Description

On 9 January 2022, a Boeing 777-300 (A6-EQA) being operated by Emirates Airline on a scheduled passenger flight from Dubai to Hyderabad as EK524 was cleared to line up on runway 30R whilst another Boeing 777-300 (A6-EBY) also being operated by Emirates Airline and on a scheduled passenger flight from Dubai to Bengaluru as EK568 was cleared to cross near the midpoint of the same runway in night VMC. The aircraft cleared to line up then began its takeoff roll from the full length of the runway without clearance and the controller did not notice that this takeoff was occurring until the aircraft was at high speed. The first instruction to stop was ignored but when repeated it was actioned such that, the aircraft still stopped well before the crossing point. Both flights subsequently departed operated by their existing flight crews.

Investigation

An Investigation was carried out by the UAE GCAA Air Accident Investigation Sector (AAIS). Data recorded on the FDR of both aircraft weres successfully downloaded but relevant data on both CVRs had been overwritten. ATC radar and voice recordings were also available. The flying experience of the pilots involved was not recorded.

What Happened

The Hyderabad flight (EK 524), with 187 occupants including a two person flight crew on board, was cleared by the south runway controller to taxi from the south side terminal area via taxiways Z, Z16 and K to hold short of landing runway 30L at the K12 lit stop bar until after a landing SpiceJet Boeing 737 had passed and then to cross runway 30L and proceed to holding point M15A. (see the chart extract below). Note that a significant area of taxiway Mike was closed due to WIP on the day of the investigated incursion and this had led to full length takeoffs from runway 30R as well as different taxi routes for departing aircraft and suspension of independent control of the arrival and departure runways.

After some confusion when the controller briefly switched off the stop bar after the landing aircraft had passed as expected, the aircraft began to move but was then almost immediately told to stop and did so with the stop bar being lit again after a short delay with the nose landing gear still ahead of it. The crossing clearance with the stop bar lighting again extinguished was then given almost a minute later after the next landing aircraft, an Air Algérie Airbus A330-200, had passed the intersection. As the aircraft continued northwards, the south controller queried if it was ready for departure and on confirmation that it was, cleared it to continue to holding point M15A for a full length departure from runway 30R and instructed it to change frequency to the north runway controller.

On being contacted, the north controller instructed the crew to line up on runway 30R and the Captain, as PM read back as “line up runway 30R Emirates 524”. He then turned on the landing lights and the First Officer proceeded to align the aircraft with the runway centreline. Whilst this was happening, another Emirates Boeing 777-300 flight taxiing for departure (EK568) checked in with the north controller and advised that they were holding short runway 30R at M5A (just over half way along runway 30R) and was immediately instructed to cross runway 30R and expedite, and after crossing turn right on taxiway N and proceed to holing point N9. The clearance was read back and crossing commenced. At almost the same time, EK524 had lined up on the runway but instead of stopping, immediately commenced takeoff. The north controller did not immediately notice this and by the time he did and instructed it to “hold position”, the aircraft was accelerating through 97 knots ground speed. There was no response to this instruction so six seconds later, the controller called the aircraft to “stop immediately”. This was again not acknowledged but the aircraft began to decelerate and stopped abeam taxiway M9 (see the aerodrome chart extract) sixteen seconds later after reaching a maximum ground speed of 125 knots. The stopping position was 1,000 metres before the intersection crossing being made at the time by the other aircraft. Once it was stopped, the controller emphasised that they had not been cleared for takeoff.

An extract from the Aerodrome Chart. [Reproduced from the Official Report]

The positions of the two aircraft. Reproduced from the Official Report]

Almost immediately after this, the north controller began to hand over his position in a brief which although it contained pertinent traffic information, made no mention of the rejected takeoff which had just happened. As the crossing aircraft exited the runway via N4 and onto taxiway P, the position handover was completed. The rejected takeoff aircraft was cleared to exit the runway and a little over three minutes later, the Ground Movement Planner contacted Airside Operations to request a runway 30R inspection which was completed after nine minutes. Once off the runway, the aircraft then remained on the taxiway for fifteen minutes “for the crew to evaluate the occurrence with the company MCC before reporting ready for taxi”. Departure in sequence followed and it subsequently took off half an hour after the unauthorised earlier takeoff commencement.

The Causes of the flight cleared to line up on runway 30R (EK524) beginning to take off without clearance were, in summary, recorded as follows:

• When the runway 30R controller enquired if the flight crew were ready for departure, the crew perceived that as a clearance for takeoff from runway 30R.
• When the flight was transferred to the runway 30R controller, it was given “clearance to line up” which was mistakenly perceived as “take-off clearance”.
• Having assumed that takeoff clearance had been given, the flight crew did not expect the other company Boeing 777 (EK568) to cross the active runway as the controller had not directly advised them of this.
• Sight of the crossing aircraft was hindered by the long distance to the crossing point from the beginning of the takeoff, the work in progress adjacent to the left side of the runway and the fact that it was dark.
• Having assumed that takeoff clearance had been given, the crew carried out a rolling takeoff on runway 30R and did not stop after lining up on runway 30R.
• The crew did not monitor the communication between the runway 30R controller and the crew of the Boeing 777 crossing runway 30R ahead as they were completing the Before Takeoff Checklist.

Classification of Runway Incursion Severity

This Serious Incident was classified as Category ‘B’ Runway Incursion in accordance with the UAE CAR Part VIII Subpart 4, Attachment A, where this is defined as “a runway incursion in which the separation decreases and there is significant potential for collision (and) may result in a time-critical corrective/evasive response to avoid a collision.” 

It was noted that “this includes a runway incursion occurring while a departing aircraft has commenced its take-off roll or an arriving aircraft has crossed the threshold”.

Safety Action initiated by Emirates Airline as a result of the Serious Incident was noted as having included the following:

• Arranged meetings with the ANSP to review the current line-up phraseology and align it with best industry practices.
• Commenced discussions with the airport operator to discuss the benefits and feasibility of installing an Autonomous Runway Incursion Warning System at the airport.
• Commenced a review of procedures applicable to the Management Pilot on Duty (MPOD) to ensure provision of sufficient guidance on what information should be gathered and from which sources in order to assess the continuation of a flight after a safety event.

Three Safety Recommendations were issued as a result of the Findings of the Investigation as follows:

• that Emirates Airline addresses the risks associated with before takeoff activities and implements necessary mitigations through the Crew Resource Management (CRM) scheme. Dividing the tasks between the PF and PM during the Before Takeoff Checklist accomplishment will improve the crew's situational awareness. [SR01/2024]
• that Dubai Air Navigation Services (dans) reviews the Dubai Manual of Air Traffic Services (DMATS) and eliminates inconsistencies in runway inspection policies and procedures. [SR02/2024]
• that Dubai Airports initiates, in coordination with the GCAA, dans and Emirates Airline, a safety case study on the need to enhance the ground based alert systems that provide warnings and alerts of detected runway incursions to ATC controllers and flight crews. [SR19/2012]

The Final Report of the Investigation was issued on 20 February 2024.

Related Articles

• Take-off without ATC Clearance
• Runway Incursion
• Runway Holding Position
• Runway Holding Point Lighting
• Stopbars (Skyclip)
• Rejected Takeoff