Embraer EMB-145EP N13929 and Cessna 172P N54120 incident near Gulfport, Mississippi

Probable cause

the Gulfport control tower local controller cleared two aircraft for takeoff from runways with intersecting departure flight paths without ensuring the first aircraft had passed the flight path intersection prior to clearing the second aircraft for takeoff.

NTSB analysis

N54120, a Cessna 172, called ready for takeoff on runway 18. The tower local controller (LC) cleared the Cessna for takeoff on runway 18. Sixteen seconds later, (Jet Link) BTA2555/Embraer ERJ145 called ready for takeoff for runway 14. The LC cleared the ERJ145 for takeoff. The departure flight path of runway 18 intersects runway 14. The local controller was working the LC position combined with Ground Control (GC), Clearance Delivery (CD)/Flight Data (FD) and Controller-In-Charge (CIC) positions. The Cessna was airborne crossing taxiway Charlie when the ERJ145 passed through the intersecting flight paths airborne in front of the Cessna. Both aircraft were estimated to be at 300 feet. No traffic was issued to either aircraft by the LC. Closest proximity was estimated to be 0 feet vertically and 300 feet laterally. According to FAA Order 7110.65, Air Traffic Control, paragraph 3-9-8, Intersecting Runway Separation:

a. Issue traffic information to each aircraft operating on intersecting runways.

b. Separate departing aircraft from an aircraft using an intersecting runway, or runways when the flight paths intersect, by ensuring that the departure does not begin takeoff roll until one of the following exists:

1. The preceding aircraft has departed and passed the intersection, has crossed the departure runway, or is turning to avert any conflict.

Text from the NTSB. Open the NTSB docket for OPS11IA673 for the full record.