# NTSB CHI95LA031: Boeing 757-231, N518US, St Paul, MN, November 6, 1994 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Limited investigation · Final report - Date: November 6, 1994, 13:05 local (19:05 UTC) - Place: St Paul, MN - Coordinates: 44.880702, -93.199234 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.8807&lon=-93.1992&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Highest injury: Serious injuries - Injuries: 1 serious, 123 uninjured; on the ground: 1 serious - Status: Completed, report September 24, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 9792 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI95LA031 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9792/pdf - Page: https://openairdocs.org/ntsb/CHI95LA031 ## Probable cause FAILURE OF GROUND PERSONNEL TO IDENTIFY THE UNSAFE/HAZARDOUS SITUATION REGARDING THE CLOSENESS OF THE AIRPLANE TO THE BAGGAGE CARTS, AND THE CAPTAIN'S IMPROPER PLANNING/DECISION CONCERNING THE SITUATION. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Propeller blast or jet exhaust/suction, taxi - to takeoff - object - other - unsafe/hazardous condition - not identified, ground personnel (cause) - planning/decision - improper, pilot in command (cause) - object - other person ## Analysis 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. ## Factual narrative 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. ## Aircraft - Registration: [N518US](https://openairdocs.org/deregistered/N518US-2014-04-28), registration cancelled 2014-04-28, S/N 23206, built 1986 (OpenAirDocs) - Reported make and model: BOEING 757-231 - Registry model: [Boeing 757-251](https://openairdocs.org/model/boeing-757-251) (registry code 1384970) (OpenAirDocs) - Registry engine: [Pratt & Whitney PW2037](https://openairdocs.org/engine/pratt-whitney-pw2037) (registry code 52117, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 23206 - Airframe hours: 26862 - Engines: P&W 2037 37000 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: Northwest Airlines - Registered owner: First National Bank Of Boston - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, November 6, 1994, 4 hours before - Departed: MSP - Destination: DCA, WASHINGTON, DC - Flight plan: IFR - Airport: MSP, Minneapolis-St Paul Intl ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 3,260 total, 469 in this make and model, 132 in the last 90 days, 38 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 8 knots - Visibility: 15 statute miles - Lowest ceiling: none - Temperature: 48 °F, dew point 37 °F - Altimeter: 30.00 inHg - Observed at: MSP From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.