By Simon Hradecky, created Wednesday, Feb 3rd 2021 18:47Z, last updated Wednesday, Feb 3rd 2021 18:47Z

A MartinAir Boeing 747-400 freighter, registration PH-CKA performing flight MP-7551 (dep Jan 15th) from Amsterdam (Netherlands) to Sao Paulo Viracopos,SP (Brazil), was enroute at FL310 about 80nm north of Lisbon (Portugal) when the crew decided to turn around and return to Amsterdam. The crew descended the aircraft to FL210 for the return, advised they did have an electrical issue with a backup system that was needed for the Oceanic Crossing. The aircraft dumped fuel over the North Sea and landed safely back on Amsterdam's runway 18R about 4.5 hours after departure.

The aircraft remained on the ground in Amsterdam for about 43 hours before returning to service.

The airline reported the aircraft encountered technical problems while over Spain, the crew tried to reset the system without success. It was thus decided to return the aircraft to Amsterdam where all repair options are available rather than limited options at a remote airport.

The occurrence came to light during a research into a report by the Dutch Safety Board (DSB) reporting that on Jan 16th 2021 it was discovered upon arrival at the destination that a Boeing 747-400 cargo aircraft had lost a panel from its underside presumably during climb after departure out of Amsterdam. The investigation was opened on Jan 16th 2021. It remains unclear whether this return and the lost panel are related.