JUNKERS-52/3m underwater recovery near Leros island
On October 3rd, 2006, members of the HAF Underwater Operations Team (KOSYTHE) helped recover a historic Ju-52/3m carrier aircraft from the sea near the island of Leros.
The aircraft had been shot down on November, 13th 1943, during the second day of operations of the Battle of Leros. The previous day 400 German paratroopers had landed on the island, during a dangerous operation in a very narrow area between the Bays of Alinta and Gourna. Despite suffering extended losses, the Germans managed to create a bridgehead, in order to conquest the island’s middle part, essentially cutting it in two.
The HAF decided in favour of the aircraft’s recovery, due to its high value as a museum item. After on site research and videotaping of the aircraft, all the necessary data was collected by the HAF Public Relations Directorate, in order to plan every detail of the operation.
Valuable assistants in this task were:
- The HAF Air Support Command, whose underwater operations team (KOSYTHE) was responsible for the aircraft recovery
- The HAF Air Training Command and the HAF Museum, along with the State Aircraft Factory, who helped with the restoration and transportation of the aircraft to the HAF Museum
- The Ministry of Merchant Marine and the Hellenic Coast Guard, who were patrolling the area of operations
- The Hellenic Navy, which offered its Maintenance Base and all its available facilities for the dismantling and initial stages of maintenance of the aircraft
- The Municipality of Leros and all the local authorities.
The HAF Air Support Command and KOSYTHE produced an elaborate underwater operation plan, taking into account all the elements that could affect it, namely the depth of 41 metres, the necessary decompressions, the aircraft dimensions and the duration of the whole process. All the safety precautions were taken, according to the US NAVY DIVING MANUAL, while a doctor was always present during the whole operation. Additionally, the HAF Museum obtained all the necessary tools for the initial stages of the aircraft’s restoration.
The operation started by videotaping the wreck, in order to find the best possible way for its safe recovery. Amongst many possible solutions, it was decided to use wire ropes and belts that would be placed on the strongest parts of the aircraft’s structure. A floating crane was also utilised.
Each of the diving’s performed on a daily basis from the pre-arranged points lasted between 10 and 12 minutes, as was initially planned, also making auxiliary use of the Dive Computer. Overall seventy diving cycles took place, whose total duration was twenty two hours.
In cases when the underwater operations at the depth of 41 metres lasted long, the ROV underwater vehicle played an important role in minimising the effects of the divers’ disease. Moreover, the Dive Master had the advantage of a real-time view of the situation on the site. The use of a full face mask and the utilisation of an intercom system by the members of the underwater operations team and the Dive Master, were also extremely helpful in cases when the need for very precise movements occurred. Special parachutes were also utilised for finding the best possible way to make use of the wire ropes and belts, in order to ensure the safe attachment of the fuselage to the floating crane.
During the day of the aircraft recovery and taking into account the fact that the central engine was partly broken apart from the fuselage and anchored to the bottom of the sea, all the necessary measures were taken in order to ensure that the safe geometry of the recovery would remain unaffected, even if the engine remained at the bottom of the sea. In any other case, the forces would not be correctly balanced and the aircraft could be destroyed. For that case, the ROV remained constantly underwater in front of the central engine, observing the whole operation, while constantly maintaining contact with the members of the underwater operations team (KOSYTHE).
Indeed, during the hauling up it became obvious immediately through the ROV that the central engine was strongly attached to the bottom. As a consequence, it was broken apart from the fuselage, to which it had deliberately been connected with a low strength belt and was recovered at a later stage. Due to its coverage with sand, many parts of the engine had remained in an excellent condition, an example being a part of the engine propeller, where the colour and even the date of the last check were still apparent.
After the aircraft had been securely tied to the crane, on the rear of the fuselage the remains of one of the crew members were found and later collected under the supervision of the team’s doctor.
The next day the aircraft was moved to the Hellenic Navy Maintenance Base, where experts from both the State Aircraft Factory and the Hellenic Air Force undertook the difficult task of its maintenance. The aircraft was dismantled on the island of Leros and later moved to the Museum, where the final stages of its maintenance and restoration will take place.