Narrative:

We departed and climbed to approx. 3000 ft. And orbited the runway for 3-4 patterns at that time we began to climb to 5000 ft.; after several orbits we began a downwind to base turn and I observed the manifold pressure indicator decreasing. I made an immediate turn to the runway and adjusted the throttle. The manifold pressure gauge did not react to throttle inputs. At that time I setup for best glide and changed from the right fuel tank to the left fuel tank. At some time in the guide it appeared to me that we would be high; so I extended the gear. Prior to the approach end of [the runway] is a set of train tracks and a set telephone wires. As we got closer to the airport I was not sure I was going make the runway. I had a field to my left so I choose to put the aircraft down in the field. I made a turn to align with the borrows in the field and extended flaps. After touchdown the engine was observed to still be running; I again adjusted the throttle with no observed change in engine operation. The cowl panel was removed and the throttle cable linkage was observed to be loose. The linkage was reinstalled and an engine run-up was performed. All parameters appeared to be normal. I performed a test taxi and then parked the aircraft in the corner of the field for inspection.

Google
 

Original NASA ASRS Text

Title: A Beechcraft M35 pilot lost manifold pressure while descending and turning downwind to base leg. He immediately turned toward the runway while noticing that the manifold pressure gauge did not respond to throttle inputs and landed in a field near the airport. Upon inspection; the throttle cable linkage was observed to be loose.

Narrative: We departed and climbed to approx. 3000 ft. and orbited the runway for 3-4 patterns at that time we began to climb to 5000 ft.; after several orbits we began a downwind to base turn and I observed the Manifold pressure indicator decreasing. I made an immediate turn to the runway and adjusted the throttle. The manifold pressure gauge did not react to throttle inputs. At that time I setup for best glide and changed from the right fuel tank to the left fuel tank. At some time in the guide it appeared to me that we would be high; so I extended the gear. Prior to the approach end of [the runway] is a set of train tracks and a set telephone wires. As we got closer to the airport I was not sure I was going make the runway. I had a field to my left so I choose to put the aircraft down in the field. I made a turn to align with the borrows in the field and extended flaps. After touchdown the engine was observed to still be running; I again adjusted the throttle with no observed change in engine operation. The cowl panel was removed and the throttle cable linkage was observed to be loose. The linkage was reinstalled and an engine run-up was performed. All parameters appeared to be normal. I performed a test taxi and then parked the aircraft in the corner of the field for Inspection.

Data retrieved from NASA's ASRS site 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.