Narrative:

On may/sat/02 at XA15, I called for taxi instructions from my super cub at the GA ramp just south of runway 8/26 and just east of runway 17/35 at the eastern wv regional/shepherd airport (mrb), martinsburg, wv. The controller asked which way we were going. I replied that we were heading south toward front royal, va. He instructed me to taxi to runway 17 and turn left at taxiway C, the intersection of the taxiway I was on, and runway 26/8. I acknowledged with my call sign, but did not read back the clearance to taxi, nor did the controller ask me to. Proceeded across runway 26, bearing a bit left to give the northeast corner of the runway intersection a comfortable distance, intercepted the centerline of runway 17/35, and back taxied on runway 17 to its approach end. There is no parallel taxiway. About 100 yards north of runway 26 on the centerline of runway 17/35, the controller asked what my intentions were. I said I was taxiing to runway 17, but could take a departure from present position if he desired. He then said I had just been involved in a runway incursion. I said I thought he said to taxi to runway 17. He said my instructions had been to turn left at taxiway C and that he was going to give me an intersection departure. That was the first time he had mentioned an intersection departure. I started to explain further, but stopped, not wanting to saturate the frequency. He cleared me for takeoff from that position on runway 17. I read back the clearance, turned the airplane to 170 degrees, took off, turned south and remained on the frequency until he cleared me off, wishing me a safe flight. I acknowledged with my call sign, thanked him and changed frequencys. I had flown into mrb only once before and should have studied the airport diagram more. I also should have read back the taxi clearance and/or asked for progressive taxi. The controller didn't say anything to me from the time he gave me taxi instructions until he asked what my intentions were. His instructions and his intentions would have been very clear if he had told me to expect an intersection departure and told me how many ft remained, when he gave me my taxi instructions.

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Original NASA ASRS Text

Title: A PA18 PLT, TAXIING FOR TKOF AT MRB, TAXIED ONTO ASSIGNED RWY WITHOUT A CLRNC.

Narrative: ON MAY/SAT/02 AT XA15, I CALLED FOR TAXI INSTRUCTIONS FROM MY SUPER CUB AT THE GA RAMP JUST S OF RWY 8/26 AND JUST E OF RWY 17/35 AT THE EASTERN WV REGIONAL/SHEPHERD ARPT (MRB), MARTINSBURG, WV. THE CTLR ASKED WHICH WAY WE WERE GOING. I REPLIED THAT WE WERE HDG S TOWARD FRONT ROYAL, VA. HE INSTRUCTED ME TO TAXI TO RWY 17 AND TURN L AT TXWY C, THE INTXN OF THE TXWY I WAS ON, AND RWY 26/8. I ACKNOWLEDGED WITH MY CALL SIGN, BUT DID NOT READ BACK THE CLRNC TO TAXI, NOR DID THE CTLR ASK ME TO. PROCEEDED ACROSS RWY 26, BEARING A BIT L TO GIVE THE NE CORNER OF THE RWY INTXN A COMFORTABLE DISTANCE, INTERCEPTED THE CTRLINE OF RWY 17/35, AND BACK TAXIED ON RWY 17 TO ITS APCH END. THERE IS NO PARALLEL TXWY. ABOUT 100 YARDS N OF RWY 26 ON THE CTRLINE OF RWY 17/35, THE CTLR ASKED WHAT MY INTENTIONS WERE. I SAID I WAS TAXIING TO RWY 17, BUT COULD TAKE A DEP FROM PRESENT POS IF HE DESIRED. HE THEN SAID I HAD JUST BEEN INVOLVED IN A RWY INCURSION. I SAID I THOUGHT HE SAID TO TAXI TO RWY 17. HE SAID MY INSTRUCTIONS HAD BEEN TO TURN L AT TXWY C AND THAT HE WAS GOING TO GIVE ME AN INTXN DEP. THAT WAS THE FIRST TIME HE HAD MENTIONED AN INTXN DEP. I STARTED TO EXPLAIN FURTHER, BUT STOPPED, NOT WANTING TO SATURATE THE FREQ. HE CLRED ME FOR TKOF FROM THAT POS ON RWY 17. I READ BACK THE CLRNC, TURNED THE AIRPLANE TO 170 DEGS, TOOK OFF, TURNED S AND REMAINED ON THE FREQ UNTIL HE CLRED ME OFF, WISHING ME A SAFE FLT. I ACKNOWLEDGED WITH MY CALL SIGN, THANKED HIM AND CHANGED FREQS. I HAD FLOWN INTO MRB ONLY ONCE BEFORE AND SHOULD HAVE STUDIED THE ARPT DIAGRAM MORE. I ALSO SHOULD HAVE READ BACK THE TAXI CLRNC AND/OR ASKED FOR PROGRESSIVE TAXI. THE CTLR DIDN'T SAY ANYTHING TO ME FROM THE TIME HE GAVE ME TAXI INSTRUCTIONS UNTIL HE ASKED WHAT MY INTENTIONS WERE. HIS INSTRUCTIONS AND HIS INTENTIONS WOULD HAVE BEEN VERY CLR IF HE HAD TOLD ME TO EXPECT AN INTXN DEP AND TOLD ME HOW MANY FT REMAINED, WHEN HE GAVE ME MY TAXI INSTRUCTIONS.

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.