Narrative:

I was flying VFR with flight following. My route of flight was going to be along the shore; my rate of climb was 650 FPM; [and] I reached about 5;000 ft. I reduced my rate of climb at 350 FPM to maintain the cht below 380. Reaching 12;500 ft I turned the boost pump off; reduced to 2;500 RPM and I checked all my parameters. They were all green; so I leaned the mixture using lean assist. I started at 15 gph (that's for best power) [and] reduced mixture to an economic cruise [setting]. When I reached 13 gph the engine started to cough [and] I thought the engine was going to quit so I did emergency procedures. I turned on the boost pump; mixture rich; throttle full forward. The coughing reduced a little; so I retarded the throttle to a normal position for cruise; but I remained with full mixture and boost pump on. I said to the controller; 'approach (I don't remember if it was with approach or center); I have engine problems; I need immediate assistance to the nearest airport.' the controller said; 'fly heading 200; you have the airport [at] 12 o'clock; 16 miles; you are cleared to land.' then the controller asked me if I was in control of the aircraft [and] I told him yes I am. Also; he asked me if I can contact the tower [and] I said yes. Then I flew direct to the airport and I did 2 spiral descents since I was very high. I was on 7 mile final (I don't remember the exact distance; that's approximate). I did a side slip descent in order to lose altitude and maintain current speed; and when I got to the threshold line of the runway; I [reduced] the throttle to idle and the engine was running in a high RPM mode for no reason; so I cut the mixture and the engine still ran at high RPM. I turned off magnetos and the engine lost a little manifold pressure; but the engine was running still. I was cruising on final at 148 KTS and I [would] reduce throttle [and] speed [to] make the flare using the entire runway since it was a long runway. I want to clear something up -- I maintained my mixture and throttle settings because it was working for me. The engine was coughing; but was working. I didn't want to reduce throttle before reaching the runway and have an engine failure. I did the flare cruising above 140 KTS and I landed hard; with no damage to the propeller; fuselage; or landing gear; only a small crack on the main boot of the tire. Then the tower controller told me; 'if it is possible; taxi via to the right.' I told him; 'I have the engine running and yes I can;' and suddenly the engine stops. Everybody arrived to the entry of the taxiway except the FAA and I [explained] how everything happened to all the airport crew. The next day I contacted FAA. I spoke with an FAA inspector. I told him everything and he told me to send him a report via email; fix the airplane with cirrus; and send him certified logbooks to his office before departing for my planned destination; because he was going to give me the green light to depart. Also; I told the inspector that a pilot from cirrus was coming with the mechanic from cirrus so he can examine and determine if a flight was possible. The mechanic and the pilot came and determined the aircraft was good to make the flight to cirrus center; so the pilot made the flight.

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Original NASA ASRS Text

Title: A VFR SR22 pilot reported a coughing engine at 12;500 FT; which required that he declare an emergency and divert to a nearby airport. After a high speed landing with the throttle at idle and the mixture off; the engine continued running at a high RPM for a short period.

Narrative: I was flying VFR with flight following. My route of flight was going to be along the shore; my rate of climb was 650 FPM; [and] I reached about 5;000 FT. I reduced my rate of climb at 350 FPM to maintain the CHT below 380. Reaching 12;500 FT I turned the boost pump off; reduced to 2;500 RPM and I checked all my parameters. They were all green; so I leaned the mixture using lean assist. I started at 15 GPH (that's for best power) [and] reduced mixture to an economic cruise [setting]. When I reached 13 GPH the engine started to cough [and] I thought the engine was going to quit so I did emergency procedures. I turned on the boost pump; mixture rich; throttle full forward. The coughing reduced a little; so I retarded the throttle to a normal position for cruise; but I remained with full mixture and boost pump on. I said to the Controller; 'Approach (I don't remember if it was with Approach or Center); I have engine problems; I need immediate assistance to the nearest airport.' The Controller said; 'Fly heading 200; you have the airport [at] 12 o'clock; 16 miles; you are cleared to land.' Then the Controller asked me if I was in control of the aircraft [and] I told him yes I am. Also; he asked me if I can contact the Tower [and] I said yes. Then I flew direct to the airport and I did 2 spiral descents since I was very high. I was on 7 mile final (I don't remember the exact distance; that's approximate). I did a side slip descent in order to lose altitude and maintain current speed; and when I got to the threshold line of the runway; I [reduced] the throttle to idle and the engine was running in a high RPM mode for no reason; so I cut the mixture and the engine still ran at high RPM. I turned off magnetos and the engine lost a little manifold pressure; but the engine was running still. I was cruising on final at 148 KTS and I [would] reduce throttle [and] speed [to] make the flare using the entire runway since it was a long runway. I want to clear something up -- I maintained my mixture and throttle settings because it was working for me. The engine was coughing; but was working. I didn't want to reduce throttle before reaching the runway and have an engine failure. I did the flare cruising above 140 KTS and I landed hard; with no damage to the propeller; fuselage; or landing gear; only a small crack on the main boot of the tire. Then the Tower Controller told me; 'If it is possible; taxi via to the right.' I told him; 'I have the engine running and yes I can;' and suddenly the engine stops. Everybody arrived to the entry of the taxiway except the FAA and I [explained] how everything happened to all the airport crew. The next day I contacted FAA. I spoke with an FAA Inspector. I told him everything and he told me to send him a report via email; fix the airplane with Cirrus; and send him certified logbooks to his office before departing for my planned destination; because he was going to give me the green light to depart. Also; I told the Inspector that a pilot from Cirrus was coming with the Mechanic from Cirrus so he can examine and determine if a flight was possible. The Mechanic and the pilot came and determined the aircraft was good to make the flight to Cirrus center; so the pilot made the flight.

Data retrieved from NASA's ASRS site as of April 2012 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.