Cessna Single Piston Undifferentiated or Other Model
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial
Flight Crew Last 90 Days 22.7; Flight Crew Total 2861.3; Flight Crew Type 7.8
Situational Awareness
Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue
Flight Crew Landed in Emergency Condition
Procedure; Human Factors; Aircraft
Prior to the incident; I received an instructional ride and completed my C-172 checkout. I then flew with a passenger and solo; for a total of 5.3 hours in the bird. In all three of those flights; I observed erroneous fuel quantity indications; including intermittent cycling of the gauges to zero and LH Fuel Low Level Warning light coming on intermittently. An [instructor] told me this condition was well known; typical for this aircraft and not uncommon for general aviation aircraft. I discussed the erroneous fuel quantity indications with the Chief Pilot; and asked him if I should write them up. He said no; that the indications were within the spec; which requires only that they read accurately when empty.The purpose of [this] flight was to complete my mountain flying checkout. I was in the left seat and my instructor pilot occupied the right seat. Our plan was to fly from [base] Airfield to [intermediate] Airfield; then plan our return leg based on existing and forecast weather in the...mountains; while attempting to fulfill the requirements (3 hours in the mountains and 3 landings at high altitude airfields) for the checkout.... We preflighted the aircraft and paid special attention to the fuel load as we would be flying for a total 3 hours and 30 minutes; longer than a typical aero club flight; but required to complete the mountain flight checkout. [The instructor] checked fuel levels at the filler caps in the right and left wing tanks. A full load of fuel (52 gallons) was physically confirmed; and the fuel quantity gages indicated full. From this we knew we had about 46 gallons of usable fuel. According to the performance charts in the pilot/operators manual; we should expect at least 4 hours and 30 minutes of endurance. [After departure] we paid special attention to fuel flow; including leaning to approximately 9 GPH. We also kept a close watch on the fuel quantity indicators. Due to the aforementioned erroneous fuel quantity indications; we knew to take the fuel quantity indications with a 'grain of salt' and rely on fuel flow and performance calculations to maintain fuel quantity awareness. During the outbound leg; I noticed occasional intermittent fuel quantity indications of zero; and an occasional left fuel quantity low warning light illuminated. This was consistent with what I had observed on past missions. We negotiated [several] passes without incident; landing at [a...] County Airport in accordance with established mountain flying procedures; we did not take on fuel. This would improve our climb performance and increase our maximum attainable altitude so that we could safely clear mountain passes on the second and final leg of our flight. As we had used a few minutes less than an hour of our endurance; we knew we had at least 3 hours and 30 minutes of fuel remaining. We headed south and climbed to 13;500 FT MSL Fuel flow remained around 9 gallons per hour; but the fuel quantity indicators continued their intermittent erroneous readings; sometimes displaying half full; other times displaying empty. We did a touch and go at [an airfield]; then headed back east; climbing to 13;500 FT. Level off checks were performed according to the checklist. [The instructor] became increasingly concerned about the fuel on board the aircraft. We observed not only the fluctuating fuel quantity readings mentioned above; but now also the right fuel low level warning light. I checked the Pilot's Operating Handbook (POH) to confirm that the fuel low level warning lights come on steady at 9 gallons (6 gallons usable) fuel remaining in each tank. This should have given us at least one more hour of endurance. We established a course direct to [the...] Airfield. When within radio contact we informed the Aero Club that we were planning a precautionary approach using the shortest route to the airfield. We began a descent to the traffic pattern altitude and established ourselves on a left base. I was flying the airplane; as Ihad most of the flight. As I was modulating the throttle and lowering flaps; not more than a minute from touchdown; we both noticed a loss of engine thrust and realized there was no longer any response to throttle inputs. [The instructor] took control of the airplane; and I initiated an air start with the propeller windmilling. The air start was unsuccessful. With the strong headwind and no engine thrust; we successively realized we would not make the airfield. [The instructor] elected to dead stick the airplane into a (not so) grassy field. [The instructor's] short field; soft field and dead stick landing techniques were absolutely outstanding. We rolled to a stop in an estimated 500 FT.Evidently the flameout was due to fuel starvation. This is despite a total Hobbs meter reading for the day of only 3 hours and 30 minutes. A post flight inspection revealed no fuel in the right wing and little if any usable fuel in the left wing. If this is correct; the airplane ran out of fuel more than an hour earlier than advertised. It is unfortunate that the fuel quantity indications were suspect; but we thought we knew where we were fuel-wise using careful flight planning; physical inspection of the fuel quantity in each wing; close monitoring of fuel flow in the cockpit and careful in-flight calculations. Another minute or two of fuel and we would have made it safely to the airfield.
C-172 instructor and student pilot flying an aircraft with known fuel gauge problems; landed off-field near their destination due to fuel starvation. Although the fuel quantity was visually confirmed prior to departure; the aircraft flew approximately one hour less than standard burn rate would predict.