Narrative:

Severe weather rolled across the dfw airport from the west moving east with high wind speeds generating LLWAS and mba alerts with gusts over 41kts. In anticipation of the weather event; dfw tower tmc coordinated a flow change that was intended to minimize the effect of tailwind components to arriving and departing aircraft. The initial runway flow change proceeded orderly and without incident. Yet due to weather concerns the airspace was soon to be impacted with weather being the dominating factor. North flow arrivals soon balked at arriving runway 35 or 36 due to strong crosswinds as did numerous departures stating that the gusts must be 30kts or less before pilots would accept a departure off runway 35 or 36. After several missed approaches due to winds aloft D10 and tower made another flow change to arrive and depart northwest flow. This is the least efficient use of airspace at dfw and requires the simultaneous use of landings and departures to move aircraft. Another problem encountered was the loss of runway 31R due to construction. This placed all departures and arrivals at dfw to use runway 31L. All arrivals required an opposite direction taxi off runway 31L to counter flow the departure queue. So all departures that had not already reached the runway departure queue for runway 35L were subsequently taxied to runway 31L. As weather continued to move across dfw slowly; dfw airport became a one runway airport. Prior to weather arriving at the field some reroutes were being issued to departures that anticipated a diversion around weather. Severe weather avoidance program or swap was being selectively applied to some flights to mitigated the overall delay and expedite the departure backlog that would ensue. All north jet departures had to make left downwind departures before the initial runway flow change from south to north; then all south jets had top make right downwind departures. So some originally westbound jets were on the east side of dfw making what would be a south swap to go west. Most of the departures were on the west side of dfw. Then as the weather improved the airport made another flow change back to south flow using all available runways except the closed runway 13L. During the flow change; tmc planned that the west tower would taxi and depart west and north jets while the east tower would taxi and depart east and south jets. Ground taxied accordingly and as jets reached the runway queue for south departures there were some south jets queued at runway 18L and south jets queued for runway 17R. Weather became less of a factor as it diminished and moved eastward. Yet due to strong winds both towers were using initial radar vectors on all departures. As departure resumed and flow into and out of dfw stabilized; the action plan was put in place and each tower assumed hat departure status to effectively move aircraft with minimal coordination. The west tower local assist requested and I approved the release of some north jets and two south jets filed over nelyn. The east tower also had a nelyn in the departure queue. I worked with local east to allow the west tower to flush their off-hat jets for better flow and reduce the coordination it would take for multiple calls. That was accomplished. Aircraft X was the nelyn who had waited to depart runway 17R. Both towers were set on their departure hat status. With no conflicting routes aircraft X was cleared for takeoff runway 17R on a 160 heading. I observed that aircraft X was in suspense and tagged as a 0L. I slewed to the target and told the cpc what was occurring. After the slew; aircraft X tagged on the radar scope as a 'Z' symbol indicating that DR2 was combined to DR3. Yet before I could do anything else; the trainee instructed aircraft X to contact departure. My attention was immediately called to by the tmc who asked if that was a podde departure off runway 17R. I told him the flight plan I had was a nelyn. In almost the same sentence; the tmc said he was a podde. I coordinated the information to the lwi assist so that additional spacing could be applied to allow aircraft X to be vectored west. Recommendation; the reality with the flight plans in changing weather conditions is that due to flow restrictions some flight plans will be changed several times before the aircraft is airborne. Route changes are not unusual. The weather and flow dictate how aircraft will arrive and depart an airport. Multiple runway changes in succession create the environment for off-hat aircraft to be on the wrong side of the airport for direction of flight. This situation was probably part ATC; part pilot. I do not know when the pilot received his reroute that placed him back on a podde SID versus a nelyn SID. It is significant if the pilot received his reroute after he accepted a taxi for departure to runway 17R or if the pilot was already at runway 17R when the reroute was issued. It would have been incumbent upon the pilot to advise the tower controller that he just received a west departure SID. This situation would have been prevented if the ARTS information on the asde-X was accurate. Radar vectors were being used to provide initial separation between successive departures. Since severe weather avoidance procedures (swap) were not being applied; the checks and balances that are part of swap procedures with route changes were not followed. If the tower controller knew that a swap procedure was terminated then tmc would have been more involved in ensuring that aircraft taken off the initial reroute were returned to their original flight plan. Had RNAV procedure for issuing the RNAV to phraseology been applied then the disconnect with the route filed as opposed to one being used by ATC would have triggered verbal queue that the wrong flight plan was displayed. We depend on flight plan information is accurate and universally understood. The route structure that placed the majority departures on the west side of the airport due to wind was in part weather avoidance as well as weather compliance. When repeated flow changes are the result of weather and weather avoidance then it is inevitable that multiple route amendments will occur. In this situation; a normally west routed departure was changed to a south route departure by either tmc or flight dispatch to avoid weather. As a flow change occurs it would be the responsibility of tmc to ensure that the correct route structure exists that allows for minimal coordination. Plain and simple; mistakes happen. It is how we react to them that make the difference. After all; anyone can work in ideal circumstances.

Related reports:

Google
 

Original NASA ASRS Text

Title: DFW controller provided a long and detailed report describing a single runway operation caused by winds and runway closure/s all resulting in confusion; non compliance with normal route assignments and coordination failures.

Narrative: Severe weather rolled across the DFW Airport from the West moving East with high wind speeds generating LLWAS and MBA alerts with gusts over 41kts. In anticipation of the weather event; DFW Tower TMC coordinated a flow change that was intended to minimize the effect of tailwind components to arriving and departing aircraft. The initial runway flow change proceeded orderly and without incident. Yet due to weather concerns the airspace was soon to be impacted with weather being the dominating factor. North flow arrivals soon balked at arriving Runway 35 or 36 due to strong crosswinds as did numerous departures stating that the gusts must be 30kts or less before pilots would accept a departure off Runway 35 or 36. After several missed approaches due to winds aloft D10 and Tower made another flow change to arrive and depart Northwest flow. This is the least efficient use of airspace at DFW and requires the simultaneous use of landings and departures to move aircraft. Another problem encountered was the loss of Runway 31R due to construction. This placed all departures and arrivals at DFW to use Runway 31L. All arrivals required an opposite direction taxi off Runway 31L to counter flow the departure queue. So all departures that had not already reached the Runway Departure queue for Runway 35L were subsequently taxied to Runway 31L. As weather continued to move across DFW slowly; DFW Airport became a one runway airport. Prior to weather arriving at the field some reroutes were being issued to departures that anticipated a diversion around weather. Severe Weather Avoidance Program or SWAP was being selectively applied to some flights to mitigated the overall delay and expedite the departure backlog that would ensue. All North jet departures had to make left downwind departures before the initial runway flow change from South to North; then all South jets had top make right downwind departures. So some originally westbound jets were on the East side of DFW making what would be a South SWAP to go west. Most of the departures were on the West side of DFW. Then as the weather improved the airport made another flow change back to South Flow using all available runways except the closed Runway 13L. During the flow change; TMC planned that the West Tower would taxi and depart west and North jets while the East Tower would taxi and depart East and South Jets. Ground Taxied accordingly and as jets reached the Runway queue for South departures there were some South jets queued at Runway 18L and South jets queued for Runway 17R. Weather became less of a factor as it diminished and moved eastward. Yet due to strong winds both towers were using initial RADAR vectors on all departures. As departure resumed and flow into and out of DFW stabilized; the action plan was put in place and each tower assumed hat departure status to effectively move aircraft with minimal coordination. The West Tower Local Assist requested and I approved the release of some North jets and two South jets filed over Nelyn. The East tower also had a Nelyn in the departure queue. I worked with Local East to allow the West tower to flush their off-hat jets for better flow and reduce the coordination it would take for multiple calls. That was accomplished. Aircraft X was the Nelyn who had waited to depart Runway 17R. Both towers were set on their departure hat status. With no conflicting routes Aircraft X was cleared for takeoff Runway 17R on a 160 heading. I observed that Aircraft X was in suspense and tagged as a 0L. I slewed to the target and told the CPC what was occurring. After the slew; Aircraft X tagged on the RADAR scope as a 'Z' symbol indicating that DR2 was combined to DR3. Yet before I could do anything else; the Trainee instructed Aircraft X to contact departure. My attention was immediately called to by the TMC who asked if that was a PODDE departure off Runway 17R. I told him the flight plan I had was a Nelyn. In almost the same sentence; the TMC said he was a PODDE. I coordinated the information to the LWI assist so that additional spacing could be applied to allow Aircraft X to be vectored west. Recommendation; the reality with the Flight Plans in changing weather conditions is that due to flow restrictions some flight plans will be changed several times before the aircraft is airborne. Route changes are not unusual. The weather and flow dictate how aircraft will arrive and depart an airport. Multiple runway changes in succession create the environment for off-hat aircraft to be on the wrong side of the airport for direction of flight. This situation was probably part ATC; part pilot. I do not know when the pilot received his reroute that placed him back on a PODDE SID versus a NELYN SID. It is significant if the pilot received his reroute after he accepted a taxi for departure to Runway 17R or if the pilot was already at Runway 17R when the reroute was issued. It would have been incumbent upon the pilot to advise the tower controller that he just received a West departure SID. This situation would have been prevented if the ARTS information on the ASDE-X was accurate. RADAR vectors were being used to provide initial separation between successive departures. Since severe weather avoidance procedures (SWAP) were not being applied; the checks and balances that are part of SWAP procedures with route changes were not followed. If the tower controller knew that a SWAP procedure was terminated then TMC would have been more involved in ensuring that aircraft taken off the initial reroute were returned to their original flight plan. Had RNAV procedure for issuing the RNAV TO phraseology been applied then the disconnect with the route filed as opposed to one being used by ATC would have triggered verbal queue that the wrong flight plan was displayed. We depend on flight plan information is accurate and universally understood. The route structure that placed the majority departures on the West side of the airport due to wind was in part weather avoidance as well as weather compliance. When repeated flow changes are the result of weather and weather avoidance then it is inevitable that multiple route amendments will occur. In this situation; a normally West routed departure was changed to a South route departure by either TMC or Flight Dispatch to avoid weather. As a flow change occurs it would be the responsibility of TMC to ensure that the correct route structure exists that allows for minimal coordination. Plain and simple; mistakes happen. It is how we react to them that make the difference. After all; anyone can work in ideal circumstances.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.