Arabia A320 at Sharjah on Sep 18th 2018, intersection line up departed in wrong direction

Last Update: January 10, 2022 / 16:21:11 GMT/Zulu time

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Incident Facts

Date of incident
Sep 18, 2018

Classification
Incident

Airline
Air Arabia

Flight number
G9-111

Departure
Sharjah, United Arab Emirates

Destination
Salalah, Oman

Aircraft Registration
A6-ANV

Aircraft Type
Airbus A320

ICAO Type Designator
A320

An Air Arabia Airbus A320-200, registration A6-ANV performing flight G9-111 from Sharjah (United Arab Emirates) to Salalah (Oman) with 42 passengers and 6 crew, was taxiing for departure from Sharjah's runway 30, the aircraft entered the runway for an intersection departure from taxiway B14 and turned into direction runway 12 (opposite to intended direction), takeoff distance available from B14 on runway 12 was 1020 meters/3350 feet instead of 3010 meters/9900 feet in direction of runway 30, including the paved runway end safety area a paved surface of 1150 meters/3760 feet was available in direction of runway 12. The crew commenced takeoff from intersection B14 along direction runway 12, managed to become airborne in time to avoid any obstacles, climbed out to safety and continued to Salalah for a landing without further incident.

On Sep 19th 2018 Air Arabia instructed their pilots that all intersection departures were banned with immediate effect after one of their flights took off from an intersection in the wrong direction. The airline further re-iterates that ATC in Sharjah might clear flights to taxi to the runway full length via taxiway B rather than taxiway A, great attention to ATC instructions is needed.

Both pilots have been suspended pending the investigation.

On Oct 5th 2018 The United Emirates GCAA reported: "Air Arabia flight ABY111 was cleared for takeoff at OMSJ runway 30, B14 intersection. However, crew mistakenly lined up for runway 12. After entering the runway, and realizing that the remaining distance for takeoff was short (about 1,100 meters), the commander took over controls and continued the takeoff while selecting flaps at 2nd used TOGA power. The aircraft took off at the end of runway. After takeoff, a call from ATC was received informing the crew about the wrong runway used." The occurrence was rated a serious incident and is being investigated by the GCAA.

On Jan 10th 2022 the GCAA released their final report the probable causes of the serious incident were:

The Air Accident Investigation Sector of United Arab Emirates (AAIS) determines that the cause of the runway confusion was the Copilot steering the Aircraft right onto the wrong runway during a rolling takeoff.

Entry to the wrong runway was due to degraded situation awareness of the Aircraft direction by both flight crewmembers due to lack of external peripheral visual watch and runway confirmation.

Contributing Factors to the Serious Incident

A contributing factor to the Incident was that the air traffic controller did not monitor the Aircraft movement after take-off clearance was given.

The GCAA reported the first officer under training (34, MPL, 159 hours total, 159 hours on type) occupying the right hand seat was pilot flying, the training captain (51, ATPL, 22,184 hours total, 15,536 hours on type) in the left hand seat was pilot monitoring. A rolling takeoff was to be conducted.

The GCAA summarized the sequence of events:

Tower air traffic control gave clearance for an intersection takeoff from taxiway Bravo 14 for runway 30, which required a left turn for the correct runway. Thereafter, the before takeoff checklist ‘below the line’ items were completed by the flight crew.

Instead of steering the Aircraft left following runway 30 lead-on lines from Bravo 14 intersection, the Copilot steered the Aircraft right for runway 12. The Copilot called out that RWY was not showing on the flight mode annunciation (FMA) after the thrust levers were moved to the FLX/MCT detent. As the Aircraft accelerated through 57 knots, the Commander realized that the Aircraft was on the wrong runway and immediately took over control. His decision to continue the takeoff was based on his perception that there was insufficient available runway for rejecting the takeoff. The Commander advanced the thrust levers to TOGA detent and nine seconds after, changed the Aircraft flap setting from 1+F to flap 2 position. The Aircraft lifted off 20 to 40 meters beyond the end of runway 12. No. 3 main wheel tire received cuts when it struck one approach light during the liftoff.

Tower controller did not detect that the Aircraft had turned unto runway 12 and only noticed when the Aircraft was about eight seconds before liftoff.

The Commander handed over controls to the Copilot and the flight continued uneventfully to the planned destination.

The GCAA described the damage:

The No. 3 main wheel tire on the right main landing gear struck a runway approach light located at the runway-end safety area, which resulted in cuts to the inboard sidewall and tread (figure 1). The tire remained inflated during the flight. As per the Commander's statement, he could not notice any cuts on the tire as the cut was on the lower invisible part of the tire.

The No. 3 main wheel tire struck the runway 30 approach light. The support post of the approach light was made of steel and was bolted to the runway surface with a height of 70 centimeters. The base of the light support structure was completely detached, and the light assembly was broken. The damaged approach light was located on the runway end safety area (RESA).

Captain and first officer had already flown 4 uneventful sectors together the previous days including two departures from Sharjah, both on runway 12, both were flown by the first officer.

The GCAA reported with respect to rejecting takeoff:

For flight ABY111, taking into consideration the dry runway surface, Aircraft take-off weight, Aircraft configuration and performance, and take-off wind conditions, the Investigation requested the Aircraft manufacturer to calculate if the Commander could have safely rejected the takeoff based on the following two scenarios:

- Applying maximum reverse thrust at the time when the Commander had selected TOGA thrust when the Aircraft CAS was 57 knots.

- Applying maximum reverse thrust instead of flap configuration 2 when the Commander selected flap 2 configuration with Aircraft CAS was 109 knots.

According to the Aircraft’s manufacturer calculation that at the time of the take-off initiation, the runway remaining was 984 meters. For both scenarios, it was possible to safely stop the Aircraft if maximum engine reverse thrust was used, automatically applying maximum braking. The calculated runway distance remaining were:

- For the first scenario, the Aircraft would have stopped 653 meters before the end of the runway.

- For the second scenario, the Aircraft would have stopped 45 meters before the end of the runway.

The GCAA analysed:

Nine seconds after the Commander correctly read back ATC take-off clearance for departure from runway 30, autobrake MAX deceleration rate was set, the parking brake was selected OFF and shortly after the Aircraft started to move beyond Bravo 14 holding point. The Copilot started gradual increments of engine thrust beyond idle about 51 seconds after the parking brake was selected OFF. After another 22 seconds, with the Aircraft's ground speed increasing and passing 20 knots, the Copilot almost simultaneously applied a nose down sidestick input and advanced both thrust leavers to FLX/MCT detent. Because there was no need to stop the Aircraft on the runway, the Copilot continued to steer and align the Aircraft onto runway 12 centerline for the rolling takeoff.

When the Copilot noticed that the FMA was not indicating RWY, she realized that the Aircraft not aligned to the pre-selected runway which was entered to the flight management system (FMS). However, she announced the FMA modes but not RWY mode as it was blank.

After the callout by the Copilot, the Commander quickly decided to continue the takeoff and advanced both thrust levers to the takeoff/go-around (TOGA) detent position with the Aircraft speed passing 57 knots calibrated airspeed (CAS). Unknown to the flight crew, the remaining runway 12 available for an accelerate-stop was about 730 meters.

The Commander’s perception that the Aircraft was approaching the threshold of runway 30, and his judgment that the liftoff may not be accomplished safely with the pre-set configuration, prompted him to move the flaps lever to flap 2 position while passing 109 knots CAS. That was about nine seconds from when the Commanded advanced the thrust levers to TOGA position. After two seconds, the Aircraft entered the displaced threshold area for runway 30.

By extending the flaps from position 1 to position 2, the Commander expected to shorten the take-off distance. The Aircraft eventually became airborne after traversing runway 12 stop-way area by about 30 meters with passing 132 knots CAS. The flight crew and air traffic controller were not aware that one of the approach lights of runway 30 was damaged by No. 3 main wheel tire during the Aircraft liftoff

From engine thrust lever movement to TOGA detent until liftoff, the Aircraft rolled along the runway for about 780 meters in 14, accelerating from 57 knots when the thrust leave was advanced to 132 knots when the Aircraft rotates.

Analyzing the FDR data, Aircraft taxi speeds, ATC transcript, and based on the simulator sessions conducted by the Investigation, the Investigation found that there was no departure time constraint imposed by ATC, and that the cockpit workload was normal as the crewmembers had sufficient time to complete the required checklist items and monitor the Aircraft position prior to takeoff. There were no cues that the crew had been affected by hurry-up syndrome to expedite the takeoff.

The Aircraft systems and engines were functioning as designed. However, the Aircraft was not equipped with the A320 industry-known software features that aid the flight crew to maintain situational awareness during taxi and takeoff. These awareness augmentation systems, such as runway awareness and advisory system (RAAS) and take-off surveillance (TOS2) system, provide aural and/or visual alerts in detecting and mitigating taxiway and runway confusion risks.

Considering that this was a training flight with the trainee Copilot as the pilot flying, as well as the shorter taxi time of about three minutes from the pushback position for the intersection at Bravo 14 holding point when compared to Bravo 20 holding point, the Investigation believes that the Commander’s decision to carry out a single-engine taxi followed by the second engine start during taxi could have potentially put the flight crewmembers under extra workload.

For better crew resource and workload management in the cockpit and the short taxi time anticipated, the Commander could have considered conducting a dual-engine start prior to commencement of the taxi as the economic benefit of conducting single-engine taxi procedure was probably negligible. Therefore, the Investigation recommends that the Operator improve its singleengine policy that takes into consideration taxi time to the runway holding point and the cockpit crew gradient.

...

It took the Commander about six seconds to mentally process the information of the approximate position of the Aircraft on the runway, Aircraft speed, perception of remaining runway available, take control of the Aircraft, decide to continue the takeoff, and advance both thrust levers to TOGA detent.

A decision to take control of the Aircraft from the Copilot required the Commander to call “I have control” and then for the Copilot to transfer control by responding “You have control” and for the Copilot to then assume pilot monitoring functions. In addition, when the Commander mentally decided to continue the takeoff, he was required to make his intentions known with the callout ‘Go’.

The investigation believes that these callouts were not accomplished from the statements and interviews with the flight crew.

The Commander perceived that the remaining runway available was insufficient to reject the takeoff as indicated by his statement to the Investigation “I saw the end of runway coming.” The Aircraft manufacturer's guidance and the Operator’s policy for a rejected takeoff recognizes the risks involved with such a decision. This is why the manufacturer divided the take-off speeds into high-speed and low-speed regimes. The Commander applied the principle of ‘go-minded’ similar to the decision of continuing a takeoff at or beyond 100 knots

The Commander’s decision was based on his perception of the runway available to stop the Aircraft. His immediate reaction to his realization that the takeoff was from the wrong runway was by advancing the thrust levers to TOGA. He misjudged that the remaining runway would have been sufficient to reject the take-off safely.

The nonstandard action by the Commander of moving the flap lever position from 1+F to Flap 2 position during the take-off roll would have required him to shift his attention from outside peripheral view during the take-off roll to the cockpit flap lever and engine and warning display (E/WD) to confirm that flaps/slats are moving to the selected position. This action could have caused lateral disruption in control of the Aircraft during takeoff due to the shift of sight. The Investigation believes that the Commander's efforts aimed at liftoff before reaching the end of the runway rather than rejecting takeoff at lower than 100 knots airspeed. That judgment and consequent decision were indications of a ‘take-off minded’ situation.

The Commander was aware of the ‘High/Low rejected take-off speed’ criteria, and was trained on rejected takeoff. There was no provision in the Operator’s flight crew operating manual (FCOM) to provide the flight crew with information about the runway accelerate-stop distance, aircraft take-off weight, or aircraft take-off speeds. Therefore, a decision to reject a takeoff was left to the flight crew.

Had the Commander decided to reject the takeoff any time within the low-speed regime below 100 knots, and should he have applied maximum reverse engine thrust, which would automatically engage maximum autobrakes, the Aircraft would have safely stopped on runway 12. This was confirmed by the performance calculations provided by the Aircraft manufacturer and the simulated flight sessions.