Narrative:

After departure from wiley post airport in oklahoma city on an IFR flight plan to kansas city downtown, significant turbulence led to altitude deviations of from 200-500' from assigned. Especially from per to emp on V354, turbulence from a developing thunderstorm cell was significant. Because the arwy centerline lay directly in the cell, I advised center of my course deviation to the west. My deviation, although 15-20 mi west of the cell, was insufficient to keep me out of major up and down drafts. I lost at least 500-1000' before regaining aircraft control and exiting the area of turbulence. Center shifted me to wichita approach after my call for assistance in circumventing/avoiding further WX. After the aircraft righted itself after a 45-50 degree updraft bank and altitude loss, clear WX reappeared. I advised wichita I believed I could proceed direct emp. I was transferred back to center. I advised center of my reappearance on frequency and my climbing to resume altitude assignment. Center cleared me direct emp and the flight continued otherwise uneventfully to mkc. Comment: evidently, some radar cannot pick up significant thunderstorm activity. Had WX conditions not been VMC or mvmc with 5-15 mi visibility, it's my belief I would have continued unaware into the middle of a storm I later learned dropped 8' of rain in southeast ks. In other words, I'm glad I wasn't in IMC.

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Original NASA ASRS Text

Title: SMA TWIN EXPERIENCED BRIEF LOSS OF CONTROL AND ALT EXCURSION IN TSTM ACTIVITY.

Narrative: AFTER DEP FROM WILEY POST ARPT IN OKLAHOMA CITY ON AN IFR FLT PLAN TO KANSAS CITY DOWNTOWN, SIGNIFICANT TURB LED TO ALT DEVIATIONS OF FROM 200-500' FROM ASSIGNED. ESPECIALLY FROM PER TO EMP ON V354, TURB FROM A DEVELOPING TSTM CELL WAS SIGNIFICANT. BECAUSE THE ARWY CENTERLINE LAY DIRECTLY IN THE CELL, I ADVISED CENTER OF MY COURSE DEVIATION TO THE W. MY DEVIATION, ALTHOUGH 15-20 MI W OF THE CELL, WAS INSUFFICIENT TO KEEP ME OUT OF MAJOR UP AND DOWN DRAFTS. I LOST AT LEAST 500-1000' BEFORE REGAINING ACFT CONTROL AND EXITING THE AREA OF TURB. CENTER SHIFTED ME TO WICHITA APCH AFTER MY CALL FOR ASSISTANCE IN CIRCUMVENTING/AVOIDING FURTHER WX. AFTER THE ACFT RIGHTED ITSELF AFTER A 45-50 DEG UPDRAFT BANK AND ALT LOSS, CLEAR WX REAPPEARED. I ADVISED WICHITA I BELIEVED I COULD PROCEED DIRECT EMP. I WAS TRANSFERRED BACK TO CENTER. I ADVISED CENTER OF MY REAPPEARANCE ON FREQ AND MY CLBING TO RESUME ALT ASSIGNMENT. CENTER CLRED ME DIRECT EMP AND THE FLT CONTINUED OTHERWISE UNEVENTFULLY TO MKC. COMMENT: EVIDENTLY, SOME RADAR CANNOT PICK UP SIGNIFICANT TSTM ACTIVITY. HAD WX CONDITIONS NOT BEEN VMC OR MVMC WITH 5-15 MI VISIBILITY, IT'S MY BELIEF I WOULD HAVE CONTINUED UNAWARE INTO THE MIDDLE OF A STORM I LATER LEARNED DROPPED 8' OF RAIN IN SE KS. IN OTHER WORDS, I'M GLAD I WASN'T IN IMC.

Data retrieved from NASA's ASRS site as of August 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.