Air traffic controllers repeatedly asked the pilots who overflew Minneapolis by 150 miles why they did not heed radio calls, according to newly-released transcripts.

The Northwest Airlines flight on 21 October had been out of contact for 77 minutes before the pilots responded.

The pilots told controllers right away that they had been "distracted", but did not give details, according to the radio conversations released by federal authorities.

After almost 90 seconds of conversation about the route they should take to Minneapolis, the controller said: "I just have to verify that the cockpit is secure."

"It is secure, we got distracted," one of the pilots responded. The transcript says the pilot then said that they never heard a call from the ground.