Narrative:

I landed on an unoccupied ball field after feeling aircraft shudder. No damage to aircraft; pilot or field. I was unwilling to risk crossing the large body of water ahead of me as I was unsure of the cause of the shudder and feared the possibility of failure over the water at low altitude. The class B airspace has a 500 ft floor. That limits available altitude when traveling past ZZZ airport. The flight originated in ZZZ1 and ended .6 hours later in the ball field. Mechanics are checking aircraft to determine origin of shudder. The engine did not actually stop until I shut it down when the landing was assured.

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Original NASA ASRS Text

Title: A C172 PLT LANDED OFF ARPT BEFORE XING A BODY OF WATER WHEN THE ACFT BEGAN SHUDDERING FOR AN UNKNOWN REASON.

Narrative: I LANDED ON AN UNOCCUPIED BALL FIELD AFTER FEELING ACFT SHUDDER. NO DAMAGE TO ACFT; PLT OR FIELD. I WAS UNWILLING TO RISK XING THE LARGE BODY OF WATER AHEAD OF ME AS I WAS UNSURE OF THE CAUSE OF THE SHUDDER AND FEARED THE POSSIBILITY OF FAILURE OVER THE WATER AT LOW ALT. THE CLASS B AIRSPACE HAS A 500 FT FLOOR. THAT LIMITS AVAILABLE ALT WHEN TRAVELING PAST ZZZ ARPT. THE FLT ORIGINATED IN ZZZ1 AND ENDED .6 HRS LATER IN THE BALL FIELD. MECHS ARE CHKING ACFT TO DETERMINE ORIGIN OF SHUDDER. THE ENG DID NOT ACTUALLY STOP UNTIL I SHUT IT DOWN WHEN THE LNDG WAS ASSURED.

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