Cessna 207 accident near Holy Cross, Alaska, June 20, 1998
On June 20, 1998 at about 3:25 am local time, a Cessna 207, registered N1673U, was substantially damaged in an accident near Holy Cross, Alaska. It was a flight of an unrecorded kind under charter and air-taxi rules (Part 135). No one was hurt; 4 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The improper installation/undertorquing of the engine crankcase bolts by company maintenance personnel, and a subsequent fracture of the engine crankshaft. A factor in the accident was unsuitable terrain for a forced landing.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- June 20, 1998 · about 3:25 am local time
- Place
- Holy Cross, Alaska · map
- Type
- Accident
- Injuries
- No one was hurt; 4 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Cessna 207 · all 207s on the register
- Registration
- N1673U · no longer on the register · serial 20700273
- Damage
- Substantial damage
- Flight
- Flight of an unrecorded kind · charter and air-taxi rules (Part 135)
The NTSB's narrative final · quoted from the NTSB record
The pilot and three passengers, departed on an air taxi flight over remote terrain. While in cruise flight about 2,200 feet, the engine oil pressure began to drop, and the engine oil temperature began to rise. The pilot decided to divert to the nearest airport. The engine quit running, and the pilot selected an emergency landing area on a sand bar along a river that contained several willow trees. During the landing, the airplane received damage to the wings and fuselage. The engine had accrued 1,491 hours since an overhaul. During that time, seven engine cylinder changes were performed by company maintenance personnel. An examination of the engine revealed the crankshaft was broken along the aft, lower edge of the number two cheek journal, at the forward radius of the number two main bearing journal. The fracture line was straight and flat, through the full dimension of the number two cheek journal, and was oriented perpendicular to the longitudinal axis of the crankshaft. The number two main bearing was broken and flattened. The number two main bearing saddle was flattened and distorted. The left and right engine case halves mating surface exhibited galling/fretting at the number two main journal bolt holes.
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: airline transport pilot, flight instructor, commercial pilot
- Ratings: multi-engine land; single-engine land; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 12,000 hours in all; 4,000 in this make and model; 110 in the last 90 days; 61 in the last 30 days; 12,000 as pilot in command; 200 on instruments
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 11,877 hours
- Last inspection: 100-hour inspection, May 25, 1998; 51 hours since
- Maximum gross weight: 3,800 lb
- Seats: 7
- Landing gear: fixed
- Engine: Continental IO-520-F (piston); 0 hours total
- Operator: Inland Aviation Services INC.
The flight
- Departed from: KGX Grayling AK at 9:40 pm
- Destination: BET Bethel AK
- Runway 0
Weather at the time
- Light: daylight
- Wind: from 180° at 5 knots
- Visibility: 50 statute miles
- Sky: scat at 3,000 ft
- Temperature: 61°F (16°C), dew point 50°F (10°C)
- Altimeter: 29.00 inHg
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 1 | |||
| Passengers | 3 |
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 N1673U 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.