Lake, Sea, Ocean, River

On touchdown, the float(s) struck the water and caused a flying attitude that the pilot could not control before the right wing dug in and the aircraft overturned. Contributing to the accident were conflicting wind and water conditions at the time of the occurrence.

The pilot's improper use of the throttle in not using full power for takeoff, the pilot's failure to use proper aborted takeoff procedures, and the inadvertent stall/mush. A factor associated with the accident was inadequate preflight/planning by the pilot.

The collision was due to the absence of visual detection of the other aircraft by each of the two crews in an uncontrolled Class G Airspace where collision avoidance relies exclusively on external vigilance ("See and Avoid" rule). The decision to change the flight regime and trajectory placed the crew of the Beech 1900D in an improvised and unusual flight situation with a public transport aircraft. The following contributing factors have been identified:
- The pilots, on different frequencies, were unaware of their mutual presence,
- The pilots had their attention focused on the ship 'Norway',
- The organization of the activity in the cockpit of the Beech 1900D and its ergonomics did not allow effective monitoring, particularly towards the outside of the turn,
- The dead angles of the Cessna 177 probably masked the Beech 1900D from its pilot while both aircraft were approaching each other,
- The position of the sun may have hampered the pilot of the Cessna 177,
- The Cessna 177 transponder was off, thus the aircraft could not be viewed on the ATC radar based in Lorient. As a result, he was unable to provide traffic information to the crew of the Beech 1900D.

The following factors were identified:
- It was not possible to examine the debris of the aircraft to determine the contribution of this factor to the failure of the left engine.
- It is possible that the failure to carry out a type B2 inspection and/or to carry out a type A1 inspection by an unqualified person may have contributed to the occurrence of a low oil pressure emergency, due to material deterioration or inadequate services. The impossibility of examining the aircraft could not determine this aspect.
- The owner of the air taxi company participated due to lack of adequate supervision in the planning of operations, at the technical, operational and administrative levels. This deficiency can be characterized, among other things, by the owner of the company that allowed the aircraft to fly with the type B2 inspection expired; by the excessive amount of fuel, when refueling in Manaus; by the unreasonable number of people on board, causing the aircraft to fly with excess weight, and still, by the receipt of pilots' salary to be conditioned to the accomplishment of the fateful flight.
- Errors were made by the aircraft crew due to the improper use of the resources available in the cabin, intended for the operation of the aircraft, due to non-compliance with operational rules.
- There was a mistake made by the crew due to the inadequate preparation for the flight, assuming numerous failures, such as: the non conference, by the pilots, of the cargo and passengers manifest; the lack of the realization of a briefing and still, to accept an aircraft for a flight, being the same with its inspection not carried out.
- An error was made by the crew due to inadequate evaluation of certain aspects of the flight. Such deficiency was evidenced when the first sign of failure of the lubrication system occurred, after twenty minutes of flight, and even so, they decided to proceed with the flight, when the most sensible and safe would be the return, immediately, to Manaus.
- The airline's support staff participated in the planning of weight and balance of the aircraft and the number of passengers on board, providing incorrect information to the aircraft's crew members. In addition, the mechanic who performed the A1 type inspection was not qualified for the function.
- There has been intentional non-compliance by the crew members with the operational rules established by the aircraft manufacturer.
- The Commander did not foresee what was predictable, for lack of caution, thus intentionally increasing the risk margin of the mission.

Because the nose gear doors were not recovered, it is not possible to exclude the possibility that the aircraft encountered a significant piece of flotsam which caused the doors to collapse inwards. Regardless of this, the presence of the severe corrosion in the nose gear operating mechanism torque tube can only have served to compromise the ability of the left door to resist the range of loads which might have been imposed during a water landing. The corrosion found in the torque tube had clearly developed over a long time but it went undetected because it was inside a closed area and no specific inspection of the inside of the tubes was called for. When looking at another Catalina, it was observed that there were no bungs in the aft ends of the torque tubes and it would have been possible, with suitable apparatus, to inspect the whole of the inside of the tube assemblies, particularly in the zone where the tube failed on this occasion. The Maintenance Manual and Schedule for the Catalina were developed and written in a different age when these aircraft were very differently utilised. Although both the Manual and Schedule have been developed as a result of the Catalina's continued amphibious operation, for probably much longer than originally envisaged, there are now likely to be some time related maintenance considerations which did not previously exist.

It was determined that the aircraft was overloaded by 15-25 tons regarding the actual flight conditions and 13-23 tons regarding the MTOW as published in the manuals. At the time of the accident, the OAT was +37° C, reducing climb and flight performances.

The following causal factors were identified:
- The commander had not made an appropriate allowance for adverse headwind components before or during the flight.
- The aircraft was not carrying sufficient fuel for the intended flight.
- The commander apparently ignored pre-flight and in-flight indications that he should land and refuel in France.
- The commander's chances of survival were adversely affected by not adopting the optimum configuration and heading for ditching.

Double engine failure due to fuel exhaustion.