The National Transportation Safety Board has subpoenaed an American Airlines crew involved in a runway incident at John F. Kennedy Airport.

The crew was onboard an American Airlines plane headed for London in mid-January when it crossed an active runway at JFK without air traffic clearance. The move caused a Delta Air Lines plane headed for Santo Domingo in the Dominican Republic to abort takeoff.

No one was harmed, according to the investigators’ preliminary report. “Of the six crew and 153 passengers on DAL 1943, and 12 crew and 137 passengers on AA106, there were no injuries,” the report reads. Neither plane was damaged.

The American Airlines flight crew has refused to participate in recorded interviews, according to the report, though members have already submitted written statements.

“NTSB has determined that this investigation requires that the flight crew interviews be audio recorded and transcribed by a court reporter to ensure the highest degree of accuracy, completeness, and efficiency,” the report reads. “As a result of the flight crew’s repeated unwillingness to proceed with a recorded interview, subpoenas for their testimony have been issued.”

The Allied Pilots Association, the union representing the American Airlines crew members, defended them in a statement on Friday, saying recorded interviews have previously not been the standard.

The group said the use of electronic recording devices during interviews was “more likely to hinder the investigation process.” The statement argues the previous standard method of note-taking by the parties involved, or the use of stenographers, had “long been sufficient in producing accurate records and enabling the Board to produce thorough reports and findings.”

The statement continued: “Not only may the recording of interviews lead to less candid responses from those witnesses who may choose to proceed under such requirements, but the existence and potential availability of interview recordings upon conclusion of an investigation will tend to lead many otherwise willing crew members to elect not to participate in interviews at all."