Langley Flying School – Cessna 172N – String Attached to Aircraft

C-GBPT, a Cessna 172N aircraft operated by Langley Flying School, was conducting touch and go takeoffs and landings at Vancouver/Boundary Bay, BC (CZBB). During the third and final touch and go on Runway 25 (which had a displaced threshold due to runway maintenance activities), a construction worker had a push broom removed from his hands shortly after the aircraft had flown overhead. The construction worker notified the airport operations manager (who was at the construction site) that a yellow string which he thought was trailing behind the aircraft, had entangled around his broom and subsequently removed the broom from his grasp. The broom traveled a short distance from the worker, got trapped beneath one of the construction vehicles, and broke free from the string. The airport operations manager called the tower and described what had happened. The tower attempted to contact the aircraft, however it had already departed the control zone on its way back to Langley Regional, BC (CYNJ). During cruise flight to CYNJ, the student pilot noticed an orange string going over the left wing’s leading edge and the left main landing gear. The instructor then looked behind the aircraft and noticed a long string attached to a stick, trailing approximately 200 feet behind the aircraft. The instructor contacted CYNJ ATC and advised them of the situation. A low pass was conducted at CYNJ where ATC confirmed that an object was trailing behind the aircraft. The aircraft landed on Runway 19 without further incident and stopped at the end of the runway. The instructor removed more than 200 feet of string, which was entangled between the left aileron and flap, and wrapped around the left main landing gear. The aircraft was removed from service pending further inspection for damage.