Narrative:

I was on the last leg of a VFR cross country at night. Approach cleared me into the class B for the transition to ZZZ; where the FBO is located. Upon clearing me into the class B; the approach controller also descended me to 4;000 out of 4;500. As I eased the throttle lever back in order to descend the aircraft; I noted that the engine RPM indicator did not show a decrease. I thought this may simply be due to the fact that the aircraft was descending and the prop was keeping engine RPM's up. I realized as soon as I leveled off at 4;000 that this was not the case; as the RPM's were stuck around 2;700 in level flight; no matter what position I moved the throttle lever into. After fiddling with the lever for a minute or so with no success; I explained the problem to approach. They indicated their readiness to help; before handing me off to another approach controller who was aware of the situation. I explained to this controller that I would need to descend early so that I could level off and dissipate some of the high speed that I would naturally accrue in a full-power descent. The controller gave me a vector to intercept the final approach course into ZZZ and asked for fuel and souls aboard. The airport was easy to spot with all the fire trucks at night. The controller handed me off to tower. I leveled off at about 1;000 AGL and turned final. I judged that I should cut the mixture off about 2 miles out at 1;000 AGL; which would allow the speed to dissipate to roughly 73 KIAS for the landing. I had a GPS distance to the center of the field and also asked the tower controller to call my 2 NM from threshold on final. Upon reaching what I assessed was about 1.8 NM from the threshold; I pulled the mixture and engine power ceased immediately. The aircraft slowed rapidly and it became clear within a few seconds that I would not reach the threshold of the runway. I adjusted my plan for a soft field landing on the airport grass short and left of the threshold. I moved laterally left about 100 ft so as not to land on the rabbit. What ensued was a routine soft field landing with very aggressive braking. Once stopped; I pulled the emergency fuel shut-off valve; killed all electrics; and evacuated the aircraft. No damage was done to the aircraft in the course of the flight; approach; or landing as a result of the malfunctioning throttle.

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Original NASA ASRS Text

Title: DA20 pilot reported having no throttle response on final approach; and since the throttle was at 'Full Open' he elected to secure the engine via the mixture control to complete his landing. He landed short of the runway in the grassy area with no damage to the aircraft. A Maintenance Technician reported a post landing inspection revealed that the throttle control arm had spun on the air/throttle shaft.

Narrative: I was on the last leg of a VFR cross country at night. Approach cleared me into the Class B for the transition to ZZZ; where the FBO is located. Upon clearing me into the Class B; the Approach Controller also descended me to 4;000 out of 4;500. As I eased the throttle lever back in order to descend the aircraft; I noted that the engine RPM indicator did not show a decrease. I thought this may simply be due to the fact that the aircraft was descending and the prop was keeping engine RPM's up. I realized as soon as I leveled off at 4;000 that this was not the case; as the RPM's were stuck around 2;700 in level flight; no matter what position I moved the throttle lever into. After fiddling with the lever for a minute or so with no success; I explained the problem to Approach. They indicated their readiness to help; before handing me off to another Approach Controller who was aware of the situation. I explained to this Controller that I would need to descend early so that I could level off and dissipate some of the high speed that I would naturally accrue in a full-power descent. The Controller gave me a vector to intercept the final approach course into ZZZ and asked for fuel and souls aboard. The airport was easy to spot with all the fire trucks at night. The Controller handed me off to Tower. I leveled off at about 1;000 AGL and turned final. I judged that I should cut the mixture off about 2 miles out at 1;000 AGL; which would allow the speed to dissipate to roughly 73 KIAS for the landing. I had a GPS distance to the center of the field and also asked the Tower Controller to call my 2 NM from threshold on final. Upon reaching what I assessed was about 1.8 NM from the threshold; I pulled the mixture and engine power ceased immediately. The aircraft slowed rapidly and it became clear within a few seconds that I would not reach the threshold of the runway. I adjusted my plan for a soft field landing on the airport grass short and left of the threshold. I moved laterally left about 100 FT so as not to land on the rabbit. What ensued was a routine soft field landing with very aggressive braking. Once stopped; I pulled the emergency fuel shut-off valve; killed all electrics; and evacuated the aircraft. No damage was done to the aircraft in the course of the flight; approach; or landing as a result of the malfunctioning throttle.

Data retrieved from NASA's ASRS site as of July 2013 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.