# NTSB CHI87IA135: Mcdonnell Douglas DC-9-82, N224AA, Chicago, IL, May 30, 1987

- Type: NTSB incident investigation
- Classification: Incident · No injuries · Incident investigation · Final report
- Date: May 29, 1987, 19:58 local (May 30, 1987, 00:58 UTC)
- Place: Chicago, IL
- Location: 41.8500° N, 87.6501° W: Placed by OpenAirDocs: center of Chicago, IL, within about 9 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=41.8500&lon=-87.6501&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: No injuries
- Injuries: 83 uninjured
- Status: Completed, report July 10, 1989
- Report: Approved by Office Director
- NTSB case key (mKey): 13667
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI87IA135
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/13667/pdf
- Page: https://openairdocs.org/ntsb/CHI87IA135

## Sequence of events

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

- Near collision between aircraft, climb
  - atc clearance - improper, atc personnel(lcl/gnd/clnc) (cause)
  - identification of aircraft on radar - improper, atc personnel(dep/apch) (cause)
  - supervision - inadequate, atc personnel(supervisor) (contributing factor)

## Analysis

AMERICAN FLT 637 WAS ON DEPARTURE FROM CHICAGO-O'HARE INTL ARPT (ORD), CLIMBING THRU 7300' MSL, WHEN IT PASSED AMERICAN FLT 393 WITH APRX 500' VERTICAL SEPN & 1/4 MI HORIZONTAL SEPN. THIS OCCURRED AFTER AN AIR TRAFFIC ASSISTANT, WHO WAS WORKING THE CLNC DELIVERY PSN AT ORD, HAD ISSUED THE SAME TRANSPONDER CODE TO FLT 637 & UNITED FLT 441. SUBSEQUENTLY, A TRAINEE CONTROLLER (CTLR), WHO WAS WORKING AT THE WEST DEPARTURE RADAR CONTROL POSITION, MISTOOK FLT 441'S TARGET AS THAT OF FLT 637 & ISSUED CLIMB INSTRUCTIONS TO FLT 637. THE INSTRUCTOR DID NOT RECOGNIZE THE ERROR IN TIME TO CORRECT THE CTLR'S ACTION.

## Aircraft

- Registration: [N224AA](https://openairdocs.org/deregistered/N224AA-2008-10-29), registration cancelled 2008-10-29, S/N 49174, built 1983 (OpenAirDocs)
- Reported make and model: MCDONNELL DOUGLAS DC-9-82
- 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: P&W JT8D 20850 lbs thrust turbo fan
- Damage: No damage
- Flight: Part 121
- Registered owner: American Airlines
- Airworthiness certificate: Standard, Transport
- Destination: LAS, LAS VEGAS, NV
- Flight plan: IFR

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 39; 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: 10,000 total

## Weather

- Conditions: Visual (VMC), Day
- Visibility: 15 statute miles
- Lowest ceiling: none
- Altimeter: 29.00 inHg

## Other investigations on N224AA (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 FTW96IA237](https://openairdocs.org/ntsb/FTW96IA237), Jun 5, 1996: McDonnell Douglas DC-9-82 (MD-82) (N224AA), Albuquerque, NM, incident, minor damage. Probable cause: the flightcrew's inadvertent encounter with windshear at low altitude. Factors were: variable winds, high density altitude, and the FAA's inadequate location/height of the LLWAS sensor.

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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