# NTSB FTW89IA064: Mcdonnell Douglas DC-9-82, N820NY, Houston, TX, March 1, 1989 - Type: NTSB incident investigation - Classification: Incident · No injuries · Incident investigation · Final report - Date: March 1, 1989, 10:37 local (16:37 UTC) - Place: Houston, TX - Location: 29.9897° N, 95.4583° W: Placed by OpenAirDocs from NTSB’s distance and direction from GEORGE BUSH INTCNTL/HOUSTON (IAH), within about 2 miles (OpenAirDocs) - Nearby events: https://openairdocs.org/map.md?lat=29.9897&lon=-95.4583&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 185 uninjured - Status: Completed, report June 30, 1992 - Report: Approved by Office Director - NTSB case key (mKey): 22797 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=FTW89IA064 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/22797/pdf - Page: https://openairdocs.org/ntsb/FTW89IA064 ## Probable cause (aircraft 2) FAILURE OF THE TRACON FINAL APPROACH CONTROLLER TO ASSURE RADAR SEPARATION BETWEEN THE AIRCRAFT. FACTORS RELATED TO THE ACCIDENT WERE: INADEQUATE SUPERVISION BY THE ATC SUPERVISOR, EXCESSIVE WORKLOAD FOR THE CONTROLLER, UNCLEAR INSTRUCTIONS BY THE CONTROLLER, AND A MISUNDERSTANDING OF THE ATC CLEARANCE BY THE FLIGHT CREW OF CONTINENTAL FLIGHT 122. ## Probable cause (aircraft 1) FAILURE OF THE TRACON FINAL APPROACH CONTROLLER TO ASSURE RADAR SEPARATION BETWEEN THE AIRCRAFT. FACTORS RELATED TO THE ACCIDENT WERE: INADEQUATE SUPERVISION BY THE ATC SUPERVISOR, EXCESSIVE WORKLOAD FOR THE CONTROLLER, UNCLEAR INSTRUCTIONS BY THE CONTROLLER, AND A MISUNDERSTANDING OF THE ATC CLEARANCE BY THE FLIGHT CREW OF CONTINENTAL FLIGHT 122. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Near collision between aircraft, approach - iaf to faf/outer marker (ifr) - supervision - inadequate, atc personnel(supervisor) (contributing factor) - excessive workload (task overload), atc personnel(dep/apch) (contributing factor) - information unclear, atc personnel(dep/apch) (contributing factor) - atc clearance - not understood, pilot in command (contributing factor) - radar separation - not maintained, atc personnel(dep/apch) (cause) - Near collision between aircraft, approach - iaf to faf/outer marker (ifr) - supervision - inadequate, atc personnel(supervisor) (contributing factor) - excessive workload (task overload), atc personnel(dep/apch) (contributing factor) - information unclear, atc personnel(dep/apch) (contributing factor) - atc clearance - not understood, pilot of other aircraft (contributing factor) - radar separation - not maintained, atc personnel(dep/apch) (cause) ## Analysis (aircraft 2) TWA FLT 806 (DC-9) WAS NW OF ARPT (FOR ILS RWY 9 APCH) AS CONTINENTAL FLT 122 (DC-9) WAS SW OF ARPT FOR SAME APCH. BOTH WERE IN IMC, BEING VCTRD BY FINAL TRACON CTLR (WORKING 2 SECTORS & CTLG 23 ACFT). AS FLT 122 WAS APCHG LOCALIZER (LOC) & HDG 060 DEG AT 3000' MSL, FLT 806 WAS ABT 8 MI NW OF FLT 122 & WAS CLRD TO INTERCEPT LOC. CTLR TMTD TO FLT 122 'FOUR FM THE MARKER, MAINT 2000 UNTIL ESTABLISHED ON THE LOC, CLRD ILS RWY 9 APCH, AND ARE YOU GOING THRU THE LOC TOO?' FLT 122 REPLIED 'YES SIR, YOU NEVER TOLD US TO INTERCEPT.' CTLR THEN TOLD FLT 122 'MAINT 3500 & TURN LEFT 360,' MEANING TO TURN TO A HDG OF 360 DEG. FLT 122 THOUGHT CTLR WANTED A 360 DEG CIRCLING TURN & BGN A RGT TURN. WHILE CIRCLING, FLT 122 ASKED FOR A HDG TO ROLL OUT ON. CTLR SAID TO FLY HDG 230. CTLR THEN REALIZED THE 2 ACFT WERE CONVERGING. HE TOLD FLT 122 TO DCND TO 2000' & TMTD FOR 'CONTINENTAL 806' TO MAINT 3500'. SINCE CTLR USED WRONG COMPANY DESIGNATOR, TWA FLT 806 DID NOT RESPOND. RADAR SHOWED THE 2 ACFT PASSED AT ABT 3100' WITH .079 MI SEPN. ## Analysis (aircraft 1) TWA FLT 806 (DC-9) WAS NW OF ARPT (FOR ILS RWY 9 APCH) AS CONTINENTAL FLT 122 (DC-9) WAS SW OF ARPT FOR SAME APCH. BOTH WERE IN IMC, BEING VCTRD BY FINAL TRACON CTLR (WORKING 2 SECTORS & CTLG 23 ACFT). AS FLT 122 WAS APCHG LOCALIZER (LOC) & HDG 060 DEG AT 3000' MSL, FLT 806 WAS ABT 8 MI NW OF FLT 122 & WAS CLRD TO INTERCEPT LOC. CTLR TMTD TO FLT 122 'FOUR FM THE MARKER, MAINT 2000 UNTIL ESTABLISHED ON THE LOC, CLRD ILS RWY 9 APCH, AND ARE YOU GOING THRU THE LOC TOO?' FLT 122 REPLIED 'YES SIR, YOU NEVER TOLD US TO INTERCEPT.' CTLR THEN TOLD FLT 122 'MAINT 3500 & TURN LEFT 360,' MEANING TO TURN TO A HDG OF 360 DEG. FLT 122 THOUGHT CTLR WANTED A 360 DEG CIRCLING TURN & BGN A RGT TURN. WHILE CIRCLING, FLT 122 ASKED FOR A HDG TO ROLL OUT ON. CTLR SAID TO FLY HDG 230. CTLR THEN REALIZED THE 2 ACFT WERE CONVERGING. HE TOLD FLT 122 TO DCND TO 2000' & TMTD FOR 'CONTINENTAL 806' TO MAINT 3500'. SINCE CTLR USED WRONG COMPANY DESIGNATOR, TWA FLT 806 DID NOT RESPOND. RADAR SHOWED THE 2 ACFT PASSED AT ABT 3100' WITH .079 MI SEPN. ## Aircraft 1 - Registration: N820NY (not matched to a registry record) - Reported make and model: MCDONNELL DOUGLAS DC-9-82 - Category: Airplane - Serial number: 49480 - Engines: P&W JT8D-217A 14000 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: Continental Airlines, doing business as Continental Airlines - Registered owner: Tac 820 Corp - Departed: SAT, SAN ANTONIO, TX - Destination: IAH, HOUSTON, TX - Flight plan: IFR - Airport: IAH, Houston Intercontinental, runway 9, 9,999 × 150 ft, asphalt ## Aircraft 2 - Registration: [N918TW](https://openairdocs.org/deregistered/N918TW-2007-07-27), registration cancelled 2007-07-27, S/N 49367, built 1985 (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 - Serial number: 49367 - Engines: P&W JT8D 14000 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: Trans World Airlines - Registered owner: First Security Bank Of Utah - Departed: AUS, AUSTIN, TX - Destination: IAH, HOUSTON, TX - Flight plan: IFR - Airport: IAH, Houston Intercontinental, runway 9, 9,999 × 150 ft, asphalt ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot, aircraft N820NY; age 50; airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--no waivers/lim.; flight hours: 10,000 total - Pilot, aircraft N918TW; age 46; flight instructor, airline transport; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, valid medical--w/ waivers/lim; seat: left; flight hours: 7,500 total, 2,749 in this make and model ## Weather - Conditions: Instrument (IMC), Day - Wind: 30° at 9 knots - Visibility: 12 statute miles - Lowest ceiling: 1,600 ft overcast - Temperature: 54 °F, dew point 46 °F - Altimeter: 30.00 inHg - Observed at: IAH, 7 nm away ## FAA reports on this event (2) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Incident 19890301066599I](https://openairdocs.org/incident/19890301066599I), Mar 1, 1989: Doug DC982, Houston, TX. Near miss with N918TW, ATC a factor. - [Incident 19890301066589I](https://openairdocs.org/incident/19890301066589I), Mar 1, 1989: Doug DC982, Houston, TX. Near miss N820NY, ATC a factor. 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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.