An investigation has been launched after a Battle of Britain Memorial Flight (BBMF) Lancaster bomber suffered an engine problem earlier, the RAF has confirmed.

The Avro Lancaster PA474, which had been taking part in the RAF Waddington Families Day in Lincolnshire, sent a general emergency alert as black smoke was seen coming from one of its four engines.

According to the RAF, the crew of the iconic World War Two aircraft “diagnosed unusual engine behaviour” and returned to its base at RAF Coningsby “as a precautionary measure”.

An RAF spokesperson added: “Crew are well trained to handle such events, and an investigation of the aircraft has been launched.”

None of the aircrew were injured and it’s not known if the investigation will impact upcoming scheduled appearances.

The BBMF also operates five Spitfires, two Hurricanes and a C47 Dakota.

The Lancaster is the most famous and successful RAF bomber of World War Two.

Out of 7,377 that were built, the PA474 is one of only two airworthy Lancasters left in the world.