Narrative:

I was awaiting IFR release and takeoff clearance at the ptk runway 27L run-up area, north side, for an IFR training flight. Several other aircraft also were waiting for takeoff on the south side run-up area. Other aircraft were landing. Approximately 5+ mins after receiving my route clearance, I was given what I thought was my takeoff clearance: 'small aircraft C XXX, cleared for takeoff.' I acknowledged: 'small aircraft C XXX cleared for takeoff.' I received no other reply. I looked in the direction of approaching traffic, saw none and moved out onto the active runway. I had not yet advanced the power for takeoff. At this moment I first saw another light aircraft small aircraft B single which passed directly over me and touched down well beyond my position. He had apparently just been in my upper left blind spot the instant I had looked in the approach direction before taxiing out. No evasive action was taken nor actually necessary by either of us. It was not actually that close. I knew I could not take off with the other aircraft rolling out ahead. I held my position. The controller then told me to exit off the active to the south side. I did and then he said, 'sorry for the confusion.' communication was the usual very rapid-fire to a # of aircraft for that runway. I was again cleared for my IFR takeoff. After my return, I went up to discuss the happening with the controller. He was very nice, simply explained I had not been cleared for takeoff as I was still awaiting IFR release. He said he had been talking to other traffic. I did not contest his reply nor request to hear the tape. I am very sure I heard my call # and takeoff clearance correctly, and I repeated it back as I started to move--I always do. My clearance was not denied. I had a passenger observer in the aircraft--my wife and flying companion of many yrs, also with earphones--who heard what I heard. But communication tends to be very fast and busy at pontiac on nice wkends. I don't know what the answer is, except perhaps to have a slower and more deliberate communication pace set by ATC--slower than is often heard--to allow a little more time for the exchange both ways to be expressed, responded to and acted upon west/O haste.

Related reports:

Google
 

Original NASA ASRS Text

Title: GA SMA TAXIED ONTO RWY WITHOUT CLRNC IN RESPONSE TO WRONG CALL SIGN.

Narrative: I WAS AWAITING IFR RELEASE AND TKOF CLRNC AT THE PTK RWY 27L RUN-UP AREA, N SIDE, FOR AN IFR TRNING FLT. SEVERAL OTHER ACFT ALSO WERE WAITING FOR TKOF ON THE S SIDE RUN-UP AREA. OTHER ACFT WERE LNDG. APPROX 5+ MINS AFTER RECEIVING MY RTE CLRNC, I WAS GIVEN WHAT I THOUGHT WAS MY TKOF CLRNC: 'SMA C XXX, CLRED FOR TKOF.' I ACKNOWLEDGED: 'SMA C XXX CLRED FOR TKOF.' I RECEIVED NO OTHER REPLY. I LOOKED IN THE DIRECTION OF APCHING TFC, SAW NONE AND MOVED OUT ONTO THE ACTIVE RWY. I HAD NOT YET ADVANCED THE PWR FOR TKOF. AT THIS MOMENT I FIRST SAW ANOTHER LIGHT ACFT SMA B SINGLE WHICH PASSED DIRECTLY OVER ME AND TOUCHED DOWN WELL BEYOND MY POS. HE HAD APPARENTLY JUST BEEN IN MY UPPER LEFT BLIND SPOT THE INSTANT I HAD LOOKED IN THE APCH DIRECTION BEFORE TAXIING OUT. NO EVASIVE ACTION WAS TAKEN NOR ACTUALLY NECESSARY BY EITHER OF US. IT WAS NOT ACTUALLY THAT CLOSE. I KNEW I COULD NOT TAKE OFF WITH THE OTHER ACFT ROLLING OUT AHEAD. I HELD MY POS. THE CTLR THEN TOLD ME TO EXIT OFF THE ACTIVE TO THE S SIDE. I DID AND THEN HE SAID, 'SORRY FOR THE CONFUSION.' COM WAS THE USUAL VERY RAPID-FIRE TO A # OF ACFT FOR THAT RWY. I WAS AGAIN CLRED FOR MY IFR TKOF. AFTER MY RETURN, I WENT UP TO DISCUSS THE HAPPENING WITH THE CTLR. HE WAS VERY NICE, SIMPLY EXPLAINED I HAD NOT BEEN CLRED FOR TKOF AS I WAS STILL AWAITING IFR RELEASE. HE SAID HE HAD BEEN TALKING TO OTHER TFC. I DID NOT CONTEST HIS REPLY NOR REQUEST TO HEAR THE TAPE. I AM VERY SURE I HEARD MY CALL # AND TKOF CLRNC CORRECTLY, AND I REPEATED IT BACK AS I STARTED TO MOVE--I ALWAYS DO. MY CLRNC WAS NOT DENIED. I HAD A PAX OBSERVER IN THE ACFT--MY WIFE AND FLYING COMPANION OF MANY YRS, ALSO WITH EARPHONES--WHO HEARD WHAT I HEARD. BUT COM TENDS TO BE VERY FAST AND BUSY AT PONTIAC ON NICE WKENDS. I DON'T KNOW WHAT THE ANSWER IS, EXCEPT PERHAPS TO HAVE A SLOWER AND MORE DELIBERATE COM PACE SET BY ATC--SLOWER THAN IS OFTEN HEARD--TO ALLOW A LITTLE MORE TIME FOR THE EXCHANGE BOTH WAYS TO BE EXPRESSED, RESPONDED TO AND ACTED UPON W/O HASTE.

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.