History of Flight
On April 22, 2019, at 0851 central daylight time, a Beech 58 airplane, N501CE, was substantially damaged when it was involved in an accident near Kerrville Municipal Airport (ERV), Kerrville, Texas. The pilot and five passengers died. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 business flight.
According to airport surveillance video from West Houston Airport (IWS), Houston, Texas, the pilot accomplished an abbreviated preflight inspection of the airplane, during which he appeared to visually check the exterior left-wing fuel level sight gauge but not the right-wing fuel level sight gauge; the pilot did not sump any of the 10 fuel drains. The pilot returned to the terminal to meet the passengers, and after both engines were started, the airplane departed about 0730.
According to air traffic control (ATC) and automatic dependent surveillance-broadcast (ADS-B) information, after departing IWS, the pilot obtained an instrument flight rules (IFR) clearance and was instructed to climb to 3,000 ft mean sea level (msl). The flight proceeded toward ERV, climbing to a cruise altitude of 6,000 ft msl. About 0824, the pilot requested the RNAV (GPS) instrument approach for runway 12 and was cleared for the approach via a procedure turn and to descend to 4,000 ft. About 0833, the pilot reported his descent to 4,000 ft and the controller advised that "bases were 2,400," which the pilot acknowledged.
About 0839, the pilot was cleared for the GPS instrument approach to runway 12 and instructed to maintain 4,000 ft to the initial fix for the approach (OBUCO). Once the airplane was in-bound to the airport, about 0843, the controller directed the pilot to switch to the ERV advisory frequency, which was unmonitored. The GPS instrument approach profile for runway 12 included a descent to 3,300 ft msl at 5.3 nautical miles from the runway.
According to ADS-B data, the airplane maintained an altitude of 3,900 ft until about 0844:59, when it began a steady descent; the airplane was about 13 miles from the runway. Data from the airplane's engine data monitor (EDM) indicate that the left engine lost power about 0845 followed by the right engine about 10 seconds later. ADS-B data indicated that the airplane steadily descended well below the approach profile.
EDM data indicated that, about 40 seconds after losing power, the left engine regained near full power, which it maintained until the end of recorded EDM data about 0851. ADS-B data indicated that the airplane slowed below the minimum controllable airspeed (Vmc) of 83 knots as it descended from about 500 to 300 ft agl, and the descent rate decreased. A witness on the ground saw the airplane on final approach at a low altitude, when it entered a right turn, began a right spiral, and disappeared behind a ridge line.
Aircraft Information
The airplane's fuel system comprised three fuel cells and one wet tip tank for each wing. Total fuel capacity was 200 gallons. The fuel cells and wet tip tanks were interconnected. Fuel quantity was measured by float-type units. Fuel level sight gauges on the leading edge of each wing only indicated fuel levels from 40 to 60 gallons per wing.
Weight and balance calculations based on passenger weights provided by the medical examiner indicated a takeoff weight of 5,598 lbs with 50 gallons of usable fuel, exceeding the maximum gross weight of 5,500 lbs. The center of gravity was 86.7 inches, outside the acceptable range of 77.7 to 86.2 inches for low fuel conditions.
Meteorological Information
The 1,200 ft agl ceiling reported by the ERV automated weather observation system correlated to a ceiling at the accident site of about 950 ft agl. A pilot who flew an approach to ERV reported 2,400 ft msl cloud bases, which correlated to a ceiling at the accident site of about 550 ft agl.
Wreckage and Impact Information
The airplane impacted a rocky ravine about 120 yards from the final radar data point and about 6 miles from the airport. There was no postimpact fire and the airplane came to rest upright. All flight control surfaces were present and continuity was established. The landing gear were retracted. The left-wing flap actuator corresponded to a 15° flap setting; the right-wing flap actuator was fractured. The left fuel selector was near the ON position (about 1/4 toward OFF), and the right fuel selector was ON. Both electric fuel boost pump switches were at the high position. The throttle, propeller, and mixture controls were all near the full-forward position.
About 1 gallon of fuel was drained from the left-wing fuel cells; later, about 1 cup remained. No fuel was observed in the right-wing tanks. Both engines were examined and no anomalies were found that would have prevented normal operation. The right engine propeller was not feathered and was in or near the low-pitch stop position.
Additional Information
EDM data indicated total fuel used on the accident flight was about 42 gallons (left engine 22, right engine 20). The pilot's flight planning log contained errors. The NTSB's performance study found that had the pilot feathered the propeller of the inoperative right engine and retracted the flaps, the resulting reduction in drag would have been sufficient to maintain the airplane's glideslope to the runway assuming that the left engine maintained thrust.