# NTSB ATL89IA187: Boeing 737-400, N413US, Greensboro, NC, August 2, 1989

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: August 2, 1989, 10:55 local (14:55 UTC)
- Place: Greensboro, NC
- Coordinates: 36.119136, -79.890655 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.1191&lon=-79.8907&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 106 uninjured
- Status: Completed, report September 11, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 7931
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ATL89IA187
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/7931/pdf
- Page: https://openairdocs.org/ntsb/ATL89IA187

## Probable cause

FAILURE OF THE LINE MECHANIC, A CHECK MECHANIC, AND FIRST OFFICER TO IDENTIFY AND REMOVE THE WHEEL CHOCK FROM THE WHEEL WELL DURING THE REQUIRED INSPECTIONS.

## Sequence of events

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

- Gear not extended, landing - flare/touchdown
  - landing gear,normal retraction/extension assembly - foreign object (cause)
  - landing gear,normal retraction/extension assembly - jammed (cause)
  - maintenance,inspection - inadequate, company maintenance personnel (cause)
  - aircraft preflight - inadequate, copilot/second pilot (cause)

## Analysis

DURING APPROACH TO CHARLOTTE, THE MAIN GEAR WOULD NOT EXTEND. THE FLT DIVERTED TO GREENSBORO. THE RIGHT GEAR EVENTUALLY EXTENDED AFTER APPLYING EXTENSIVE G-FORCES, BUT THE LEFT GEAR WOULD NOT. AFTER LANDING, A 29-INCH WHEEL CHOCK WAS FOUND WEDGED BETWEEN THE RADIUS OF THE LEFT WHEEL WELL AND THE INBOARD WHEEL WHICH PREVENTED THE LEFT GEAR FROM FALLING DOWN. THE AIRPLANE HAD BEEN POSITIONED SEVERAL TIMES THE NIGHT BEFORE, AND THE MECHANICS RECALLED PLACING THE CHOCKS IN THE WHEEL WELL. AN A-CHECK, AND A WALK-AROUND INSPECTION, HAD BEEN COMPLETED PRIOR TO THE FLIGHT'S DEPARTURE FROM WASHINGTON. EACH INSPECTION REQUIRED AN INSPECTION OF THE WHEEL WELL AREA. THE FIRST OFFICER STATED THAT HE DIDN'T SEE THE CHOCK WHICH WAS MARKED WITH YELLOW REFLECTIVE TAPE. A FLASHLIGHT WAS USED DURING THE INSPECTION.

## Aircraft

- Registration: [N413US](https://openairdocs.org/deregistered/N413US-2003-09-18), registration cancelled 2003-09-18, S/N 23882, built 1988 (OpenAirDocs)
- Reported make and model: BOEING 737-400
- Registry model: [Boeing 737-401](https://openairdocs.org/model/boeing-737-401) (registry code 138449B) (OpenAirDocs)
- Registry engine: [CFM International CFM56 series](https://openairdocs.org/engine/cfm-international-cfm56-series) (registry code 13802, turbo-fan) (OpenAirDocs)
- Category: Airplane
- Serial number: 23882
- Airframe hours: 2193
- Engines: GE 56-382 22100 lbs thrust turbo fan
- Damage: Minor damage
- Flight: Part 121
- Operator: Piedmont Airlines
- Registered owner: Wilmington Trust Co.
- Airworthiness certificate: Standard, Transport
- Last inspection: Continuous airworthiness, June 29, 1989, 354 hours before
- Departed: WASHINGTON, DC
- Destination: CHARLOTTE, NC
- Flight plan: IFR
- Airport: GSO, Greensboro, runway 23, 10,001 × 150 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 48; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; seat: left; flight hours: 14,019 total, 7,944 in this make and model, 189 in the last 90 days, 89 in the last 30 days, 10 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: 340° at 8 knots
- Visibility: 4 statute miles
- Lowest ceiling: none
- Temperature: 81 °F, dew point 68 °F
- Altimeter: 30.00 inHg
- Observed at: GSO

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Incident 19890802065989I](https://openairdocs.org/incident/19890802065989I), Aug 2, 1989: Boeing 737401, Greensboro, NC, Minor damage. Gear jammed in up position got all but left main down by g force. Landed on 3 gears. Mechanic put chock in gear well

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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