in rain and light to moderate turbulence until well after the event. Winds at this lower altitude and with the turn direct to the IAF had shifted to a tail wind. My GPS showed 'four and a half feathers' for winds aloft at 3;000 FT; or 45 KTS. Once cleared to the IAF; I quickly noted that a 90 degree left turn (into the wind) would be necessary to intercept the approach. I also realized that my ground speed had increased from 120 KTS (when in a quartering headwind enroute) to 160 KTS. I began pulling back power; and then was cleared to 3;000 as I approached the IAF. I'd wished I was descended sooner but I also felt I could safely lose the altitude. ATC also informed me that an aircraft that had just landed at GAI reported wind shear that caused more than a 20 KTS loss of air speed on the same approach. Winds got rougher and my groundspeed increased to 175 KTS. I further reduced power to slow ground speed; recognizing I would need to add it back as I hit the altitude and made the turn; both of which would likely happen at the same time (airspeed was 105 to 110 - 100 is the start of white arc). It was too rough for the autopilot (tends to porpoise as it tries to correct in turbulence) and I was hand-flying. I put 2;300 FT in the altitude pre-select as a reminder for the next approach altitude after 3;000 FT. I also did this to avoid looking down at the chart and losing my scan while possibly creating vertigo via the head movement. The step down is 2;200 but I was using a 100 FT buffer given the turbulence. Pausing here; I've got lessons one and two for me; even though nothing had gone wrong yet. First; given the flight conditions; I should have asked for vectoring to minimize the turn necessary for the approach; especially after getting cleared to lose another 1;000 FT that would increase my ground speed at the turn. Ground speeds caused me to slow the plane; which softened the control a bit (I was not too slow but a factor in an unusual attitude). Additionally; the turbulence and rain was going from bad to worse. I was IMC and it was getting dark. I am comfortable with increasing degrees of difficultly but looking back; this was a scenario that I could have asked ATC to help me soften the challenges. Second; I should have further considered how the tail wind would affect my track after I made the turn; meaning to avoid getting blown west of the course; I'd need to make the turn quickly and efficiently. I knew that going in but didn't factor the turbulence I was about to encounter. It was a rough ride already and I should have considered that the maximum thiry degree bank I knew I would do; even as I got my ground speed down; would have to happen without interruption to intercept the approach in a professional manner. The weather trend was getting worse; not better; thus an easy turn was less likely and I should have anticipated that. ATC was also busy and I pride myself on being low maintenance; missing the turn would affect their workload. I didn't make the turn that I wanted. As I began the turn at the IAF; just arriving at 3;000; I encountered severe turbulence and heavy rain. It also got very dark inside the cockpit (I had panel lights on). Flight Aware shows a cell of dark green and yellow right at the turn. As I made a thirty degree left turn; the plane was thrown around; violently at times. In all honesty; I hit my head on the left cockpit window on one air pocket. I immediately went to find straight and level and actually ended for a brief moment in a fifty degree right turn with strong winds at my left. I recovered quickly; just working for straight and level. I got level but stopped making the turn to intercept the course. Then; I switched the auto pilot on using heading and altitude mode so I could regroup and assess the approach. ATC called me to ask where I showed myself on the approach. Still getting through the cell; I admitted readily that I was west of the approach. ATC also asked me my altitude; which was 2;400 FT I'd lost a few hundred feet when I first hit the shear and the autopilot was taking me to 2;300 (this was my mistake - the preselect at the nest step down. It didn't occur to me at the moment I switched it on to set a higher altitude - I was just trying to regroup). The Controller told me I should advise him immediately about deviations; that I was getting close to his Dulles arrivals; that there were mountains ahead (my post flight review shows I never got close to terrain) and to climb immediately. I did not argue (never do) but explained that I was trying to get through a 'very rough ride' in my mind I thought 'thanks for the heads up on that cell'; then said to myself aviate; navigate; communicate is the right order of operations. I was one mile west of course and two or three miles from the IF step down; I climbed to 3;000 FT and made a turn to intercept the approach. Lesson three - communicate faster with ATC. I was grateful to have that Controller chime in; even if I was not making his day easier. He provided calibration for my situational awareness and instructions that I welcomed; plus a human voice after Mother Nature hit me; which is always comforting. Lesson four - don't program the autopilot altitude ahead of the approach where it's likely to be needed before that step down. I cleared the rain cell but remained IMC. I intercepted the approach; which remained turbulent. I broke out at 1;500 and made a smooth landing. Winds were 18 gusting 25 but more or less down the runway at GAI. I studied this approach incessantly when I got home. I found that I went one mile west of the approach course between the IAF and IF and descended below the approach altitude for that segment. I also studied the terrain and I got as low as 1;500 FT AGL when I should have been 2;000 plus. Had I gone and stayed at 2;300; I was never tracking to hit any obstructions. I was directly parallel the course from the IAF. Not a badge of honor but comforting to know the effects of my deviation. It was absolutely inadvertent; and while it frustrates me that I did this; I also feel very good about how I handled the cell and wind shear. It was one of the worse IMC moments in my 500 plus hours of IMC and I was able to get to straight and level quickly and maintain it through the cell. I remained in control and thinking - albeit that I could have performed better. I've been candid and taken responsibility because I did not fly the approach as published. That's my job; period; end of story. What I could have done differently; beyond the above; is ask for a climb and vector immediately upon leaving controlled flight. While I feel that I was too busy; that is a reflection of my limits (aviate; navigate; communicate is not an excuse to bust up an approach just a factor about how I responded to conditions that challenged me to stick at 'aviate'). I will be far more mindful of the fluid environments of IMC precision approaches; especially when I have evidence and experience to tell me that it is going to get worse before it gets better.

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.