NTSB Factual Report

On August 10, 2002, at 0540 eastern daylight time, a McDonnell Douglas DC-10-10, N388FE, Flight 2410, registered to and operated by Federal Express Corporation as a Title 14 CFR Part 121 supplemental scheduled domestic cargo flight, blew eight tires during landing following an in-flight failure of the No. 3 hydraulic system and an unsafe left main landing gear light on approach to the Tampa International Airport, Tampa, Florida. Visual meteorological conditions prevailed, and an IFR flight plan was filed. The airplane sustained minor damage. The airline transport-rated pilot in command, the airline transport-rated first officer, the airline transport-rated second officer, and the airline transport-rated jump seat rider reported no injuries. The flight originated from Memphis, Tennessee, at 0317 central daylight time.

The captain stated the flight was normal until approximately base leg when the gear was extended. " We heard a loud bang and the airplane shuttered seriously. The number 3 hydraulic system quantity decreased to zero and left main landing gear red unsafe lights illuminated on both pilot's and engineer's panel. An emergency was declared and we accomplished the HYDRAULIC QUANITY LEAK OR LOSS OR HYD SYS 3 ELEV OFF LIGHT ON checklist and SINGLE HYDRAULIC FAILURE SYSTEM#3 INOP checklist. Then accomplished RED GEAR LIGHT (S) ILLUMINATED (BOTH PANELS) W/HANDLE DOWN checklist. During RED GEAR LIGHT (S) ILLUMINATED checklist, the two red lights remained red. We attempted to determine gear position using main gear indicators (buttons). Because of window condition, SO was unable to visually check. Next we accomplished the LANDING PREPARATION WITH GEAR UP OR PARTIAL GEAR DOWN checklist. Next we accomplished LANDING WITH ONE GEAR UP OR UNSAFE checklist. The left gear touched down with a loud crunch and I thought the gear was collapsing. I shut down the engines in accordance with the checklists. We then accomplished the EMERGENCY QUICK EVACUATION checklist and evacuated the aircraft through R1 using the slide."

The FedEx Manager of Aircraft Maintenance stated,” examination of the landing gear system by maintenance personnel revealed a failure of the left hand main landing gear retract cylinder support frame P/N ARBO642-501, at the point it attaches to the main gear retract cylinder. Upon landing gear extension at TPA the gear extended when the landing gear door, that was supporting the gear, opened breaking the hydraulic lines attached to the retract cylinder dumping #3 hydraulic system fluid overboard. The proximity switch target that activates both the pilots and S/O's displays broke off due to the inertia of the unrestricted extension of the left main landing gear. Thus both red / unsafe lights would not extinguish. When the flight crew followed procedure 2-6-10, LANDING WITH ONE GEAR UP OR UNSAFE, the anti skid became inactive when electrical power was lost due the engines being shut down and the fire handles pulled. Thus he only had brake accumulator pressure to activate the brakes with no skid protection. The P/N of the failed part was: ARB0642-501, This part had no serial number, it had a total of 67,913 hours and 27,081 cycles since installed when the aircraft was manufactured. FedEx Express has operated the aircraft for 5,845 hours and 2,814 cycles since purchased."

Service Bulletin No. DC10-57-105, dated May 19, 1998, states, "four operators have reported seven instances of main landing gear (MLG) retract cylinder support frame assembly failures which resulted in free fall of the MLG and loss of the number 3 hydraulic system. A design engineer determined that the frames failed due to fatigue, and determined that detectable cracks may initiate after the accumulation of 4,000 landings. If not corrected failure of the support frame could cause damage to MLG adjacent structure, and/or unscheduled maintenance . Inspection of the affected frames will determine the frame condition." The Service Bulletin further states in a Note: "Replacement of the existing titanium MLG retract cylinder support frames with new like frames will require reinstatement of the repetitive inspections after the accumulation of 5,000 landings until new steel frame is installed."

FedEx acquired twenty aircraft after Service Bulletin No. DC10-57-105 was issued. A Fleet Campaign Directive was issued by FedEx on August 12, 2002, to inspect all DC10/MD10 Main Landing Gear Retract Cylinder Support Assemblies, and Landing Gear Eddy Current inspection was initiated as a result of N388FE landing incident. In addition, two other support frames were found cracked during subsequent fleet inspection. The failures occurred on aircraft having logged between 15,904 and 39, 559 flight-hours (14,306 thru 19, 485 cycles.)

FedEx provided the NTSB with a CD that contained the data recovered from the incident aircraft's flight data recorder. The NTSB Specialist's Factual Report of Investigation Solid State Flight Data Recorder Report contains information relative to this investigation.

NTSB Probable Cause

The failure of the left main landing gear retract cylinder support frame due to fatigue.