[Peetwo]

Near-collision and Operational Event involving Beech Aircraft Corp. B200, VH-OWN and Beech Aircraft Corp. B200, VH LQR, Mount Hotham Victoria on 3 September 2015

 
Investigation number: AO-2015-108
Investigation status: Active
 

• Summary
  

Updated: 11 November 2015
At approximately 0830 Eastern Standard Time[1] on 3 September 2015, four low capacity twin engine turboprop aircraft flew towards Mount Hotham Airport, Victoria, as part of a passenger charter involving a number of different operators. On arrival at Mount Hotham the weather conditions were below that required for a visual approach. As a result, it was necessary for each aircraft to carry out a published Global Navigation Satellite System (GNSS) instrument approach, in order to navigate clear of cloud before landing (Figure 1).

Figure 1: GNSS instrument approach chart for Mount Hotham Airport 

Source: Airservices Australia

The first aircraft to arrive in the Mount Hotham area was Beech Aircraft Corp. B200 King Air, registered VH-OWN. The pilot of that aircraft commenced the GNSS approach from the south-east and, having descended below the specified altitude of 7,700 ft overhead initial approach fix HOTEC, experienced tracking difficulties approaching the intermediate fix HOTEI. In response, the pilot discontinued the approach and climbed the aircraft in a north-easterly direction (Figure 2). Having climbed back to the lowest safe altitude for that area, the pilot of VH-OWN commenced manoeuvring in the airspace above the Mount Hotham Airport as the other charter aircraft progressively arrived in the area and commenced the instrument approach.

Figure 2: VH-OWN partial radar tracking during the first approach
(Note: the climb back to the lowest safe altitude is not displayed)

Source: Airservices Australia, modified by the ATSB

The second aircraft arrived at Mount Hotham on the same track as VH-OWN. The pilot of that aircraft conducted the GNSS approach and landed on runway 29.

The third aircraft to commence the approach was another B200 King Air, registered VH-LQR, which tracked inbound from the north-east at 8,000 ft. During this time the pilot of VH-OWN continued manoeuvring in this area at 7,700 ft and the two aircraft passed in close proximity of each other with a vertical separation of approximately 300 ft.

The pilot of VH-OWN then conducted a second approach and experienced similar tracking difficulties. The pilot reported becoming visual and clear of cloud during the approach and continued to descend. VH-OWN was then observed to carry out significant manoeuvring while on short final to the runway before landing.

The airspace around Mount Hotham was designated as uncontrolled Class G airspace. Civilian radar coverage was unable to track all parts of the flight, and there was no control tower or certified air/ground radio service at the airport. Neither VH-OWN nor VH-LQR were fitted with airborne traffic avoidance equipment such as the Traffic Collision Avoidance System. The primary means of separation was the use of radio communication between the pilots and flight in accordance with the published instrument approach chart.

The investigation is continuing and will include examination of the:

• navigation and autopilot system fitted to VH-OWN
  
• recorded radio and radar data
  
• planning and conduct of the multiple aircraft charter operation
  
• air traffic services provided in the Mount Hotham area.
  

 

Also recently released by the ATSB (in a mad flurry of activity) was the Final Report into a LOS incident in Williamtown airspace on 19 Sept 2013. Anyway thought the ATCO fraternity would find this one interesting : 

[*]Final Report
[*]Safety Issue
Final Report
Download Final report
[PDF: 1.95MB]
 
 
Listen to this PDF
Alternate: [DOCX: 7.19MB]
 
On 19 September 2013, the pilot of a Beechcraft B300, registered VH-FIZ, was conducting calibration activities of ground-based navigation aids at Williamtown (Newcastle Airport), New South Wales.

During the calibration activities, the aircraft conducted a 7 NM (13.0 km) orbit around Williamtown. However, the Tower air traffic controller had intended the aircraft to hold south of Williamtown over land. At the same time, other aircraft were approaching Williamtown to land.

VH-FIZ tracked on the 7 NM arc towards, and then across the coast, on a converging path with a formation of four Boeing F/A18 aircraft that were on a visual approach to Williamtown. The formation flew directly below VH-FIZ with less than the required 1,000 ft separation.

What the ATSB found
The ATSB found that the applicability of a general requirement to conduct aviation risk assessments at Department of Defence aerodromes for complex, new, unusual or irregular activities was open to interpretation. This led to an absence of prior planning for the calibration activities, resulting in an air traffic control work-around on the day of the activities that did not address all related safety aspects. One work-around was that airspace over land usually controlled by Approach was transferred to the Tower. The resultant airspace controlled by the Tower was considerably larger than normal, resulting in the Tower controllers having difficulties visually monitoring the airspace and needing to rely on the surveillance display for situation awareness.

An instruction given to VH-FIZ to ‘orbit’ was insufficiently clear, resulting in the pilot misinterpreting it as permission to conduct a pre-planned 7 NM (13.0 km) orbit around Williamtown. As a result of the Tower controller’s assumption that VH-FIZ would remain in the area they intended, the aircraft was not adequately visually monitored by the controllers in the Tower, or monitored on radar by the Approach controller. This removed any chance of early detection of the impending aircraft conflict. When the Tower controller did detect the conflict, clear control instructions were not immediately given to either VH-FIZ or the F/A18s, leading to a loss of separation.

What's been done as a result
The Department of Defence took proactive action to improve the implementation of aviation risk management (AVRM) to ensure that AVRM plans developed for unusual or irregular operations, such as calibration operations, addressed staffing and traffic levels, coordination and workload.

Safety message
Although not guaranteeing the absence of aircraft separation incidents, prior planning for unusual or irregular operations can permit the development of robust air traffic control defences that address the specific hazards of that operation. Aircraft separation safety also relies on controllers issuing specific control instructions to all pilots, along with the provision of timely and relevant traffic information to pilots of aircraft identified to be in conflict.

Williamtown Visual Terminal Chart

Source: Airservices Australia

Download Final report
[PDF: 1.95MB]

Alternate: [DOCX: 7.19MB]
 
Safety analysis
Although the opportunity for Williamtown air traffic control (ATC) to undertake prior planning for the calibration operations had existed in the 24 working days between the initial notice and the activity, no such planning took place. Defence air traffic services stipulated that any complex, new, unusual or irregular activity required a risk assessment. However, as calibration flights occurred a number of times each year, the Williamtown ATC Flight Commander did not believe that such activity required the conduct of a risk assessment. In addition, although Williamtown ATC had in place a number of generic risk assessments and treatments for unusual situations, there were no risk assessment for increased traffic complexity such as that created by the calibration activities.

Prior planning and a risk assessment had the potential to identify the need to increase staffing in both the Tower and Approach areas, provide briefings for ATC personnel and the pilots of locally-based aircraft, and ensure controllers had a thorough understanding of the calibration run sheets prior to the activity commencing. Such prior planning would have incorporated strategic separation assurance considerations.

The Williamtown Approach controller released airspace to the Tower controller that was considerably larger than that normally controlled by the Tower. That resulted in both the Tower supervisor and the Tower controller having difficultly monitoring the airspace visually, and the need for the Tower controller, though not trained in the use of radar separation, to rely on the surveillance display for situation awareness as well as separation. In situations where the location of an aircraft is known (from a position report or from observing a surveillance display), a controller could quickly use the binoculars to locate an aircraft. However, to locate an aircraft at an unknown position, the controller would need to scan the sky, possibly with the assistance of binoculars. Although binoculars were available to the controllers, binoculars could potentially limit the controller’s view. Using binoculars would also have been time-consuming.

During the morning, there had been two additional controllers in the Tower cabin than normal. They were able to assist with monitoring VH-FIZ (FIZ), and a number of the controllers present had experience with the use of surveillance data for monitoring aircraft and providing separation instructions. At the time of the occurrence, only three controllers were in the Tower cabin. One was newly endorsed in Surface Movement control, without having undertaken training in the control of airborne aircraft. The other two controllers present were not trained in separating aircraft with surveillance data.

Williamtown Base Standing Instructions (Base SIs) and 453 Squadron Williamtown Flight Standing Instructions (ATC SIs) contained restrictions and requirements, for both controllers and locally-based military aircrew, to provide strategic separation assurance between arriving locally-based military aircraft and those within the airspace normally controlled by the Tower controller. These specifically required the local aircraft to remain clear of airspace under the Tower controller’s jurisdiction until issued with traffic information. The last minute planning conducted on the morning of the occurrence by two ATC supervisors, though well intentioned, resulted in less than optimal conditions.

These included procedures that negated the established strategic separation assurance documented in both Base and ATC SIs, increased traffic complexity, and the need for the Tower controller to rely on the surveillance display when the controller was not trained to use radar separation.

The run sheet provided to ATC for the calibration of the tactical air navigation system (TACAN) numbered each required run and included a note ‘The run numbers are to assist with Pilot/ATC communications, not to indicate the order in which the runs will be completed.’ Had the pilot of VHFIZ (FIZ) used the run number (Run 1A) in the request to conduct the 7 NM (13.0 km) orbit around Williamtown, the Tower controller may not have misinterpreted the pilot’s request with a request to hold south of Williamtown in an orbit – a standard holding manoeuvre that would essentially keep the aircraft in the same area.

However, as the only calibration runs requiring 3,100 ft were the 7 NM (13.0 km) orbits of the Williamtown TACAN, the Tower controller’s reported belief that the pilot of FIZ had asked for that altitude to prepare for the next run to runway 30, for which the run sheet indicated a commencement altitude of 1,500 ft, demonstrated that the controller was either not referring to the run sheet or did not understand the run sheet.

If the Tower controller had used run numbers on the data labels for silent coordination, the Approach controller would have had the opportunity to maintain situation awareness of calibration activities. Further, the use of run numbers would have provided cues to the Tower controller. In turn, the Tower controller may then have been more likely to use the numbers in communication with the pilot of FIZ, removing the opportunity for the pilot to misunderstand the controller’s approval to conduct an orbit.

Although prompted a number of times by the Tower supervisor, the Tower controller did not issue specific holding instructions to the pilot of FIZ. Specific holding instructions could have included ‘hold over land to the south of the field’ or to hold over a specific location. Such an instruction would have resulted in the pilot of FIZ questioning their understanding of the approval to conduct an orbit.

Once the pilot of FIZ commenced the 7 NM (13.0 km) orbit around Williamtown, in line with the pilot’s interpretation of the Tower controller’s response to the request, a loss of separation assurance (LOSA) existed between the calibration aircraft and the formation of four Boeing F/A18 aircraft (F18s) tracking for runway 30. Believing that FIZ was holding to the south in an orbit, the Tower controller did not visually monitor FIZ’s position. Instead, the Tower controller relied on the Surface Movement controller to do so while the Tower controller attended to other aircraft.

An opportunity to identify the loss of separation assurance at an earlier point was lost when the Approach controller did not identify that FIZ had crossed the coast, leaving the airspace released to the Tower controller. The Tower controller had not coordinated FIZ’s entry into airspace under the jurisdiction of the Approach controller. However, the Approach controller should have observed the calibrator entering and remaining in airspace under their jurisdiction. FIZ crossed the coast into the Approach controller’s airspace prior to the F18s passing overhead Williamtown and before they were issued with a visual approach. If FIZ had been identified in the Approach controller’s airspace at this stage, the F18s could have been held away to allow FIZ to complete the 7 NM (13.0 km) orbit of Williamtown, or the Tower controller could have been instructed to turn FIZ to re-establish the calibration aircraft over land. When the Approach controller did observe FIZ and realise the potential conflict with the F18s, they immediately contacted the Tower controller and asked that a safety alert be issued.

Once the Tower controller became aware of FIZ’s position to the south-east over water, clear and urgent information was not immediately provided to the pilot to ensure separation and avoidance with the F18s. As the closure speed between the calibration aircraft and the F18s was very high, the opportunity to provide timely control instructions and traffic information was lost when the controller asked the pilot of FIZ to confirm that the aircraft was holding to the south even though the controller had observed the aircraft tracking in a northerly direction south-east of Williamtown. The absence of clear control instructions to either the calibration aircraft or the formation of F18s resulted in a loss of separation (LOS) between aircraft that had not been provided traffic information in relation to the impending conflict. The absence of traffic information in sufficient time and in sufficient detail increased the risk posed by the LOS.

Findings
From the evidence available, the following findings are made with respect to the loss of separation between a Beechcraft B300, registered VHFIZ, and a formation of four Boeing F/A18 aircraft that occurred near Williamtown (Newcastle Airport), New South Wales on 19 September 2013. These findings should not be read as apportioning blame or liability to any particular organisation or individual.

Safety issues, or system problems, are highlighted in bold to emphasise their importance. A safety issue is an event or condition that increases safety risk and (a) can reasonably be regarded as having the potential to adversely affect the safety of future operations, and (b) is a characteristic of an organisation or a system, rather than a characteristic of a specific individual, or characteristic of an operating environment at a specific point in time.
Contributing factors

• The applicability of a general requirement to conduct aviation risk assessments for complex, new, unusual or irregular activities was open to interpretation. [Safety issue]
  
• The absence of prior planning relating to the operation of the calibration aircraft resulted in a work-around that did not address all related safety aspects and negated the existing strategic separation assurance.
  
• The Williamtown Approach controller released airspace to the Tower controller that was considerably larger than that normally controlled by the Tower, resulting in both the Tower supervisor and the Tower controller having difficultly monitoring the airspace visually, and the need for the Tower controller, though not trained in the use of surveillance control, to rely on the surveillance display for separation.
  
• The absence of specific control instructions by the Tower controller to the pilot of VH-FIZ created an opportunity for the pilot to misunderstand the Tower controller's intent in relation to the pilot’s requested ‘orbit’.
  
• The Tower controller did not monitor the flight path of VH-FIZ due to an assumption the aircraft would remain in the area the controller had intended the aircraft to remain, leading to a loss of separation assurance.
  
• The Approach controller did not monitor their airspace sufficiently well to observe VH-FIZ crossing the coast into airspace under their jurisdiction, removing the chance for earlier detection of the loss of separation assurance.
  
• The Tower controller did not provide immediate and clear control instructions to either VH-FIZ or the formation of F18s once the conflict was detected, resulting in a loss of separation with the formation of Boeing F/A18 aircraft flying directly below VH-FIZ with less than 1,000 ft separation.
  
  
  Safety issues and actions
  The safety issue identified during this investigation is listed in the Findings and Safety issues and actions sections of this report. The Australian Transport Safety Bureau (ATSB) expects that all safety issues identified by the investigation should be addressed by the relevant organisation(s). In addressing those issues, the ATSB prefers to encourage relevant organisation(s) to proactively initiate safety action, rather than to issue formal safety recommendations or safety advisory notices.
  
  All of the directly involved parties were provided with a draft report and invited to provide submissions. As part of that process, each organisation was asked to communicate what safety actions, if any, they had carried out or were planning to carry out in relation to each safety issue relevant to their organisation.
  
  The initial public version of these safety issues and actions are repeated separately on the ATSB website to facilitate monitoring by interested parties. Where relevant the safety issues and actions will be updated on the ATSB website as information comes to hand.
  
  Absence of prior planning
  The applicability of a general requirement to conduct aviation risk assessments for complex, new, unusual or irregular activities was open to interpretation.
  Safety Issue No: AO-2013-160-SI-01
  
  

[*]

MTF...P2

Ps Since when was a B300 piston powered

Aircraft 2 details

Aircraft manufacturer:
Hawker Beechcraft Corporation
 
Aircraft model:
B300
 
Aircraft registration:
VH FIZ
 
Serial number:
FL 779
 
Type of operation:
Aerial Work
 
Sector:
Piston
 
Damage to aircraft:
Nil