SEVENTY year ago, Bicester Aerodrome played an important, if secret, role in ferrying Blenheim bomber aircraft to Finland.

February marked the anniversary of that operation.

By the late 1930s, Bristol Blenheim aircraft had been sold to a number of foreign air forces including Turkey, Yugoslavia and Finland.

In 1937, Finland received a batch of 18 aircraft and was granted a licence for the country to produce its own version.

War broke out in September 1939, but by November the planes were still not finished.

So the British government said Finland could have aircraft from existing RAF stocks.

Twelve planes were converted for the Finnish Air Force and in January five officers and 12 Flight Masters/Wireless Operators turned up at Filton and brought them to Bicester Airfield for the first leg of the journey home.

The Blenheim conversions carried Finnish Air Force national swastika markings which had to be whitewashed to cover them in case the planes were accidentally mistaken for enemy aircraft by local anti-aircraft defences.

But overnight rain removed much of the whitewash that disguised the Finnish Air Force markings.

Passing civilians reported that there were captured German aircraft at the airfield and rumours of the event quickly spread through the town.

There were not enough Finnish pilots to fly the planes home so local volunteer RAF crews had to help out.

In order to prevent an embarrassing diplomatic incident with the Russians, the RAF volunteers were instructed to leave their bases secretly, wear only civilian clothing and carry no form of identification that could link them with the Royal Air Force.

Many of the volunteers’ families thought that their relatives had gone absent without leave or had deserted.

The volunteer crews arrived at Bicester on February 21. They were briefed and issued with false identity papers.

The team left the town on February 23 flying to Dyce Aerodrome, near Aberdeen.

Again, rain washed the whitewash camouflage covering the markings leaving the planes open to attack from British or German forces.

Fortunately, they all arrived safely and left a day later to their designated base, a frozen lake sited at Juva in Finland.

The planes, however, were to make little difference to the Finnish war effort as the country was forced to capitulate to the Russians a few weeks after their arrival.

British airmen involved in the operation made their way to Helsinki where they were decorated for their achievement.

The story forms one of a series of lesser-known historic events connected with the wartime operations that took place at RAF Bicester.

Bomber Command Heritage want see the aerodrome used as a museum and education centre.