N146FE

HISTORY OF FLIGHTOn August 19, 2020, about 0447 Pacific daylight time, Federal Express (FedEx) flight 1026, a Boeing 767-300, N146FE, was substantially damaged after the airplane’s left main landing gear (MLG) failed to extend at Los Angeles International Airport (LAX), Los Angeles, California. The first officer sustained a serious injury while exiting the airplane using the cockpit emergency escape rope; the captain was not injured. The flight was operating under Title 14 Code of Federal Regulations Part 121 as a domestic cargo flight from Newark Liberty International Airport (EWR), Newark, New Jersey, to LAX.

The captain and the first officer provided statements to the National Transportation Safety Board about the circumstances leading to the accident. The captain stated that the preflight and the departure and en route portions of the flight were uneventful. During those flight portions, the first officer was the pilot flying, and the captain was the pilot monitoring.

In preparation for landing, Los Angeles approach control cleared the airplane for the ILS approach to runway 24R. When the airplane had descended to an altitude of about 1,800 ft, the landing gear handle was activated to lower the landing gear. The crew then received a “GEAR DISAGREE” message from the engine indicating and crew alerting system; the message illuminates when the gear position disagrees with the landing gear lever position.

The captain stated that he and the first officer elected to discontinue the approach and climbed the airplane to 5,000 ft to perform the quick reference handbook Gear Disagree checklist procedure. The checklist directed the crew to lower the landing gear using the alternate gear extension system, but the left MLG still did not extend. The next step in the checklist instructed the crew to land the airplane with all available landing gear.

The captain requested and obtained permission to fly a low approach to runway 24L so that the tower controller could try to see if the left MLG was extended. The airplane descended to an altitude of about 500 ft above ground level, but the tower controller could not tell whether the left MLG was extended. The crew then declared an emergency, the captain became the pilot flying, and he flew another low approach—this time at an altitude of about 200 to 300 ft above ground level and with airport operations personnel positioned along the runway to get a better view of the airplane. The second low approach determined that the left MLG was retracted.

Los Angeles approach control then directed the crew to climb the airplane to 5,000 ft and vectored the airplane away from the airport and over the water while the crew consulted with FedEx maintenance about the left MLG. FedEx maintenance suggested that the flight crew attempt to maneuver the airplane “in such a way as to possibly release the unsafe gear,” which the crew did without success. The flight crewmembers then discussed the remaining items on the Gear Disagree checklist and the techniques that would best accomplish the gear-up landing.

The captain stated that, once the fuel “was down to the point where it was time to execute the gear up approach/landing,” Los Angeles approach control vectored the airplane for an ILS approach to runway 25R, which was the longest runway at LAX. The captain also stated that he flew the coupled approach to about 200 ft, disconnected the autopilot, and made a “normal landing touchdown” while trying to keep the left engine nacelle from contacting the runway as the airplane decelerated. The captain further stated that, after the left engine contacted the runway, he maintained directional control “with ailerons, rudder and finally right wheel braking.” After the captain manually deployed the speedbrakes, the airplane came to a stop on the runway centerline about 2,000 to 3,000 ft from the end of the runway.

The crew executed the Evacuation checklist, and the captain reported that the left engine fire lights and bell activated. The crew began evacuating through the first officer’s (right-side) window (due to concerns about a possible fire on the left side of the airplane) using the escape rope. The first officer, who reported that he was wearing “safety gloves” at the time, lost his grip on the escape rope, fell to the runway, and fractured his left heel. As the captain was preparing to evacuate from the first officer’s window, airport rescue and firefighting personnel informed him that no fire was present and that they would provide a vehicle with a platform and stairs so that he would not have to use the escape rope. The captain evacuated the airplane uneventfully. AIRCRAFT INFORMATIONThe accident airplane was manufactured in 2017 and had accumulated 5,958 hours and 2,608 flight cycles. FedEx reported no deferred items per the minimum equipment list during the accident flight.

The Boeing 767 is equipped with left and right MLG assemblies and a nose landing gear assembly. Each MLG assembly consists of four wheels (two forward and two aft); each wheel has an independent brake. The MLG extension and retraction system includes door- and gear-operated sequence valves, door and latch actuators, transfer cylinders, truck positioners, and drag and side brace lock actuators. The landing gear control lever in the cockpit is moved to the down or up position to extend or retract the gear, respectively, using center hydraulic system pressure.

An alternate extension system is available to unlock the landing gear and doors if the MLG extension system is unable to do so. The MLG was designed to rest on the closed MLG doors when the gear is up. The alternate extension system simultaneously releases the left and right MLG doors and the nose gear, which causes all three gears to drop into the down-and-locked position. If a gear is jammed in the retracted position, the alternate extension system would still extend the other gear.

A brake rod, which is installed between each brake assembly housing and the shock strut, transfers the torque generated by the brake to the MLG. The brake rod is connected to the torque arm on the brake assembly housing using a pin, a tang washer, a retaining bolt, and two lock screws secured by safety wire, as shown in figure 1.

Figure 1. Brake rod attaching hardware. (Copyright © Boeing. Reproduced with permission.)

Postaccident examination of the left MLG assembly revealed that the No. 6 brake rod (corresponding to the aft inboard wheel) was not connected to the torque arm on the No. 6 brake assembly housing. Of note, the head of the pin would be in the down direction when the gear was in the up (retracted) position. (Other findings from the postaccident examination are discussed later in this report.)

FedEx stated that the most recent removal and replacement of the No. 6 brake rod occurred during a No. 6 brake assembly change on July 18 and 19, 2020, and that the airplane had accumulated 73 flight cycles between this maintenance and the accident flight. The maintenance personnel who performed the No. 6 brake assembly change did not recall anything unusual or concerning about the installation of the No. 6 brake assembly or brake rod. A review of the airplane’s maintenance history between June 18, 2020 (1 month before the No. 6 brake rod change), and August 19, 2020 (the accident date), revealed no other related maintenance activities. AIRPORT INFORMATIONThe accident airplane was manufactured in 2017 and had accumulated 5,958 hours and 2,608 flight cycles. FedEx reported no deferred items per the minimum equipment list during the accident flight.

The Boeing 767 is equipped with left and right MLG assemblies and a nose landing gear assembly. Each MLG assembly consists of four wheels (two forward and two aft); each wheel has an independent brake. The MLG extension and retraction system includes door- and gear-operated sequence valves, door and latch actuators, transfer cylinders, truck positioners, and drag and side brace lock actuators. The landing gear control lever in the cockpit is moved to the down or up position to extend or retract the gear, respectively, using center hydraulic system pressure.

An alternate extension system is available to unlock the landing gear and doors if the MLG extension system is unable to do so. The MLG was designed to rest on the closed MLG doors when the gear is up. The alternate extension system simultaneously releases the left and right MLG doors and the nose gear, which causes all three gears to drop into the down-and-locked position. If a gear is jammed in the retracted position, the alternate extension system would still extend the other gear.

A brake rod, which is installed between each brake assembly housing and the shock strut, transfers the torque generated by the brake to the MLG. The brake rod is connected to the torque arm on the brake assembly housing using a pin, a tang washer, a retaining bolt, and two lock screws secured by safety wire, as shown in figure 1.

Figure 1. Brake rod attaching hardware. (Copyright © Boeing. Reproduced with permission.)

Postaccident examination of the left MLG assembly revealed that the No. 6 brake rod (corresponding to the aft inboard wheel) was not connected to the torque arm on the No. 6 brake assembly housing. Of note, the head of the pin would be in the down direction when the gear was in the up (retracted) position. (Other findings from the postaccident examination are discussed later in this report.)

FedEx stated that the most recent removal and replacement of the No. 6 brake rod occurred during a No. 6 brake assembly change on July 18 and 19, 2020, and that the airplane had accumulated 73 flight cycles between this maintenance and the accident flight. The maintenance personnel who performed the No. 6 brake assembly change did not recall anything unusual or concerning about the installation of the No. 6 brake assembly or brake rod. A review of the airplane’s maintenance ...