FedEx Flight 840
McDonnell Douglas DC-10-10 · Incident: airframe, component or system failure during takeoff
From Denver International Airport (DEN) to Frederick W. Smith International Airport (MEM)
Event
- NTSB case
- DEN04IA012
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
McDonnell Douglas DC-10-10
- Aircraft type
- McDonnell Douglas DC-10
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N375FE
- Operator
- FedEx
- Onboard fatalities
- Unknown
- Route
- From Denver International Airport (DEN), Denver, COTo Frederick W. Smith International Airport (MEM), Memphis, TN
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Takeoff · roll/run
- First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Airframe, component or system failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Minor
Cause areas
- Flight control, slat › Malfunction
- Manufacturer › Material inadequate, improper
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
According to the captain, during the take-off roll, and shortly after the first officer called out the take-off decision speed (V1,158 knots), the take-off warning horn sounded. At that time, the captain initiated a Rejected Take-Off (RTO). Assured that a stop on the runway was possible, he elected not to apply maximum braking in "hopes that a more gentle brake application might avoid or mitigate any damage to the aircraft and lessen the heat and fire risk." During the RTO, DEN tower contacted the crew and reported smoke in the vicinity of the left main landing gear. Immediately thereafter, the tower reported that fire was coming from the same area. DEN tower initiated a call to alert aircraft rescue and firefighting equipment (ARFF) to the scene. The aircraft came to a stop, on the runway centerline, with approximately 1,800 feet of runway remaining. The crew completed the emergency quick evacuation checklist, and all seven persons aboard egressed via the L1 escape slide. The initial inspection of the airplane revealed that both of the nose landing gear tires, two main landing gear brake lines, all eight main landing gear brake assemblies, and all eight main landing gear tires were damaged during the RTO. Each damaged item was required to be replaced prior to towing the aircraft off the runway. The maintenance manager stated that the nose and main landing gear assemblies had "overheated," during the RTO and that each tire had deflated after the airplane came to rest, because "there was no indication that the tires had skidded." During an examination of the airplane, it was determined that the take-off warning horn was the result of a take-off configuration conflict between the inboard and outboard slats. An inspection of the inboard slat drive mechanism's lower left hand anti-torque strut, revealed that a rod-end bearing had migrated out of the rod-end, and that two washers were missing, which allowed the anti-torque strut to ride on the bolt that attaches the rod-end to the slat drive mechanism.
Probable cause
the manufacturer's improper installation of the inboard slat drive mechanism's lower left hand anti-torque strut, which resulted in the axial migration of the rod-end bearing, the binding of the anti-torque strut, and the subsequent activation of the slat take-off configuration warning horn. Contributing factors include the aborted take-off, the initiation of normal brakes during a high energy stop, and the main landing gear fire.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record DEN04IA012
- Event ID
- 20031023X01800
- Case number
- DEN04IA012
- Dataset
- historical-pre2008
- Source SHA-256
- 89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (5)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 5fed3c81601d81cde1ca73612d97fd4a44bda426b2d31a4eb5cc28cfe773b479; retrieved 2026-09-18T15:38:44.916Z.
- The NTSB's operator name is blank for N375FE; the operator shown is the name the NTSB records it doing business as.