# NTSB CHI89IA180: Mcdonnell Douglas MD-80, N490AA, Chicago, IL, August 31, 1989

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: August 31, 1989, 00:53 local (05:53 UTC)
- Place: Chicago, IL
- Location: 41.9769° N, 87.9081° W: Placed by OpenAirDocs at CHICAGO O'HARE INTL (ORD), within about a mile (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.9769&lon=-87.9081&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 4 uninjured
- Status: Completed, report September 11, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 14290
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI89IA180
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/14290/pdf
- Page: https://openairdocs.org/ntsb/CHI89IA180

## Probable cause (aircraft 2)

THE FAILURE OF THE CONTROLLER TO CLARIFY THE CONFUSING COMMUNICATIONS, TO CORRECT THE PILOT'S MISINTERPRETATION OF THE INSTRUCTIONS BEING GIVEN, AND THE FAILURE OF THE SUPERVISOR TO PROPERLY MONITOR THE SITUATION. FACTORS RELATED TO THE INCIDENT WERE THE PILOT'S MISINTERPRETATION OF THE CLEARANCE, THE CONTROLLERS EXPECTANCY AND AURAL PERCEPTION OF THE COMMUNICATIONS.

## Sequence of events

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

- Miscellaneous/other, takeoff - roll/run
  - communications - confusing, atc personnel(lcl/gnd/clnc) (cause)
  - supervision - inadequate, atc personnel(supervisor) (cause)
  - interpretation of instructions - improper, pilot in command (contributing factor)
  - interpretation of instructions - not corrected, atc personnel(lcl/gnd/clnc) (cause)
  - visual/aural perception, atc personnel(lcl/gnd/clnc) (contributing factor)
  - insufficient standards/requirements, faa(organization)
  - expectancy, atc personnel(lcl/gnd/clnc) (contributing factor)
- Miscellaneous/other, takeoff - initial climb
  - communications - confusing, atc personnel(lcl/gnd/clnc) (cause)
  - supervision - inadequate, atc personnel(supervisor) (cause)
  - interpretation of instructions - improper, pilot of other aircraft (contributing factor)
  - interpretation of instructions - not corrected, atc personnel(lcl/gnd/clnc) (cause)
  - visual/aural perception, atc personnel(lcl/gnd/clnc) (contributing factor)
  - expectancy, atc personnel(lcl/gnd/clnc) (contributing factor)

## Analysis (aircraft 2)

GLA268 (BEECH E33, N7135N) WAS CLEARED FOR TAKEOFF ON RWY 27L FROM THE BRANCH INTERSECTION BY A FULL PERFORMANCE LEVEL (FPL) CONTROLLER. AA9168 (MD-80, N490AA), WHICH HAD BEEN CLEARED TO RWY 27L BY A DEVELOPMENTAL CONTROLLER UNDER THE SUPERVISION OF THE FPL CONTROLLER, TWICE ACKNOWLEDGED THE TAKEOFF CLEARANCE FOR GLA268. GLA268 WAS AGAIN GIVEN TAKEOFF CLEARANCE BY THE FPL CONTROLLER. AT ABOUT THE SAME TIME AA9168 INITIATED ITS TAKEOFF ROLL FROM THE END OF THE RWY. AA9168 SAW GLA268 AHEAD OF IT AND QUERIED THE DEVELOPMENTAL CONTROLLER. AT THIS POINT THE FPL CONTROLLER TOOK OVER AND INSTRUCTED AA9168 TO ABORT ITS TAKEOFF. THE PILOT OF GLA268 REPORTED HE WAS ABOUT 50 FT AGL WHEN HE HEARD AA9168 ABORTING THE TAKEOFF.

## Aircraft 1

- Registration: [N490AA](https://openairdocs.org/deregistered/N490AA-2019-01-28), registration cancelled 2019-01-28, S/N 49683, built 1989 (OpenAirDocs)
- Reported make and model: MCDONNELL DOUGLAS MD-80
- Registry model: [Mcdonnell Douglas DC-9-82(MD-82)](https://openairdocs.org/model/mcdonnell-douglas-dc-9-82-md-82) (registry code 3022082) (OpenAirDocs)
- Registry engine: [Pratt & Whitney JT8D series](https://openairdocs.org/engine/pratt-whitney-jt8d-series) (registry code 52053, turbo-jet) (OpenAirDocs)
- Category: Airplane
- Engines: UNKNOWN UNKNOWN turbo jet
- Damage: No damage
- Flight: Positioning, Part 91
- Operator: American Airlines
- Airworthiness certificate: Standard, Transport
- Destination: CMH, COLUMBUS, OH
- Flight plan: IFR
- Airport: ORD, O'Hare Intl, runway 27L, 10,141 × 150 ft, asphalt

## Aircraft 2

- Registration: [N7135N](https://openairdocs.org/aircraft/N7135N), registered now, S/N CD-1139, built 1968 (OpenAirDocs)
- Reported make and model: BEECH E33
- Registry model: [Beech E33](https://openairdocs.org/model/beech-e33) (registry code 1151422) (OpenAirDocs)
- Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: CD1139
- Engines: CONTINENTAL IO-550-B1 300 horsepower reciprocating
- Damage: No damage
- Flight: Other work use, Part 91
- Operator: Great Lakes Aviation
- Destination: SPW, SPENCER, IA
- Flight plan: Company VFR
- Airport: ORD, O'Hare Intl, runway 27L, 10,141 × 150 ft, asphalt

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot, aircraft N490AA; airline transport; airplane ratings: multi-engine land; instrument ratings: airplane; medical: unknown, unknown
- Pilot, aircraft N7135N; age 24; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; flight hours: 2,521 total, 107 in this make and model, 1,558 as pilot in command, 250 in the last 90 days, 92 in the last 30 days, 8 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/bright
- Wind: 130° at 6 knots
- Visibility: 10 statute miles
- Lowest ceiling: none
- Temperature: 66 °F, dew point 57 °F
- Observed at: ORD

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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