B737, vicinity Branson MO USA, 2014
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|On 12 January 2014, a Boeing 737-700 making a night visual approach to Branson advised 'field in sight' approximately 20 miles out and was transferred to TWR and given landing clearance at approximately 6,000 feet. However, the crew had misidentified the airport and subsequently landed on a similarly-orientated runway at a different airport. The Investigation found that required flight crew procedures for such an approach had not been followed and also that applicable ATC procedures for approval of visual approaches by IFR flights were conducive to pilot error in the event that airports were located in close proximity.|
|Actual or Potential
|Type of Flight||Public Transport (Passenger)|
|Origin||Chicago/Midway International Airport|
|Intended Destination||Branson Airport|
|Actual Destination||M. Graham Clark Downtown Airport|
|Take off Commenced||Yes|
|Location - Airport|
|Airport vicinity||Branson Airport|
|Tag(s)||Approach to Wrong Airport,|
Procedural non compliance,
Ineffective Monitoring - PIC as PF
|Safety Net Mitigations|
|APM||Available but ineffective|
|Damage or injury||No|
|Causal Factor Group(s)|
Air Traffic Management
|Group(s)||Air Traffic Management|
On 12 January 2014, a Boeing 737-700 (N272WN) being operated by Southwest Airlines on a scheduled passenger flight from Chicago Midway IL to Branson MO as SWA4013 was given clearance when in night VMC to land on runway 14 at destination after its crew had reported 'field in sight'. The aircraft subsequently landed on the much shorter runway 12 at the uncontrolled M Graham Clark Downtown Airport, stopping 90 metres from its end after leaving evidence of heavy braking being used towards the end of the landing roll. There were no injuries to the 131 occupants and the aircraft was undamaged.
An Investigation was carried out by the NTSB. The 2 hour CVR and FDR were removed from the aircraft and their data were successfully downloaded. It was noted that the CVR was deactivated about 53 minutes after the landing.
It was established that the 58 year-old Captain had 15,700 total flying hours which included about 9,035 hours on the 737 and 10,400 hours in command. He had joined Southwest Airlines in 1999 as a 737 First Officer and been upgraded to Captain six years later. He stated on interview that since his last medical, "he had started to wear glasses and that he was wearing them at the time of the incident". He had not previously flown to Branson. The 62 year-old First Officer had 20,538 total flying hours including 9,880 hours in the 737. He had joined Southwest Airlines in 2001 and had subsequently failed two command upgrade attempts. His Medical required him to have near vision glasses available and on interview stated that he was not wearing them at the time of the investigated event. He had flown to Branson once before, a little over six months previously. The flight deck Supernumerary crew seat was occupied by a Company Dispatcher "as an observer".
It was established that during the cruise, it was agreed that runway 14 would be used for landing at destination off a visual approach "backed up with an RNAV instrument approach" and use of the HUD fitted only to the Captain's side, the latter being used in VMC mode with use being an option rather than a Company requirement for visual approaches. The Captain was recorded as stating at this time that he was "setting up the runway 32 LOC DME on his avionics". Prior to descent, the First Officer as PF briefed the approach during which he "indicated a plan to have radar vectors to the approach and let the RNAV line them up for a visual" and noted that the inbound track on final approach was 143°. The expected airport lighting was not included in the brief and was not required to be.
Subsequently, ATC cleared the flight to descend to 24,000 feet and then, two minutes later, direct to destination. As the aircraft descended through 18,000 feet, the First Officer called for the descent checks. Eight minutes later when the aircraft was approximately 60 nm northeast of destination, it was cleared to continue descent to 4,000 feet, advised expect a visual approach to runway 14 and to proceed direct to the final approach fix for the RNAV 14 approach.
During the next few minutes, the aircraft was transferred to Springfield ARTCC and the flight crew (and the dispatcher occupying the supernumerary crew seat) "discussed the navigation fixes and stations on the navigation display and compared them to the lights visible from the flight deck". They then collectively "confirmed which lights they believed to be Branson and which lights they believed to be Springfield". Springfield advised Branson TWR that the aircraft was "20 miles northeast of them for a visual approach to runway 14" and then advised the aircraft crew that their destination airport was at "eleven o'clock and one five miles" to which the Captain responded "field in sight". Springfield then cleared the flight for a visual approach to runway 14, terminated radar service and instructed the crew to contact Branson TWR. The Investigation noted that the corresponding ATC radar recording showed that the airport in the relative position given by the controller to the aircraft was actually M Graham Clark not Branson, the latter being at that time 20 miles away in a 10 o'clock relative position.
When the Captain checked in with TWR and reported passing 6,600 feet for 3,000 feet, TWR cleared them to land on runway 14. Six minutes later, the aircraft touched down approximately 90 metres past the displaced threshold of runway 12 at M Graham Clark Downtown Airport. As the aircraft decelerated, the Captain was recorded as saying "this ain't it" and an application of maximum braking brought the aircraft to a stop approximately 90 metres before the end of the runway paved surface. Thirty seconds later, the Captain called Branson TWR and stated "I assume I'm not at your airport".
Both pilots subsequently stated that once they had what they believed to be their destination in sight, they had ceased referring to the available on-board navigation guidance and relied completely on outside visual reference. It was noted that the Southwest Airlines Flight Operations Manual specified pilot flying and pilot monitoring duties for all approaches and required that both pilots "monitor flight and navigation instruments and crosscheck for consistency and accuracy" and that documented guidance was provided that "flight crews should, when conducting a visual approach, reference an issued charted procedure contained in the FMC navigation database to assist with lateral and vertical guidance to the correct runway". The Investigation noted that whilst the HUD can be "used for descent rate reference in VMC mode by adjusting rate of descent to hold a reference line over the point of intended touchdown, (it) does not provide navigation or flight director guidance in that mode".
It was noted that Branson Airport is 8 miles SSE of the city of Branson and the single grooved concrete runway was 2175 metres long and 45 metres wide. For the 14 direction of use, there was a PAPI on the left side of the runway and with the full length as LDA and outlined by runway end identification and high intensity edge lights. The non-Towered M Graham Clark Downtown Airport was located 1 mile south of the city with a single grooved asphalt runway 1139 metres long and 30 metres wide. The 12 direction of use had no visual approach slope guidance and an 88 metre displaced threshold giving an LDA of 1051 metres. The available runway end identification and medium intensity runway edge lights had to be activated by pilot control via the Common Traffic Advisory Frequency (CTAF).
It was noted that Branson TWR did not have radar and that Springfield would lose radar contact with aircraft arriving in the Branson area once aircraft descended below between 2600 feet and 2200 feet altitude. The effect of this was that no MSAW Alerts were provided during the investigated event. It was also noted that although the Branson TWR controller stated that they had switched on the runway edge lights after receiving notification of the arriving aircraft from Springfield and prior to it checking on their frequency, no record of lighting in use were kept.
Whilst accepting that the actions of the pilots meant that they had been responsible for the wrong airport landing, the Investigation considered that aspects of the ATC service provided had facilitated the misidentification. It was concluded that "issuing a landing clearance for an aircraft to land at an airport when it has not yet passed other nearby airports may confuse pilots, particularly when executing a visual approach". FAA Procedures applicable at the time were found to allow ATC to clear an aircraft for a visual approach to an airport located in "close proximity" to another with which it may be confused without restriction, provided that the location of such an airport was notified. It was noted that this requirement had not been satisfied by the identification by the Springfield ARTCC controller of the potentially confusing airport as the intended destination and the absence of any mention of a potentially confusing airport in the vicinity of the intended destination.
The Investigation found that the Probable Cause of the event was "the flight crew's failure to properly identify the airport and runway of intended landing".
The following Contributory Factors were also identified:
- the flight crew's failure to comply with procedures for use of navigation information and visual cues to verify the airport and runway of intended landing.
- the air traffic controller's issuance of erroneous airport geographic information without including the location of proximate airports.
Safety Action taken by Southwest Airlines as a result of the investigated event included modifying their requirements for any visual approach brief to include explicit reference to runway lighting.
On 4 May 2015, during the course of this Investigation, and aware of other related events under concurrent investigation, the NTSB issued by letter a Safety Recommendation to the Federal Aviation Administration in respect of ATC Service provided to IFR flights as follows:
- that the Federal Aviation Administration amends air traffic control procedures so that controllers withhold landing clearance until the aircraft has passed all other airports that may be confused with the destination airport. [A-15-9]
The Final Report of the Investigation was approved on 2 September 2015 and subsequently published.