Date: 201812
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: RV-4
Operator: Personal
Operating under: Part 91
Flight plan: None
Mission: Training
Flight phase: Takeoff / Launch
Airspace: Class C ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Engine
Component problem: Failed
Reporter organization: Personal
Reporter function: Instructor; Pilot Not Flying
Reporter qualification: Flight Crew Flight Instructor; Flight Crew Instrument; Flight Crew Multiengine
Human factors: Situational Awareness
Second reporter function: Pilot Flying
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Other / Unknown; Ground Excursion Runway; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Landed in Emergency Condition; Flight Crew Took Evasive Action
Contributing factors: Aircraft; Human Factors
Primary problem: Aircraft

Narrative: I was the flight instructor for a training mission for a tail wheel endorsement with a private pilot in his Vans RV4. Departed ZZZ; transitioned to ZZZ1 for longer wider runways. We had made 4 landings on Runway XX; changed to XYR; made one landing with the intention of returning back to ZZZ on departure of XYR. Engine quit about 200-300 AGL (I was in the rear of the plane and could not see the altimeter); I called that I had the aircraft; the private pilot confirmed and I then informed ZZZ1 Tower that I was engine out and would be landing on the parking ramp for the passenger terminal; had a significant tailwind and was unable to stop on the ramp; picked up to miss taxiway lights and a drainage ditch; continued across grass to the east ramp. No damage to aircraft or property and no injuries to either of us. After the plane was moved; we determined that there was a piece of something stuck under the o-ring of the right hand tank fuel sump as there were blue streaks under the right wing. Fuel sump still drained fuel at this point when activated and the gauge showed 2-3 gallons. Had the FBO add 10 gallons to that tank; it then showed 16 gallons at rest and 13 after a short taxi. I figure the loss of engine power was fuel starvation due to a leaky sump; and between not watching gauges closely enough even though we had been airborne an hour or less and maybe inaccurate gauges it was not caught in a timely manner. Will certainly be more aggressive on telling lower time pilots to keep an eye on fuel quantities regardless of time flow thus far on the mission.


Second narrative: I went out with my instructor for a training mission for my tail wheel endorsement in my Vans RV4. We departed ZZZ with about 17 gallons of fuel to ZZZ1 and did 4 landings on Runway XX for longer wider runways. After a few practices we switched to XYR to practice cross wind. We did 1 landing on XYR and departed with intentions on going back to ZZZ. At about 200 AGL the engine quit and my instructor took over from the back seat. He informed Tower that we had an engine out and would be landing on the terminal ramp. As we came down; we were too fast to stop on the terminal ramp so he picked up to avoid a ditch and obstacles and stopped it on the east ramp. There was no damage to any property or aircraft; and no injuries to either of us. Once stopped; we pushed the plane to [the FBO] to do a report with the airport. After further inspection of the plane we found some trash and gunk in the right hand side fuel sump o-ring along with blue streaks under the wing. The sump continued to drain and the fuel gauge read about 2 gallons still. We had [the FBO] add 10 gallons to that tank and then the gauge read about 15-16 gallons and then 13 gallons after taxi. We determined that the loss of power was due to fuel starvation. This happened because of fuel drainage through the leaking fuel sump and not being caught because of the misreading fuel gauges. In the future I will definitely be more cautious and aware of how much fuel we have on board knowing that the fuel gauges are inaccurate.


Synopsis: RV4 pilot and flight instructor reported a loss of engine power and off runway landing due to fuel leak and fuel starvation.