# NTSB CHI89MA047: Dassault-Breguet Falcon 900, N901B, South Bend, IN, January 20, 1989

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Major investigation · Final report
- Date: January 20, 1989, 08:14 local (13:14 UTC)
- Place: South Bend, IN
- Coordinates: 41.720909, -86.33094 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.7209&lon=-86.3309&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report July 12, 1991
- Report: Approved by Office Director
- NTSB case key (mKey): 14428
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI89MA047
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14428/pdf
- Page: https://openairdocs.org/ntsb/CHI89MA047

## Probable cause

FAILURE OF THE THRUST REVERSER ACTUATOR LINKS DUE TO A MANUFACTURING/DESIGN PROBLEM. FACTORS RELATED TO THE ACCIDENT WERE: THE ADVERSE RUNWAY CONDITIONS AND THE CROSSWIND.

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, landing - roll
  - thrust reverser,actuator - failure,total (cause)
  - acft/equip,inadequate design, manufacturer (contributing factor)
  - airport facilities,runway/landing area condition - snow covered (contributing factor)
  - airport facilities,runway/landing area condition - slush covered (contributing factor)
  - landing gear,tire - failure,total
- Loss of control - on ground/water, landing - roll
  - weather condition - crosswind (contributing factor)
  - directional control - not possible
- Main gear collapsed, landing

## Analysis

THE PLTS RPRTD THAT WHILE LNDG ON A SNOW & SLUSH CVRD RWY, THEY USED FULL REVERSE THRUST & MAX BRAKING WITH ANTI-SKID, BUT THE ACFT DID NOT DECELERATE. THEY SELECTED THE #2 BRAKE SYS WITHOUT ANTI-SKID. SUBSEQUENTLY, THE MAIN TIRES FAILED (BLEW-OUT) & THE ACFT SLID OFF THE LEFT SIDE OF THE RWY, COLLAPSING THE LEFT MAIN GEAR. INV REVEALED THAT BOTH THRUST REVERSER ACTUATOR LINKS ON THE #2 ENG HAD FAILED. WITH THESE FAILURES THE #2 ENG WOULD HAVE CONTD TO PROVIDE FWD THRUST,PROPELLING THE ACFT DWN THE RWY. (ON THIS MODEL OF ACFT, ONLY THE #2 ENG WAS EQUIPPED WITH REVERSE THRUST CAPABILITY.) METALLURGICAL EXAMS OF THE FWD ROD END FITTINGS OF BOTH REVERSE THRUST ACTUATOR LINKS (P/N 8140-06LK) REVEALED THE BEARING LOOPS HAD FAILED FROM OVERSTRESS. MANDATORY SERVICE BULLETIN (S/B) F900-78-1 WAS ISSUED ON 5/18/89 TO PROVIDE A SAFETY SYSTEM TO PREVENT ACTIVATION OF THE THRUST REVERSER ABOVE IDLE, WHILE THE AIRCRAFT IS ON THE GROUND. ALSO, MANDATORY S/B F900-78-2 WAS ISSUED ON 7/19/89 TO REINFORCE THE THRUST REVERSER ACTUATING MECHANISMS.

## Aircraft

- Registration: N901B (not matched to a registry record)
- Reported make and model: DASSAULT-BREGUET FALCON 900
- Category: Airplane
- Serial number: 024
- Airframe hours: 886
- Engines: GARRETT TFE-731 4500 lbs thrust turbo fan
- Damage: Substantial damage
- Flight: Executive/Corporate, Part 91
- Registered owner: Bristol-Myers Co.
- Airworthiness certificate: Standard, Transport
- Last inspection: Continuous airworthiness, December 22, 1988, 74 hours before
- Departed: PHL, PHILADELPHIA, PA
- Flight plan: IFR
- Airport: SBN, Michiana Regional, runway 27, 7,089 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 42; flight instructor, commercial, flight engineer, airline transport; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: right; flight hours: 10,985 total, 500 in this make and model, 8,400 as pilot in command, 119 in the last 90 days, 52 in the last 30 days, 2 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 330° at 13 knots, gusting 27
- Visibility: 7 statute miles
- Lowest ceiling: 4,100 ft overcast
- Temperature: 30 °F, dew point 25 °F
- Altimeter: 30.00 inHg
- Observed at: SBN, 5 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 19890120001059A](https://openairdocs.org/incident/19890120001059A), Jan 20, 1989: Amd FALCON900, South Bend, IN, Substantial damage. Appears thrust reverse actuated without aircraft firmly on runway,broke rods,stopped full deploy. Antiskid shut off

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.

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