Date: 201401
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 25
Light: Daylight
Aircraft: Skyhawk 172/Cutlass 172
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Cruise
Airspace: Class E ZZZ
ATC / advisory: TRACON ZZZ
Aircraft component: Engine
Component problem: Malfunctioning
Reporter organization: Personal
Reporter function: Pilot Flying; Single Pilot
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor
Human factors: Distraction; Situational Awareness; Troubleshooting; Workload
Anomaly: Aircraft Equipment Problem Critical
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Diverted; Flight Crew Landed in Emergency Condition; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action; General Declared Emergency
Contributing factors: Aircraft
Primary problem: Aircraft

Narrative: I was on a cross country flight that was to last 2 hours in a Cessna 172. We left for the trip with approximately 38 gallons on board as visually checked. We left at approximately noon and flew to a distant airport near Class B Airspace. I was flying back to home base and at approximately 15 miles from home base the engine started to run rough and lose power. I took over controls and looked at fuel indications and started heading into land as we were over the Ocean. I started to troubleshoot and checked fuel supply and engine instruments. The left tank was showing approximately the same level as right about 1/2 full which was about the position I expected it to be on our trip. Engine oil pressure was in the green range and oil temperature was also in the green but dropping I tapped on the fuel indicator for the left tank and it dropped slightly just over 1/4 indication. The right tank indication didn't change. I applied Carburetor heat; checked the magnetos and primer to make sure that I was locked in. Then I switched to the right tank and the engine started to run again and I continued to the closest suitable airport for inspection. The engine ran for approximately 5-7 minutes and I tried to gain altitude without giving up airspeed.   As I was approaching the divert airport the engine quit again. I then decided that I would have to stretch the glide in order to make the airport and it was not worth the risk to make divert airport and I decided to make an off field landing for the safety of the flight. I looked out for a suitable landing site and I noticed that I could make it to a military air strip ramp. I closed the throttle and told Approach that I needed to switch frequencies because I was having engine trouble and need to land at the airstrip. Approach told me to contact the controlling agency and asked me to hold while she looked up the frequency. I informed the Controller that I knew the frequency; switched; called them and told them that I had an engine failure and was landing on the strip. The Controller was talking to another aircraft on UHF then asked me to repeat. I told them what I was doing and stopped transmission to land the aircraft. I was able to land on the landing strip and bring the aircraft to a complete stop without damage to aircraft or injuries to passengers.




Synopsis: A C-172 engine began running roughly on a training flight then quit as the instructor was attempting to return so he landed at the nearest available strip which was a military base.