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C56X, Aarhus Denmark, 2019
From SKYbrary Wiki
|On 5 August 2019, a Cessa 560XLS touched down in runway undershot at Aarhus whilst making a night ILS approach there and damage sustained when it collided with parts of the ILS LOC antenna caused a fuel leak which after injury-free evacuation of the occupants then ignited destroying most of the aircraft. The Investigation attributed the accident to the Captain’s decision to intentionally fly below the ILS glideslope in order to touch down at the threshold and to the disabling of the EGWPS alerting function in the presence of a steep authority gradient, procedural non-compliance and poor CRM.|
|Actual or Potential
|Air-Ground Communication, Controlled Flight Into Terrain (CFIT), Fire Smoke and Fumes, Human Factors, Weather|
|Aircraft||CESSNA 560X Citation Excel|
|Type of Flight||Public Transport (Passenger)|
|Intended Destination||Aarhus Airport|
|Take off Commenced||Yes|
|Location - Airport|
|Tag(s)||LVPs in Place|
Vertical navigation error,
Undershoot on Landing
|Tag(s)||Post Crash Fire,|
Inappropriate crew response - skills deficiency,
Procedural non compliance,
Ineffective Monitoring - PIC as PF
|Tag(s)||Evacuation on Cabin Crew initiative|
|Damage or injury||Yes|
|Aircraft damage||Hull loss|
|Causal Factor Group(s)|
On 5 August 2019, a Cessna 560XLS (D-CAWM) being operated by AeroWest on a non-scheduled passenger flight from Oslo to Aarhus collided with the ILS antenna for runway 28L at Aarhus whilst making an approach to runway 10R in night IMC (although completing it with full visual reference), touched down ahead of the runway threshold partially collapsing the landing gear before ending up on the runway where a fuel-fed fire started. The three crew and 7 passengers evacuated without injury but the aircraft was largely destroyed by impact damage and a subsequent fire and substantial impact damage was caused to the runway 28R localiser antenna.
An Investigation into the Accident was carried out by the Aviation Unit of the Danish Accident Investigation Board. Data from the SSCVR and SSFDR were successfully downloaded for use by the Investigation by the BFU Germany.
The 53 year-old Captain, who was acting as PF for the accident sector, held an Austrian-issued licence and had a total of 2,757 hours flying experience which included 1,311 hours on type. The 36 year-old First Officer held a German-issued licence, had a total of 654 hours flying experience all on type and was in his first job as a professional pilot. Following his most recent Operator's Proficiency Check (OPC) assessment just over two months prior to the accident, his performance against the 29 “elements” was found to have been recorded as either “acceptable” (the majority) or “poor”. As a consequence of these “poor” assessments, the operator’s Head of Training & Standards had restricted the First Officer to operating with “supervision commanders”. It was noted that the inclusion of a cabin crew member was not a regulatory requirement and their duties were only to “serve and entertain the passengers” and they had not received any aircraft-specific training and had no formal responsibility for cabin flight safety.
The pre departure TAF had indicated that fog patches could be expected for the arrival at Aarhus. During descent, it was decided not to descend below FL170 if the reported conditions were below approach minima and that in this case, a diversion to the alternate, Billund, would be made. Having obtained the latest weather from Aarhus TWR to facilitate this decision, the First Officer passed it to the Captain but stated that the prevailing visibility was 2,500 metres rather than the 250 metres which he had been informed it was. However, all other details were provided correctly, including the RVRs for the expected landing runway of 900 metres / 750 metres / 400 metres and the lowest cloud FEW at 200 feet aal. These conditions were within the approach minima applicable to the runway 10R ILS and the Captain then completed an approach briefing accordingly.
Aarhus APP subsequently provided radar vectors to the 10R ILS LOC having advised that LVPs were in force. Once established on the LOC level at 2000 feet QNH with the AP remaining engaged, the Captain called for flap 15. Shortly before beginning descent on the ILS GS, the Captain called visual contact with the ALS (approach light system) through shallow fog and the First Officer stated that he had also observed the ALS together with the green runway threshold lights. Both pilots could see that a fog patch was present above the middle of the runway. With the landing gear selected down and flaps 35 selected, configuration for landing was complete and the flight was cleared to land with the wind reported to be virtually calm.
Passing approximately 1500 feet agl, the TDZ and both ends of the 2702 metre-long runway were visible and the PAPI indication confirmed that the aircraft was descending in accordance with the ILS GS. At approximately 900 feet agl, the Captain disconnected the AP and when the First Officer made a call “500 to minimum”, the Captain responded with “runway in sight”. He then informed the First Officer that he intended to touch down right at the beginning of the runway so as to avoid entering fog patches during the landing roll. He stated that he then flew one dot below the GS in order to touch down on the threshold but he had not communicated this intention to the First Officer.
As the aircraft began to descend below the GS, the First Officer asked if he should disable EGPWS alerting to which the Captain responded in the affirmative and this action was taken at approximately 500 feet agl. Shortly afterwards, the GS deviation reached one dot below the GS and the Captain noted that the PAPI was indicating one white and three red lights. The automated ‘MINIMUMS’ call was annunciated at the procedure DA (281 feet QNH) with a full scale GS deviation displayed and thereafter the beginning of thrust reduction towards flight idle was recorded. The Captain called “continue” and subsequently stated that he had continued to have visual contact with both the approach and runway lighting. The First Officer stated that he had concluded that the Captain “had sufficient visual cues to continue the approach and landing”. CVR data showed that the First Officer had not at any time made calls of altitude or GS deviation.
The commander subsequently stated that he had “noticed passing a white crossbar, a second white crossbar and then red lights” which he had considered “indicated the beginning of runway 10R” and so he had initiated the flare. Almost immediately the aircraft collided with the runway 28L ILS LOC antenna infrastructure at a distance of 450 metres from the runway threshold and then touched down on the grass surface of the 28L RESA after a further 60 metres. After a further 60 metre landing roll, the nose landing gear impacted another part of the antenna assembly and collapsed. The aircraft then rolled on the main landing gear whilst skidding on the nose section and entered the runway 28L stopway, before finally, at an approximate distance of 230 metres past the runway threshold, coming to a stop.
Due to the disposition of the prevailing fog patches, neither the personnel in the airport office nor the TWR controller had had visual contact with the aircraft at any time when it was on the approach or on the ground so the latter was surprised when the First Officer called, reportedly in a calm voice, saying “Tower, Delta Whiskey Mike, we had a crash landing” (no MAYDAY call was made). The controller responded by asking him to “say again” but when there was no response, he initiated airport emergency procedures and notified the area emergency despatch centre.
Meanwhile, in the absence of any instructions from the flight deck, the cabin crew had opened the main cabin door and oversaw the evacuation of the passengers. As this was being accomplished, fuel leaking from the left wing of the aircraft, which had been damaged by the first LOC antenna impact, ignited. The First Officer entered the cabin, saw that it was already empty and observed through the cabin door that fuel was leaking onto the ground and had ignited sufficiently for the resultant heat to be felt. He quickly alerted the Captain about the fire and then left the aircraft and ran towards the group of passengers and the cabin crew with them with the Captain following soon afterwards.
Almost 90 seconds after the First Officer’s only post crash transmission, the airport RFFS chief requested and received ATC permission to enter the runway with one first response vehicle and two fire engines. After a little over half a minute, he reported back to ATC saying that he had obtained visual contact with the aircraft at a range of about 350 metres. After a further three and a half minutes, the RFFS chief called ATC and reported that all those on board had been accounted for and that none of them had sustained any injury. The fuel fed fire slowly increased in intensity, eventually completely destroying the left side of the aircraft rendering it a hull loss.
The Findings of the Investigation based on analysis of the available evidence included the following:
- The reported controlling RVR values were above the applicable CAT 1 approach minima and did not prevent the flight crew from performing the ILS approach for runway 10R.
- From an operational point of view, the commander’s concern about entering fog patches during the landing roll was unjustified.
- The Captain communicated to the First Officer his intention to touch down at the beginning of the runway but not how he intended to achieve this. The First Officer did not then challenge this stated intention and thereafter made no other calls relating to the deviation from the correct vertical profile which then followed.
- Both pilots agreed that EGPWS alerting of potential or actual terrain proximity hazards should be disabled which was directly contrary to procedures applicable to this equipment.
- The First Officer seemed to be familiar with the non-standard procedure of flying below the ILS GS, notably by making the initial suggestion that, given the Captain’s intention to land at the beginning of the runway, the EGPWS terrain proximity alerting function should be disabled.
- The First Officer mentally seemed to rely on the commander’s perception of external visual cues and, although expected to monitor the flights instruments, did not challenge when a full scale GS deviation was reached.
- The Captain may have confused the two red omnidirectional aerodrome perimeter fence obstacle lights with the stopway red edge lights for runway 28L and may have also have “misinterpreted” the configuration of the (entirely standard) approach and runway lighting system associated with runway 10R.
- A touchdown on soft but solid ground in a landing attitude at low airspeed absorbed most of the impact forces and reduced the risk of serious injuries to passengers and crew.
- The Captain’s seniority and experience at the operator might have resulted in the First Officer’s reluctance to effectively monitor the final hazardous stages of the approach by creating a steep authority gradient.
- The actual flight and duty time on the day of the accident was within required limitations and flight crew fatigue was not identifiable as a factor in respect of any aspect of what happened.
- A combination of lack of visual contact with the aircraft on the runway from both the ATC position and the Aerodrome Office together with the absence of a post crash distress (MAYDAY) call from the aircraft resulted in an extended aerodrome emergency response time.
The Investigation formally identified five Causal Factors which it concluded had led to the accident:
- An action plan on flying below the GS, performing an approach aimed at touching down on the threshold in dark night and low visibility conditions.
- The deactivation of a hardware safety barrier.
- Deviations from SOP.
- Less than optimum CRM.
- Confusion over and a misinterpretation of the CAT 1 approach and runway lighting system of runway 10R.
The Final Report was published on 10 June 2020. No Safety Recommendations were issued.