Sunday, September 22, 2019

Aerodynamic Stall / Spin: Raytheon G36 Bonanza, N7215J; fatal accident occurred September 09, 2017 in Benicia, Solano County, California

The National Transportation Safety Board traveled to the scene of this accident.

Additional Participating Entities:

Federal Aviation Administration / Flight Standards District Office; Oakland, California
Continental Motors; Mobile, Alabama
Textron Aviation; Wichita, Kansas
Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board: 

Location: Benicia, CA
Accident Number: WPR17FA200
Date & Time: 09/09/2017, 1413 PDT
Registration: N7215J
Aircraft Damage: Substantial
Defining Event: Aerodynamic stall/spin
Injuries: 2 Fatal
Flight Conducted Under: Part 91: General Aviation - Personal 

On September 9, 2017, about 1413 Pacific daylight time, a Raytheon Aircraft Company G36 airplane, N7215J, sustained substantial damage when it impacted terrain in Benicia, California about 9 miles northwest of the Buchanan Field Airport (CCR), Concord, California. The private pilot and passenger were fatally injured. The airplane was registered to Vallee Development Corporation and the pilot was operating the airplane as a Title 14 Code of Federal Regulations Part 91 personal flight. Visual meteorological conditions prevailed at the time of the accident, and no flight plan had been filed for the cross-country flight. The flight originated from CCR about 1406 and was destined for California Redwood Coast-Humboldt County Airport, Arcata-Eureka, California.

Radar data revealed that the airplane departed from CCR on a northwest heading, which was consistent with its intended destination. The first few minutes of the data showed the airplane in a climb. The surface winds in the area were about 330° at 12 knots, which would give the airplane about a 12-knot headwind during climb out. The airplane continued the climb to a maximum altitude of about 2,500 ft mean sea level (msl).

The last two minutes of the data revealed that the airplane's ground speed began to decrease as the airplane was nearing its level off altitude. During the last 15 seconds of data, the airplane's ground speed further decreased. At 1412:29, when the airplane was at an altitude of 2,400 ft msl, the ground speed was 69 knots; at 1412:32, the airplane was still at an altitude of 2,400 ft msl, but the ground speed had decreased to 56 knots. At 1412:42, the time of the last data return, the airplane's ground speed was 55 knots and the airplane's altitude had decreased by 600 ft to 1,800 ft msl, at a descent rate of about 3,600 ft per minute. In addition, the radar data showed that the airplane had entered a sharp right turn.

The Federal Aviation Administration (FAA) issued an alert notification for the airplane at 1926 after a family member reported that the airplane was overdue. A search ensued, and the Civil Air Patrol located the airplane wreckage the next morning near the top of a hillside in Benicia, California.

Terry Dale Vallee

Pilot Information

Certificate: Private
Age: 67, Male
Airplane Rating(s): Single-engine Land
Seat Occupied:Left 
Other Aircraft Rating(s): None
Restraint Used:
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed:Yes 
Medical Certification: Class 3 Without Waivers/Limitations
Last FAA Medical Exam: 05/06/2017
Occupational Pilot: No
Last Flight Review or Equivalent:
Flight Time:  (Estimated) 528 hours (Total, all aircraft), 2.7 hours (Total, this make and model)

The pilot held a private pilot certificate with an airplane single-engine land rating. The pilot had received a high-performance airplane endorsement on March 18, 2003, and a complex airplane endorsement on May 8, 2015. He also held a third-class airman medical certificate issued on May 6, 2017, with no limitations. A review of the pilot's logbook revealed that he had accumulated about 528 hours of total flight experience. Most of the pilot's flight time was logged in Piper PA-28 and Cessna C-182 airplanes. He had logged 3 flights, for a total duration of 2.7 hours, in the accident airplane. The three flights occurred in July 2017, with the accident pilot operating as the pilot-in-command and no dual time was logged that may have indicated flight training.

Preston Riley Vallee

The passenger held a student pilot certificate and a third-class medical certificate dated February 21, 2003. The passenger did not reapply for the medical certificate after it expired and did not receive a pilot's license. 

Aircraft and Owner/Operator Information

Registration: N7215J
Model/Series: G36 NO SERIES
Aircraft Category: Airplane
Year of Manufacture: 2006
Amateur Built: No
Airworthiness Certificate: Normal
Serial Number: E-3715
Landing Gear Type: Retractable - Tricycle
Date/Type of Last Inspection: 12/03/2016, Annual
Certified Max Gross Wt.: 4000 lbs
Time Since Last Inspection:
Engines: 1 Reciprocating
Airframe Total Time: 1535.6 Hours as of last inspection
Engine Manufacturer: Continental
ELT: C91A installed, not activated
Engine Model/Series: IO-550B-39B
Registered Owner: On file
Rated Power: 300 hp
Operator: On file
Operating Certificate(s) Held: None 

The Raytheon Aircraft Company G36 was a six-seat, low-wing, retractable-gear airplane, that was manufactured in 2006. The G36 is a variant of the Beechcraft Bonanza 36 airplane.

The airplane was powered by a Continental IO-550-B39B engine with a three-bladed constant speed propeller. The engine was modified with a Tornado Alley Turbo, turbonormalizer system (under Supplemental Type Certificate SA5223NM), which was installed on September 19, 2008. The airplane's maintenance records showed that the most recent airframe annual inspection was completed on December 3, 2016, with a Hobbs meter time of about 1,536 hours. The most recent engine inspection occurred on August 14, 2017; at that time, the Hobbs meter time was about 1,600 hours.

According to the Beechcraft Model G36 Bonanza Pilot's Operating Handbook and FAA Approved Airplane Flight Manual, the airplane's stall speed at an airplane weight of 3,600 pounds and flaps up, was 68 knots indicated airspeed (KIAS) at a 0° bank angle, and 73 KIAS at a 30° bank angle. Using calibrated airspeed reflected about the same stall speeds in the chart.

The Airplane Flight Manual Supplement -550, for airplanes with engines that have the turbonomalizer system installed, increased the airplane's takeoff gross weight to 4,000 pounds. The manual supplement stated that the performance of airplanes equipped with the turbonormalizer system "is equal to or better than the performance listed in the original flight manual." The manual supplement also stated that when operating the airplane at the increased weights authorized, the pilot should expect a decreased rate of climb of up to 13% and to increased stall speeds of up to 7%.

The airplane's most recent weight and balance form was not located during the investigation, and the airplane's weight and balance at the time of the accident could not be determined. Paperwork submitted to the FAA's Aircraft Registration Branch in April 2017, when the pilot purchased the airplane, showed that the airplane's maximum gross weight was 4,000 pounds, and that the useful load was 1,209 pounds.

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: CCR, 26 ft msl
Distance from Accident Site: 9 Nautical Miles
Observation Time:1353 PDT 
Direction from Accident Site:155° 
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling:None 
Visibility (RVR):
Wind Speed/Gusts: 12 knots /
Turbulence Type Forecast/Actual: / None
Wind Direction: 330°
Turbulence Severity Forecast/Actual:
Altimeter Setting: 29.96 inches Hg
Temperature/Dew Point: 30°C / 17°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: CONCORD, CA (CCR)
Type of Flight Plan Filed: None
Destination: ARCATA/EUREKA, CA (ACV)
Type of Clearance: None
Departure Time: 1406 PDT
Type of Airspace: Unknown 

The 1353 weather observation at CCR, (about 20 minutes before the accident occurred) indicated the following conditions: wind 330° at 12 knots, visibility 10 statute miles, sky clear, temperature 30°C, dew point 17°C, and an altimeter setting of 29.96 inches of mercury. 

Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Substantial
Passenger Injuries: 1 Fatal
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 2 Fatal
Latitude, Longitude: 38.106667, -122.126111 (est) 

The airplane came to rest on top of a mesa on flat terrain with dense vegetation at an elevation of about 587 ft msl. The fuselage was in an upright position on a magnetic heading of about 125°. Most of the fuselage and engine were contained within an area that measured about 8 ft long, 4 ft wide, and 1 ft deep. The engine was partially buried in the ground. All major structural components of the airplane were located within the wreckage debris area.

The airplane damage and ground signatures were consistent with a wings-level, nose-down, high angle-impact with terrain.

The airplane's wings remained attached to the fuselage but sustained significant compression damage. The leading edges of both wings were crushed aft to the spar. The left and right leading- edge skins, and the main fuel bladders, were ruptured and their fragments were scattered about 170 ft in front of the airplane. The front and bottom portions of the wing tip tanks sustained compression damage corresponding to about a 60° nose-down impact angle. The landing gear and flaps were retracted.

Flight control cable continuity was confirmed from all flight control surfaces to the forward floor assembly area. The elevator trim remained attached to the respective sprocket, and the left and right actuators indicated a position of about 2° to 3° tab up.

The empennage and cabin roof had been removed by first responders. The empennage was separated from the fuselage about 2 ft forward of the vertical stabilizer. The rudder and elevators were attached at all their respective attachment points.

The engine sustained impact damage and was separated from its mounts. The propeller separated at the crankshaft, just aft of the propeller flange, and was located near the engine in the wreckage debris area. Two of the three blades were bent aft about mid-span and two of the three blades exhibited twisting. A hole was observed in the right section of the crankcase between cylinders Nos. 1 and 3 that was consistent with impact forces. All of the accessories mounted on the rear of the engine sustained damage.

The airframe and engine were further examined at the Plain Parts facility in Pleasant Grove, California. The examination revealed no evidence of preimpact mechanical malfunctions or failures that would have precluded normal operation. 

Medical And Pathological Information

An autopsy of the pilot was performed by the Solano County Sheriff's Office, Fairfield, California. The autopsy determined that the pilot's cause of death was "multiple blunt force injuries."

Toxicology testing was performed on the pilot and passenger at the FAA Forensic Sciences Laboratory. The results for the pilot and the passenger were negative for tested drugs. The testing identified ethanol and propanol in the pilot's muscle and liver samples. The testing also identified ethanol in the passenger's brain and muscle samples.

The ethanol detected in the pilot's muscle and liver samples had differing concentrations. Additionally, the presence of propanol, an alcohol produced postmortem along with ethanol and other alcohols, in the pilot's sample's suggested that some or all of the alcohol present was from sources other than consumption. The small amounts of ethanol detected in the passenger's samples also suggested that some or all of the alcohol present was from sources other than consumption.

Additional Information

According to the FAA's Handbook of Aeronautical Knowledge, "true airspeed (TAS) is calibrated airspeed (CAS) corrected for nonstandard altitude and temperature…therefore, for a given CAS, TAS increases as altitude increases. A pilot can find TAS by two methods. The most accurate method is the use of a flight computer…A second method, which is a rule of thumb, provides the approximately TAS. Simply add 2 percent to the CAS for each 1,000 ft of altitude." The handbook also states that the groundspeed is "the actual speed of the airplane over the ground. It is TAS adjusted for wind. Groundspeed decreases with a headwind and increases with a tailwind."

On the accident flight the groundspeed on the last radar return, at an altitude about 2,500 ft, was 55 knots. Adjusting the groundspeed for about a 12-knot headwind would make the TAS about 67 knots. A calculation using the atmospheric pressure, temperature, and airplane's speed, revealed that the CAS was about 5 knots slower than the TAS. Therefore, CAS was estimated to be about 62 knots at the last return.

The FAA's Airplane Flying Handbook, states "transition to a complex airplane, or high-performance airplane, can be demanding for most pilots without previous experience. Increased performance and complexity both require additional planning, judgement, and piloting skills. Transition to these type airplanes, therefore, should be accomplished in a systematic manner through a structured course of flight training by a qualified flight instructor."

Six SD data cards associated with a Garmin G1000 system were located at the accident site. The cards were provided to the NTSB's Vehicle Recorders Division for potential data download. In addition, an engine temperature sensor found at the accident site was provided to the Vehicle Recorders Division to determine if the sensor contained non-volatile memory and could be a source of engine data for the investigation. Some of the SD cards could be read, but they contained data that were not pertinent to the investigation. The engine sensor was not capable of recording data.


  1. Perhaps engine was failing while the autopilot with alt hold was engaged. The AP held it in the the air maintaining altitude until the plane fell out of the sky.

  2. I wouldn't think of flying a new-to-me model of aircraft without taking my CFII along for a check-out. Cheap life insurance.

    1. This is what happens when the pilot buys the aircraft with the attitude that he can and will fly and nobody is stopping him. It was unfair and uncaring of him to take his son with him.