Diamond Aircraft Ind Inc DA 20 C1 N309EF and Cessna 150M N6211K accident near Van Nuys, California

Probable cause

Both pilots' failure to see and avoid each other, which resulted in an on-ground collision while taxiing. Contributing to the accident was the ground controller's failure to notify either pilot about the presence of the other airplane on the taxiway.

Both pilots’ failure to see and avoid each other, which resulted in an onground collision while taxiing. Contributing to the accident was the ground controller’s failure to notify either pilot about the presence of the other airplane on the taxiway.

NTSB analysis

A Cessna 150M and a Diamond DA20 collided on the ground during taxi operations. The student pilot of the Diamond received clearance from the ground controller to taxi to the run-up area for runway 16R via taxiway A1. The Diamond student reported that he stopped and looked in both directions before slowly proceeding left onto taxiway A (not A1 as instructed), at which point he observed the Cessna moving to his left around a jet on taxiway A and approaching his position. The Diamond student stopped to see what the Cessna pilot was going to do, and his airplane was then struck by the Cessna.

The Cessna pilot reported that, while taxiing on taxiway A as he approached A1, he observed an airplane at his 10-o'clock position, which appeared to be entering his path. The Cessna pilot applied the brakes but was unable to avoid striking the Diamond. The Diamond sustained damage to both propeller blades, and the Cessna sustained substantial damage to the leading edge of the left wing.

A review of airport surveillance video showed the Cessna taxiing on taxiway A and converging with the Diamond before the collision. The surveillance video and on-site documentation of the area did not reveal any obstructions that would have prevented the pilots from seeing and avoiding the other airplane before the collision.

Review of radio transmissions revealed that both pilots received and acknowledged clearance instructions from ground control; however, neither pilot was given information about the other aircraft's position on the taxiway. Seventeen seconds before the collision occurred, the ground controller began issuing instructions to another aircraft pilot; this transmission continued as the collision occurred. It is likely that the ground controller's attention was diverted to issuing instructions to the other aircraft pilot, which led to his failure to notify the accident pilots about the presence of the other airplane on the taxiway.

Text from the NTSB. Open the NTSB docket for WPR15LA154 for the full record.