NTSB Factual Report

On February 19, 2004, about 1410 eastern standard time, a Dutch registered Boeing 767-300 ER airplane, PH-MCL, had a landing gear component failure while landing at the Miami International Airport, Miami, Florida. The airplane was being operated by Martinair Holland, under Title 14, CFR Part 129, as an instrument flight rules (IFR) international cross-country scheduled passenger flight. There were no injuries to the two pilots, eight flight attendants, or the 280 passengers. Visual meteorological conditions prevailed, and an instrument flight plan was filed. The flight originated on February 19, about 0923 Universal Coordinated Time (UTC), from the Amsterdam Schiphol International Airport, the Netherlands, and was en route to the Miami International Airport.

The flight crew reported to their Miami based contract maintenance company personnel that during landing rollout on runway 12, as they applied the brakes, they noted a significant airframe vibration, and a pronounced rumbling noise as the airplane slowed. During a postincident inspection, maintenance personnel discovered a broken landing gear pivot pin on the right main landing gear truck.

On February 20, 2004, in the presence of the National Transportation Safety Board (NTSB) investigator-in-charge, the landing gear bogie pivot pin was removed from the incident airplane's main landing gear bogie beam. During the removal process, a residual amount of dried grease was noted on the fractured pivot pin and associated bogie beam bushings. The pivot pin was sent to the NTSB's Materials Laboratory in Washington, DC, for a metallurgical examination.

According to Martinair, the pivot pin was installed in the incident airplane in February of 2001. The pivot pin had attained 2,232 landing cycles prior to the event. According to Boeing Commercial Airplane Group, the landing gear bogie pivot pin has a 50,000 landing cycle limit.

According to the NTSB Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2) submitted by Martinair, the incident airplane had accumulated a total time of 63,592.6 flight hours. The most recent A check inspection was accomplished on February 12, 2004, 103.3 hours before the incident. According to Boeing Commercial Airplane Group, the landing gear bogie pivot pin should be lubricated during the A-check inspection.

A senior materials engineer from the NTSB's Materials Laboratory reported that most of the chromium plating was missing from the pin's shank, and the underlying steel was worn, corroded, and displayed signs of heat damage. He noted that the originating fracture region contained corrosion pits. The fracture features noted are typical of stress corrosion cracking. A complete copy of the NTSB's materials laboratory factual report is included in the public docket for this incident.

The airplane's flight data recorder (FDR) was removed and shipped to the NTSB's Washington, DC, laboratory for analysis. The FDR readout showed that the incident landing was within normal operating tolerances.

According to Boeing Commercial Airplane Group, nine operators of Boeing 767 airplanes reported ten additional pivot pin fractures, with six of the fractures being reported within the last two years. On January 20, 2004, Boeing Commercial Airplane Group issued a fleet team digest (FTD) notice to operators of Boeing 767 airplanes, addressing cracked pivot pins, and the importance of correct grease usage. Boeing updates the FTD regularly, with the latest revision released December 16, 2004. In addition, the fleet team digest notice states, in part: "Boeing plans to release service bulletin 767-32A0199 which recommends that current pivot pins be replaced at overhaul, or heavy maintenance (D) check. SB release is currently planned for April-2004, based on availability of new pins."

On April 8, 2004, Boeing Commercial Airplane Group issued Alert Service Bulletin (ASB) 767-32A0199, which requires the replacement of the current pivot pins with pivot pins made of a different type of steel called Aermet 100. According to Boeing Commercial Airplane Group, Aermet 100 is more resistant to heat damage, and less susceptible to stress corrosion cracking.

The Safety Board shipped the FDR to Martinair in Holland on March 4, 2004. At the request of Martinair, the fractured landing gear bogie pivot pin was shipped to the Boeing Commercial Airplane Group, Seattle, Washington, on August 31, 2004.

NTSB Probable Cause

The inadequate quality of material in the main landing gear bogie pivot pin, which resulted in a premature fracture of the pin.