Navion NAVION G accident near Adrian, Michigan, August 11, 2017
On August 11, 2017 at about 4:00 pm local time, a 1964 Navion NAVION G, registered N249KC, was substantially damaged in an accident during maneuvering near Adrian, Michigan (Lenawee County airport). It was an instructional flight under general aviation rules (Part 91). 2 people were seriously injured. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
A leak in the gascolator, which allowed air to enter the fuel system and resulted in a partial loss of engine power.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 11, 2017 · about 4:00 pm local time
- Place
- Adrian, Michigan · Lenawee County · map
- Type
- Accident
- Injuries
- 2 people were seriously injured.
- Weather
- visual conditions (good weather)
- Aircraft
- Navion NAVION G, built 1964 · all NAVION Gs on the register
- Registration
- N249KC · no longer on the register · serial NAV-4-2499
- Damage
- Substantial damage
- Flight
- Instructional flight · general aviation rules (Part 91)
The NTSB's narrative final · quoted from the NTSB record
The flight instructor and private pilot had completed training maneuvers and were returning to the airport when the engine experienced a partial loss of power about 1,000 to 1,500 ft above ground level. They were unable to glide the airplane to an open field and descended into a wooded area. The airplane impacted trees and became wedged between trees, suspended above the ground. The engine and empennage separated from the rest of the airplane and came to rest on the ground nearby. The fuel tanks were damaged and most of the remaining fuel spilled onto the ground. A postaccident examination of the engine revealed no pre-impact anomalies that would have precluded normal operation or production of rated horsepower; however, an examination of the gascolator showed that it had been leaking fuel from three locations and contained a significant amount of debris. In a postaccident examination, the gascolator was subjected to the relevant service bulletin testing and did not pass the test due to the leaking seals and drain valve. Since the gascolator was unable to seal properly, it would have allowed air into the fuel system, which would have resulted in a loss of engine power. A review of the airplane maintenance records revealed no record of compliance with the service bulletin, nor was compliance mandatory.
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
- Powerplant sys/comp malf/fail during maneuvering
- Loss of engine power (partial) during maneuvering defining event
- Off-field or emergency landing during maneuvering
The NTSB's findings
- cause Aircraft › Aircraft systems › Fuel system › Fuel distribution › Damaged/degraded
- cause Aircraft › Aircraft systems › Fuel system › Fuel distribution › Not serviced/maintained
- Personnel issues › Task performance › Inspection › Scheduled/routine inspection › Maintenance personnel
- Personnel issues › Task performance › Maintenance › Scheduled/routine maintenance › Maintenance personnel
Flight instructor
- Certificate: flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 1,700 hours in all; 32 in this make and model; 80 in the last 90 days; 30 in the last 30 days; 1,500 as pilot in command; 1,000 on instruments
- Last flight review: June 23, 2016
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: rgt
- Injury: serious injuries
Pilot
- Certificate: private
- Ratings: single-engine land; instrument: airplane
- Last flight review: December 13, 2015
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: left
- Injury: serious injuries
The aircraft
- Airframe total time: 2,089.1 hours
- Last inspection: annual inspection, July 5, 2017; 5 hours since
- Seats: 4
- Landing gear: retractable
- Engine: Continental Motors IO-520BA (piston); 1,555 hours total
- Operator: Skywalker Flight School, LLC.
The flight
- Departed from: ADG Adrian MI at 2:00 pm
- Destination: ADG Adrian MI
- Flight plan: none
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 220° at 7 knots
- Visibility: 10 statute miles
- Sky: clear
- Temperature: 72°F (22°C), dew point 64°F (18°C)
- Altimeter: 29.98 inHg
- Observation at 3:53 pm from KADG, 2 miles away
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 2 |
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.
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 documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text 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 CEN17LA316.