CEN18LA032

The pilot's improper in-flight fuel management and reliance on a faulty fuel gauge, which resulted in fuel starvation during approach for landing, and his failure to follow the emergency checklist after losing engine power.

The public aircraft aerial survey flight with a commercial pilot and three survey crewmembers had a planned duration of 1 hour 45 minutes. The pilot stated that the airplane departed with full fuel in the left- and right-wing fuel tanks, which provided a usable fuel capacity of 36.5 gallons per tank. His fuel consumption calculations for the flight determined that a total of 27 gallons would be used for 1 hour 30 minutes of flight; he stated that he planned to use fuel from the left fuel tank for 1 hour 30 minutes and then switch to the right fuel tank. After 1 hour 30 minutes of flight time, when the airplane was 10 minutes from the destination, the pilot observed the left fuel gauge "rapidly shifting from full to 1/4." The pilot had observed similar indications before with the left gauge, as it was "often stuck at a full reading then flicked back and forth between full and the actual fuel level," on previous flights; he thought there was 1/4 tank of fuel remaining. He planned to switch to the right fuel tank when he entered the airport traffic pattern. When the airplane entered the base leg, the engine sputtered before the pilot switched fuel tanks. The pilot then selected the right fuel tank, pushed the throttle control full forward, and selected the auxiliary fuel pump to HI and then LOW; the engine continued to sputter. He did not follow the airplane manufacturer's emergency checklist for engine failure restart, which instructed to select the auxiliary fuel pump switch to ON, select the fuel tank containing fuel, position the throttle to half open, and then turn the auxiliary fuel pump switch off. Unable to restart the engine, the pilot chose a road for a forced landing. During his approach, the stall warning horn sounded periodically and the airspeed indicated 65 knots, which was below the recommended engine-out glide airspeed of 80 knots. The pilot lowered the airplane's nose to increase airspeed, and the airplane descended "rapidly." He was still unable to restart the windmilling engine. When the airplane was over the road, he fully extended the flaps and then veered the airplane right to land in the dirt next to the road to soften the landing. The airplane sustained substantial damage to the nose landing gear and fuselage. Postaccident examination of the airplane revealed that the left fuel tank contained no useable fuel, and the right tank contained full fuel. Further examination of the fuel system found that the left fuel quantity transmitter did not move smoothly from the upper stop to the lower stop and repeatedly stuck in place. There was no evidence of other preimpact engine or fuel system malfunctions or failures that would have precluded normal operation. Two of the survey crewmembers reported that they had witnessed a similar discrepancy with the left fuel gauge during flights 7 months before the accident. However, no writeups of the discrepancy were made. The airplane had annual and 50-hour inspections less than 1 month before the accident; the airplane service manual called for troubleshooting of the fuel gauges at these inspections. However, maintenance personnel were not aware of the discrepancy with the left fuel gauge and, therefore, did not troubleshoot it and identify that the transmitter needed replacement. Regardless, the pilot did not manage the fuel properly by switching fuel tanks when he planned and instead continuing toward his destination for another 10 minutes, relying on a faulty fuel gauge, which led to the fuel tank he was using becoming devoid of fuel, which led to fuel starvation. Further, once the airplane lost engine power, he did not follow the emergency checklist procedures for restoring power.

HISTORY OF FLIGHT On November 15, 2017, at 1515 mountain standard time, a Cessna T207A, N9825M, experienced a total loss of engine power and impacted terrain during a forced landing about two miles west of Rock Springs-Sweetwater County Airport (RKS), Rock Springs, Wyoming. The airplane sustained substantial damage. The commercial pilot and one survey crewmember received minor injuries, and two survey crewmembers received serious injuries. The airplane was registered to Slickrock Air Guides Inc and operated by Aerowest Aviation, dba Redtail Air Inc under Title 14 Code of Federal Regulations Part 91 as a public-use aerial wild horse and burro survey flight for the Bureau of Land Management (BLM). Visual meteorological conditions prevailed at the time of the accident. The flight originated from Miley Memorial Field Airport (BPI), Big Piney, Wyoming at 1320 and was returning to RKS after having completed the aerial survey. The pilot stated he was to fly the three crewmembers on the survey, which he estimated to have a flight duration of 1:45 hours. The fight duration consisted of 1:15 hours for the survey and 30 minutes for the return to RKS. The altitude of the survey portion of the flight was 1,000 feet above ground level (AGL). He stated the flight departed with full fuel in the left and right fuel tanks for a total of 80 gallons, of which 36.5 gallons were useable in each tank. His fuel consumption calculations for start, taxi, takeoff, climb, and cruise yielded a total of 27 gallons for 1:30 hour of operation. He planned to use fuel from the left fuel tank for 1:30 hours. He stated that the survey was completed about 1:20 hours, and the GPS indicated the return to RKS was 20 minutes. After 1:30 hours of flight time and 10 minutes from the airport, he looked at the left fuel gauge and "it was rapidly shifting from full to ¼." He stated that he had seen this behavior with the left gauge before as it was "often stuck at a full reading then flicked back and forth between full and the actual fuel level," when the fuel level in the tank was lower. He thought there was ¼ tank of fuel remaining and planned to switch to the right fuel tank upon entry into the airport traffic pattern. The airplane was on a base leg about 3.5 miles from runway 9, about 900-1,000 feet AGL (700 feet above airport elevation) when the pilot was going to select the right fuel tank. Just before he switched to the right fuel tank, the engine sputtered. The pilot then selected the right fuel tank, pushed the throttle control full forward, and selected the auxiliary fuel pump to HI and then LOW, but the engine continued to sputter. He looked for a place to land and turned toward State Highway 370 for a forced landing. During the approach to the road, the stall warning horn sounded; the pilot looked at the airspeed indicator and saw it indicated 65 knots. He lowered the airplane nose to increase airspeed, and the airplane was "descending rapidly." He was unable to restart the wind-milling engine with periodic selection of the auxiliary pump HI setting and by using the engine starter. The pilot stated that the stall warning horn would sound periodically, which prompted him to lower the airplane nose each time. When the airplane was over the road, he extended the flaps to full. He realized it was going to be a hard landing when the airplane was close to the road surface. He veered the airplane right to land in the dirt next to the road to soften the landing. A United States Geological Service (USGS) employee, who was seated behind the pilot in the aft left seat, stated the engine sputtered and quit while the airplane was about 700 feet AGL, and he heard the stall warning horn when the airplane was about 200 feetAGL. He said that another one of the operator's pilots that flew the accident airplane the first week of the survey would use fuel from the right fuel tank for an hour then use fuel from the left fuel tank. The employee stated that the accident pilot would use fuel from the left fuel tank until it was empty and then use fuel from the right fuel tank. A BLM employee, who was seated in the right front seat, stated that he did not hear the stall warning during the accident flight. He witnessed the same procedure used by the accident pilot in fuel management as reported by the USGS employee. PERSONNEL INFORMATION According to the operator's training records for the pilot, the pilot began employment for the operator on April 9, 2013 as pilot-in-command (PIC) on Cessna 172 airplanes under Part 135. On April 7, 2014, he began flying as PIC on Cessna 207 airplanes and subsequently as PIC on Quest Kodiak 100 airplanes under Part 135. The pilot passed his last proficiency check, which was a Part 135 proficiency check that was 0.8 hours in duration, using a Cessna 207 airplane. The check airman for the proficiency check was the operator's director of operations, who was also a FAASTeam Representative. The records showed that the operator provided all the pilot's ground and flight training prior to the accident. AIRCRAFT INFORMATION The airplane was a 1981 Cessna T207A operated and maintained by Aerowest Aviation, dba Redtail Air Inc. In addition to its Part 91 operations, the airplane was also operated and maintained under a Part 135 air carrier and operator certificate. Aircraft Maintenance Information The airplane and engine underwent their last annual inspections, dated October 27, 2017 and were performed by Red Tail Aircraft Services, Moab, Utah. The tachometer time of the inspections was 4,007.2 hours, the airframe total time was 12,990.9 hours, and the engine time since major overhaul was 1,024.3 hours. A 50-hour inspection of the airplane, dated November 13, 2017, was performed by the Red Tail Aircraft Services at a tachometer time of 4,047.3 hours. The Hobbs and tachometer indications at the time of the accident were 9,395.9 hours and 4,057.3 hours, respectively. The USGS employee stated he witnessed the same discrepancy of an inoperative fuel gauge on previous survey flights flown in April 2017. The BLM employee stated that he witnessed the left fuel gauge as inoperative on previous flights flown in April 2017. On September 23, 2003, the FAA issued a Revised Special Airworthiness Information Bulletin (SAIB) CE-03-43R1, which updated information issued in SAIB CE-03-43, dated June 27, 2003. The SAIB, which was not mandatory, informed owners or operators of Cessna model 100, 200, 300, and 400 series airplanes, that a safety concern exists regarding resistance and capacitance-type fuel quantity gauging systems. The SAIB recommended an FAA-certificated mechanic or repair station accomplish the detailed calibration procedure within the next 100 hours of operation or at the next annual. Further, the calibration procedure should be repeated by a properly FAA-certificated mechanic or repair station at 5-year intervals or any time the fuel gauging system components are disturbed or accuracy is suspect. According to the Cessna 207 and T207 Series Service Manual, the fuel quantity indicators and transmitters were to be inspected after a 50-hour and 100-hour/annual inspection. Section 16-50 of the manual, Troubleshooting – Fuel Quantity Transmitters, lists in part: Part 91.205, Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements, stated in part, that no person may operate a powered civil aircraft with a standard category U.S. airworthiness certificate in any operation under visual flight rules unless that aircraft had a fuel gauge indicating the quantity of fuel in each tank that was in an operable condition. According to the FAA principle maintenance inspector assigned to the operator, the operator's maintenance personnel were never notified nor were there any write ups prior to the accident regarding the left fuel gauge in the flight logs, as required by Part 13