Date: 201201
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 20
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Personal
Flight phase: Initial Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Reciprocating Engine Assembly
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Instructor
Reporter qualification: Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Commercial
Second reporter function: Pilot Flying; Trainee
Anomaly: Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; General Maintenance Action
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

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.


Second narrative: Two hours after takeoff and on approach for landing; we experienced engine problems and called to the Tower to alert them. We declared an emergency and descended toward a farm field; landing on a farm road approximately 1.5 miles from the airport. No damage was sustained to the air craft. The engine continued to run following the landing.

Second callback: The owner states that adding fuel was the only maintenance action preformed and the aircraft has had no further issues during several flights.

Synopsis: 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.