# NTSB CHI89IA084: Fokker F-27 MK500, N511AW, Moline, IL, May 4, 1989

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: May 3, 1989, 20:07 local (May 4, 1989, 01:07 UTC)
- Place: Moline, IL
- Coordinates: 41.480182, -90.480628 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=41.4802&lon=-90.4806&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed, report August 26, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 14283
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI89IA084
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14283/pdf
- Page: https://openairdocs.org/ntsb/CHI89IA084

## Probable cause

MATERIAL FAILURE OF THE LANDING GEAR RETRACTION AND EXTENSION ASSEMBLY. INADEQUATE MAINTENANCE AND TROUBLESHOOTING PROCEDURES IN COMPANY DIRECTIVES WERE FACTORS IN THIS INCIDENT.

## Sequence of events

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

- Main gear collapsed, landing - flare/touchdown
  - landing gear,normal retraction/extension assembly - binding(mechanical) (cause)
  - maintenance,inspection - inadequate, company/operator management (cause)
  - procedure inadequate, company/operator management (contributing factor)

## Analysis

THE AIRPLANE LANDED WITH THE RIGHT MAIN LANDING GEAR NOT FULLY DOWN AND LOCKED. WHEN THE AIRPLANE TOUCHED DOWN, THE LANDING GEAR WOULD NOT SUPPORT THE WEIGHT OF THE AIRPLANE AND IT COLLAPSED. THE AIRPLANE SUSTAINED MINOR DAMAGE AND NEITHER OF THE TWO CREWMEMBERS ABOARD THE AIRPLANE WERE INJURED. THE LANDING GEAR MALFUNCTION HAD BEEN DISCOVERED WHEN THE LANDING GEAR WOULD NOT CYCLE PROPERLY DURING A MAINTENANCE CHECK FLIGHT. WHEN THE FLIGHT CREW ATTEMPTED TO LOWER THE LANDING GEAR AFTER RETRACTION, THE RIGHT MAIN LANDING GEAR WOULD NOT FULLY EXTEND. ATTEMPTS TO EXTEND THE LANDING GEAR USING EMERGENCY PROCEDURES WERE NOT SUCCESSFUL.

## Aircraft

- Registration: [N511AW](https://openairdocs.org/deregistered/N511AW-1994-04-11), registration cancelled 1994-04-11, S/N 10690 (OpenAirDocs)
- Reported make and model: FOKKER F-27 MK500
- Registry model: [Fokker F.27MK 500](https://openairdocs.org/model/fokker-f-27mk-500) (registry code 4990629) (OpenAirDocs)
- Category: Airplane
- Serial number: E 10690
- Airframe hours: 6005
- Engines: Rolls-Royce DART 552-7R 508 horsepower turbo prop
- Damage: Minor damage
- Flight: Part 121
- Operator: Air Wisconsin
- Registered owner: Wilmington Trust Co.
- Airworthiness certificate: Standard, Transport
- Last inspection: Continuous airworthiness, April 21, 1989, 81 hours before
- Departed: ORD, CHICAGO, IL
- Flight plan: IFR
- Airport: MLI, Quad Cities, runway 27, 8,507 × 150 ft, concrete

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; 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: 17,121 total, 2,262 in this make and model, 14,988 as pilot in command, 175 in the last 90 days, 66 in the last 30 days, 6 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/bright
- Wind: 200° at 5 knots
- Visibility: 12 statute miles
- Lowest ceiling: none
- Temperature: 61 °F, dew point 43 °F
- Altimeter: 30.00 inHg
- Observed at: MLI

## Other investigations on N511AW (1)

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.

- [NTSB CHI88IA015](https://openairdocs.org/ntsb/CHI88IA015), Oct 29, 1987: Fokker F27-500 (N511AW), Chicago, IL, incident, no damage

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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