Mcdonnell Douglas DC-8-63F incident near Seattle, Washington, July 18, 1998
On July 18, 1998 at about 2:00 pm local time, a Mcdonnell Douglas DC-8-63F, registered N921R, suffered minor damage in an incident near Seattle, Washington (Seattle-Tacoma Intl airport). It was a flight of an unrecorded kind under scheduled airline rules (Part 121). No one was hurt; 5 people were on board or involved. The weather was instrument conditions (cloud, fog or low visibility).
The NTSB's probable cause their words, unchanged
The flight crew's failure to perform a missed approach upon failing to attain and/or maintain proper course/runway alignment and glidepath on final approach, resulting in a high-sink-rate landing and subsequent separation of a main landing gear wheel from the aircraft. Factors contributing to the incident included: low ceiling; the first officer's failure to attain and/or maintain proper course/runway alignment and glidepath on approach; insufficiently defined company procedures for responding to deviations from a stabilized approach profile; inadequate FAA principal operations inspector approval of company operating procedures; and a worn main landing gear wheel retaining nut.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 18, 1998 · about 2:00 pm local time
- Place
- Seattle, Washington · Seattle-Tacoma Intl · map
- Type
- Incident
- Injuries
- No one was hurt; 5 people were on board or involved.
- Weather
- instrument conditions (cloud, fog or low visibility)
- Aircraft
- Mcdonnell Douglas DC-8-63F
- Registration
- N921R · no longer on the register · serial 46145
- Damage
- Minor damage
- Flight
- Flight of an unrecorded kind · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
The flight was cleared for an instrument landing system (ILS) approach. The ceiling was 200 feet overcast, visibility was 1 mile (runway visual range was greater than 6,000 feet) and the first officer was the pilot flying (according to company operating procedures, the minimum ceiling for first officer flying is normally 500 feet.) Air traffic control (ATC) radar indicated that the aircraft was left of the localizer course and/or below glide path, outside of the company's stabilized approach limits, for the majority of the final approach segment below 1,000 feet above touchdown. The aircraft broke out approximately at minimums (200 feet above touchdown), left of (and diverging away from) the runway centerline. The captain called, "push it down, push it down, push it down", and asked, "you got it or you want me to get it?". The first officer replied, "I can get it", and the captain said, "OK." The aircraft pitched down and banked up to approximately 14 degrees in correcting back to the runway. A high sink rate existed in the last few seconds before touchdown; the flight data recorder registered a vertical acceleration of about 1.8 G at touchdown. The aircraft's number 1 main landing gear wheel separated from the aircraft at or shortly after touchdown. The separated wheel entered the airport ramp area and struck two parked trucks and a baggage cart in front of the main passenger terminal. Post-incident examinations of the aircraft's number 1 wheel retaining nut disclosed that the nut threads were worn approximately 0.030 inch beyond engineering drawing specifications. FAA guidance directs FAA principal operations inspectors (POIs) to ensure their operators' operations manuals contain stabilized approach criteria as well as required actions in the event of deviations ("i.e. missed approach or go/around [sic]"). The company's DC-8 operations manual states only that deviations from the stabilized approach profile "are cause for consideration to abandon the approach."
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, commercial pilot
- Ratings: multi-engine land; single-engine land; single-engine sea; instrument: airplane
- Flight time: 6,772 hours in all
- Medical certificate: Class 1 (valid medical--no waivers/lim.)
- Seat: left
The aircraft
- Airframe total time: 63,996 hours
- Last inspection: continuous airworthiness programme, July 11, 1998; 60 hours since
- Maximum gross weight: 355,000 lb
- Seats: 5
- Landing gear: retractable
- Engine: P&W JT3D-7 (turbojet); 0 hours total
- Operator: Emery Worldwide Airlines
The flight
- Departed from: DAY Dayton OH at 9:51 am
- Destination: SEA
- Flight plan: IFR
- Runway 34R, 11,900 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: at 4 knots
- Visibility: 1 statute miles
- Sky: overcast at 200 ft; not recorded
- Temperature: 135°F (57°C), dew point 131°F (55°C)
- Altimeter: 30.00 inHg
- Observation at 1:56 pm from SEA
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 5 |
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.
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.