Cessna 170 accident near Herron, Washington, March 1, 2004
On March 1, 2004, a Cessna 170, registered N2534V, was destroyed in an accident near Herron, Washington. It was a personal flight under general aviation rules (Part 91). 2 people were killed. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The failure of the left muffler while maneuvering, resulting in a carbon monoxide leak into the cabin rendering the pilot incapacitated, and the subsequent uncontrolled descent and impact with water.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- March 1, 2004
- Place
- Herron, Washington · map
- Type
- Accident
- Injuries
- 2 people were killed.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 170 · all 170s on the register
- Registration
- N2534V · no longer on the register · serial 18038
- Damage
- Destroyed
- Flight
- Personal flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The airplane was en route when according to the last nine minutes of radar data, the airplane descended from 3,400 to 300 feet. Sixteen days after the aircraft was reported missing Search and Rescue personnel located the airplane in a water inlet at a depth of 132 feet; 19 days later the aircraft was recovered from the accident site. A postaccident examination of the engine and the airframe revealed that the left exhaust muffler had separated at the forward seam, with evidence of sooting noted on the scat hoses surrounding the area. It was also observed that the forward end cap and exhaust riser were separated from the main body of the muffler. Magnified examinations found that almost all of the fractures were blackened and severely oxidized. The failure of the muffler was the result of undetected oxidation and cracking resulting from normal thermal degradation. The cracking would have allowed exhaust gases direct access to cabin air through the heater system. Toxicological testing of the pilot and his passenger revealed carbon monoxide levels of 45 percent and 46 percent, respectively.
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
Pilot
- Certificate: private
- Ratings: single-engine land
- Flight time: 1,475 hours in all
- Medical certificate: Class 3 (valid medical--no waivers/lim.)
- Seat: left
- Injury: fatal
The aircraft
- Airframe total time: 3,847.1 hours
- Last inspection: annual inspection, September 13, 2003; 8.7 hours since
- Maximum gross weight: 2,200 lb
- Seats: 4
- Landing gear: fixed
- Engine: Continental O-300-A (piston); 0 hours total
The flight
- Departed from: 2WA1 Sequim WA at 11:45 pm
- Destination: S50 Auburn WA
- Flight plan: none
Weather at the time
- Light: daylight
- Visibility: 10 statute miles
- Sky: a few clouds at 8,000 ft
- Temperature: 48°F (9°C), dew point 36°F (2°C)
- Altimeter: 30.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
Other NTSB records under N2534V the same tail number, which may have belonged to a different aircraft at the time
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.