Departure and Flight
The aircraft was scheduled to depart Lisbon at 0700 local time, but the departure was postponed to midday due to poor weather conditions. It finally left Lisbon-Cabo Ruivo Seaplane Base at 1223 local time, bound for Funchal, Madeira Island.
Flight Progress
Shortly after takeoff, the crew was cleared to climb to 8,000 feet. Seventeen minutes later, the pilot requested permission to descend to 6,000 feet. At 1321 local time, the captain was able to send a brief message: 'QUG emergency'. The signal 'QUG' is defined in the international code as 'I am forced to alight immediately'. When followed by an indication of a place, it may also mean 'I will be forced to alight at...'.
Search and Suspension
As nothing further was heard from the crew, search and rescue (SAR) operations were conducted. However, they were eventually suspended a few days later when no trace of the aircraft or its 36 occupants was found.
Message Interpretation
The brevity of the message 'QUG EMERGENCY' and the absence of an answer to questions indicate that there was an abnormal situation on board. The signal 'QUG' may also be used to indicate a forced alighting location when followed by that location's designation.
Official Findings
Due to lack of evidence, the exact cause of the accident could not be determined with certainty. However, the assumption that the accident may have been the result of an explosion or a major technical issue was not ruled out.