C172 student pilot with instructor experience a rough running engine during approach. The instructor...

Narrative:

Fuel added 14.15 gallons; estimated flight duration 2 hours. Estimated fuel needed: 14 gallons; 12 gallons for cruise flight and 2 gallons for taxi; run-up; and climb. Total fuel on board: 19 gallons; visual verification. Estimated fuel consumption: 6 gallons per hour. Departed on a VFR flight and the crew of the airplane was the owner/student pilot; and an instructor pilot. Approximately two (2) miles from the destination airport; we received landing clearance. Our altitude was 1;900 ft MSL and we were on a modified right base entry per the tower's instructions. The airplane's engine began to run rough. The student pilot was controlling the airplane. As the instructor pilot; I took control of the airplane and elected to make a precautionary landing on a road just short of the airport runway. The precautionary landing did not damage the airplane and no one was injured either in the airplane or on the ground. No other property was damaged. During the time the engine was running rough; I accomplished the following: 1. Mixture full rich 2. Carburetor heat on 3. Check fuel selector and selected the fullest tank; left tank. 4. Continued to pump the throttle. 5. Moved the fuel selector to the other positions with no appreciable change in engine power. Engine continued to run during this time with surges; but did not regain sufficient power to sustain level flight to reach the airport. Precautionary landing was accomplished on a dirt road. After stopping; the airplane's engine continued to run at idle. Radio calls were completed and we shut the airplane down. The FAA arrived at the precautionary landing area and the airplane and obtained their needed information. The mechanics from the local FBO inspected the airplane and drained a total of 3 gallons of fuel from the airplane. Fuel was added to the airplane; and operational check was completed; permissions from the authorities; land owners; and insurance company were received and the airplane was flown from the precautionary landing area to the airport without further incident.

Original NASA ASRS Text

Title: C172 Student pilot with Instructor experience a rough running engine during approach. The instructor assumes control and lands on a farm road short of the airport. Three gallons of fuel were found to be on board when maintenance came to inspect the aircraft.

Narrative: Fuel added 14.15 gallons; estimated flight duration 2 hours. Estimated Fuel needed: 14 gallons; 12 gallons for cruise flight and 2 gallons for taxi; run-up; and climb. Total fuel on board: 19 gallons; visual verification. Estimated fuel consumption: 6 gallons per hour. Departed on a VFR flight and the crew of the airplane was the owner/student pilot; and an instructor pilot. Approximately two (2) miles from the destination airport; we received landing clearance. Our altitude was 1;900 FT MSL and we were on a modified right base entry per the Tower's instructions. The airplane's engine began to run rough. The student pilot was controlling the airplane. As the instructor pilot; I took control of the airplane and elected to make a precautionary landing on a road just short of the airport runway. The precautionary landing did not damage the airplane and no one was injured either in the airplane or on the ground. No other property was damaged. During the time the engine was running rough; I accomplished the following: 1. Mixture full rich 2. Carburetor heat on 3. Check fuel selector and selected the fullest tank; left tank. 4. Continued to pump the throttle. 5. Moved the fuel selector to the other positions with no appreciable change in engine power. Engine continued to run during this time with surges; but did not regain sufficient power to sustain level flight to reach the airport. Precautionary landing was accomplished on a dirt road. After stopping; the airplane's engine continued to run at idle. Radio calls were completed and we shut the airplane down. The FAA arrived at the precautionary landing area and the airplane and obtained their needed information. The mechanics from the local FBO inspected the airplane and drained a total of 3 gallons of fuel from the airplane. Fuel was added to the airplane; and operational check was completed; permissions from the authorities; land owners; and insurance company were received and the airplane was flown from the precautionary landing area to the airport without further incident.

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.

Attributes
ACN	991251
Time
Date	201201
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Skyhawk 172/Cutlass 172
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Direct
Flight Plan	None
Component
Aircraft Component	Reciprocating Engine Assembly
Person 1
Function	Instructor
Qualification	Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Commercial Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 80 Flight Crew Total 2500 Flight Crew Type 1000
Person 2
Function	Trainee Pilot Flying
Qualification	Flight Crew Student
Experience	Flight Crew Last 90 Days 4 Flight Crew Total 65 Flight Crew Type 65
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Fuel Issue

C172 student pilot with instructor experience a rough running engine during approach. The instructor assumes control and lands on a farm road short of the airport. Three gallons of fuel were found to be on board when maintenance came to inspect the aircraft.