K2 Aviation Piper PA-31-350 incident
Piper PA-31-350 · Incident en route
From Talkeetna Airport (PATK) to an unrecorded destination
Event
- NTSB case
- ANC02IA093
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Charter & commuter
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Piper PA-31-350
- Aircraft type
- Piper PA-31
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N828KT
- Operator
- K2 Aviation
- Onboard fatalities
- Unknown
- Route
- From Talkeetna Airport (PATK), Talkeetna, AKTo not recorded
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 135: Air Taxi & Commuter
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- En route · cruise
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Miscellaneous/other
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- None
Cause areas
- Passenger › Incapacitation(loss of consciousness)
- Passenger › Physical impairment(cardiovascular)
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
A passenger with a history of coronary artery disease, and coronary surgery, became unconscious in a non-pressurized twin-engine airplane during a sightseeing flight at 21,000 feet. All passengers on the flight were utilizing supplemental oxygen from the airplane's oxygen system. The passenger was supported in an upright, seated position as the flight returned to the departure airport where she was met by emergency medical personnel and transported by ambulance, lying down on a stretcher. The passenger regained consciousness en route to a hospital for initial treatment where diagnostic studies were consistent with heart attack and congestive heart failure. Although her initial diagnosis included possible high altitude pulmonary and cerebral edema, this is unlikely since the flight was less than 1 hour and these symptoms usually occur only after a day or more exposure to high altitude. The passenger's condition was most likely related to her previous history of heart disease, exacerbated by exposure to decreased oxygen supply, and continuous vertical position for many minutes following her loss of consciousness. The passenger was subsequently released for in-home rehabilitation two months later with a diagnosis of an anoxic brain injury. According to the pilot's operating handbook, the FAA approved passenger oxygen mask for the incident airplane is a partial rebreather mask equipped with a reservoir bag at a flow rate of 1.5 or 2.0 liters per minute, however, on the incident flight, the passengers were using a disposable, hospital type oxygen mask without a reservoir bag, at a flow rate of 1.5 liters per minute. FAA oxygen system certification standards, at 21,000 feet, require a minimum flow rate of about 1.8 liters per minute, and the recommended upper altitude limit for use of an oxygen mask without a reservoir bag is 15,000 feet. Following the incident, the operator changed the passenger oxygen masks to an FAA approved mask with a reservoir bag, at a flow rate of 3.0 liters per minute.
Probable cause
The passenger's incapacitation during a high altitude flight due to a loss of consciousness as the result of a pre-existing cardiovascular condition. A contributing factor in the incident was the operator's improper use of disposable oxygen masks without a reservoir bag above the recommended upper altitude limit for use of this type mask.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ANC02IA093
- Event ID
- 20020829X01491
- Case number
- ANC02IA093
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates, damage. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 67a69179762b2e07e066f5461f5d7a6d0068caadb42ffb3b5440cf7043c375d0; retrieved 2026-09-18T16:01:26.987Z.
- The NTSB's operator name is blank for N828KT; the operator shown is the name the NTSB records it doing business as.