Sunday, January 26, 2020

Loss of Visual Reference: Grumman G-164B, N3629E; fatal accident occurred March 27, 2018 in Stockton, San Joaquin County, California

Tyler Graham Haymore

The National Transportation Safety Board did not travel to the scene of this accident.

Additional Participating Entities:
Federal Aviation Administration / Flight Standards District Office; Oakland, California
Honeywell Aerospace; Phoenix, Arizona 
Aviation Accident Factual Report - National Transportation Safety Board:

Investigation Docket - National Transportation Safety Board: 

Location: Stockton, CA
Accident Number: WPR18LA113
Date & Time: 03/27/2018, 1405 PDT
Registration: N3629E
Aircraft Damage: Substantial
Defining Event: Loss of visual reference
Injuries: 1 Fatal
Flight Conducted Under: Part 137: Agricultural

On March 27, 2018, about 1405 Pacific daylight time, a Schweizer Aircraft Corporation G-164B restricted category agricultural airplane, N3629E, was substantially damaged after colliding with high transmission power lines and a subsequent impact with terrain about 10 nautical miles southwest of Stockton, California. The commercial pilot was fatally injured. The airplane was owned and operated by Haley Flying Service of Tracy, California, as a Title 14 Code of Federal Regulations Part 137 agricultural application flight, and a flight plan was not filed. Visual meteorological conditions prevailed for the local flight, which had departed the operator's private airstrip about 30 minutes before the time of the accident.

In a statement submitted to the National Transportation Safety Board (NTSB), a company ground crewman who witnessed the accident reported that the field being sprayed had transmission towers angling across it to support transmission power lines. After the pilot finished spraying the field in a north to south orientation, the witness advised the pilot to spray the area on the west side of the transmission towers to ensure proper coverage. As the witness watched the spray being dispensed, he saw "a flash," looked up, and observed the airplane impact the ground. The witness indicated, in a statement to local law enforcement personnel, that, while the pilot was flying southbound below and under two sets of high transmission power lines, the airplane clipped the second set of lines, which caused it to impact the ground nose first. There was no postimpact fire.

Pilot Information

Certificate: Commercial
Age: 29, Male
Airplane Rating(s): Single-engine Land
Seat Occupied: Single
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 2 Without Waivers/Limitations
Last FAA Medical Exam: 10/04/2017
Occupational Pilot: Yes
Last Flight Review or Equivalent: 04/16/2016
Flight Time:  703 hours (Total, all aircraft), 156 hours (Total, this make and model), 604 hours (Pilot In Command, all aircraft), 95 hours (Last 90 days, all aircraft), 41 hours (Last 30 days, all aircraft), 6 hours (Last 24 hours, all aircraft)

The pilot held a commercial pilot certificate with a rating for airplane single-engine land. His most recent Federal Aviation Administration (FAA) second-class medical certificate was issued on October 4, 2017, at which time he reported accumulating about 703 hours total flight experience and about 156 hours in the accident airplane make and model. The pilot completed his most recent flight review on April 16, 2016.

Aircraft and Owner/Operator Information

Registration: N3629E
Model/Series: G 164B B
Aircraft Category: Airplane
Year of Manufacture: 1984
Amateur Built: No
Airworthiness Certificate: Restricted
Serial Number: 744B
Landing Gear Type: Tailwheel
Seats: 1
Date/Type of Last Inspection: 03/13/2018, Annual
Certified Max Gross Wt.: 6162 lbs
Time Since Last Inspection: 17 Hours
Engines: 1 Turbo Prop
Airframe Total Time: 16689.7 Hours as of last inspection
Engine Manufacturer: Garrett
ELT: Not installed
Engine Model/Series: TPE-331
Rated Power: 715 hp
Operator: On file
Operating Certificate(s) Held: None 

The airplane's most recent annual inspection was performed on March 13, 2013, at a total time of 16,689.7 hours, with 17.2 hours since that last inspection. The airplane was equipped with a Honeywell TPE-331-201A turboprop engine, rated at 715 horsepower, with a total time of 15,520 hours. The operator indicated that there were no mechanical issues with either the airplane or the engine that would have precluded normal operation. 

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: SCK, 33 ft msl
Distance from Accident Site: 10 Nautical Miles
Observation Time: 1355 PDT
Direction from Accident Site: 50°
Lowest Cloud Condition: Clear
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 7 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: 320°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting: 30.2 inches Hg
Temperature/Dew Point: 21°C / 4°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Tracy, CA (NA)
Type of Flight Plan Filed: None
Destination: Tracy, CA (NA)
Type of Clearance: None
Departure Time: 1330 PDT
Type of Airspace: Class G

Wreckage and Impact Information

Crew Injuries: 1 Fatal
Aircraft Damage: Substantial
Passenger Injuries: N/A
Aircraft Fire: None
Ground Injuries: N/A
Aircraft Explosion: None
Total Injuries: 1 Fatal
Latitude, Longitude: 37.847778, -121.516111 (est) 

Medical And Pathological Information

An autopsy was performed by the Office of the Sheriff-Coroner, County of San Joaquin, French Camp, California. The autopsy determined that the pilot's cause of death was blunt force trauma.

Toxicology testing performed at the FAA Forensic Sciences Laboratory identified doxylamine (an antihistamine) and dextrorphan (a cough suppressant) in the pilot's blood and urine specimens. No carbon monoxide was detected in the pilot's blood specimens, and no ethanol was detected in the pilot's vitreous specimens. Testing for cyanide was not performed.


  1. Maybe the ground crew could have cautioned pilot about power lines? They can be difficult to spot from the plane.

  2. One of the many hazards of aerial application.

    I worked on the planes at one time ... Wanted to fly the planes ... Never had the desire to actually do the job. A lot of risk.