IT ALL STARTED WHEN we came across a document concerning a German Junkers Ju-88 bomber that had been brought down near Odessa, the Black Sea port in southern Ukraine. The aircraft had been lost in the waters of Odessa Bay.
Our research was into Air Regiment 69, a combat unit that took part in the Soviet defence of Odessa against the Germans during World War Two, and it appeared that the Junkers 88 had been brought down by Hero of the Soviet Union Topolsky Vitaliy Timofeyevitch.
Last year, the Department of Underwater Heritage of the Archaeological Institute of Ukraine accorded official status to an expedition to find the aircraft, with the practical part of the research entrusted to divers of the Laboratory of Underwater Technologies, led by Vlad Tobak.
The search for the plane began in the vicinity of Vorontsovsky lighthouse in September, and it took only a few days for the clear contours of an aircraft to show up on the side-scan sonar. We were sure that they indicated a Ju-88.
We watched the first diver plunge in to fasten the line. Visibility was about 3m, water temperature 8°C, and at the wrecks depth of 23m, it was as dark as night.
I remember the thrill and anticipation we felt as we watched the divers bubbles. When he surfaced, he paused for a long time before informing us that: The plane is overturned.
Excitedly, the next couple of searchers prepared to dive. We were all bursting for action!
But when we compared our description of the Ju-88 to the information delivered by this second buddy-pair, it became clear that this wreck was something different.
The propeller blades remained intact, but their construction was two-blade.
A right-angled section of fuselage carried a corrugated skin - and there were no bombs beneath the wings.

IT WAS CLEAR TO US THAT THIS WAS NOT a Ju-88 at all, but it was a Junkers.
It had to be a Ju-52/3m, nicknamed Auntie Ju, or Iron Annie. During the Spanish Civil War, the Ju-52 was called the Pava, which means turkey.
The Ju-52/3m (the 3m stands for drei motoren or three-engined) formed the basis of the Luftwaffes passenger and military transportation. It would be difficult to confuse this three-engined giant with anything else, so we had 100% identification of the model.
However, we had come across no mention of a crashed Ju-52 in this area. The plane seemed to be a ghost!
The aircraft was now under the protection of the Department of Underwater Heritage, with our own team given access to research facilities that might enable further information to be gleaned.
Nothing emerged, however, and autumn and winter storms prevented any more work under water. The discovery was kept secret until its announcement at the start of 2009.
At last, pleasant spring weather allowed our vessel Calypso to put to sea. Back at the wreck site, we buried ourselves in silt, and in turbid water and zero visibility we searched around the cabin windows, largely by touch.
The results were intriguing.We lifted a number of objects that had lain under water for 60 years. There was a Thermos flask carrying the signature
of its owner, Wichert, probably a crewman, and a belt of his - the buckle was signed Wich. We also found boots and shoes.
The footwear indicated that at least one of the crew had survived. The Wehrmachts standing order was that, in case of a landing on water, aircrew had to remove their shoes and overclothes as a precaution against drowning.
New work began on the wreck in summer. To complete identification, we needed to find more items carrying names, but everything was lying under 1.5m of silt mixed with sea-shells. We couldnt do it without an airlift.
Clearing the plane has had to be done slowly and laboriously, to avoid the risk of damaging any documents, but a diver can spend only so long at a time at 20m-plus, even working in shifts.
As I write, a year has passed since we discovered the plane, and we have only recently managed to penetrate it. It was very narrow inside, and zero visibility complicated proceedings.
At first we recovered from the seabed personal items such as a shaving brush, toothpaste and brush, a torch, part of some goggles, and a cap that one of the crewmen must have kept since the Spanish Civil War.
Then our findings became more interesting: cassettes; part of a sword-belt bearing the name Koch; and a briefcase containing a folder with colourful air maps, each separated by foil sheets in case of fire.
In September 2009, the items were officially handed over to the Department of Underwater Heritage.
Then, while working through the cabin, we reached the desk of a radio operator. We were close now to our ultimate prize - the doors into the cockpit. We cleared the silt beneath the doors and opened the narrow left-hand fold, but the other was blocked by pieces of the planes load-bearing skin.
It took some time to clear this blockage and open the second fold. The cockpit was covered in silt, and we could see that much work lay ahead to remove it, but by now the weather was getting worse, so we had leave it for the year.
When we penetrate the cockpit, we expect to solve the final pieces of the mystery of this Ju-52.
Finding the works number on the instrument sub-panel and above the doors will give us 100% identification.
While in service, this plane seems to have undergone no fewer than seven basic modifications. Each Ju-52 had six usage options/designations: transport (E), regular (passenger) (R), trainer (H), military transport (St), sanitary (S), or parachute landing force (F).
Meanwhile, at the Department of Underwater Heritage, laborious work is being carried out to restore and preserve the maps we discovered.
Only a few pages have been processed so far, but we understand that the entire itinerary of every flight made by this plane is marked, as well as some marks in ink pencil.
When this work is complete, the life of this Iron Annie will be laid out before us.