Tuesday, April 30, 2019

Panzl S331E, registered to the pilot operating under the provisions of Title 14 Code of Federal Regulations Part 91, N331ST: Fatal accident occurred July 22, 2017 in Apple Valley, San Bernardino County, California

Margo Su Chase 
 Margo was a lifelong learner, an intrepid adventurer and a fierce competitor. These attributes led her to develop a passion for flying and aerobatics, taking to the sky to perform unusual maneuvers, competing nationally with precision and skill. She was quoted in an interview, saying, “I draw in the sky.”

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

Additional Participating Entities:

Federal Aviation Administration / Flight Standards District Office; Riverside, California
Lycoming Engines; Williamsport, Pennsylvania 
Aviation Accident Factual Report - National Transportation Safety Board: https://app.ntsb.gov/pdf

Investigation Docket - National Transportation Safety Board: https://dms.ntsb.gov/pubdms


Margo Su Chase

Location: Apple Valley, CA
Accident Number: WPR17FA161
Date & Time: 07/22/2017, 1500 PDT
Registration: N331ST
Aircraft Damage: Substantial
Defining Event: Flight control sys malf/fail
Injuries: 1 Fatal
Flight Conducted Under: Part 91: General Aviation - Personal 

On July 22, 2017, about 1500 Pacific daylight time, an Applegate Panzl S331E airplane, N331ST, impacted terrain while conducting aerobatic maneuvers near Apple Valley, California. The private pilot was fatally injured and the airplane sustained substantial damage. The airplane was registered to the pilot who was operating the airplane under the provisions of Title 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed, and no flight plan was filed for the local personal flight, which originated from Apple Valley Airport (APV), Apple Valley, California, about 1445.

The pilot was practicing her aerobatics routine and was performing the sixth figure of a nine-figure routine when the accident occurred. A witness, who was familiar with the pilot's routine, reported that, as planned, the airplane entered a 45° descent and executed a right snap roll before entering a left roll. The airplane continued its descent, rolling at a slower rate, until it impacted the ground. The witness stated that, when she entered the maneuver, the pilot had adequate altitude to complete it.

An in-cockpit video from a camera mounted over the pilot's right shoulder captured the entirety of the accident flight. During the before takeoff engine run-up, the pilot confirmed flight control continuity; the video showed that the aileron surfaces moved accordingly. The pilot departed and began the aerobatic routine about 3 minutes into the flight. About 4 minutes into the routine, the pilot entered a 45° inverted downline and the airplane performed 1.5 snap rolls to the right. The pilot momentarily stopped the roll at 4,100 ft and started a roll to the left. The right aileron surface was observed trailing edge down, and the left aileron surface could not be seen in the video. The pilot moved her body toward the right of the cockpit, consistent with making a right control stick input; however, the airplane continued to roll left and the roll rate increased; the pilot continued to lean toward the right. About this time, the right aileron could be seen in the video with an upward deflection. The deflection of the left aileron could not be determined. The airplane continued to roll to the left until it impacted the ground. The pilot did not transmit any distress calls before the accident.

Margo Su Chase

Pilot Information

Certificate: Private
Age: 59, Female
Airplane Rating(s): Single-engine Land; Single-engine Sea
Seat Occupied: Single
Other Aircraft Rating(s): None
Restraint Used: 5-point
Instrument Rating(s): None
Second Pilot Present: No
Instructor Rating(s): None
Toxicology Performed: Yes
Medical Certification: Class 3 With Waivers/Limitations
Last FAA Medical Exam: 11/15/2016
Occupational Pilot: No
Last Flight Review or Equivalent: 06/14/2017
Flight Time:  982 hours (Total, all aircraft), 189 hours (Total, this make and model) 

The pilot's most recent third-class Federal Aviation Administration (FAA) medical certificate was issued November 15, 2016. On the application for that certificate, she reported 982 total hours of flight experience, 39 hours of which were in the previous six months. The pilot had been flying aerobatics since 2006. The pilot purchased the airplane in 2015 and accrued about 189 flight hours in the airplane since that time, 45 hours of which were in the previous 12 months. 

Aircraft and Owner/Operator Information

Aircraft Make: APPLEGATE
Registration: N331ST
Model/Series: PANZL S331E
Aircraft Category: Airplane
Year of Manufacture: 2005
Amateur Built: Yes
Airworthiness Certificate: Experimental
Serial Number: 001
Landing Gear Type: Tailwheel
Seats: 1
Date/Type of Last Inspection: 12/08/2016, Condition
Certified Max Gross Wt.:
Time Since Last Inspection:
Engines:  1 Reciprocating
Airframe Total Time: 318 Hours as of last inspection
Engine Manufacturer: Lycoming
ELT: Not installed
Engine Model/Series: IO-540 EXP
Registered Owner: On file
Rated Power: 290 hp
Operator: On file
Operating Certificate(s) Held: None 

The airplane's most recent annual inspection was completed on December 8, 2016. The maintenance log entry for the inspection indicated that the airplane was disassembled and reassembled. A new control stick was installed, and the ailerons and aileron hinges and attach points were inspected and all were recorded as satisfactory at this time.

Meteorological Information and Flight Plan

Conditions at Accident Site: Visual Conditions
Condition of Light: Day
Observation Facility, Elevation: KVCV, 2885 ft msl
Distance from Accident Site: 12 Nautical Miles
Observation Time: 1455 PDT
Direction from Accident Site: 265°
Lowest Cloud Condition: Scattered / 11000 ft agl
Visibility:  10 Miles
Lowest Ceiling: None
Visibility (RVR):
Wind Speed/Gusts: 6 knots /
Turbulence Type Forecast/Actual: None / None
Wind Direction: 150°
Turbulence Severity Forecast/Actual: N/A / N/A
Altimeter Setting:
Temperature/Dew Point: 38°C / 6°C
Precipitation and Obscuration: No Obscuration; No Precipitation
Departure Point: Apple Valley, CA (APV)
Type of Flight Plan Filed: None
Destination: Apple Valley, CA (APV)
Type of Clearance: None
Departure Time: 1445 PDT
Type of Airspace:

Airport Information

Airport: Apple Valley (APV)
Runway Surface Type: N/A
Airport Elevation: 3062 ft
Runway Surface Condition: Unknown
Runway Used: N/A
IFR Approach: None
Runway Length/Width:
VFR Approach/Landing: None 

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: 34.603611, -117.132778 

The airplane impacted sandy desert terrain in an approximate 45° nose down, upright attitude. The engine was mostly embedded in a 2-ft-deep crater; the wood propeller blades were fractured near the propeller hub and fragments were found at the bottom of the crater. The engine cowling, cabin, and both wing skins were heavily fragmented and completely separated from the underlying structure. Impact marks consistent with the leading edges of both wings were visible in the sand. The cabin area was heavily damaged. The skin was still attached to the aft fuselage but exhibited crush damage. The empennage was mostly intact and undamaged.

Control continuity was established throughout the airframe with two breaks, one in the left aileron control assembly and one in the elevator control assembly. The fracture surfaces of the left aileron control rod end and the elevator control were examined by the National Transportation Safety Board (NTSB) Materials laboratory. Both fracture surfaces of the left aileron control rod end exhibited relatively flat areas emanating from the inner diameter of the outer ring, which transitioned to angular planes adjacent to the outer diameter. One of the fracture surfaces exhibited smearing damage on much of its flat area that obscured most of the finer features. The other fracture surface exhibited feathery features in the flat area, consistent with fatigue cracking. The elevator control fracture exhibited features consistent with shear overstress.

The engine sustained significant crush damage to the oil sump, exhaust system, and induction system. The magnetos were heavily damaged and could not be tested; the ignition harness was destroyed. The top spark plugs were removed; their coloring varied but was consistent with normal operation when compared to the Champion check-a-plug chart. The fuel nozzles were clear of debris and blockages. Borescope examination of the cylinders revealed no mechanical damage or evidence of detonation or foreign object ingestion. The engine was rotated by hand and continuity was established throughout, thumb compression was obtained on all cylinders and the valves moved appropriately. Examination revealed no anomalies that would have precluded normal operation. 

Medical And Pathological Information

The San Bernardino County Coroner, San Bernardino, California, performed an autopsy of the pilot. The cause of death was listed as multiple blunt force injuries.

The FAA Bioaeronautical Sciences Research Laboratory performed forensic toxicology on specimens from the pilot with negative results for carbon monoxide, and drugs. 85 mg/dL ethanol was detected in blood, which was likely the result of postmortem production.

1 comment:

  1. I dont see her flying enough to remain proficient, that being said, it looks like something may have broken in the plane, or she was in a stalled condition, and the plane didnt respond to right aileron