A BE33 pilot experienced engine surging descending on a practice instrument approach. He elected to ...

Attributes
ACN	843934
Time
Date	200907
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Bonanza 33
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Other GPS rwy XX
Flight Plan	None
Component
Aircraft Component	Reciprocating Engine Assembly
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Instrument Flight Crew Commercial
Experience	Flight Crew Last 90 Days 11.7 Flight Crew Total 1723 Flight Crew Type 1216.6
Events
Anomaly	Aircraft Equipment Problem Critical

Narrative:

When powering back for descent from 2400' to 1900' for practice instrument approach; engine sagged and seemed to lose power with minor decrease of manifold pressure. Noticed fuel flow drop and a drop in RPM. Applied full power and engine surged. Could not re-establish smooth running engine. Engine would either surge or sag. Decided to land in soybean field as I could not hold power and felt I could not make it back to the airport which was about twelve miles ahead and I was concerned about crash landing in trees if I attempted to fly back to airport. Landed in recently planted soybean field; which was flat; with firm surface and about 4000 ft long. No damage to aircraft; no injuries to pilot and no property damage except running over some 3 ft soybean plants. Field inspection done by mechanic. Found induction air leak due to loose clamp and readjusted low throttle settings. Engine test run on ground and found to operate okay. Aircraft departed field without incident.

Original NASA ASRS Text

Title: A BE33 pilot experienced engine surging descending on a practice instrument approach. He elected to land in a field to avoid the possibly crashing in trees while trying to reach the airport.

Narrative: When powering back for descent from 2400' to 1900' for practice instrument approach; engine sagged and seemed to lose power with minor decrease of manifold pressure. Noticed fuel flow drop and a drop in RPM. Applied full power and engine surged. Could not re-establish smooth running engine. Engine would either surge or sag. Decided to land in soybean field as I could not hold power and felt I could not make it back to the airport which was about twelve miles ahead and I was concerned about crash landing in trees if I attempted to fly back to airport. Landed in recently planted soybean field; which was flat; with firm surface and about 4000 FT long. No damage to aircraft; no injuries to pilot and no property damage except running over some 3 FT soybean plants. Field inspection done by mechanic. Found induction air leak due to loose clamp and readjusted low throttle settings. Engine test run on ground and found to operate okay. Aircraft departed field without incident.

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.