Boeing MD-10-10F accident near Memphis, Tennessee, July 28, 2006
On July 28, 2006 at about 4:25 pm local time, a Boeing MD-10-10F, registered N391FE, was substantially damaged in an accident near Memphis, Tennessee (Memphis International airport). It was flown under scheduled airline rules (Part 121). No one was hurt; 3 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
the failure of the left main landing gear due to fatigue cracking in the air filler valve hole on the aft side of the landing gear. The fatigue cracking occurred due to the presence of stray nickel plating in the air filler valve hole. Contributing to this was the inadequate maintenance procedures to prevent nickel plating from entering the air filler valve hole during overhaul.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 28, 2006 · about 4:25 pm local time
- Place
- Memphis, Tennessee · Memphis International · map
- Type
- Accident
- Injuries
- No one was hurt; 3 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing MD-10-10F
- Registration
- N391FE · no longer on the register · serial 46625
- Damage
- Substantial damage
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
The approach and landing were stabilized and within specified limits. Recorded data indicates that the loads experienced by the landing gear at touchdown were within the certification limits for an intact landing gear without any pre-existing cracks or flaws. The weather and runway conditions did not affect the landing. The application of braking by the accident crew, and the overall effect of the carbon brake modification did not initiate or contribute to the landing gear fracture. Post-accident modifications to the MD-10 carbon brake system were implemented due to investigative findings for the purposes of braking effectiveness and reliability. Post accident emergency response by the flight crew and ARFF was timely and correct. The left main landing gear (LMLG) outer cylinder on the accident airplane had been operated about 8 ½ years since its last overhaul where stray nickel plating likely was introduced in the air filler valve hole. Nickel plating is a permissible procedure for maintaining the tolerances of the inner diameter of the outer gear cylinder, however the plating is not allowed in the air filler valve bore hole. Literature and test research revealed that a nickel plating thickness of 0.008" results in a stress factor increase of 35%. At some point in the life of the LMLG, there was a load event that compressively yielded the material in the vicinity of the air filler valve hole causing a residual tension stress. During normal operations the stress levels in the air filler valve hole were likely within the design envelope, but the addition of the residual stress and the stress intensity factor due to the nickel increased these to a level high enough to initiate and grow a fatigue crack on each side of the air filler valve hole. The stresses at the air filler valve hole were examined via development of a Finite Element Model (FEM) which was validated with data gathered from an instrumented in-service Fedex MD-10 airplane. The in-service data and FEM showed that for all of the conditions, the stress in the air filler valve hole was much higher than anticipated in the design of the outer cylinder. Fatigue analysis of the in-service findings and using the nickel plating factor resulted in a significantly reduced fatigue life of the gear cylinder compared with the certification limits. During the accident landing the spring back loads on the LMLG were sufficient to produce a stress level in the air filler valve hole that exceeded the residual strength of the material with the fatigue cracks present.
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
- Ratings: multi-engine land; single-engine land; instructor: airplane multi-engine; instructor: airplane single-engine; instructor: instrument airplane; instrument: airplane
- Flight time: 11,262 hours in all; 4,402 in this make and model; 9,522 as pilot in command
- Last flight review: July 19, 2006
- Medical certificate: Class 1 (without waivers/limitations)
- Seat: left
- Injury: no injuries
Co-pilot
- Certificate: airline transport pilot, flight engineer
- Ratings: multi-engine land; single-engine land; instrument: airplane
- Flight time: 854 hours in all; 244 in this make and model
- Last flight review: June 20, 2006
- Medical certificate: Class 1
- Seat: rgt
- Injury: no injuries
The aircraft
- Airframe total time: 73,283 hours
- Last inspection: approved inspection programme, July 28, 2006
- Maximum gross weight: 443,000 lb
- Seats: 3
- Landing gear: retractable
- Engine 1: General Electric CF-6 (turbofan); 0 hours total
- Engine 2: General Electric CF-6 (turbofan); 0 hours total
- Engine 3: General Electric CF-6 (turbofan); 0 hours total
- Fire on the ground
- Operator: Federal Express CORP
The flight
- Departed from: SEA Seattle WA at 12:57 pm
- Destination: KMEM Memphis TN
- Flight plan: IFR
- Runway 18R, 9,329 ft by 150 ft
- A second pilot was aboard
Weather at the time
- Light: daylight
- Wind: from 270° at 14 knots, gusting 18
- Visibility: 10 statute miles
- Sky: overcast at 15,000 ft; a few clouds at 7,500 ft
- Temperature: 79°F (26°C), dew point 64°F (18°C)
- Altimeter: 30.14 inHg
- Observation at 4:30 pm from MEM
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Crew | 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.
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.