# NTSB NYC94LA144: de Havilland DHC-8-311, N433AW, Washington, DC, August 1, 1994 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: August 1, 1994, 17:45 local (21:45 UTC) - Place: Washington, DC - Location: 38.9475° N, 77.4599° W: Placed by OpenAirDocs at WASHINGTON DULLES INTL (IAD), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=38.9475&lon=-77.4599&mi=10 - Phase of flight: [Standing](https://openairdocs.org/ntsb-phases/150) (OpenAirDocs' grouping) - Highest injury: Minor injuries - Injuries: 1 minor, 53 uninjured; on the ground: 1 minor - Status: Completed, report December 7, 1994 - Report: Approved by Office Director - NTSB case key (mKey): 38807 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=NYC94LA144 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/38807/pdf - Page: https://openairdocs.org/ntsb/NYC94LA144 ## Probable cause THE VEHICLE OPERATOR'S IMPROPER HANDLING OF THE BAGGAGE TRACTOR RESULTING IN LOSS OF CONTROL OF A SECOND BAGGAGE TRACTOR BEING PUSHED AND ITS SUBSEQUENT COLLISION WITH THE AIRPLANE. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - On ground/water collision with object, standing - object - vehicle - equipment,other - improper use of, driver of vehicle (cause) ## Analysis THE COMMUTER AIRPLANE WAS PARKED AT THE GATE WITH 50 SEATED PASSENGERS, AND A CREW OF THREE. THE ENGINES WERE STOPPED, THE CHOCKS WERE IN PLACE, THE PILOTS WERE SEATED IN THE COCKPIT COMPLETING PAPER WORK, AND THE AIRSTAIR DOOR WAS OPEN. A BAGGAGE TRACTOR (DH4) HAD BROKEN DOWN, AND THE OPERATOR ASKED ANOTHER BAGGAGE TRACTOR OPERATOR (DH65), TO PUSH HIM TO THE END OF THE RAMP TO AWAIT SERVICE. DH65 BEGAN PUSHING DH4, WHICH STEERED TO PASS 15 TO 20 FEET TO THE LEFT OF THE AIRPLANE. AS DH4 ENTERED THE SERVICE ROAD, IT BEGAN TO TURN RIGHT TO HEAD WEST. AT THIS POINT, DH65 HAD NOT YET ENTERED THE SERVICE ROAD AND CONTINUED SOUTHWESTERLY FOR AN ADDITIONAL FEW FEET. AT THIS TIME, THE LEFT SIDE OF DH65'S FRONT HITCH, CONTACTED THE RIGHT SIDE OF DH4'S REAR HITCH. THE HITCH CONTACT JERKED THE FRONT OF DH65 TO THE RIGHT WHICH CAUSED THE DRIVER TO BE PITCHED HALFWAY OFF THE LEFT SIDE OF DH65. AS THE DRIVER FELL, HIS HAND PULLED DOWN ON THE STEERING WHEEL AND HIS FOOT PRESSED DOWN ON THE ACCELERATOR PEDAL. DH65 THEN VEERED INTO THE NOSE OF THE AIRPLANE. ## Factual narrative On August 1, 1994, at 1745 eastern daylight time, a DeHavilland DHC-8-311, N433AW, operated by Atlantic Coast Airlines and doing business as United Express Flight 6578, was substantially damaged while parked at a gate and struck by a ground support vehicle, at Dulles International Airport, Washington, D.C. The three crewmembers and 50 passengers were not injured. Visual meteorological conditions prevailed and a instrument flight rules flight plan had been filed for the flight operating under 14 CFR 121. In the NTSB Form 6120.1/2, the Regional Flight Manager stated that the airplane was parked at the passenger gate and was being prepared for departure. The engines were stopped, the chocks were in place, the pilots were seated in the cockpit completing weight and balance paperwork, and the airstair door was open. He further stated: "...Baggage tractor DH4 had broken down. The operator asked the operator of baggage tractor DH65 to push disabled DH4 to the west end of the ramp where it could await servicing. DH65 began pushing DH4...DH4 steered so as to pass 15 to 20 feet to the left of [N433AW's] nose when approaching the service road. As DH4 entered the service road it began to turn right to head west. At this point DH65 had not yet entered the service road and for the next few feet continued in a somewhat southwesterly direction. The left side of the hitch on the front of DH65 apparently contacted the right side of the hitch on the rear of DH4. Since [they]...were actually heading in different directions (DH4 west and DH65 southwest), the effect of the hitch interaction was to jerk the front of DH65 sharply to the right causing the driver to lose his seat and be pitched halfway off the left side of DH65... the driver's right hand pulled the steering wheel down to the right, and his right foot pressed on the accelerator pedal...DH65 smashed into the left side of the nose of 433 doing extensive damage..." ## Aircraft - Registration: N433AW (not matched to a registry record) - Reported make and model: de Havilland DHC-8-311 - Category: Airplane - Serial number: 305 - Airframe hours: 6283 - Engines: P&W PW-123 2000 horsepower turbo prop - Damage: Substantial damage - Flight: Part 121 - Operator: Atlantic Coast Airlines, doing business as United Express - Registered owner: Air Wisconsin Inc. - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, July 18, 1994, 122 hours before - Flight plan: IFR - Airport: IAD, Washington-Dulles ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 29; airline transport, commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 6,200 total, 3,000 in this make and model, 150 in the last 90 days ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: 2,700 ft broken - Temperature: 84 °F, dew point 73 °F - Altimeter: 30.00 inHg - Observed at: IAD 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.