Narrative:

The plane had been inspected by a mechanic after the last person flying it reported smoke in the cockpit. A faulty circuit breaker was found to be the possible cause of the smoke and was replaced. The takeoff was uneventful and the plane was established on a climb to 6000 ft at the usual speed of 110 IAS. Upon reaching 2500 ft; a slight decrease in airspeed was noticed accompanied by a slight decrease in the rate of climb. This was initially attributed to the high temperature combined with a recent manifold pressure adjustment to a lower setting after the newly overhauled engine frequently reached redline at full power. Later in the climb; the decrease in airspeed became more noticeable. An attempt to lower the nose resulted in the expected increase in airspeed and; shortly after that; a climb attitude was re-established. Pitot heat was applied as a precaution but; as expected considering the high temperature and the absence of clouds; it had no effect. At that time; the controller inquired about the slow rate of climb and verified that I could maintain terrain clearance. A quick look outside confirmed that terrain avoidance would not be an issue. The controller subsequently requested a left 360 degrees to gain altitude and asked if a diversion to another airport was needed. The offer was initially declined and a 'best rate-of-climb' attitude was established visually; only to achieve a couple hundred FPM climb on the vertical speed indicator. Shortly thereafter; the controller informed me that he had declared an emergency and that ZZZ was ahead to my left. After the poor climb performance during the turn despite the high pitch attitude; I informed the controller that I was about to ask for a diversion to ZZZ as well. I was given a heading and provided with airport information. At that point; the altimeter indicated approximately 5300 ft and the poor rate of climb was still attributed to the engine not developing full power; a problem we had encountered before with this newly overhauled engine. With ZZZ in sight and the plane in a straight and level attitude; the alternate static source was selected (but I do not recall seeing any immediate effect) and the gear was lowered. At that precise moment; the vertical speed indicator showed a 4000 FPM rate of climb; the altimeter went from 5300 ft to over 9000 ft; the airspeed showed a rapid increase but ultimately settled to zero and; only at that time; did it become obvious that I had experienced a partial static system failure; possibly combined with a partially blocked pitot tube. This perceived rapid change in altitude immediately triggered another query from the controller before I was asked to switch to ZZZ tower frequency. Realizing that I had been climbing at a normal rate of climb since takeoff and that I was at 9000 ft instead of 5000 ft; I reduced the throttle to idle and was surprised to feel no deceleration at all. I do not remember all the gauge indications as I was preoccupied by the approach and by this additional issue. However; a much higher fuel flow indication than that expected for a closed throttle caught my attention. The combination of the fuel flow indication and the smoke in the cockpit experienced by the other pilot prior to this flight triggered the decision to shut down the engine; knowing that I was high enough to glide to the runway. The landing was uneventful and the plane came to an end on a taxiway off runway xxr. 3 attempts to restart the engine were unsuccessful and the plane was towed to parking. A local mechanic later found a broken fuel line located on top of the engine; which prompted him to comment on how lucky I was to have shut down the engine. A quick look at the pitot tube did not reveal any problem but a full inspection of the entire pitot static system has been scheduled. How the problem arose: failure to immediately recognize a partial blockage of the pitot tube and/or a partial failure of the static system. In my opinion (and now experience); this is one of the more difficult problems to diagnose. Contributing factors: 1) the perceived confirmation by the controller that I was not able to climb; 2) the failure to immediately realize that the altitude displayed on a controller screen comes from the plane transponder which; if linked to a faulty static system; will display the same erroneous altitude on the controller screen; 3) the past problems encountered with the rebuilt engine not developing full power and; 4) the recent readjustment of the manifold pressure all pointed out (initially) to an engine problem rather than a pitot static issue. How it was discovered: the airspeed indication later decreasing to below stall speed and; ultimately; to zero while the GPS indicated a 195 KT ground speed during descent to ZZZ airport. The altimeter's and the vertical speed indicator's sudden burst to drastically different values. The fuel leak was discovered when the throttle was closed. I do not know when the leak started but there was no indication of fuel flow higher than normal and/or fuel smell during the run-up or at anytime before reducing the throttle. Corrective actions: selection of alternate static source and estimate of proper landing speed from the GPS ground speed. The lack of response after reducing the throttle and the high fuel flow indication triggered the engine shut down before landing; as a precaution. Actions or inactions: the continuous climb based on the erroneous altimeter display resulted in flying through the assigned altitude of 6000 ft to about 9000 ft while both the controller and myself believed the plane was at approximately 5300 ft; a potentially very dangerous situation. An independent way for a radar system/controller to determine an aircraft's altitude would provide an added safety level. Factors affecting the quality of human performance: the heightened level of caution after the smoke in the cockpit incident and the awareness of past engine problems probably affected my ability to diagnose the pitot static problem in a timely manner.

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Original NASA ASRS Text

Title: PA46 PLT SUFFERS INACCURATE PITOT STATIC INDICATIONS AFTER TKOF. ATC FEARS HE WILL BE UNABLE TO CLEAR HIGH TERRAIN AND DECLARES EMERGENCY. ACFT LANDS AT A NEARBY ARPT NOT FAR FROM DEP ARPT.

Narrative: THE PLANE HAD BEEN INSPECTED BY A MECH AFTER THE LAST PERSON FLYING IT RPTED SMOKE IN THE COCKPIT. A FAULTY CIRCUIT BREAKER WAS FOUND TO BE THE POSSIBLE CAUSE OF THE SMOKE AND WAS REPLACED. THE TKOF WAS UNEVENTFUL AND THE PLANE WAS ESTABLISHED ON A CLB TO 6000 FT AT THE USUAL SPD OF 110 IAS. UPON REACHING 2500 FT; A SLIGHT DECREASE IN AIRSPD WAS NOTICED ACCOMPANIED BY A SLIGHT DECREASE IN THE RATE OF CLB. THIS WAS INITIALLY ATTRIBUTED TO THE HIGH TEMP COMBINED WITH A RECENT MANIFOLD PRESSURE ADJUSTMENT TO A LOWER SETTING AFTER THE NEWLY OVERHAULED ENG FREQUENTLY REACHED REDLINE AT FULL PWR. LATER IN THE CLB; THE DECREASE IN AIRSPD BECAME MORE NOTICEABLE. AN ATTEMPT TO LOWER THE NOSE RESULTED IN THE EXPECTED INCREASE IN AIRSPD AND; SHORTLY AFTER THAT; A CLB ATTITUDE WAS RE-ESTABLISHED. PITOT HEAT WAS APPLIED AS A PRECAUTION BUT; AS EXPECTED CONSIDERING THE HIGH TEMP AND THE ABSENCE OF CLOUDS; IT HAD NO EFFECT. AT THAT TIME; THE CTLR INQUIRED ABOUT THE SLOW RATE OF CLB AND VERIFIED THAT I COULD MAINTAIN TERRAIN CLRNC. A QUICK LOOK OUTSIDE CONFIRMED THAT TERRAIN AVOIDANCE WOULD NOT BE AN ISSUE. THE CTLR SUBSEQUENTLY REQUESTED A L 360 DEGS TO GAIN ALT AND ASKED IF A DIVERSION TO ANOTHER ARPT WAS NEEDED. THE OFFER WAS INITIALLY DECLINED AND A 'BEST RATE-OF-CLB' ATTITUDE WAS ESTABLISHED VISUALLY; ONLY TO ACHIEVE A COUPLE HUNDRED FPM CLB ON THE VERT SPD INDICATOR. SHORTLY THEREAFTER; THE CTLR INFORMED ME THAT HE HAD DECLARED AN EMER AND THAT ZZZ WAS AHEAD TO MY L. AFTER THE POOR CLB PERFORMANCE DURING THE TURN DESPITE THE HIGH PITCH ATTITUDE; I INFORMED THE CTLR THAT I WAS ABOUT TO ASK FOR A DIVERSION TO ZZZ AS WELL. I WAS GIVEN A HDG AND PROVIDED WITH ARPT INFO. AT THAT POINT; THE ALTIMETER INDICATED APPROX 5300 FT AND THE POOR RATE OF CLB WAS STILL ATTRIBUTED TO THE ENG NOT DEVELOPING FULL PWR; A PROB WE HAD ENCOUNTERED BEFORE WITH THIS NEWLY OVERHAULED ENG. WITH ZZZ IN SIGHT AND THE PLANE IN A STRAIGHT AND LEVEL ATTITUDE; THE ALTERNATE STATIC SOURCE WAS SELECTED (BUT I DO NOT RECALL SEEING ANY IMMEDIATE EFFECT) AND THE GEAR WAS LOWERED. AT THAT PRECISE MOMENT; THE VERT SPD INDICATOR SHOWED A 4000 FPM RATE OF CLB; THE ALTIMETER WENT FROM 5300 FT TO OVER 9000 FT; THE AIRSPD SHOWED A RAPID INCREASE BUT ULTIMATELY SETTLED TO ZERO AND; ONLY AT THAT TIME; DID IT BECOME OBVIOUS THAT I HAD EXPERIENCED A PARTIAL STATIC SYS FAILURE; POSSIBLY COMBINED WITH A PARTIALLY BLOCKED PITOT TUBE. THIS PERCEIVED RAPID CHANGE IN ALT IMMEDIATELY TRIGGERED ANOTHER QUERY FROM THE CTLR BEFORE I WAS ASKED TO SWITCH TO ZZZ TWR FREQ. REALIZING THAT I HAD BEEN CLBING AT A NORMAL RATE OF CLB SINCE TKOF AND THAT I WAS AT 9000 FT INSTEAD OF 5000 FT; I REDUCED THE THROTTLE TO IDLE AND WAS SURPRISED TO FEEL NO DECELERATION AT ALL. I DO NOT REMEMBER ALL THE GAUGE INDICATIONS AS I WAS PREOCCUPIED BY THE APCH AND BY THIS ADDITIONAL ISSUE. HOWEVER; A MUCH HIGHER FUEL FLOW INDICATION THAN THAT EXPECTED FOR A CLOSED THROTTLE CAUGHT MY ATTN. THE COMBINATION OF THE FUEL FLOW INDICATION AND THE SMOKE IN THE COCKPIT EXPERIENCED BY THE OTHER PLT PRIOR TO THIS FLT TRIGGERED THE DECISION TO SHUT DOWN THE ENG; KNOWING THAT I WAS HIGH ENOUGH TO GLIDE TO THE RWY. THE LNDG WAS UNEVENTFUL AND THE PLANE CAME TO AN END ON A TXWY OFF RWY XXR. 3 ATTEMPTS TO RESTART THE ENG WERE UNSUCCESSFUL AND THE PLANE WAS TOWED TO PARKING. A LCL MECH LATER FOUND A BROKEN FUEL LINE LOCATED ON TOP OF THE ENG; WHICH PROMPTED HIM TO COMMENT ON HOW LUCKY I WAS TO HAVE SHUT DOWN THE ENG. A QUICK LOOK AT THE PITOT TUBE DID NOT REVEAL ANY PROB BUT A FULL INSPECTION OF THE ENTIRE PITOT STATIC SYS HAS BEEN SCHEDULED. HOW THE PROB AROSE: FAILURE TO IMMEDIATELY RECOGNIZE A PARTIAL BLOCKAGE OF THE PITOT TUBE AND/OR A PARTIAL FAILURE OF THE STATIC SYS. IN MY OPINION (AND NOW EXPERIENCE); THIS IS ONE OF THE MORE DIFFICULT PROBS TO DIAGNOSE. CONTRIBUTING FACTORS: 1) THE PERCEIVED CONFIRMATION BY THE CTLR THAT I WAS NOT ABLE TO CLB; 2) THE FAILURE TO IMMEDIATELY REALIZE THAT THE ALT DISPLAYED ON A CTLR SCREEN COMES FROM THE PLANE XPONDER WHICH; IF LINKED TO A FAULTY STATIC SYS; WILL DISPLAY THE SAME ERRONEOUS ALT ON THE CTLR SCREEN; 3) THE PAST PROBS ENCOUNTERED WITH THE REBUILT ENG NOT DEVELOPING FULL PWR AND; 4) THE RECENT READJUSTMENT OF THE MANIFOLD PRESSURE ALL POINTED OUT (INITIALLY) TO AN ENG PROB RATHER THAN A PITOT STATIC ISSUE. HOW IT WAS DISCOVERED: THE AIRSPD INDICATION LATER DECREASING TO BELOW STALL SPD AND; ULTIMATELY; TO ZERO WHILE THE GPS INDICATED A 195 KT GND SPD DURING DSCNT TO ZZZ ARPT. THE ALTIMETER'S AND THE VERT SPD INDICATOR'S SUDDEN BURST TO DRASTICALLY DIFFERENT VALUES. THE FUEL LEAK WAS DISCOVERED WHEN THE THROTTLE WAS CLOSED. I DO NOT KNOW WHEN THE LEAK STARTED BUT THERE WAS NO INDICATION OF FUEL FLOW HIGHER THAN NORMAL AND/OR FUEL SMELL DURING THE RUN-UP OR AT ANYTIME BEFORE REDUCING THE THROTTLE. CORRECTIVE ACTIONS: SELECTION OF ALTERNATE STATIC SOURCE AND ESTIMATE OF PROPER LNDG SPD FROM THE GPS GND SPD. THE LACK OF RESPONSE AFTER REDUCING THE THROTTLE AND THE HIGH FUEL FLOW INDICATION TRIGGERED THE ENG SHUT DOWN BEFORE LNDG; AS A PRECAUTION. ACTIONS OR INACTIONS: THE CONTINUOUS CLB BASED ON THE ERRONEOUS ALTIMETER DISPLAY RESULTED IN FLYING THROUGH THE ASSIGNED ALT OF 6000 FT TO ABOUT 9000 FT WHILE BOTH THE CTLR AND MYSELF BELIEVED THE PLANE WAS AT APPROX 5300 FT; A POTENTIALLY VERY DANGEROUS SITUATION. AN INDEPENDENT WAY FOR A RADAR SYS/CTLR TO DETERMINE AN ACFT'S ALT WOULD PROVIDE AN ADDED SAFETY LEVEL. FACTORS AFFECTING THE QUALITY OF HUMAN PERFORMANCE: THE HEIGHTENED LEVEL OF CAUTION AFTER THE SMOKE IN THE COCKPIT INCIDENT AND THE AWARENESS OF PAST ENG PROBS PROBABLY AFFECTED MY ABILITY TO DIAGNOSE THE PITOT STATIC PROB IN A TIMELY MANNER.

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.