Background
A certified professional controller (CPC) was providing on-the-job training to a developmental controller (DEV) at the North Local Control position. The DEV was certified on all positions except local control, having completed 150 of the allotted 180 hours of training. The active runway configuration (Plan X) involved landings and departures on runways 4 and 9.
Incident Sequence
Lufthansa flight 437 (DLH437), an Airbus A319, was instructed to taxi into position and hold on runway 4L, awaiting the exit of a previous arrival. Chautauqua flight 7826 (CHQ7826), an Embraer E145, was issued taxi-into-position-and-hold on runway 9L and advised that DLH437 would depart from runway 4L. The distance from the runway 9L threshold to the intersection with runway 4L is approximately 1,900 feet.
After the preceding traffic on runway 9L exited, DLH437 was cleared for takeoff. Thirty-five seconds later, the DEV cleared CHQ7826 for takeoff on runway 9L. Neither the Local Monitor nor the CPC heard the DEV issue this clearance. Shortly thereafter, the Local Monitor observed both aircraft rolling and alerted the CPC, who canceled takeoff instructions to both aircraft. The closest proximity between the two aircraft was 100 feet when both stopped at the runway intersection. The Airport Movement Area Safety System (AMASS) did not generate an alarm because it lacked crossing runway logic.
Aftermath
The pilot of DLH437 later contacted the tower and reported that they had observed the E145 and were in the process of aborting the takeoff when the controller instructed them to stop. No damage or injuries were reported.