Accident Details
Probable Cause and Findings
The pilot's failure to maintain adequate airspeed after a loss of engine power, which resulted in an aerodynamic stall at a low altitude from which the pilot was unable to recover. The loss of engine power resulted from the pilot's improper selection for the electric fuel pump setting during climbout, which caused an excessively high fuel flow to the engine. Contributing to the accident was the pilot's failure to follow the airplane manufacturer's emergency procedures for a low-altitude loss of engine power.
Aircraft Information
Registered Owner (Historical)
Analysis
HISTORY OF FLIGHT
On July 13, 2017, about 1245 Pacific daylight time, a Cirrus Design Corporation SR22T airplane, N821SG, was destroyed when it impacted terrain in Schellville, California, about 1/2 mile west of Sonoma Skypark Airport (0Q9), Sonoma, California. The private pilot and a passenger were fatally injured, one passenger was seriously injured, and one passenger received minor injuries. The airplane was owned by DDLV LLC and operated by the pilot as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed for the time of the accident, and no flight plan had been filed for the cross-country flight. The flight originated from 0Q9 and was destined for Reid-Hillview Airport of Santa Clara County, San Jose, California.
According to data from the airplane's recoverable data module, at 1244:10, the engine power was increased for takeoff. At the start of the takeoff roll, the engine power was about 113%, the manifold pressure was about 37.5 inches of mercury (inHg). The fuel flow was about 43.5 gallons per hour (gph), and the engine speed just above 2,500 rpm.
At 1244:30, the time of the takeoff rotation, the airplane's indicated airspeed was about 73 knots. The data showed that the airplane then accelerated and climbed for the next 5 seconds at an airspeed of about 87 knots.
During the climb out, which was conducted at a pitch attitude of about 15° nose up, the manifold pressure was 36.5 inHg, the fuel flow was between 43.2 and 43.8 gph, and the engine speed was at or above 2,500 rpm.
At 1244:40, the engine speed reached a peak value of 2,563 rpm, and the manifold pressure reached its peak value of 37.8 inHg. Two seconds later, the fuel flow reached its peak value of 46.6 gph, and the engine speed decreased to 2,402 rpm during the next second.
At 1244:44, the engine speed and fuel flow parameters began to decrease, and the airplane's airspeed also began to decrease from 86 knots. At this time, the airplane leveled off at an altitude of about 209 ft mean sea level (msl). The airplane's pitch decreased, and then immediately increased, and the airspeed continued to decrease.
At 1244:45, the engine speed was 1,788 rpm, the fuel flow was 40.5 gph, and the airspeed decreased to 81 knots. Three seconds later, when the airspeed was 72 knots, the airplane reached its peak altitude of 227 ft msl, and then the airplane began to descend. At 1244:49, the stall warning system activated. One second later, the engine speed was 1,212 rpm, the altitude was 185 ft msl, the airspeed was 71 knots, and the vertical speed was -608 ft. At 1244:51, the stall warning activated again; at that time, the altitude was 157 ft msl, engine was 1,236 rpm, airspeed was 76 knots, and the vertical speed was -768 ft.
The airplane was equipped with a Cirrus Aircraft Parachute System (CAPS). At 1244:52, the system handle was pulled; at that time, the airplane was banked about 27° to the left, the altitude was about 130 ft msl, and the airspeed was 75 knots. The last recorded data at 1244:53, showed the airplane's altitude was about 90 ft msl, airspeed was about 75 knots, pitch was about 16° nose down, and bank was about 68° to the left and that the engine's speed was 1,174 rpm, and fuel flow was 30.4 gph.
Several witnesses located at or near 0Q9 reported that they heard the engine "sputter" or "pop" a few times as the airplane passed their position. Subsequently they heard a louder sound and shortly thereafter, observed the airplane's parachute system deploying. Most of the witnesses saw the airplane descending just before they lost sight of the airplane at treetop level, which was just before the airplane impacted the ground.
PERSONNEL INFORMATION
The pilot held a private pilot certificate with ratings for airplane single-engine land, and instrument airplane. The pilot was issued a third-class medical certificate on July 11, 2017, with no limitations. The pilot's application for his medical certificate indicated that he had accumulated 550 hours of total flight experience, 30 hours of which were accumulated in the previous 6 months.
A review of the pilot's logbook revealed that he had logged about 604 hours of total flight experience. The pilot logged about 390 hours in the Cirrus SR22; most of this time was logged in the accident airplane, which he began flying on August 1, 2011. In the previous 7 months, the pilot flew the accident airplane on nine flights (not including the accident flight) with a total flight time of about 19.8 hours.
AIRCRAFT INFORMATION
The low-wing, fixed-gear airplane, was manufactured in 2011. It was powered by a 315-horsepower Continental Motors TSIO-550-series reciprocating engine. The engine was equipped with a three-bladed, constant-speed composite propeller.
The airframe logbook was not located during the investigation. A recovered airplane document revealed that the airplane's most recent conditional inspection was completed on November 10, 2016, at an airframe total time of about 349 hours.
The Cirrus SR22T Pilot's Operating Handbook (POH), listed the upper warning range for the engine speed as greater than 2,550 rpm. The manifold pressure upper warning range was between 37.5 and 40.0 of inHg. The normal range for the fuel flow was between 10 and 45 gph. The POH stated that "for maximum power operations (Power lever full forward - 2,500 rpm, 36 inHg manifold pressure), fuel flow should be in the green arc"
The POH section titled Takeoff Power Check stated in part the following:
"Check full-throttle engine operation early in takeoff run. The engine should run smoothly and turn approximately 2,500 rpm. All engine parameters are not in caution or warning ranges. Discontinue takeoff at any sign of rough operation or sluggish acceleration…. Manifold pressure may temporarily increase to 36.0 - 37.0 in. Hg on first flight of the day due to cooler oil temperatures and associated higher oil pressures. This is acceptable under these conditions, but normal full throttle manifold pressure should be 36.0 in. Hg. The fuel flow will normally also increase in proportion to the increase in manifold pressure. If manifold pressure exceeds 37.0 in. Hg on takeoff or during full power climbs, reduce power to maintain no more than 37.0 in. Hg."
The POH also listed the stall speeds. At an airplane weight of 3,400 pounds (the maximum gross weight), and no bank angle, the stall speed is at 73 knots at the most forward center of gravity (CG) and at 72 knots at the most aft CG. At 30° of bank, the stall speed is 76 knots, at both the forward and aft CG limits. A warning in the POH stated "extreme care must be taken to avoid uncoordinated accelerated or abused control inputs when close to the stall, especially when close to the ground." Further, a note in the POH stated "altitude loss during a wings level stall may be 250 ft or more."
The POH emergency checklist for an engine failure duirng takeoff at low altitude stated the following:
"If the engine fails immediately after becoming airborne, abort on the runway if possible. If altitude precludes a runway stop but is not sufficient to restart the engine, lower the nose to maintain airspeed and establish a glide attitude. In most cases, the landing should be made straight ahead, turning only to avoid obstructions."
The best glide speed was listed as 88 knots, for all airplane weights.
The POH stated that no minimum altitude for CAPS deployment had been set but that "if circumstances permit, it is advisable to activate CAPS at or above 2,000 ft." The handbook also stated that "at any altitude, once the CAPS is determined to be the only alternative available for saving the aircraft occupants, deploy the system without delay."
The airplane's fuel system consists of an engine driven fuel pump and an electrically powered auxiliary fuel pump. The electric fuel pump is controlled by a three-position rocker switch located in the cockpit center console to the left of the power lever. The forward selection of the switch is the "Boost" position, which is used for takeoff, climb, landing, and switching fuel tanks; the center (neutral) selection is the "Off" position, and the aft selection is the "High Boost/Prime" position, which is used for priming the engine before it is started (and for suppressing vapor formation in flight above 18,000 ft). The engine control panel had a placard that indicated that the fuel pump must be selected to Boost for takeoff, climb, landing, and switching tanks.
The POH stated that the Boost position energizes the fuel pump in the low-speed mode regardless of engine speed or manifold pressure and delivers a continuous 4 to 6 psi boost to the fuel flow. For the High Boost/Prime position, a lockout relay controls the fuel pump operation and allows operation when the manifold pressure is greater than 24 inHg or when the engine speed is less than 500 rpm during engine starting. The High Boost/Prime position delivers a continuous high boost to the fuel flow. The pump is rated at 16 psi and 42 gph.
The manufacturer's airplane maintenance manual provided information about the fuel pump setup. The information stated in part the following: "Advance throttle to 2500 RPM (full power) and turn boost pump on to BOOST position. The recommended fuel flow at 36.5 inHg, at a range between 37.4-40.5 gph."
METEOROLOGICAL INFORMATION
The recorded weather conditions at Petaluma Municipal Airport, Petaluma, California, which was about 8 miles west of the accident site, at 1255, were wind variable at 6 knots, visibility 9 statute miles, sky clear, temperature 25°C, dew point 13°C, and an altimeter setting of 30.00 inHg.
AIRPORT INFORMATION
0Q9 is a privately owned, non-towered airport with a reported field elevation of 20 ft msl. The airport was equipped with an asphalt runway, 08/26 which was 2,480 ft long and 40 ft wide.
WRECKAGE AND IMPACT INFORMATION
The airplane impacted the ground and came to r...
Data Source
Data provided by the National Transportation Safety Board (NTSB). For more information on this event, visit the NTSB Records Search website. NTSB# WPR17FA150