Incident Sequence
On October 8, 2019, a Boeing 737-800 (registration SP-ENQ) operating from Funchal Airport (LPMA, Madeira) experienced a Master Caution warning shortly after takeoff while retracting the flaps. The flight crew examined the overhead panel and identified a Low Pressure light, along with a loss of hydraulic fluid in System B.
The crew initiated the Non-Normal Checklist for Loss of System B, followed by NITS and TDODAR analyses. After evaluating the situation, they decided to continue to the intended destination, Katowice-Pyrzowice Airport (EPKT). The landing was performed without further incident.
Investigation Findings
The Polish State Commission on Aircraft Accident Investigation determined that the incident was caused by damage to a clamp securing a hydraulic line upstream of the Electric Motor Driven Pump (EMDP). This clamp failure allowed the hydraulic line to shift, resulting in chafing against the housing of the EMDP electrical connector. The exact time of clamp damage and duration of chafing could not be established.
No contributing factors were identified. The investigation did not assign any additional safety recommendations beyond those proposed by the operator.
Preventive Actions
In response to the incident, the operator issued a bulletin for maintenance organizations to inspect hydraulic flexible lines and their clamps. Additionally, pilots were advised to pay closer attention to the condition of hydraulic lines and clamps during Pre-Departure Control checks.