ASN logo
ASN Wikibase Occurrence # 212663
Last updated: 19 July 2018
This information is added by users of ASN. Neither ASN nor the Flight Safety Foundation are responsible for the completeness or correctness of this information. If you feel this information is incomplete or incorrect, you can submit corrected information.

Date:03-SEP-2015
Time:08:53 LT
Type:Silhouette image of generic BE20 model; specific model in this crash may look slightly different
Beechcraft B200 Super King Air
Owner/operator:Corporate and Leisure Aviation
Registration: VH-OWN
C/n / msn: BB-936
Fatalities:Fatalities: 0 / Occupants: 9
Other fatalities:0
Aircraft damage: None
Category:Serious incident
Location:near Mount Hotham, VIC (MHU/YHOT) -   Australia
Phase: Approach
Nature:Domestic Non Scheduled Passenger
Departure airport:Melbourne-Essendon Airport, VIC (MEB/YMEN)
Destination airport:Mount Hotham, VIC (MHU/YHOT)
Investigating agency: ATSB
Narrative:
At about 08:25 LT on 3 September 2015, five low-capacity twin-engine turboprop aircraft flew from differing originating aerodromes towards Mount Hotham Airport, Victoria, as part of a passenger charter involving a number of different operators.
As the weather on arrival at Mount Hotham was below that required for a visual approach, the aircraft needed to carry out the published area navigation (RNAV) Global Navigation Satellite System (GNSS) instrument approach in order to navigate clear of cloud before landing.
The first aircraft to arrive in the Mount Hotham area was a Beech B200 King Air, registered VH-OWN. At about 08:29, the pilot of VH-OWN commenced the RNAV (GNSS) approach for runway 29 from the south via the initial approach fix (IAF) waypoint HOTEC using the autopilot, but experienced tracking difficulties on reaching the intermediate fix waypoint HOTEI.
Radar data showed that from HOTEC to HOTEI, VH-OWN descended to 7,300 ft, 400 ft below the minimum permitted safe altitude. At 08:30 the aircraft did not turn to intercept the inbound approach track at HOTEI, but instead continued tracking to the north of the prescribed approach path and continued to descend to 6,300 ft. In response to the tracking difficulties, the pilot eventually discontinued the approach.
The pilot then climbed the aircraft to the minimum safe altitude of 7,700 ft while still tracking towards the north, rather than via the prescribed missed approach track. At 08:34, the pilot of VH-OWN advised the air traffic controller that he was in the missed approach, and commenced manoeuvring in the airspace in the Mount Hotham area, as the other charter aircraft progressively arrived for the RNAV (GNSS) approach for runway 29.
Due to surveillance limitations to the north of Mount Hotham, surveillance data for VH-OWN was not available to the controller from 08:32 to 08:38. During that time, the aircraft tracked from the east of Mount Hotham at 6,400 ft, to a position about 4 NM (7 km) east of the airfield at 7,900 ft. At 08:38, the aircraft’s position did not match the pilot’s reported tracking details, though the controller did not comment on the erroneous tracking when providing the pilot with position information.
The second aircraft, also a King Air, arrived at Mount Hotham on the same track as VH-OWN, commencing the approach at 08:41 as the pilot of VH-OWN reported that he would track to waypoint
HOTEB and hold. The pilot of that aircraft conducted the RNAV (GNSS) approach from waypoint HOTEC and landed on runway 29 at about 08:46, having become visual with the ground close to the approach minimum altitude (741 ft above the runway).
Shortly after the pilot of VH-OWN reported tracking for HOTEB, the pilot of another aircraft tracking for Mount Hotham advised him on the area radio frequency that they were trying to talk to him on the Common Traffic Advisory Frequency (CTAF). The CTAF at Mount Hotham was not recorded, nor was it monitored by air traffic control.
The third aircraft to commence the approach was another King Air, registered VH-LQR. On receiving advice from the pilot of VH-OWN on the CTAF that he was to the west of Mount Hotham, the pilot of VH-LQR tracked inbound from the north-east on descent to 7,700 ft to commence the approach at the IAF HOTEA. It was reported that subsequent broadcasts from the pilot of VH-OWN on the CTAF indicated that the pilot was unsure of his position. Consequently, the pilot of VH-LQR stopped descent at 8,000 ft while still to the north of HOTEA.
At 08:48, the controller attempted to contact the pilot of VH-OWN and, when not successful, advised the pilot of VH-LQR that VH-OWN was going to conduct an approach in front of VH-LQR. This information was surmised by the controller from the observed track of VH-OWN. The pilot of VH-LQR advised the controller that he believed the pilot of VH-OWN was ‘on the approach’ but he was unable to contact him. Shortly afterwards, the pilot of VH-LQR advised the controller that VH-OWN was ‘turning inbound at HOTEB for the approach’. However, surveillance data showed that, at that time, VH-OWN was just to the south of HOTEI at 7,700 ft tracking in a north-easterly direction.
From 08:49, when VH-LQR was about 18 NM (33 km) north of HOTEA at flight level (FL) 141 to 08:54 when the aircraft was about 1 NM (2 km) north of HOTEA at 8,200 ft, surveillance data for VH-LQR was not available to the controller. Surveillance data remained available for VH-OWN during that period that showed the aircraft tracked to the east of HOTEI and towards HOTEA at 7,700 ft.
Although not available on the controller’s surveillance display, data from the Department of Defence radar to the south of Mount Hotham at East Sale, Victoria, showed that VH-OWN passed 300 ft below VH-LQR, just north of HOTEA at 08:53.
The pilot of VH-OWN then attempted another approach and experienced similar tracking difficulties. Radar data shows that the pilot again continued to descend to the north of the RNAV (GNSS) approach track to 5,800 ft, with the pilot later stating that he became visual and clear of cloud during the descent. The aircraft was then observed to carry out significant manoeuvring close to the ground while establishing the aircraft on short final to the runway before landing at about 09:18.


Contributing factors:
- Due to difficulties with the operation of the GPS and coupled autopilot, VH-OWN did not turn at the intermediate fix to intercept the final approach course. As these difficulties were not corrected by the pilot, the aircraft deviated outside of the tracking tolerances of the approach, while descending below the lowest safe altitude during each of the multiple approach attempts.
- Due to high workload and difficulties with the operation of GPS/autopilot system, the pilot of VH-OWN did not broadcast accurate position reports, resulting in reduced separation, and a near-collision, with VH-LQR.
- The pilot’s ability to follow established tracks and accurately communicate the aircraft’s position was likely adversely affected by experiencing a high workload, due to factors including singlepilot IFR operations while conducting an area navigation (RNAV) Global Navigation Satellite System (GNSS) approach, existing weather minimums and the reduced available flight automation.
- Despite intermittent surveillance coverage in the area of the Mount Hotham Airport, there was sufficient radar data to identify that the pilot of VH-OWN was having tracking difficulties and that the aircraft was tracking towards the expected position of VH-LQR. Due possibly to a focus on higher priority tasks, this information was not communicated to the affected pilots contrary to the intent of the traffic information service they were receiving.

Sources:

ATSB

Accident investigation:
cover
  
Investigating agency: ATSB
Status: Investigation completed
Duration: 2 years and 9 months
Download report: Final report


Revision history:

Date/timeContributorUpdates
27-Jun-2018 10:27 harro Added

Corrections or additions? ... Edit this accident description