PLT OF SMA LANDS ON CLOSED RWY TO SIGHT DITCH ACROSS RWY. ON ATTEMPTED GAR MAIN GEAR HITS THE DITCH.

Narrative

THE FLT WAS THE FINAL DAY OF A 12 DAY CROSS COUNTRY TRIP FROM SAT (SAN ANTONIO; TX) TO MCI (KANSAS CITY INTL; MO) TO MDW (CHICAGO MIDWAY; IL) TO BRD (BRAINARD; MN) TO A RETURN DEST OF SEP/XX/94. I FILED AN A.M. COMPUTER FLT PLAN FOR BRD-RDK (RED OAK; IA). AFTER TKOF; I RECEIVED NO RESPONSE FROM PRINCETON RADIO SO PRESUMED I WAS HAVING RADIO TROUBLE AND DID NOT GET THE FLT PLAN OPEN. I LANDED AT RDK FOR A FUEL TOP OFF. I ASKED THE UNICOM MAN THAT FUELED THE PLANE IF HE HEARD MY RADIO XMISSIONS. HE SAID HE HAD BUT IT WAS A BIT GARBLED. THE RADIO SEEMED TO WORK OFF/ON; BUT WAS NOT A MAJOR PROB. I PLANNED TO LAND SHORT OF SAT AND CALL THE TWR; REQUESTING ADVANCE SQUAWK CODE IN CASE THE RADIO ACTED UP. I CALLED FORT DODGE FSS (VIA PHONE) AND GOT A WX BRIEFING FOR MY NEXT LEG FOR RDK-SWO (STILLWATER; OK). I RECEIVED A BRIEFING AND 2 NOTAMS FOR SWO: RCO CHANGED FROM 122.3 TO 122.4 AMD SW 2200 FT OF RWY 4-22 CLOSED; WHICH I WROTE DOWN. THERE WAS NO MENTION OF RWY 17-35 BEING CLOSED. AFTER TKOF FROM RDK; I TRIED TO REACH FORT DODGE RADIO AND NO RESPONSE SO AGAIN DID NOT OPEN MY FILED FLT PLAN. I ARRIVED AT SWO ANNOUNCING POS TO CTAF AND UNICOM FOR LNDG RWY 17 (MOST FAVORABLE WITH OKC ATIS NOVEMBER SHOWING WINDS OF 150/12). I ENTERED A L DOWNWIND AND NOTED THE X'S ON THE SW PORTION 4-22. I ANNOUNCED DOWNWIND; BASE AND FINAL. I SAW AN X OFF THE END OF RWY 17 IN THE GRASS SLOPE BEFORE THE PAVEMENT BUT NOTHING ON THE RWY. THERE WERE WHAT APPEARED TO BE FRESHLY PAINTED MARKINGS DOWN THE RWY; SO I PRESUMED WITH THE CONSTRUCTION; THE ARPT HAD A DISPLACED THRESHOLD OR SOMETHING LIKE RWY 4-22; WHERE AN X REALLY DIDN'T MEAN THAT WHOLE RWY WAS CLOSED. I AIMED FOR THE FRESH PAINT AND TOUCHED DOWN SHORTLY AFTER IT. IN THE SECONDS AFTER INITIAL TOUCHDOWN; I SAW WHAT AT FIRST LOOKED LIKE A TWO-TONED RWY (IE; A LIGHTER STRIP OF ASPHALT SIDEWAYS). THE SHADOWS CLARIFIED AND I SAW THE ROUGH BOTTOM OF A CONCRETE CUTOUT APPROX 1 FOOT DEEP BY 20 FT AND COMPLETELY ACROSS THE RWY. I IMMEDIATELY HIT FULL THROTTLE FOR GAR. I THOUGHT MY NOSE WHEEL CLRED BUT BOTH REAR WHEELS HIT THE FAR SIDE OF THE 'PIT' AND I WAS AIRBORNE. I EXITED THE PATTERN AND WHILE CONTEMPLATING OPTIONS; NOTED THE R WHEEL WAS CHIPPED AND THE TIRE HAD A PUNCTURE. THE L TIRE LOOKED GOOD. I DECIDED NOT TO LAND AT STILLWATER BUT OPTED FOR HSD (SUNDANCE; OK); WHICH IS CLOSER TO PARTS AND EMER OPS; SHOULD I ELECT TO DECLARE ONE. ANOTHER FACTOR WAS THE 1/2 HR EXTRA FUEL BURN TO REDUCE CHANCE OF FLAMES SHOULD THE LNDG TURN UNCTLED. I DECIDED TO SQUAWK 7600 ENRTE TO HSD. I MONITORED TFC IN PATTERN AT HSD PERFORMING TOUCH AND GOES. I STAYED CLR TILL THEY DID A FULL STOP; AND ALSO ALLOWED ANOTHER PLANE TO LAND IN CASE I 'TIED UP' THE RWY. I RADIOED UNICOM AND COULD HEAR OTHER TFC BUT GOT NO RESPONSE. I CALLED TO OTHER TFC TWICE AND NO RESPONSE. (TFC LATER SAID HE HEARD ME AND WOULD HAVE RESPONDED BUT WAS TOO BUSY.) I TRIED TO LAND CLOSE TO THE RWY EXIT AS I DIDN'T EXPECT A LONG ROLL AND SLOWED AS MUCH AS I COULD; PREPARING FOR ASYMMETRICAL BRAKING. BOTH WHEELS WOUND UP BEING FLAT SO THE DRAG WAS SYMMETRICAL AND WAS A PRETTY GOOD LNDG. I TAXIED CLR OF ACTIVE RWY 17 AND ANNOUNCED SAME ON CTAF.