# NTSB MIA95LA218: Boeing 737-4Q8, N405KW, Miami, FL, September 6, 1995 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: September 6, 1995, 12:20 local (16:20 UTC) - Place: Miami, FL - Location: 25.7954° N, 80.2901° W: Placed by OpenAirDocs at MIAMI INTL (MIA), within about a mile (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=25.7954&lon=-80.2901&mi=10 - Phase of flight: [Pushback/towing](https://openairdocs.org/ntsb-phases/200) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 78 uninjured - Status: Completed, report April 1, 1996 - Report: Approved by Office Director - NTSB case key (mKey): 37823 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=MIA95LA218 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/37823/pdf - Page: https://openairdocs.org/ntsb/MIA95LA218 ## Probable cause IMPROPER PLANNING/DECISION BY THE COMPANY DRIVER OF THE VEHICLE (PAYMOVER) AND UNCOMMANDED MOVEMENT OF THE PAYMOVER FOR UNDETERMINED REASONS. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - On ground/water collision with object, taxi - pushback/tow - object - ground power unit (cause) - miscellaneous equipment - uncontrolled, driver of vehicle (cause) - planning/decision - improper, driver of vehicle (cause) ## Analysis A GROUND SUPPORT EMPLOYEE WAS ATTEMPTING WITHOUT ASSISTANCE TO CONNECT THE TOWBAR TO THE PAYMOVER TO PUSH BACK THE AIRPLANE FROM THE GATE. THE PAYMOVER REPORTEDLY MOVED UNCOMMANDED REARWARD AND COLLIDED WITH OTHER GROUND EQUIPMENT. THE ENGINE OF THE PAYMOVER WAS SHUT DOWN AND A GROUND SUPPORT SUPERVISOR BOARDED THE PAYMOVER TO AGAIN ATTEMPT TO PUSHBACK THE AIRPLANE. THE SUPERVISOR STATED THAT WHILE STANDING ON THE PAYMOVER WITH THE PARKING BRAKE RELEASED AFTER STARTING THE ENGINE, THE PAYMOVER MOVED UNCOMMANDED FORWARD. ATTEMPTS TO STOP IT WERE UNSUCCESSFUL. THE PAYMOVER COLLIDED WITH THE TOWBAR THEN WITH A GROUND POWER UNIT WHICH WAS PUSHED INTO THE FUSELAGE. THE NORMAL BRAKE SYSTEM WHICH WAS NOT REPAIRED AFTER THE ACCIDENT WAS OPERATIONALLY TESTED AFTER THE ACCIDENT; NO DEFECTS WERE NOTED. OPERATIONAL TEST OF NEUTRAL SAFETY SWITCH COULD NOT DUPLICATE THE MALFUNCTION. SIMILAR DISCREPANCIES REGARDING UNCOMMANDED MOVEMENT OF THE PAYMOVER WERE REPORTED. ## Factual narrative On September 6, 1995, about 1220 eastern daylight time, a Boeing 737-4Q8, N405KW, registered to International Lease Finance Corporation, operated by Carnival Air Lines, Inc., was substantially damaged while attempting to push back from a gate at the Miami International Airport, Miami, Florida. Visual meteorological conditions prevailed at the time and an IFR flight plan was filed for the 14 CFR Part 121 scheduled, international, passenger flight. The captain, first officer, cabin crew of 4, and 72 passengers were not injured. The flight was originating at the time of the accident. An employee of the company that provides ground support stated that the towbar was first connected to the airplane. He then positioned the paymover and attempted without assistance to connect the towbar to the paymover. The paymover then moved uncommanded rearward and collided with a container loader. The engine of the paymover was then shut down and the captain and a ground support supervisor who were on the flight deck inspected the airplane for damage; none was noted. The captain returned to the flight deck and the supervisor boarded the paymover. The supervisor stated that while standing on the paymover he disengaged the parking brake, applied the normal brakes, and started the engine of the paymover. Immediately after the engine was started the paymover moved uncommanded forward and attempts to stop the paymover using the normal brakes were unsuccessful. The paymover then collided with the towbar and a ground power unit which was pushed into the fuselage. The supervisor further stated that he operates similar paymovers daily. Following the accident, damage to the tug was repaired; however, the normal brake system of the tug was not worked on. The neutral safety switch which is designed to prevent starting of the engine with the transmission in drive or reverse was operationally checked for failure or malfunction, with no defects noted. Additionally, postaccident operational testing of the normal brakes at near full acceleration revealed no evidence of failure or malfunction. According to the cargo manager, the paymover involved in the accident had been in the shop for maintenance on August 28, 1995, and during testing, the engine started once while the transmission selector was in the "drive" position. Attempts to duplicate were unsuccessful. The paymover was returned to service. According to the training manager he experienced a similar occurrence involving uncommanded movement of the same paymover but the normal brakes stopped the paymover. He also stated that discrepancies with ground support equipment are verbally reported to maintenance. Review of maintenance work orders for the accident paymover from March 1994, to the date of the accident revealed no similar discrepancies. ## Aircraft - Registration: N405KW (not matched to a registry record) - Reported make and model: BOEING 737-4Q8 - Category: Airplane - Serial number: 24704 - Airframe hours: 10624 - Engines: CFM CFM-56-3C-1 22500 lbs thrust turbo fan - Damage: Substantial damage - Flight: Part 121 - Operator: Carnival Air Lines, Inc. - Registered owner: International Lease Finance Co - Airworthiness certificate: Standard, Transport - Last inspection: AAIP, August 19, 1995, 154 hours before - Departed: MIA - Destination: MTPP, PORT-AU-PRINCE, OF - Flight plan: IFR - Airport: MIA, Miami International ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; flight engineer, commercial, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 11,276 total, 5,455 in this make and model, 8,197 as pilot in command, 176 in the last 90 days, 58 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 130° at 7 knots - Visibility: 7 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 88 °F, dew point 73 °F - Altimeter: 29.00 inHg - Observed at: MIA, 1 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 19950906032649A](https://openairdocs.org/incident/19950906032649A), Sep 6, 1995: Boeing 7374Q8, Miami, FL, Substantial damage. Attempt to push back at gate. Trouble hooking bar. Paymotor made uncommanded run. Pushed power unit into fuselage. 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.