Narrative:

I had filed btv-mss-art-syr on my way to 9g3. Flying from btv to mss at 8000 ft into a 35 KT headwind, resulting in a slower than normal ground speed, ZBW asked if I wanted to divert direct to syr. I was given a 240 degree heading and told to descend to 7000 ft to avoid military activity. This put me into IMC conditions. After a few mins we also encountered rain and moderate turbulence, making it difficult to hold a steady heading. I was too far from syr to pick up their VOR so I used triangulation from the mss and btv vors to determine my position. During this process I did not keep sufficient attention to my altitude. When I picked up my scan of the instruments I noticed my altitude had dropped to 6600 ft. I immediately climbed back to my assigned altitude of 7000 ft. Contributing factors to my deviation in altitude were the WX conditions, IMC and moderate turbulence, and that I was flying off of any airways out of range of my destination's VOR making it more difficult to determine my position. My lack of attention to the instruments while my attention was diverted to determining my location caused me to deviate beyond acceptable limits from my assigned altitude. I need to continue my scan of the instruments when my attention is diverted to cockpit management in order to prevent a recurrence of this situation.

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Original NASA ASRS Text

Title: INST RATED PVT PLT OF AN SMA DSNDED BELOW ASSIGNED CRUISING ALT DUE ENCOUNTER WITH RAIN AND TURB.

Narrative: I HAD FILED BTV-MSS-ART-SYR ON MY WAY TO 9G3. FLYING FROM BTV TO MSS AT 8000 FT INTO A 35 KT HEADWIND, RESULTING IN A SLOWER THAN NORMAL GND SPD, ZBW ASKED IF I WANTED TO DIVERT DIRECT TO SYR. I WAS GIVEN A 240 DEG HDG AND TOLD TO DSND TO 7000 FT TO AVOID MIL ACTIVITY. THIS PUT ME INTO IMC CONDITIONS. AFTER A FEW MINS WE ALSO ENCOUNTERED RAIN AND MODERATE TURB, MAKING IT DIFFICULT TO HOLD A STEADY HEADING. I WAS TOO FAR FROM SYR TO PICK UP THEIR VOR SO I USED TRIANGULATION FROM THE MSS AND BTV VORS TO DETERMINE MY POS. DURING THIS PROCESS I DID NOT KEEP SUFFICIENT ATTN TO MY ALT. WHEN I PICKED UP MY SCAN OF THE INSTS I NOTICED MY ALT HAD DROPPED TO 6600 FT. I IMMEDIATELY CLBED BACK TO MY ASSIGNED ALT OF 7000 FT. CONTRIBUTING FACTORS TO MY DEV IN ALT WERE THE WX CONDITIONS, IMC AND MODERATE TURB, AND THAT I WAS FLYING OFF OF ANY AIRWAYS OUT OF RANGE OF MY DEST'S VOR MAKING IT MORE DIFFICULT TO DETERMINE MY POS. MY LACK OF ATTN TO THE INSTS WHILE MY ATTN WAS DIVERTED TO DETERMINING MY LOCATION CAUSED ME TO DEVIATE BEYOND ACCEPTABLE LIMITS FROM MY ASSIGNED ALT. I NEED TO CONTINUE MY SCAN OF THE INSTS WHEN MY ATTN IS DIVERTED TO COCKPIT MGMNT IN ORDER TO PREVENT A RECURRENCE OF THIS SIT.

Data retrieved from NASA's ASRS site as of July 2007 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.