CHI95LA031

The captain reported that after being cleared to taxi for departure, the tug driver pushed the airplane back to a spot close to the gate. To conserve fuel, only the right engine was started for taxiing. Due to the position of other aircraft and closeness of the gate, the captain elected to make a 270 degree right turn to taxi to the runway. During the turn, jet blast from the right engine overturned three baggage carts. One of the carts hit a ground worker, which resulted in serious injury. The company operations manual stated that taxi thrust should be kept below 45% N1. The flight data recorder indicated the right engine N1 peaked at 49.73% as the throttle was advanced to initiate the turn.

On November 6, 1994, about 1305 central standard time, an airline ground service employee was seriously injured when a Boeing 757-251, N518US, operated by Northwest Airlines, Inc., blew over a baggage cart as the airplane departed the gate at the Minneapolis/St. Paul International Airport, St. Paul, Minnesota. The scheduled domestic flight was operating under 14 CFR Part 121, as Flight 100 with a destination of Washington, D.C. There was no damage to the airplane. An IFR flight plan was filed, and visual meteorological conditions prevailed at the time.

The Captain reported in his written statement that the tug driver "pushed us to a spot close to the gate with our left wing overlapping some carts." After the airplane was pushed back from gate 63, the right engine was started. The Captain reported, "After assessing the situation, I figured that I was too close to turn left out of the gate. With only one engine going I staged my turn. As I slowed I straightened the nose rather than add power... ."

An approximate 270 degree right turn was made on the ramp to taxi to the taxiway. While the airplane was making the turn, jet blast from the right engine overturned three baggage carts. The baggage carts were located near the left wing of N518US as it was parked in the gate. One of the baggage carts struck a ground service employee. The employee received a dislocated shoulder and a fractured right hip, along with several minor contusions and abrasions.

Prior to this incident Northwest Airline's Boeing 757 Aircraft Operations Manual (AOM) stated that taxi thrust should be kept below 45% N1. According to flight data recorder information obtained from Northwest Airlines, the right engine N1 peaked momentarily at 49.73% as the throttles were advanced to initiate the turn. The throttles were then reduced and N1 was decreased to 44% or below. Since this accident, Northwest Airlines has revised the AOM to state, "Always verify with ground personnel that the area behind the aircraft is clear if you must exceed 40% N1." In addition to this change in the AIM, an Exhaust Velocity Contours chart was added.