Cessna 501 accident near Texarkana, Arkansas, May 24, 2016
On May 24, 2016 at about 2:56 am local time, a 1980 Cessna 501, registered N804ST, was substantially damaged in an accident during enroute near Texarkana, Arkansas. It was an executive or corporate flight under general aviation rules (Part 91). 3 people had minor injuries; 1 other was unhurt. The weather was visual conditions (good weather).
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The NTSB's probable cause their words, unchanged
The pilot's failure to use supplemental oxygen as required during high-altitude flight, which resulted in his loss of consciousness following a loss of cabin pressurization. Contributing to the accident was the separation of the air conditioning system's primary pressurization duct and the subsequent failure of the aft pressure bulkhead check valve flapper due to progressive weakening from age.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 24, 2016 · about 2:56 am local time
- Place
- Texarkana, Arkansas · map
- Type
- Accident
- Injuries
- 3 people had minor injuries; 1 other was unhurt.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 501, built 1980 · all 501s on the register
- Registration
- N804ST · registry record · serial 501-0146
- Damage
- Substantial damage
- Flight
- Executive or corporate flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The small jet airplane, which was being operated by a single pilot, experienced a loss of cabin pressurization during cruise flight about 43,000 ft. The pilot and passengers lost consciousness and the airplane entered an uncontrolled descent. The pilot regained consciousness and control of the airplane at 7,000 ft and landed the airplane at an alternate destination without further incident. The airplane sustained substantial damage to both wings due to the excessive aerodynamic loads incurred during the descent/recovery. Given the airplane's cruise altitude, the pilot was required by Federal Aviation Regulations to wear a supplemental oxygen mask; however, he was not doing so at the time of the loss of pressurization. Postaccident examination of the airplane revealed that the aft pressure bulkhead check valve flapper was fractured. Additionally, the air conditioning system's primary pressurization duct leading to the cabin was separated from its connection with the water separator due to a loose retaining clamp on the duct's metal worm-gear. Material analysis of the fractured flapper valve indicated the presence of progressive cracking and a loss of mechanical properties due to physical aging; exposure to atmospheric pollutants and oxygen can degrade the flapper material. The airplane lost pressurization when the air conditioning system's primary pressurization duct separated and the pressurized air was discharged into the unpressurized section of the airplane. The subsequent failure of the flapper valve then allowed the pressurized air to escape the cabin.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Aircraft inspection event during prior to flight
- Pressure/environ sys malf/fail during enroute defining event
- Loss of control in flight during enroute
- Attempted remediation/recovery during uncontrolled descent
The NTSB's findings
- cause Personnel issues › Action/decision › Action › Incorrect action selection › Pilot
- cause Aircraft › Aircraft systems › Air conditioning system › Air distribution system › Failure
- cause Aircraft › Aircraft systems › Oxygen system › Crew oxygen system › Not used/operated
- cause Personnel issues › Physical › Impairment/incapacitation › Other loss of consciousness › Pilot
- cause Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Dynamic load › Capability exceeded
- factor Aircraft › Aircraft oper/perf/capability › Performance/control parameters › Altitude › Not specified
Pilot
- Certificate: airline transport pilot, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: glider; instrument: airplane; instrument: helicopter; rotorcraft: glider; rotorcraft: helicopter
- Flight time: 15,000 hours in all; 5,000 in this make and model; 50 in the last 90 days; 20 in the last 30 days; 14,800 as pilot in command; 300 on instruments
- Last flight review: May 11, 2016
- Medical certificate: Class 2 (without waivers/limitations)
- Seat: left
- Injury: no injuries
The aircraft
- Airframe total time: 7,424.8 hours
- Last inspection: continuous airworthiness programme, April 15, 2016
- Maximum gross weight: 12,500 lb
- Seats: 8
- Landing gear: retractable
- Engine 1: Williams International Company FJ44-2A (turbofan); 847 hours total
- Engine 2: Williams Internatinal Company FJ44-2A (turbofan); 847 hours total
- Operator: Eagle II Aero LLC
The flight
- Departed from: K02 Perryville MO at 1:56 am
- Destination: SAT San Antonio TX
- Flight plan: IFR
Weather at the time
- Light: night, dark
- Wind: from 120° at 4 knots
- Visibility: 10 statute miles
- Sky: scat at 9,500 ft
- Temperature: 73°F (23°C), dew point 64°F (18°C)
- Altimeter: 29.94 inHg
- Observation at 2:53 am from TXK
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flig | 1 | |||
| Passengers | 2 | 1 |
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The docket at the NTSB holds the report as a PDF and the investigation's photographs and documents. This site never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number CEN16LA197.