A Polish 737 Boeing airliner, carrying 89 passengers, nearly crashed with another plane in mid-air over London’s Heathrow Airport because its pilots did not understand English, The Daily Mail reported from an investigation concluded Tuesday by the Air Accidents Investigations Branch (AAIB).

The June 2007 incident occurred after the navigation system on the LOT Polish Airlines plane shut down and the pilots had to rely on instructions given in English by air traffic controllers. The plane flew around for nearly half an hour as the pilots struggled to understand the instructions.

The navigation problems occurred because the co-pilot had entered the wrong coordinates before takeoff, causing the navigation system — which also runs the auto-pilot — to shut down.

The pilots were then forced to use emergency controls and rely on directions from the ground.

On several occasions, the co-pilot steered the plane in a different direction than the air traffic controllers instructed, The Mail reported.

The airliner almost crashed into another airplane at one point, forcing the other plane to change its course.

They were eventually guided to the runway, which enabled the pilots to land safely.

The incident caused a “Short Term Conflict Alert,” not serious enough to be termed a “near-miss,” a spokesperson for the Aviation Accidents Investigation told The Daily Mail.

"The crew of LOT 282 were not able to communicate adequately the nature and extent of their problem. The commander, who was making the radio calls was not able to understand some of the instruction,” the AAIB report said.

Only a few Polish pilots understand English, which is the international language of aviation, The Daily Mail reported. Many countries have failed to ensure that their pilots were proficient in Engilsh by March this year, a deadline set by the International Civil Aviation Organization.

Click here to read more on this story from The Daily Mail.