What happened
On September 4, 2018, during flight LO162 traveling from London Gatwick (LLGB) to Warsaw Chopin (EPWR), the crew of a Boeing 737-800, registration SP-LWB, identified a "LOW PRESSURE ENG1" warning. This indication was accompanied by a total loss of hydraulic fluid in system "A". Following established emergency checklists, the crew elected to divert to Warsaw Chopin (EPWA) for an immediate landing. The aircraft landed safely under the supervision of airport fire and rescue services.
Upon post-landing inspection, investigators discovered sheared bolts on the shimmy damper compensator located at the right main landing gear. This mechanical failure caused the hydraulic system to leak. The leak was extensive, with fluid traces visible within the main landing gear bay and extending along the fuselage from the gear bay toward the tail. The spill also contaminated airport surfaces, specifically Runway 31, Taxiway O, and Stand 71, covering a total area of 257 square meters.
The investigation
The PKBWL investigation focused on identifying the source of the hydraulic pressure loss and the extent of the environmental impact. The investigation established that the loss of pressure in system "A" was directly linked to the physical damage found on the landing gear assembly. The commission also documented the contamination of the airfield infrastructure resulting from the fluid leak.
Findings
- The primary cause of the incident was the damage to the shimmy damper on the right main landing gear.
- The shearing of the mounting bolts on the shimmy damper compensator led to the depressurization and subsequent leakage of hydraulic fluid.