IS THERE A PILOT IN THE PLANE?

In early June a small plane flew into Bulgarian airspace from the northwest and landed at what used to be a commercial airport near Vidin. Apparently, the aircraft refuelled. It is unclear whether the pilot or pilots got any on-the-ground assistance from anyone or just poured fuel into the plane's tank from canisters. Guards from a private security company that was supposed to protect the ruins of Vidin Airport noticed the activity and alerted the local police. But the aircraft was quicker. It took off before the police arrived.

The aircraft flew off eastward and landed at Targovishte, some 400 kilometres away. There, its passengers covered it with a piece of tarpaulin, installed a camera and left – before anyone could do a thing.

Since then the Bulgarian police and prosecutors have been unable to identify who the aircraft belonged to, why it flew through half of Bulgaria without getting intercepted and most importantly who and why flew it into this country one stormy night last June.

Reportedly, the aircraft, a 60-year-old Piper PA-23-250 Aztec, belonged to a Lithuanian, a former Air Force captain. The man, based in Panevėžys, had put it up for sale on an aviation Internet site in the UK. The asking price was $35,000. The Piper apparently took off in Lithuania, crossed Poland and Slovakia, and landed at a small airfield at Hajdúszoboszló, Hungary, where it refuelled. The Hungarian police approached but the plane took off as soon as their cars went onto the runaway. The plane then continued its journey over Serbia and Romania, and landed at Vidin. Through its voyage over several East European NATO member states it was followed by military interceptors. Except in Bulgaria.

Various Bulgarian officials, including the defence and the interior ministers, explained the aircraft was not followed because it flew at a very low altitude, 500 metres at most, to avoid a brewing storm.

Once the plane was discovered at Targovishte the local police checked it for explosives, reconnaissance equipment and narcotics. They found none.

An assortment of experts of various shades and hues were quick to promulgate wildly divergent theories about what the Piper was doing over Bulgaria. Some immediately saw Vladimir Putin's long hand: the plane was either on a top secret reconnaissance mission or just tested what NATO's response would be. Others conjectured illegal drugs or arms. Some thought the plane had been hijacked by Ukrainians desperate to flee the war. Interior Minister Boyko Rashkov said his department would release any information as soon as it became available.

So far, nothing has happened. The plane remains covered with tarpaulin on the long-abandoned airport at Targovishte. Its pilot, pilots or passengers have vanished into thin air.