Aviation Accident Summaries

Aviation Accident Summary CEN16LA069

Watertown, WI, USA

Aircraft #1

N5PF

CIRRUS DESIGN CORP SR22

Analysis

The private pilot had spent several hours flying practice instrument approaches to various airports. He stated that he became distracted and failed to monitor the airplane's fuel state. His normal habit was to alternate between the airplane's wing fuel tanks every 30 minutes; however, he did not perform this action during the last hour of the accident flight. Shortly after takeoff to return to his home airport in night visual meteorological conditions, the airplane's engine experienced a total loss of power. The pilot turned back toward the departure airport, but the airplane did not have sufficient altitude to complete a power-off glide to the runway. The pilot stated that he did not switch the airplane's fuel selector following the loss of engine power. About 344 ft above ground level, the pilot activated the airplane's airframe parachute system. The low-altitude activation resulted in an incomplete deployment of the parachute and a nose-down impact with the ground, during which the pilot sustained serious injury. The pilot stated that there were no mechanical malfunctions or anomalies that would have precluded normal operation of the airplane. Postaccident examination revealed that the airplane's fuel system was intact. The right wing tank, which was selected, contained about 21 oz of fuel, and the left wing tank contained about 22 gallons. Therefore, the total loss of engine power was consistent with fuel starvation.

Factual Information

On December 27, 2015, about 1656 central standard time, a Cirrus SR22 airplane, N5PF, was substantially damaged during ground impact after departing from the Watertown Municipal Airport (RYV), Watertown, Wisconsin. The pilot, the sole occupant, sustained serious injuries. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Night visual meteorological conditions prevailed for the flight, which was on an instrument flight rules (IFR) flight plan with a planned destination of Kenosha Regional Airport (ENW), Kenosha, Wisconsin. The pilot flew multiple instrument approaches at various airports prior to his departure from RYV. Recorded data showed that about 4 minutes after departing RYV, the engine began to surge and subsequently lost power. The pilot attempted unsuccessfully to regain engine power and turned back to RYV. After recognizing his altitude was insufficient to glide to RYV, and with concerns of a forced landing in night conditions, the pilot deployed the Cirrus Airframe Parachute System (CAPS). The fuselage was subsequently damaged during a nose down impact with the ground. Examination of the airplane revealed that the fuel system, from the fuel selector to the fuel tanks, remained intact, with no breaches noted. Twenty-one ounces of fuel were recovered from the right fuel tank system and the fuel selector was in the right tank position. The left fuel tank system contained about 22 gallons of fuel. The electric boost pump was connected to a battery and operated normally. No pre-accident anomalies were noted with the engine or engine-related components. The airplane's non-volatile data was downloaded for the accident flight, which revealed that during the last departure climb, fuel pressure dropped, followed by a short rise in exhaust gas temperature (EGT) that rapidly decreased to zero. Fuel flow during the departure climb was about 30 gallons per hour (gph), before dropping and fluctuating between 1.5 and 11.5 gph for the last two minutes of the flight. Rocket extraction of the parachute from its enclosure to full line stretch typically takes about 1-2 seconds and complete parachute inflation typically takes about 4-6 seconds from initial activation. The accident airplane's reefing line cutters were designed to fire 8 seconds after the parachute extraction activates them. Once the reefing line cutters fire, the rear harness "unsnubs" (lengthens), which lowers the tail of the airplane into its optimized landing attitude. The accident airplane's rear harness was found snubbed and still folded, with tack stitching present. The reefing line cutters were present in their Velcro enclosure and expended, which was consistent with the reefing line cutters firing after touchdown of the airplane. The airplane's non-volatile data was examined to estimate the CAPS deployment height. Based on a review of the airplane's longitudinal deceleration, indicated airspeed, pitch attitudes, and altitudes, CAPS activation was estimated to have occurred about 344 feet agl. CAPS activation at this altitude and descent profile was consistent with the incomplete CAPS deployment and nose down ground impact found at the accident site. Although the pilot's normal habit pattern was to alternate between fuel tanks every 30 minutes using the timer on the GPS, he became distracted and did not accomplish this action during the last hour of the accident flight. After the engine lost power, the pilot did not attempt to switch fuel tanks with the fuel selector, as directed by the Cirrus SR22 pilot operating handbook (POH) engine failure checklist. The pilot stated that his goal on future flights was a more regimented adherence to checklists and flows during distractions, as well as ingraining emergency procedures to muscle memory (e.g. switching fuel tanks with fuel selector). The airplane was equipped with a fuel caution light that illuminates if the fuel quantity in both fuel tanks falls below 14 gallons; the caution light does not illuminate if one tank is low (or empty) and the other tank contains greater than 14 gallons of fuel.

Probable Cause and Findings

The pilot’s improper in-flight fuel management, which resulted in a total loss of engine power due to fuel starvation. Contributing to the accident was the pilot’s failure to switch fuel tanks after the engine lost power, and his delayed decision to activate the airframe parachute system, which resulted in his serious injury due to incomplete deployment of the system and the airplane’s improper attitude upon touchdown.

 

Source: NTSB Aviation Accident Database

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