DCA24FA017

The takeoff by the flight crew of N269AA, without a takeoff clearance, which resulted in a collision with N510HM that was landing on an intersecting runway. Contributing to the accident was the N269AA crew’s expectation bias and distraction.

A Raytheon Hawker 850XP, N269AA, operated by DuPage Aerospace, collided with a Textron Aviation Inc 510 Citation Mustang, N510HM, at the intersection of runways 13R and 22 at William P. Hobby Airport (HOU) in Houston, Texas. N510HM was rolling after landing on runway 13R, and N269AA was on its takeoff roll on runway 22. About the time of lift-off, the left wingtip of N269AA struck the left side of N510HM’s tail cone, resulting in substantial damage to N510HM. N269AA continued its takeoff, and during initial climb advised the HOU air traffic control tower (ATCT) that they needed to return to the airport. The local control (LC) controller provided vectors to runway 13R, where N269AA landed uneventfully. About 4.5 minutes prior to the collision, the LC controller cleared N510HM to land while it was on a 9-mile final. About 2.5 minutes before the collision, N510HM reported a 4-mile final. About 2 minutes prior to the collision the LC controller cleared N269AA to “line up and wait” (LUAW) on runway 22. The pilot monitoring (PM) correctly readback the clearance with “line up and wait uh, two two uh, six nine Alpha Alpha”. During post-accident interviews, the PM recalled hearing the LUAW clearance and a subsequent clearance for takeoff, and the pilot flying (PF) recalled hearing only a clearance for takeoff. However, a review of the certified air traffic control voice recordings revealed that there was no takeoff clearance issued to N269AA (or other airplanes) at that time. This discrepancy was likely due to the pilots’ expectation bias, a cognitive phenomenon where individuals perceive what they expect to hear or see and act accordingly. Both Hawker pilots recalled that near the time of the LUAW clearance, the programmed V-speed references were no longer displayed on their instruments. They discussed the issue, and the PM began re-entering data into the flight management system to restore the speeds. The PF stated he felt “a little bit rushed” due to the perceived takeoff clearance and he did not want to delay on the runway. The crew discussed the speeds and elected to proceed with the takeoff. This activity may have distracted the pilots and exacerbated their expectation bias. Additionally, when the LC controller issued the LUAW clearance, they did not provide a traffic advisory to either airplane, which is a required procedure. A traffic advisory would have provided more context and awareness for both crews about the location and activity of the other airplane. However, the PM correctly acknowledged the LUAW clearance, which should be sufficiently clear that a delay was required before takeoff could commence, regardless of the reason. Therefore, it is unlikely that the lack of a traffic advisory contributed to the outcome. The N269AA crew taxied onto the runway and began the takeoff without a clearance from the ATCT. The ATCT controllers observed its movement and the Airport Surface Detection Equipment – Model X (ASDE-X) in the ATCT sounded a warning of a perceived collision. The LC controller twice instructed N269AA to stop and hold position but received no response. The pilots recalled that as they began the takeoff roll, two events occurred. First, they noticed that the rudder bias system had activated, which they resolved by adjusting the thrust such that both engines were set to similar power setting. The PF did this, and the rudder bias system deactivated. Second, the elevator trim warning system activated, and the PM then adjusted the pitch trim (by rolling it nose down about 1/16 inch) which extinguished the warning. These activities likely distracted the pilots and prevented them from recognizing the instructions from the LC controller to stop. They continued their takeoff roll, and both pilots recalled that they did not see N510HM until about 1 second before the collision. According to the chief pilot of DuPage Aerospace, company policy and training (and as part of every takeoff briefing) specify that takeoffs should be aborted for “any fault or failure” below 80 knots. He elaborated that if a fault were indicated on the annunciator panel [which is where the elevator trim warning system indictor is displayed], “then you should be aborting.” He further stated that “it depends what the fault or failure is” and described that if the elevator trim warning activated during takeoff, while the trim setting was very near either end of the takeoff range, that he would re-trim the airplane and then move the throttles back into the takeoff position and make sure the warning did not reactivate. If it were to reactivate, he would then abort the takeoff. Similarly, the PM noted during his interview that the elevator trim warnings are common in the Hawker, particularly when the trim setting was at or near the very aft mark of the [takeoff range] of the trim indicator. He said that typically a slight roll forward of the trim wheel would extinguish the light. This suggests there is some discrepancy or exceptions between the operator’s policy and at times, the in-practice procedures, with regard to conditions that warrant an aborted takeoff. In this case, the elevator trim warning (and the activation of the rudder bias) was temporary and easy to quickly remedy, though it happened to occur at a critical time as ATC was attempting to stop the takeoff roll. Separately, the chief pilot stated that it was company policy (and an element of the before start checklist) to test the cockpit voice recorder (CVR) prior to every flight. After the accident, the CVR was found to be inoperative due to activation of the impact or G switch, which interrupts electrical power to the CVR and its control unit in the cockpit. This can occur for several reasons, including hard landings or during maintenance operations. Review of the recording revealed audio consistent with maintenance activities. The CVR does not record date and time, however it likely became inoperative at some time prior to this crew’s pairing, which began two flights prior to the accident flight. Post accident testing of the CVR and the impact switch revealed they operated as designed. The flight crew should have been aware of the CVR’s nonoperational status during the before start checklist prior to the accident and the two previous flights, had they 1) pressed the CVR test button and 2) noticed that none of the indicator lights on the CVR control unit had illuminated, because the control unit (and CVR) were not powered. Normally, the indicator lights show the progress of the self-test, and whether the test passes or fails. However, during normal operation (no faults, and not in self-test mode) none of the indictor lights on the cockpit voice control unit are illuminated. Therefore, the control unit would look the same if 1) the CVR was running normally, or 2) if it was completely unpowered by the activated inertial switch. The only methods for the flight crew to determine if the unit is functioning are to use the self-test function, or by monitoring the audio through the headset jack on the control panel. Since the CVR was inoperative, the relevant crew conversations that would have provided additional insight to the investigation were not captured. This demonstrates the importance of properly testing the CVR before each flight.

N510HM Pilot The pilot, age 40, held a FAA Private Pilot certificate with ratings for Airplane Multi-engine Land, Airplane Single-Engine Land, Instrument Airplane, and type ratings in the CE-510 and CE-510S. He had a FAA Third Class medical certificate issued on May 3, 2023, with no restrictions or limitations. The pilot’s estimated flight hours were based on the information he provided during a post-accident interview. He estimated he had about 1,000 total hours of flight experience and about 300 of those hours were in the accident airplane make and model. N269AA Crew The PF was 69 years old and had a FAA Airline Transport Pilot certificate with ratings for Airplane Single- and Multi-engine Land, with type ratings for B-737, B-757, B-767, B-777, B-787, DC-9, and HS-125. Additionally, he had a Flight Engineer certificate with rating of Turbojet Powered and a Mechanic certificate with Airframe and Powerplant. He had a FAA First Class medical certificate issued on May 12, 2023, with limitations: Must use correct lens(es) to meet vision standards at all required dista[nces]. The PF’s estimated flight hours were based on interview, company and FAA records. His total flight experience was about 24,000 hours, of which about 300 were in the accident airplane make and model. He was seated in the left seat for the flight. He had a temporary residence in Aurora, Illinois, about a 30-minute drive from the DuPage airport. He had been in Illinois since October 12 or 13th flying short trips lasting 2 or 3 days. On October 22, 2023, he flew a trip and arrived back to DuPage about 16:00. He arrived at his temporary residence close to 18:00, had dinner and was in bed between 20:00 and 21:00. On October 23, the PF set his alarm for 03:30 because he had a 06:30 departure from DuPage. He felt rested that day. He took about an hour nap, went to the gym, had dinner, and then went to bed. His bedtime was unknown. On October 24, he woke up about 08:30 and had breakfast at 09:00. He had an extended checkout and completed paperwork and training before the flight. He thought he dozed off while completing the training but felt rested for the flight. He did not recall if they took an Uber or shuttle to the airport. He had no issues falling asleep or staying asleep and had never talked to his doctor about a sleep disorder. He thought he needed 7 hours of sleep on average per night to feel rested. He may sleep up to 10 hours when arriving back home in San Diego after flying. The PM was also the pilot in command (PIC) for the flight. He was also a training captain for DuPage Aerospace. He was 67 years old and held an FAA Airline Transport Pilot Certificate with ratings for Airplane Single- and Multi-engine Land and type ratings of B-727, B-737, CE-500, DA-20, DC-9, G-200, HS-125, and LR-JET. Additionally, he held a Flight Engineer certificate with rating of turbojet powered. He held a First-Class medical certificate, dated September 26, 2023, with a limitation: Must use corrective lens(es) to meet vision standards at all required dista[nces]. According to his interview he had about 28,000 hours of total flight experience and approximately 3,800 hours of flight experience in the accident aircraft make and model. He was seated in the right seat for the flight. He had flown a multi-day trip which ended on Saturday, October 21, 2023. He was off duty on Sunday, October 22. He did work around his house. He thought he went to bed about 21:00 and got a good night’s sleep. On Monday, October 23, he had an early show, he thought 04:30, for a 06:30 departure from DuPage. He thought he woke up about 02:30 or 03:00. They flew to Waukesha, then to Houston, and then went to the hotel. He thought he may have napped sometime during the afternoon. He went to dinner and thought he returned to the hotel about 20:30 or 21:00. He went to bed after Monday Night Football ended. On Tuesday, October 24, he woke up by 08:30 with his alarms, which were set for 08:00, 08:15 and 08:30, and went downstairs for a coffee and breakfast snack. He went back to his room and got ready for his day. He did not nap prior to the accident flight. He thought Signature picked them up and took them to the airport. He felt “perfect” and was excited to go flying. He had no issues falling asleep or staying asleep. DuPage Aerospace Corporation is a 14 CFR Part 135 operator, located at DuPage Airport in West Chicago, Illinois. At the time of the accident their fleet consisted of 8 aircraft, of which 5 were the same make and model as the accident airplane. According to Hawker 800/800XP systems description documents provided by DuPage Aerospace Corporation: Elevator Out of Trim Warning System The elevators provide primary control of the aircraft in the pitch axis either mechanically through control column movement or electronically through the autopilot elevator servo. A microswitch in each trim jack monitors elevator trim setting. If the elevator trim is set outside the takeoff range with weight-on-wheels, advancing the throttles to about the 60% N1 RPM position activates microswitches which in turn illuminate the amber ELEV/AIL TRIM annunciator on the MWS [master warning system] panel. Setting the elevator trim within the takeoff setting range extinguishes the annunciator. Rudder Bias System The rudder bias system automatically provides rudder movement in response to an engine failure or malfunction to assist with directional control. A spring strut reduces the rudder bias effect at large rudder deflections. Engine bleed air from the LP [low pressure] stage of each engine drives the rudder bias system. LP bleed air from each engine travels to opposite ends of a double-acting pneumatic strut. Under symmetrical power conditions, the LP bleed air pressure balances within the struts, resulting in no net rudder input. Under asymmetric power conditions, air pressure differential between the engines operates the pistons so the rudder moves to counteract the asymmetric thrust. Both of the N269AA pilots underwent post-accident urine drug testing and breathalyzer alcohol testing on the day of the accident as a part of the Department of Transportation’s Drug and Alcohol Testing program. No tested-for substances (6-aceytate morphine, marijuana metabolites, cocaine metabolites, amphetamines, MDMA, opiates, and phencyclidine) nor alcohol were detected. On October 24, 2023, about 15:20 central daylight time, a Raytheon Hawker 850XP, N269AA, was taking off on runway 22 when its left wing collided with the vertical stabilizer of a Textron Aviation (Cessna) Citation Mustang, N510HM, which was landing on runway 13R at William P. Hobby Airport (HOU), Houston, Texas. Day visual meteorological conditions prevailed at the time of the accident. There were no injuries to the two pilots and one passenger aboard N269AA or to the one pilot and three passengers aboard N510HM. N269AA sustained minor damage and N510HM was substantially damaged during the collision. N269AA was operating as a Title 14 Code of Federal Regulations (CFR) Part 135 on-demand passenger flight from HOU to Waukesha County Airport (UES), Waukesha, Wisconsin. N510HM was operating as a Title 14 CFR Part 91 flight from Fulton County Executive Airport/Charlie Brown Field (FTY), Atlanta, Georgia, to HOU. HOU has intersecting runways, and at the time of the accident N510HM was rolling out after landing on runway 13R, while N269AA was on its takeoff roll on runway 22. See figure 1. Figure 1. View of both airplanes’ flight tracks with the area the ground collision occurred highlighted in yellow. The blue line represents the N510HM flight track, and the red line represents the N269AA flight track. A review of certified air traffic control voice recordings provided by the Federal Aviation Administration (FAA) revealed that at 1514:09, before N269AA began its taxi, the flight crew contacted ground control (GC) to request clearance to taxi