After reducing power, throttle wouldn't respond to power increase. Aircraft landed in field.

Attributes
ACN	327297
Time
Date	199602
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : gsh
State Reference	IN
Altitude	agl bound lower : 0 agl bound upper : 2800
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : ont
Operator	general aviation : instructional
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Operating Under FAR Part	Part 91
Flight Phase	cruise other descent other landing other
Flight Plan	VFR
Person 1
Affiliation	Other
Function	instruction : trainee
Experience	flight time total : 44
ASRS Report	327297
Person 2
Affiliation	Other
Function	instruction : instructor
Qualification	pilot : cfi pilot : commercial pilot : instrument
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Went to reduce power for slow flight practice, throttle set at 1700 RPM, but wouldn't respond when pushed forward. In process of trying to restore power went to 1200 RPM. Found it necessary to land in corn field. When emergency landing was eminent instructor took controls over. Landed plane with no injury to instructor, myself or damage to aircraft. Problem has not been determined at this time.

Original NASA ASRS Text

Title: AFTER REDUCING PWR, THROTTLE WOULDN'T RESPOND TO PWR INCREASE. ACFT LANDED IN FIELD.

Narrative: WENT TO REDUCE PWR FOR SLOW FLT PRACTICE, THROTTLE SET AT 1700 RPM, BUT WOULDN'T RESPOND WHEN PUSHED FORWARD. IN PROCESS OF TRYING TO RESTORE PWR WENT TO 1200 RPM. FOUND IT NECESSARY TO LAND IN CORN FIELD. WHEN EMER LNDG WAS EMINENT INSTRUCTOR TOOK CTLS OVER. LANDED PLANE WITH NO INJURY TO INSTRUCTOR, MYSELF OR DAMAGE TO ACFT. PROB HAS NOT BEEN DETERMINED AT THIS TIME.

Data retrieved from NASA's ASRS site as of July 2007 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.