Date: 201808
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Light: Daylight
Aircraft: Cessna 210 Centurion / Turbo Centurion 210C; 210D
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Test Flight / Demonstration
Flight phase: Final Approach
Airspace: Class D ZZZ
ATC / advisory: Tower ZZZ
Aircraft component: Fuel Selector
Reporter organization: Personal
Reporter function: Pilot Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Human factors: Distraction; Human-Machine Interface; Situational Awareness; Troubleshooting
Second reporter function: Instructor; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Ground Event / Encounter Gear Up Landing; Inflight Event / Encounter Fuel Issue
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Aircraft Damaged; Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; General Flight Cancelled / Delayed
Contributing factors: Procedure; Human Factors
Primary problem: Human Factors

Narrative: My friend; who is a Gold Seal CFII; and I departed to do an engine break-in flight in my Cessna. I was in the left seat. We had waited about 2 hours for the ceilings to lift above 1000 feet so that we would have visual conditions if we were to have an engine failure. My mechanic had flown my Cessna for about 0.5 hours the previous day to do an initial check-out of the newly overhauled engine that he had installed. We climbed VFR until we passed through a broken layer of clouds starting at 1200 feet with tops at 7200 feet and entered a holding pattern while in contact with ATC at 8000 feet. Traffic increased so ATC had us hold north east at 9000 feet. During almost the entire time we were; as intended; within gliding distance of four other airports based on looking at the ForeFlight glide range display. I did note that I was not holding altitude as well as I would like with deviations up to 200 feet; probably from not flying for nearly 8 months. Fuel flow was much higher than I expected as I had to keep the mixture richer than the aircraft manual flow numbers to keep cylinder head temperatures below 400 degrees.We discussed a practice instrument approach; but thought it would put us too far from our destination since our fuel levels were low; and we would need to use lower engine power levels that were recommended by the break-in procedure; so we requested direct. I thought we were on the fullest fuel tank at that time. ATC vectored us further east than we desired before turning us toward the runway a little north of the ILS approach. I should have cancelled IFR and kept high enough to be within gliding range an airport at all times. Flying the ILS certainly does not provide that margin. Instead; I even let myself drop 400 feet lower than the ATC requested altitude while looking for the airport. We were slightly above the glide slope and north far enough that the localizer needle was fully deviated to the left inbound on a Visual Approach. We had the gear extended with an airspeed of about 140 knots (higher than normal 120 knots as break-in procedure specified keep power above 65% if possible and to reduce power slowly).Somewhere about a mile out from the airport; we both thought we heard a little pop; and the engine stopped producing power. There was no response to the throttle; so I pulled the prop back to full coarse pitch; and my friend raised the gear to increase our glide ratio. I raised the nose slightly to reduce speed to about 85 knots (a little over no wind best glide speed; but we had a slight headwind). I was very concerned that we would not make it over the embankment on the west side of the highway; but we managed to clear it by [about] 40 feet. I turned left to avoid the structure supporting the approach lights; remembered to switch fuel tanks; and then leveled the wings for landing. There was no time to extend the gear so I just landed with the gear up; roughly about 35-45 seconds after the engine stopped producing power. The landing did not seem much rougher than some landings I have had on rough gravel strips many years ago. Neither of us had any physical injuries at all.Fuel flow rates during a break-in procedure may need to be much higher than even the rich of peak expected fuel flows in the aircraft manual in order to keep cylinder head temperatures below the levels that cause cylinder damage. Fuel flow rates were roughly twice the fuel flow rate I use when flying lean of peak with my GAMIjectors. I remembered to switch tanks too late as I assumed it was the newly overhauled engine that had failed. I thought we had switched tanks before leaving the holding area; but apparently I did not because the left tank I switched to had about 10 gallons showing on the fuel gauge and the right tank fuel gauge showed empty when the FAA requested the engine installer to check the fuel after the aircraft was towed back to the hangar. Had I switched fuel tanks immediately after the engine stopped producing power; perhaps the engine would have fired back up in time to prevent my off runway landing if the empty left tank was really the problem. I also forgot to turn the master switch off and crack the aircraft doors before landing. In the future; I will have the emergency procedures memorized before flying because I only had seconds to make decisions.Verbalize checklists while high enough above the ground to allow configuration changes. With another pilot in the adjacent seat; have that pilot verify the configuration matches the checklist. Stay within predicted glide range to an airport with about a 500 feet vertical margin when doing an engine break-in procedure so you are guaranteed to make the runway in the case of a complete engine failure. It also gives the extra time to diagnose what the problem might be. In the case of my aircraft; it is easy to slip it with full flaps and gear down as needed to lose altitude once it is guaranteed that you can make the runway.


Second narrative: The flight was with owner of aircraft to break-in a newly overhauled engine. The owner was flying. We spent about 2 hours flying large holding patterns above several airports in the area; trying to stay within gliding distance of an airport. We did not trust the new engine. About an hour and a half into the flight; I realized we were down to about an hour of fuel remaining; since we were running at very high power and full rich for the break in. My personal habit is to always be on the ground when fuel gets down to an hour; and I explained this to the owner/pilot. For some reason; I let him convince me it was 'OK' and we did one more holding pattern; then got vectors back to the home base for an ILS approach. When we made the decision to continue; an airport with fuel available was right below us in VFR conditions. Why didn't we land and get gas? Because we were focused on the engine break-in! We also could have canceled IFR; since we were in VMC; and simply entered the pattern at the home airport. But instead; we let ATC give us long vectors to a Visual Approach.On Final; about 1 mile from the runway threshold; there was a 'pop' and the engine stopped producing power. We both assumed it was a failure of the new engine; and proceeded with an engine-out landing. The airport is on top of a small [hill]; and we were gliding for impact with the embankment well short of the runway. So; we agreed to raise the gear to improve our glide angle; and pull the prop control back to reduce drag. We cleared the embankment by less than 50 feet; just missed the approach lights for the runway; and came to a stop after skidding 300 feet; and only 600 feet short of the threshold. The time from the 'pop' sound to coming to a stop gear-up on the dirt and grass was no more than 45 seconds. Maybe even only 30 seconds. Neither of us was hurt at all. It has not been determined was caused the power loss. Maybe a mechanical problem? May running a tank dry?How to prevent this? Nearly all of our focus was on performing the engine break-in; which caused us to ignore simple; basic flying practices; like having lots of fuel. We didn't even keep the idea of not trusting the engine at the front of our minds; on final approach; we could have come in at a much steeper angle so a glide to the runway was assured; but instead we flew a 'standard' ILS.


Synopsis: C210 pilot and flight instructor reported landing short of the runway due to mismanagement of the fuel system.