Narrative:

While taxiing west from runway 16 I announced to pittsburg traffic I was clear of all runways; I had not heard any other traffic during my approach or landing; I then turned on the south taxiway headed for the hangar. There was a small business jet stopped with taxi/navigation lights on that was somewhat in that south taxiway; I slowly taxied around that aircraft only to be confronted with a helicopter. The helicopter's rotor did not at first appear to be turning but then as I got 20 to 30 feet closer it started rotating; I moved further to the west only to find myself off the asphalt into the grass; where I stopped the airplane. The helicopter pilot blinked his landing light which I took for a signal for me to taxi on by but when I increased power the right main tire rolled no more than an inch before it was against a sewer manhole cover that stands at least 12 inches above the ground. I shut the engine down; the helicopter pilots got out and helped me and my passenger push back onto the asphalt. There were no injuries or damage. What caused the problem; I didn't stop when I saw the rotor begin to turn. I was only creeping along but I fixated on the rotor as it began to rotate thinking it might hit my wing. It didn't occur to me at the time but I should have also been talking to the helicopter pilot on the radio to find out his intentions. What can be done to prevent a recurrence; as the new helicopter pad appears too close to the taxiway it should be moved to another spot on the airport. A manhole cover that close to the taxiway should be at ground level as well.callback conversation with reporter revealed the following information: the reporter stated that after the helicopter rotors began to rotate; he became fixated on the proximity of his wing to the rotors. He departed the taxiway; and after stopping; realized that he was unable to resume his taxi. After shutting down; the manhole cover was discovered and is located approximately 10 ft from the edge of the taxiway. The city has been notified with regard to the height and location of manholes. Their response was that although it was not possible to reduce the height or change the location of the manholes; perhaps paint could be applied to the covers to increase their visibility to taxiing aircraft.

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Original NASA ASRS Text

Title: C140 TAXIED OFF TAXIWAY AND MAIN GEAR CAME INTO CONTACT RAISED WITH MANHOLE COVER.

Narrative: WHILE TAXIING WEST FROM RWY 16 I ANNOUNCED TO PITTSBURG TRAFFIC I WAS CLEAR OF ALL RUNWAYS; I HAD NOT HEARD ANY OTHER TRAFFIC DURING MY APPROACH OR LANDING; I THEN TURNED ON THE SOUTH TAXIWAY HEADED FOR THE HANGAR. THERE WAS A SMALL BUSINESS JET STOPPED WITH TAXI/NAVIGATION LIGHTS ON THAT WAS SOMEWHAT IN THAT SOUTH TAXIWAY; I SLOWLY TAXIED AROUND THAT AIRCRAFT ONLY TO BE CONFRONTED WITH A HELICOPTER. THE HELICOPTER'S ROTOR DID NOT AT FIRST APPEAR TO BE TURNING BUT THEN AS I GOT 20 TO 30 FEET CLOSER IT STARTED ROTATING; I MOVED FURTHER TO THE WEST ONLY TO FIND MYSELF OFF THE ASPHALT INTO THE GRASS; WHERE I STOPPED THE AIRPLANE. THE HELICOPTER PILOT BLINKED HIS LANDING LIGHT WHICH I TOOK FOR A SIGNAL FOR ME TO TAXI ON BY BUT WHEN I INCREASED POWER THE RIGHT MAIN TIRE ROLLED NO MORE THAN AN INCH BEFORE IT WAS AGAINST A SEWER MANHOLE COVER THAT STANDS AT LEAST 12 INCHES ABOVE THE GROUND. I SHUT THE ENGINE DOWN; THE HELICOPTER PILOTS GOT OUT AND HELPED ME AND MY PASSENGER PUSH BACK ONTO THE ASPHALT. THERE WERE NO INJURIES OR DAMAGE. WHAT CAUSED THE PROBLEM; I DIDN'T STOP WHEN I SAW THE ROTOR BEGIN TO TURN. I WAS ONLY CREEPING ALONG BUT I FIXATED ON THE ROTOR AS IT BEGAN TO ROTATE THINKING IT MIGHT HIT MY WING. IT DIDN'T OCCUR TO ME AT THE TIME BUT I SHOULD HAVE ALSO BEEN TALKING TO THE HELICOPTER PILOT ON THE RADIO TO FIND OUT HIS INTENTIONS. WHAT CAN BE DONE TO PREVENT A RECURRENCE; AS THE NEW HELICOPTER PAD APPEARS TOO CLOSE TO THE TAXIWAY IT SHOULD BE MOVED TO ANOTHER SPOT ON THE AIRPORT. A MANHOLE COVER THAT CLOSE TO THE TAXIWAY SHOULD BE AT GROUND LEVEL AS WELL.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE REPORTER STATED THAT AFTER THE HELICOPTER ROTORS BEGAN TO ROTATE; HE BECAME FIXATED ON THE PROXIMITY OF HIS WING TO THE ROTORS. HE DEPARTED THE TAXIWAY; AND AFTER STOPPING; REALIZED THAT HE WAS UNABLE TO RESUME HIS TAXI. AFTER SHUTTING DOWN; THE MANHOLE COVER WAS DISCOVERED AND IS LOCATED APPROXIMATELY 10 FT FROM THE EDGE OF THE TAXIWAY. THE CITY HAS BEEN NOTIFIED WITH REGARD TO THE HEIGHT AND LOCATION OF MANHOLES. THEIR RESPONSE WAS THAT ALTHOUGH IT WAS NOT POSSIBLE TO REDUCE THE HEIGHT OR CHANGE THE LOCATION OF THE MANHOLES; PERHAPS PAINT COULD BE APPLIED TO THE COVERS TO INCREASE THEIR VISIBILITY TO TAXIING ACFT.

Data retrieved from NASA's ASRS site as of May 2009 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.