CL30, Subang Malaysia, 2019

CL30, Subang Malaysia, 2019

Summary

On 18 March 2019, a Bombardier Challenger 300 had just touched down at Subang when it collided with an unseen and apparently unlit vehicle destroying it and critically injuring its occupant. Significant left wing leading edge damage was then found. The destroyed vehicle and another one had been cleared onto the runway by ATC for routine runway maintenance purposes by a single controller who then did not tell another colleague taking over that the runway was occupied. Use of single controller position manning was non-standard and airside vehicle and aircraft communications were routinely using different communication channels preventing situational awareness. 

Event Details
When
08/03/2019
Event Type
HF, RI
Day/Night
Night
Flight Conditions
VMC
Flight Details
Type of Flight
Public Transport (Passenger)
Intended Destination
Take-off Commenced
Yes
Flight Airborne
Yes
Flight Completed
Yes
Phase of Flight
Landing
Location - Airport
Airport
General
Tag(s)
Inadequate ATC Procedures
HF
Tag(s)
Procedural non compliance
RI
Tag(s)
ATC error, Ground Collision
Outcome
Damage or injury
Yes
Aircraft damage
Major
Non-aircraft damage
Yes
Non-occupant Casualties
Yes
Number of Non-occupant Fatalities
1
Occupant Injuries
None
Occupant Fatalities
None
Off Airport Landing
No
Ditching
No

Description

On 18 March 2019, a Bombardier Challenger 300 (9M-TST) being operated by Berjaya Air on an international passenger flight from Jaipur, India to Subang, Malaysia completed an uneventful ILS approach to runway 15 at destination in night VMC but during the landing roll, it was in collision with an unseen vehicle and both the vehicle and the aircraft sustained severe damage. It was subsequently discovered that the vehicle had been stationary and facing in the landing direction and its only occupant had been severely injured and subsequently died as a result. Three other workers also on the runway saw the aircraft on short final and had been able to board their vehicle and exit the runway. There were no injuries to the 12 occupants of the aircraft but the damage it sustained was considerable, mainly to the left wing leading edge and main spar, to its trailing edge and its flight control surfaces and the lower surface of the wing.             

CL30 Subang 2019 aircraft damaged wing

The damaged left wing of the aircraft. [Reproduced from the Official Report]

CL30 Subang 2019 vehicle wreck

The wrecked escort vehicle. [Reproduced from the Official Report]

Investigation 

An Accident Investigation was carried out by the Malaysian Air Accident Investigation Bureau. Relevant data were recovered from the CVR and a transcript of ATC communications was available.

The 37 year-old Captain had a total of 7,039 hours flying experience including 582 hours on type and the 61 year-old Co-Pilot had a total of 6,309 hours flying experience including 663 hours on type. It was found that during the night period when the accident occurred, four controllers had been on TWR duty with just one combined position open between 0001 and 0600. Having commenced duty at 2300 hrs the previous day, the controllers had agreed that each would consecutively man the combined position for consecutive 90 minute periods per shift, an undocumented system known as ‘Break Shift’. It was noted that such a shift was “not published in any document as an approved ATC Tower manning system”

What happened

A vehicle containing a team of three airport authority contractors had been granted access to the runway to repaint the white centreline markings. This team had no means of communicating with ATC or awareness of TWR communications with aircraft. They were accompanied by an escort vehicle whose driver, an airport authority electrician, was responsible for communications with TWR using a walkie-talkie on a discrete frequency. He also had no listening access to the TWR controller’s air traffic frequency and was parked 1200 metres from the runway 15 threshold facing the direction of aircraft use and was about 120 metres from the separate vehicle which the contractors had used to access the runway.

Shortly after 0300L, and following over two hours without any aircraft movements, which was why the painting team had been granted access to the runway by ATC, an inbound Bombardier Challenger 300 was cleared to land on runway 15, the occupied runway, without any action being taken by ATC to instruct the contractors and their escort to vacate the runway. At a late stage in the approach of the aircraft, the leader of the contractor’s team saw the landing lights of the aircraft and realised that it was going to land. Recognising the imminent danger, all three workers in the contractors team boarded their vehicle and it was driven clear of the runway. Whilst making a 360 degree turn, the driver saw that the escorting vehicle was still in position on the runway and reported having flashed the headlights several times to try and attract the attention of the escort vehicle driver but observed no response. As the aircraft was rapidly getting closer, the driver then drove clear of the runway and stopped on taxiway ‘F’.

Soon after touchdown following an approach in CAVOK (cloud and visibility OK) conditions with the Captain as PF, the aircraft was decelerating though around 100 knots when both pilots became aware that the aircraft must have hit an obstruction and an exclamation by one of them - “we hit something” - was recorded on the CVR. The Captain stopped the aircraft on the runway adjacent to taxiway ‘F’ to allow the Cabin Crew to carry out a visual inspection which found that the left wing was badly damaged. Since there was apparently no consequence for continued taxiing of the aircraft, it was decided to continue to taxi in to the assigned parking bay and on arrival there all passengers were disembarked for immigration clearance.

An external inspection of the left wing found that its leading edge had sustained severe damage in a collision with the escort vehicle with metal parts from the roof of the latter impaled on the wing. The airport RFFS attended the impact location and found the vehicle badly damaged and with its entire roof missing and slightly further along the runway than it had been before the impact. Its driver was found trapped in the driver’s seat with severe head injuries. He was removed from the vehicle and taken to hospital but died as a result of his injures the following day.

The following three pictures show the relative positions of the landing aircraft and the two vehicles prior to and at impact with the various runway access points identified. 
CL30 Subang 2019 vehicles stationary

The two vehicles in their initial stationary positions. [Reproduced from the Official Report]

CL30 Subang 2019 vehicle vacating

The contractors’ vehicle facing the landing aircraft begins to exit into taxiway ‘G’. [Reproduced from the Official Report]

CL30 Subang 2019 vehicle and ac collide

The aircraft left wing hits the escort vehicle which was facing in the direction the aircraft landed. [Reproduced from the Official Report]

Why it happened

The initial duty controller in position from 0001 cleared a vehicle to enter the threshold area of Runway 15 at 0050 to accomplish lighting maintenance work. Ten minutes later, two more vehicles - an escort vehicle and a maintenance vehicle carrying three contractor employees - were also cleared to enter the runway so that the latter could paint the runway centreline. All communications between the lighting and escort vehicles and the TWR controller were through the walkie talkie - the contractor’s vehicle had no means of communications with TWR controller. At 0130, the second controller took over the position and was briefed about the three vehicles on the runway. At 0215 the lighting maintenance vehicle advised vacating the runway on completion of his tasks. However, the second controller then erroneously recorded in the tower logbook that all maintenance work on the runway had been completed and all vehicles had vacated the runway despite the fact that the two vehicles and four persons involved in the centreline painting were still on the runway.

At 0300, a third controller took over the position and the handover with the information that there was no work in progress on the runway (as recorded in the log book) and there was also no indication of ‘Work in Progress’ as a reminder on the flight progress strip bay at the Tower console. At 0308, the inbound aircraft reported on a 9 mile final on the ILS for runway 15 and after looking out on the runway to check on any abnormal activity or unusual lighting which might indicate the presence of vehicles on the runway, the controller cleared the flight to land.

The apparent absence of lights on the two vehicles which were still on the runway was noted as being contrary to the applicable Regulations which were found to state that all vehicles permitted to enter active runways must be equipped with a rotating beacon “with its colour and characteristic as may be determined by Director General”.

The recommendation in ICAO Doc 9870 ‘Manual on the Prevention of Runway Incursions’ that all vehicles on an active runway should be in radio communication with runway controller on the same VHF frequency as that used by aircraft taking off or landing on the same runway was also noted. Whilst neither the controller in position nor the pilots of the landing aircraft saw any lights on the escort vehicle and such a light was not visible on a pre impact CCTV playback, it was noted that the painting contractors had stated that the vehicle was displaying a light. The Investigation was unable to determine the intensity of the light bulb used for the beacon installed on the escort vehicle because of the extensive impact damage to both the light and its switches. It was also found that there was “no written specification on the minimum intensity required for the beacon light to be used by vehicles operating within the manoeuvring area” and there was no other similar vehicle in use at the airport which could have been inspected.

The Probable Cause of the Accident was determined as "incorrect information of vehicle activities on the runway handed over to the taking over controller led to the landing clearance given without realising the runway is occupied".

Three Safety Recommendations were made as a result of the findings of the Investigation as follows:

  • that the Civil Aviation Authority of Malaysia ensures that shift manning, especially during low traffic density, takes into consideration human fatigue as recommended in the ICAO Doc 9966 'Manual for the Oversight of Fatigue Management Approaches’. Any amendment or changes of shift manning need to be officially published.
  • that the Civil Aviation Authority of Malaysia and Malaysia Airports need to coordinate an effort to ensure that the means of communication between ground vehicle operating within the manoeuvring area and Air Traffic Controller is in accordance to ICAO Doc 9870 - ‘Manual on The Prevention of Runway Incursion’, Chapter 4, Paragraph 4.2.6 which require the use of VHF radio.
  • that the Civil Aviation Authority of Malaysia and Malaysia Airports add a specific Chapter or Annexes in the existing SOP listing the specification of vehicle to be used for manoeuvring area including vehicle accessories which need to be installed. For example, the intensity of beacon light to be used on vehicles, coordination phraseology between ATC and driver, etcetera.

The Final Report was issued on 2 December 2020.    

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