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NTSB investigation record

DCA24LA318

Completed

Embraer Erj170-100Lr· N772MR

Date
September 25, 2024
Location
Chicago, IL
Conditions
VMC
Record
Published February 25, 2026

Primary finding

Probable cause

The flight crew’s misidentification of the intended landing runway, which resulted in an approach to and landing on the wrong runway due to their planned continuation bias. Contributing to the incident was the flight crew’s decision to continue the approach without the correct ILS frequency in the FMS. Also contributing was air traffic control’s failure to notify the flight crew that the were lined up with the incorrect runway contrary to FAA directives.

Investigator assessment

Analysis narrative

This incident occurred when the flight crew of Envoy Airlines flight 3936 (ENY3936), an Embraer 170-100 LR, was cleared for a visual approach to land on runway 10C at Chicago O’Hare International Airport (ORD), Chicago, Illinois, however, the flight crew inadvertently landed on runway 10L. While on descent and upon initial check-in with the ORD approach controller, the flight crew was instructed to expect runway 10C. They were subsequently cleared for the instrument landing system (ILS) to runway 10C. The flight crew acknowledged and correctly read back the approach clearance. The flight crew stated that the captain, who was the pilot monitoring, briefed the approach, programmed the flight management computer (FMC) with the ILS approach to runway 10C to back up the planned visual approach. However, they were not receiving the ILS identifier. The captain attempted to troubleshoot why the localizer frequency would not autotune by reloading the approach in the FMC and manually tuning the frequency. Unable to resolve the issue they elected to proceed visually. The captain contacted the air traffic control tower (ATCT) controller stating they were on the visual approach to runway 10C, and the airplane was cleared to land on runway 10C. However, the airplane was aligned with and landed on runway 10L. The flight crew’s decision to continue the approach without the correct ILS frequency was likely affected by their task saturation and planned continuation bias, and their inability to perceive and efficiently integrate available information. Planned continuation bias is an unconscious cognitive phenomenon to continue with the original plan in spite of changing conditions. Once a plan is made and committed to, it becomes increasingly difficult for stimuli or changing conditions to be recognized as necessitating a change to the plan. In addition, as workload increases conditions that may appear obvious to individuals external to the situation are difficult for people caught up in the plan to recognize. Recorded data from the flight data recorder revealed that while flying a heading to intercept the ILS 10C, the localizer frequency in the Nav 1 radio was correctly tuned to 108.95 MHz, the frequency for the ILS 10C localizer, for four seconds. Subsequently, the Nav 1 radio was changed to 108.4 MHz and Nav 2 radio was changed to 113.0 MHz for the remainder of the flight. Although the correct ILS frequency (108.95 MHz) was briefly tuned in the Nav 1 radio, it was subsequently changed to an incorrect frequency (108.4 MHz), and Nav 2 was tuned to a non-ILS frequency (113.0 MHz), preventing the crew from confirming alignment with runway 10C. The FAA mandatory occurrence report (MOR) revealed that the ATCT controller noticed the runway alignment error and coordinated with the runway 10L controller to allow ENY3936 to land on the incorrect runway as no traffic conflicts were noted. The air traffic control (ATC) services provided by the controller were deficient and contrary to FAA directives. Specifically, the controller failed to notify ENY3936 of their alignment error and did not issue control instructions to prevent the wrong surface landing. Had the controller notified the flight crew of the alignment error or provided control instructions it is likely that the wrong surface landing would have been prevented.

Source record

Factual narrative

The flight was operated by Envoy Air Inc., a wholly owned subsidiary of American Airlines Group, doing business as American Eagle. The Honeywell Pilots Guide Rev 8 stated in part: Nav Tuning: Autotune is indicated by the magenta NAV active frequency on the PFD and green FMS AUTO on the adjacent field to the active NAV frequency on the MCDU RADIO page. When VOR or LOC is selected as the navigation source on EDS with autotuning active, autotuning ceases and manual tune is shown on the PFD active NAV frequency in green. FMS AUTO is removed from the MCDU RADIO page. With autotuning active, when Preview is selected, autotuning discontinues. However the PFD and MCDU RADIO pages continue to indicate autotune. When Preview is deselected, autotuning resumes. In Preview mode, the FMS automatically tunes the ILS specified in the arrival procedure when either the aircraft sequences onto an active ILS approach procedure leg or the aircraft is within 30 NM of the destination runway. This is indicated by the PFD active NAV frequency shown in green and FMS AUTO removed from the MCDU RADIO page. ORD is the largest of the three airports in the Chicago metropolitan area, located 17 miles northwest of the downtown financial district. Located at latitude/longitude N41º58.6’ W087º54.5’ and a field elevation of 680 ft msl. The airport serves as a main hub for United and American Airlines. ORD is owned and operated by the City of Chicago and is serviced by a FAA ATCT that is in operation 24-hours a day. Approach radar services were provided by Chicago Approach Control located about 25 miles southwest of ORD. At the time of the incident, ORD had 8 paved landing surfaces designated as runways 4R/22L, 4L/22R, 9R/27L, 9C/27C, 9L/27R, 10L/28R, 10C/28C, and 10R/28L. Runway 10C/28C had 9,756 ft landing distance available and was 200 ft wide. Runway 10C was serviced by a 4 light precision approach path indicator (PAPI) on the left and centerline lights. Runway 10L/28R had 11,133 ft landing distance available and was 150 ft wide. Runway 10L was serviced by a 4 light PAPI on the left side and centerline lights (see figure 3). Figure 3. ORD 20-9 Airport Diagram (Source: Jeppesen) Following the incident, the flight recorders were sent to National Transportation Safety Board (NTSB) Headquarters in Washington, D.C. The NTSB Vehicle Recorder Division received a Universal Avionics cockpit voice flight data recorder (CVFDR) with a recorder independent power supply (RIPS), a dual function recorder providing both flight data recorder (FDR) and cockpit voice recorder (CVR) functions with an integrated RIPS. The FDR function records airplane flight information in a digital format using solid-state flash memory. The recorder was in good condition, and the data were extracted normally. The FDR recording contained 140.61 hours of data. The event flight duration was approximately 2 hours and 9 minutes. The airplane was equipped with a 2-hour CVR as required by federal regulation. The airplane flew multiple flights following the incident flight, therefore, the CVR was overwritten before it could be quarantined for download. Captain The captain was 54 years-old and held an Airline Transport Pilot (ATP) certificate with a rating for airplane multi-engine land, commercial pilot privileges; single-engine land, and type ratings on the CL-65, ERJ-17014, and ERJ-190 which included limitations of English Proficient; ATP Circling approach – Visual Meteorological Conditions (VMC) only; CL-65, ERJ-170, ERJ-190. He held an FAA first-class medical certificate dated August 19, 2024, with the limitation must use corrective lens(es) to meet vision requirements at all distances. During his interview he reported wearing his corrective lenses during the incident. The captain was hired by Envoy Airlines on April 13, 2023, and had accumulated about 7,112 hours total flight time, about 585 hours of which were in the ERJ 170/175. First Officer The first officer was 46 years-old and held an ATP certificate with a rating for airplane multi-engine land, commercial pilot privileges; single-engine land, and type ratings on the ERJ-170, and ERJ-190 which included limitations of English Proficient; ATP Circling approach – VMC only; ERJ-170, ERJ-190. A flight instructor certificate with airplane single-engine; instrument airplane rating, He held an FAA first-class medical certificate dated July 29, 2024, with no limitations. The FO was hired by Envoy Airlines on April 11, 2024, and had accumulated about 1,619 hours total flight experience, about 76 hours of which were in the ERJ 170/175. During an interview with the captain, he stated that while employed at Envoy he had flown into ORD and landed on runway 10C “only a handful of times”. The most recent was about two weeks before the incident. The first officer stated during his interview that it was his second time operating into ORD since his employment began with Envoy. Both crew members stated that this pairing was the first time they had flown together. Cognitive Phenomena Planned continuation bias is a psychological phenomenon which is the unwillingness to deviate from a previously determined course of action, despite the arrival of circumstances precipitating the need for a change. Once a plan is committed to, it becomes increasingly difficult for stimuli or changing conditions to be recognized. In addition, as workload increases conditions and cues that may appear obvious to individuals external to the situation are difficult for people caught up in the plan to recognize and therefore alter the plan. On September 25, 2024, about 1526 central daylight time (CDT), Envoy Airlines flight 3936, an Embraer 170-100 LR, N772MR, was cleared for a visual approach to land on runway 10C at ORD, Chicago, Illinois. However, the flight crew landed on runway 10L instead. None of the 68 occupants aboard the airplane were injured, and the airplane was not damaged. The regularly scheduled passenger flight was operated under the provisions of Title 14 Code of Federal Regulations Part 121 from Norfolk International Airport (ORF), Norfolk, Virginia, to ORD. The flight crew reported that before departure, based on the current weather conditions at ORD, they had planned for the ILS runway 27R via the WATSON4 RNAV arrival. Before beginning their descent into the terminal area, they obtained automatic terminal information service (ATIS) information which indicated they should expect runway 9L. Subsequently, ATC assigned the ESSPO5 arrival which was programmed into the FMCs and briefed. They discussed which runway they should expect and concluded that they would likely be assigned runway 10R. After checking in with the ORD approach controller they were assigned runway 10C. The captain, who was the pilot monitoring, briefed the approach and programmed the FMC with the ILS approach to runway 10C to back up their planned visual approach. However, they were not receiving the ILS identifier. The captain attempted to troubleshoot why the localizer frequency would not autotune by reloading the approach in the FMC and manually tuning the frequency. Unable to resolve the issue they elected to proceed visually. The captain contacted the ATCT controller stating they were on the visual approach to runway 10C, and the airplane was cleared to land on runway 10C. However, the airplane was aligned with and landed on runway 10L. The airplane touched down and turned left to exit the runway (see figure 1). Figure 1. -Google Earth image of incident flight's ground track. A review of ATC communications revealed that after checking in with ORD approach control, ENY3936 was told to expect runway 10C. About 6 minutes later, ENY3936 was instructed to turn to a 060° heading and intercept the 10C localizer. ENY3936 read back turn right heading 090° to intercept. To which the controller corrected ENY3936 and reissued the 060° heading which was read back by ENY3936 corr

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