WPR24LA003

NTSB accident investigation · Cessna 340A · Hayward, CA · October 2, 2023

Accident · No injuriesClass 3 · LimitedFinal report
Date
October 2, 2023, 12:50 local (19:50 UTC)
Place
Hayward, CA
Injuries
2 uninjured
Damage
Substantial damage
Phase of flight
Taxi
Aircraft
N121CBCessna 340A
Defining event
Taxi: Medical event
Weather
Visual (VMC) · Day
Status
Completed · report September 30, 2025
Report
Approved by Office Director
Investigation class
Class 3
NTSB office
Western Pacific Region
Parties
FAA
FAA report
20231002020729A
Case key
193184

From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.

On this page

Probable cause

The pilot’s sudden incapacitation from effects of a previously undiagnosed underlying heart disease, which resulted in his loss of control of the airplane and subsequent impact with terrain.

Findings · 3

NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings. Under each, the cases with the same finding.

Terrain: sloped/uneven terrainEnvironmental issues › Physical environment · Contributed to outcomeCessna 340A: 1 caseAll aircraft: 270 casesProbable cause

Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident. Under each, the cases with the same event anywhere in their sequence.

Analysis

The pilot had just removed the airplane from his hangar and started both engines. While setting up the avionics, the pilot was suddenly incapacitated, and the airplane began to move across a taxiway. The passenger attempted to wake the pilot, but the airplane continued across a taxiway intersection and into the runway safety area before it collided with a swale. The nose landing gear collapsed and both wings sustained substantial damage. Postaccident medical examination of the pilot attributed the loss of consciousness to an episode of abnormal heartbeat due to a previously undiagnosed underlying heart disease. Thus, the pilot’s sudden incapacitation from effects of previously undiagnosed heart disease likely caused the accident. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.

Factual narrative

On October 2, 2023, about 1250 Pacific daylight time, a Cessna 340A airplane, N121CB, was substantially damaged when it was involved in an accident near Hayward, California. The pilot and passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that the airplane was parked next to his hangar and that he had just started the engines for the upcoming flight. He turned on the avionics and shortly thereafter lost consciousness. The airplane started moving onto taxiway A and into the runway safety area next to the runway. The nose landing gear collapsed and the engines came to a stop. The pilot woke up at the accident site and shut off the fuel and avionics. The pilot’s wife, who was the passenger, attempted to wake him up while the airplane was in motion. On arrival to the emergency department, the pilot was awake and alert with no recollection of the event. He denied any prior chest pain or dizziness. He did report that in February 2023, about 8 months before the accident, he had been evaluated for an acute illness and had undergone an ECG that had been abnormal. He had been referred for a cardiac stress test by his primary care physician but had not completed it by the time the accident occurred. The pilot, who held a Class 3 medical certification from the FAA without waivers, was evaluated by a cardiology provider in the emergency department, who reviewed the ECG and noted findings consistent with a possible previous heart attack but saw no definitive changes indicating a current heart attack. The cardiology provider documented that the pilot’s elevated troponin was likely the result of a recent arrhythmia, as the pilot did not have a history of chest pain. The cardiology provider stated that it seemed likely that the syncopal episode was the result of some kind of acute arrhythmia. The pilot was admitted to the hospital for monitoring overnight and discharged with follow-up appointments the next day. On follow-up with the cardiologist, the pilot underwent a cardiology evaluation that included a Holter monitor, cardiac MRI, stress test, and cardiac catheterization. The catheterization found significant coronary artery narrowing that was treated with percutaneous transcatheter angioplasty and placement of a coronary artery stent.

Aircraft

Registration
N121CB
Reported as
Cessna 340A
Category
Airplane
Serial number
340A0087
Built
1976
Engines
Continental TSIO-520, 325 horsepower, reciprocatingContinental TSIO-520, 325 horsepower, reciprocating
Damage
Substantial damage
Flight
Personal · Part 91
Airworthiness certificate
Standard, Normal
Last inspection
Annual · September 22, 2023 · 6 hours before
Destination
KMRY · Monterey, CA
Airport
KHWD · Hayward Executive Airport
Equipment
Electronic multifunction display, Electronic primary flight display, Stall warning system, ADS-B, Auto-pilot, Electronic flight bag or handheld device

Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.

Flight crew

As NTSB recorded them. NTSB leaves out names.

Role
Pilot
Age
70
Injuries
None
Certificate
Commercial
Airplane ratings
Single-engine land, Multi-engine land
Instrument ratings
Airplane
Medical
Class 3, Without waivers/limitations
Last flight review
March 15, 2022
Seat
Left
Restraint
3-point
Flight hours
2,135 total · 304 in this make and model · 29 in the last 90 days · 3.8 in the last 30 days

Weather

Conditions
Visual (VMC) · Day
Wind
270° at 7 knots
Visibility
10 statute miles
Lowest ceiling
None
Temperature
70 °F, dew point 52 °F
Altimeter
30.04 inHg
Icing
Unknown
Turbulence
Unknown
Observed at
KHWD
METAR
KHWD 021954Z 27007KT 10SM CLR 21/11 A3004 RMK AO2 SLP180 T02060111

Docket · 7

The files NTSB released with the investigation on September 30, 2025, on NTSB’s docket system: statements, records, photos and specialists’ reports. 130 MB in all.

FAA reports on this event · 1

The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.