# NTSB OPS16IA008: Embraer S A EMB-505, N304QS, Dallas, TX, April 7, 2016 - Type: NTSB incident investigation - Classification: Incident · Class 3 · Incident · Final report - Date: April 7, 2016, 18:36 local (23:36 UTC) - Place: Dallas, TX - Coordinates: 32.89722, -97.03778 - Nearby events: https://openairdocs.org/map.md?lat=32.8972&lon=-97.0378&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi-from runway: Runway incursion veh/AC/person](https://openairdocs.org/ntsb-events/320) - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Operational Factors Division - NTSB case key (mKey): 93000 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=OPS16IA008 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/93000/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=93000 - Page: https://openairdocs.org/ntsb/OPS16IA008 ## Probable cause (aircraft 1) The controller's miscommunication of a clearance and failure to recognize and correct the readback resulting in the flight crew initiating takeoff without a clearance. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 1 - [Action: incorrect action selection](https://openairdocs.org/ntsb-findings/02041010): Personnel issues › Action/decision · Flight crew (probable cause), aircraft 1 - [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 2 - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · ATC personnel (probable cause), aircraft 2 - [Info processing/decision: expectation/assumption](https://openairdocs.org/ntsb-findings/02041525): Personnel issues › Action/decision · Flight crew (probable cause), aircraft 2 ## Analysis (aircraft 1) This runway incursion resulted from communications errors. The local control east controller (LE1) misspoke when intending to issue a landing clearance for a flight on approach to runway 35C and instead issued the flight on approach a takeoff clearance from runway 35L. The pilot of AAL2408, already in line up and wait position on runway 35L, interpreted the communication to be a takeoff clearance for his flight, acknowledged the takeoff clearance, and initiated takeoff. Immediately prior to AAL2408 initiating takeoff roll, the LE1 controller had cleared three different aircraft to cross runway 35L on three different taxiways. As AAL2408 began its takeoff roll the Runway Status Lights (RWSLs) on runway 35L activated Activation of the RWSL illuminated the Runway Entrance Lights (RELs) at the hold short locations of the three aircraft that had just been instructed to cross runway 35L and illuminated the Takeoff Hold Lights (THLs) at the approach end of the runway. The RELs provided a visual signal to the pilots holding short of runway 35L indicating the runway was unsafe to enter or cross. The THLs provided a visual signal to the pilot of AAL2408 that the runway was occupied however, data indicate that AAL2408 had progressed too far down the runway to observe the THLs by the time they had illuminated. Of the three aircraft holding short of runway 35L, only one proceeded across runway 35L. As that aircraft cleared the runway at taxiway K8 the Airport Surface Detection Equipment, Model-X indicated AAL2408's speed to be 120 knots and the closest proximity between the two aircraft was approximately 2,800 feet. In this incident, the LE1 controller adjusted his speech rate to the traffic volume while attempting to comply with the requirements of issuing explicit runway crossing clearances for each runway that intersects a taxi route resulting in an excessive speech rate by the LE1. During a System Service Review after the event, controllers identified a recent procedural change that required additional verbiage when issuing crossing instructions, and an increased speech rate associated with increased workload. ## Factual narrative (aircraft 1) On April 7, 2016 at 1836 central daylight time, a runway incursion occurred on runway 35L at Dallas-Fort Worth International Airport (DFW), Dallas, Texas, when a Boeing 737-800, N896NN, was on takeoff roll while an Embraer 505, N304QS, crossed the runway downfield. The closest proximity between the two airplanes was approximately 2,800 feet when the speed of the Boeing was about 120 knots. The Boeing 737-800 was operated by American Airlines as flight 2408, under the provisions of 14 Code of Federal Regulations Part 121 as a regularly scheduled passenger flight (AAL2408). The Embraer 505 was operated by NetJets Aviation under the provisions of 14 Code of Federal Regulations Part 91K as a fractional ownership flight (EJA304). Visual meteorological conditions prevailed and there were no injuries to the passengers or crew of either flight. EJA304 had landed on runway 35C and was instructed by the LE1 controller to taxi to the terminal via taxiway M and K8. At 1834:20 the pilot of EJA304 was directed to hold short of runway 35L on taxiway K8. An MD-82, AAL2256, was holding short of runway 35L at taxiway EK, and an E170, ENY3192 taxiing to the gate after landing, was instructed to taxi via taxiway M to taxiway EJ and to hold short of runway 35L. At 1835:14, the LE1 controller cleared a flight (AAL2304) for takeoff on runway 35L and eight seconds later, at 1835:22, instructed the pilot of AAL2408 to LUAW on runway 35L. At 1835:39, the pilot of SKW5432, an arriving CRJ7 regional jet, reported outside the JOBBS airspace fix for landing runway 35C. The LE1 controller responded "Skywest fifty-four thirty-two, DFW tower, wind zero two zero at one five gusts two zero, runway three five left, cleared for takeoff". The pilot of SKW5432 did not respond however, the pilot of AAL2408, in position at the approach end of runway 35L, responded with "American twenty-four oh eight cleared for takeoff three five left". The LE1 controller did not respond to the incorrect readback by the pilot of AAL2408. As the previous departure (AAL2304) passed the taxiways intersecting runway 35L where aircraft were holding, the LE1 controller, in successive progression, directed the pilots of EJA304, AAL2256, and ENY3192 to cross runway 35L. All three pilots acknowledged the crossing clearance. As AAL2408 began its takeoff roll the Runway Status Lights (RWSLs) on runway 35L activated illuminating the Runway Entrance Lights (RELs) at the hold short locations of the three aircraft that had just been instructed to cross runway 35L, as well as the Takeoff Hold Lights (THLs) at the approach end of the runway. The RELs provided a visual signal to the pilots holding short of runway 35L. The THLs provided a visual signal to the pilot of AAL2408 that the runway was occupied however, data indicate that AAL2408 had progressed too far down the runway to observe the THLs by the time they had illuminated. Of the three aircraft holding short of runway 35L, only EJA304 proceeded across runway 35Lwith AAL2408 departing the same runway. After takeoff but before switching to departure control, the pilot of AAL2408 commented to the LE1 controller about the business jet that was on the runway as he departed. As EJA304 cleared runway 35L, the ASDE-X indicated AAL2408's speed to be 120 knots and the closest proximity between the two aircraft was approximately 2,800 feet. The ASDE-X did not alarm. During a System Service Review after the event, controllers identified a recent procedural change that required additional verbiage when issuing crossing instructions, and an increased speech rate associated with increased workload. ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi-from runway: Runway incursion veh/AC/person](https://openairdocs.org/ntsb-events/320) (defining event), aircraft 1 - [Takeoff: Airport occurrence](https://openairdocs.org/ntsb-events/070), aircraft 2 ## Aircraft 1 - Registration: [N304QS](https://openairdocs.org/aircraft/N304QS), registered now, S/N 50500143, built 2013 (OpenAirDocs) - Reported make and model: EMBRAER S A EMB-505 (NO SERIES) - Registry model: [Embraer S A EMB-505](https://openairdocs.org/model/embraer-s-a-emb-505) (registry code 326040C) (OpenAirDocs) - Registry engine: [Pratt & Whitney Canada PW535E](https://openairdocs.org/engine/pratt-whitney-canada-pw535e) (registry code 52297, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 50500143 - Year built: 2013 - Engines: P&W CANADA PW535E turbo fan; P&W CANADA PW535E turbo fan - Damage: No damage - Flight: Part 135 - Operator: Netjets Sales Inc - Registered owner: Netjets Sales Inc - Airworthiness certificate: Unknown - Departed: SAT, SAN ANTONIO, TX - Destination: DFW, Dallas, TX - Flight plan: IFR - Airport: DFW, Dallas-Fort Worth Intl, runway 35L, 13,401 × 200 ft, concrete ## Aircraft 2 - Registration: [N896NN](https://openairdocs.org/aircraft/N896NN), registered now, S/N 33224, built 2012 (OpenAirDocs) - Reported make and model: BOEING 737 823 (823) - Registry model: [Boeing 737-823](https://openairdocs.org/model/boeing-737-823) (registry code 13844CB) (OpenAirDocs) - Registry engine: [CFM International CFM56-7B24E series](https://openairdocs.org/engine/cfm-international-cfm56-7b24e-series) (registry code 13804, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 33224 - Year built: 2012 - Engines: CFM INTL CFM56-7B24E turbo fan; CFM INTL CFM56-7B24E turbo fan - Damage: No damage - Flight: Part 121 - Operator: American Airlines - Registered owner: Wells Fargo Bank Northwest Na Trustee - Airworthiness certificate: Unknown - Departed: DFW, Dallas, TX - Destination: ATL, ATLANTA, GA - Flight plan: IFR - Airport: DFW, Dallas-Fort Worth Intl, runway 35L, 13,401 × 200 ft, concrete ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 17 knots - Visibility: 10 statute miles - Lowest ceiling: 25,000 ft broken - Temperature: 81 °F, dew point 39 °F - Altimeter: 29.93 inHg - Observed at: DFW ## Docket (3 files) The files NTSB released with the investigation on February 2, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=93000. 1.9 MB in all. - Air traffic control (item 1, PDF, 14 pages, 133 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=5485189&FileExtension=pdf&FileName=OPS16IA008AB%20Final%20ATC%20Factual%20Report%208-28-2017-Rel.pdf - Air traffic control factual report - attachment 1 (item 2, PDF, 19 pages, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=5486264&FileExtension=pdf&FileName=OPS16IA008AB%20Attachment%201%20Figures%20and%20Illustrations-Rel.pdf - Air traffic control factual report attachment 2 (item 3, PDF, 9 pages, 50 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=5486594&FileExtension=pdf&FileName=OPS16IA008AB%20-%20Attachment%202%20-%20Interview%20Summaries-Rel.pdf From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; 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.