Narrative:

The flight departed ZZZ1 at approximately XA45 local for a familiarization flight of the area generally east and southeast of ZZZ1. No landing was planned except upon return to ZZZ1. While in the localizer indicated above, the oil pressure was observed to fluctuate and began to decline. As this was the first flight since an oil change on the previous evening, I feared that an oil leak must have developed (no oil quantity gauge on this aircraft). The safest course of action was obviously to land at the nearest suitable airport, ZZZ2. I called the ZZZ3 unicom to declare an emergency and request airport and traffic advisories. I planned to do a straight in approach to ZZZ2 if possible. I was unable to establish radio contact on unicom, but continued to make position calls to alert other traffic, if any was present. A climb was initiated to provide a better angle to see the airport and to enhance my options should the engine fail. Time remaining was used to familiarize myself with the airport by reviewing the airport directory as I had not been to ZZZ2 previously. Since I had not received any advisories, I elected to enter the pattern on a high upwind leg in order to be sure the runway was open and usable, landing was without incident. After landing, airport personnel confirmed that this airport was in the ZZZ4 no fly zone. I contacted the ZZZ3 FSDO shortly thereafter to report the situation, and was surprised to hear that I may receive a violation. As I write this (nov/sun/01) the aircraft remains at ZZZ2 awaiting inspection to determine the cause of the indicated pressure loss.

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Original NASA ASRS Text

Title: C-150 PLT, AFTER DECLARING AN EMER, LANDED AT THE NEAREST SUITABLE ARPT. ARPT WAS IN A TFR AREA. THE FAA FSDO HAD THREATENED A PLT VIOLATION.

Narrative: THE FLT DEPARTED ZZZ1 AT APPROX XA45 LCL FOR A FAMILIARIZATION FLT OF THE AREA GENERALLY E AND SE OF ZZZ1. NO LNDG WAS PLANNED EXCEPT UPON RETURN TO ZZZ1. WHILE IN THE LOC INDICATED ABOVE, THE OIL PRESSURE WAS OBSERVED TO FLUCTUATE AND BEGAN TO DECLINE. AS THIS WAS THE FIRST FLT SINCE AN OIL CHANGE ON THE PREVIOUS EVENING, I FEARED THAT AN OIL LEAK MUST HAVE DEVELOPED (NO OIL QUANTITY GAUGE ON THIS ACFT). THE SAFEST COURSE OF ACTION WAS OBVIOUSLY TO LAND AT THE NEAREST SUITABLE ARPT, ZZZ2. I CALLED THE ZZZ3 UNICOM TO DECLARE AN EMER AND REQUEST ARPT AND TFC ADVISORIES. I PLANNED TO DO A STRAIGHT IN APCH TO ZZZ2 IF POSSIBLE. I WAS UNABLE TO ESTABLISH RADIO CONTACT ON UNICOM, BUT CONTINUED TO MAKE POS CALLS TO ALERT OTHER TFC, IF ANY WAS PRESENT. A CLB WAS INITIATED TO PROVIDE A BETTER ANGLE TO SEE THE ARPT AND TO ENHANCE MY OPTIONS SHOULD THE ENGINE FAIL. TIME REMAINING WAS USED TO FAMILIARIZE MYSELF WITH THE ARPT BY REVIEWING THE ARPT DIRECTORY AS I HAD NOT BEEN TO ZZZ2 PREVIOUSLY. SINCE I HAD NOT RECEIVED ANY ADVISORIES, I ELECTED TO ENTER THE PATTERN ON A HIGH UPWIND LEG IN ORDER TO BE SURE THE RWY WAS OPEN AND USABLE, LNDG WAS WITHOUT INCIDENT. AFTER LNDG, ARPT PERSONNEL CONFIRMED THAT THIS ARPT WAS IN THE ZZZ4 NO FLY ZONE. I CONTACTED THE ZZZ3 FSDO SHORTLY THEREAFTER TO RPT THE SIT, AND WAS SURPRISED TO HEAR THAT I MAY RECEIVE A VIOLATION. AS I WRITE THIS (NOV/SUN/01) THE ACFT REMAINS AT ZZZ2 AWAITING INSPECTION TO DETERMINE THE CAUSE OF THE INDICATED PRESSURE LOSS.

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.