The fire was determined to have been caused by hydraulic fluid leaking onto a hot filter.
The damping is achieved by hydraulic fluid (typically oil) being driven through holes in a piston, as that piston moves in response to a force.
Moving parts do not include any moving fluids, such as fuel, coolant or hydraulic fluid.
The top is filled with nitrogen at high pressure, up to 75 bar, the bottom connects to the car's hydraulic fluid circuit.
It is operated by a source of energy, typically electric current, hydraulic fluid pressure, or pneumatic pressure, and converts that energy into motion.
Some 15 minutes after takeoff arcing wiring ignites hydraulic fluid.
Accident investigators established that the undercarriage's failure to lock down was caused by a loss of hydraulic fluid from both the main and emergency systems.
Extensive trials, however, revealed that it was still prone to hydraulic fluid leakage from the long-recoil mechanism.
