Date: 201704
Local time of day: 1801-2400
Location: ZZZ.Airport, US
Flight conditions: VMC
Weather elements / visibility: 20
Light: Night
Aircraft: DA20 Undifferentiated
Operator: FBO
Operating under: Part 91
Flight plan: VFR
Mission: Training
Flight phase: Final Approach
Airspace: Class E ZZZ
ATC / advisory: TRACON ZZZ
Reporter organization: FBO
Reporter function: Instructor; Pilot Not Flying
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor
Human factors: Situational Awareness; Training / Qualification
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; General Maintenance Action
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: A chain of events led to a situation where our aircraft ran out of fuel as my student and I turned final to land. The chain began in the planning stages of the flight when researching FBOs at the destination airport. Prior experience taught me that there are two FBOs and that one of them closes early. I helped my student to identify that FBO; and we made plans to taxi to the opposite site. What we failed to discover until we arrived was that the second FBO also closes [in the late evening]. We arrived [after they closed] to find a darkened building and no access to fuel. This was a detail I should have caught before we ever left the building.The second link in the chain of events was my student's unpreparedness. I had instructed him to arrive two hours early to finish his planning; and that I would arrive one hour prior to review his planning; authorize the flight; let him file his flight plan; be dispatched a plane; and go preflight it. My student didn't arrive until I did; thinking he would be able to quickly finish his planning and accomplish all the other tasks. It took him longer than he thought; and we were not airborne until [later in the evening than planned].The third link was my erroneous decision making when faced with how to solve the problem at [the airport with no fuel available]. I dipped the tank and found that having started the flight with 12 gallons of gas; we now had 6 gallons. This meant that we had spent 6 gallons to get [there]. It had taken us approximately 1 hour from takeoff to shut down in front of the closed FBO. This fairly closely matched my student's calculations. My student's calculations showed that with the prevailing winds; it should take us approximately 30 minutes to do the reverse trip. If I had 6 gallons left; and it was only going to take 30 minutes; I should have 30 minutes in reserve. What I failed to remember was that night reserve regulatory requirements are 45 minutes; not 30. I decided we had enough gas to get back home; unwittingly breaking a federal regulation.These three things were errors committed that were under my control that I take full responsibility for as the PIC of the flight. One thing that was out of my control that lured me into a false sense of security was the gas gauge. Before we left; we dipped the tank and had 12 gallons. When we started the engine; the gauge showed exactly half a tank. When we landed; we again dipped the tank and found 6 gallons. When we started the plane again; the gauge showed exactly 1/4 tank. In a 24-gallon tank; these gauge readings were perfect. My reasoning led to the conclusion that I would have 3 gallons left; or 30 minutes of reserve fuel; or 1/8 of a tank when I arrived [back home]. 1/8 tank is exactly what the fuel gauge showed when I landed. Despite the seemingly trustworthy fuel gauge showing 1/8 tank; I was; in fact empty when I turned final. By luck alone was I able to keep the engine sputtering enough to drag us across the threshold line. The engine stopped rotation the moment the wheels touched down.This experience has taught me some lessons. First; if my student is not prepared to take off at the specified time; allowing him to finish and leave late only encourages rushing. Rushing is how things get missed and errors are made. In the future; I will be more willing to cancel a flight due to inability to be prepared to leave on schedule. Second; I need to be more involved in ensuring my student has done all the necessary research about an unfamiliar airport. I made assumptions about a class C airport having 24-hour attendance that proved to be untrue. I knew that the tower closed [in the late evening]; but my assumption was that the FBO would remain attended. Third; even though I have been repeatedly warned about 'get home-itis'; I still fell prey to this phenomenon. I found myself with a problem when we were denied access to fuel; and I felt I had to come up with a way to get us home. I feared reprisal if I left the plane 75 NM from home overnight. I made too many assumptions about the fuel required to return home; and even failed to consider the regulatory requirements for reserve fuel for VFR night flight. I had my iPad with Foreflight with me which would have been a great resource to find an airport with 24 hour 'self-serve' fuel in the close vicinity. I could have even opted to stop at [another airport close to departure airport]. Even if [they were] closed and fuel was unavailable; we still could have left the plane there and gotten a taxi home. 'Get home-itis' blinded me to any of these options.As a result of this occurrence; the plane has been grounded to inspect the calibration on the fuel gauge since it didn't show empty when the tank was empty. I have also been grounded by my flight school pending a review of this occurrence and remedial training that may be found necessary.




Synopsis: DV20 instructor pilot reported the engine quit due to fuel deprivation while turning final.