Loss of separation

Kiwi 52, an A4 Skyhawk, on a missed approach from a runway 35 ILS approach, had been issued with missed approach instructions to maintain runway heading and maintain 6000 feet. When Kiwi 52 was about four miles north of the aerodrome, the aircraft was instructed to turn right heading 070 degrees and to climb to and maintain 6500 feet. The altitude restriction was to maintain separation with VH-PZL, overflying at 7500 feet.

As Kiwi 52 approached VH-PZL, Kiwi 52s altitude readout reached 7400 feet. When asked to confirm his level, the pilot of Kiwi 52 reported maintaining 6500 feet. Kiwi 52 was passed traffic information on VH-PZL. Shortly afterwards Kiwi 52s altitude readout returned to 6500 feet. The two aircraft closed to about two miles radar separation with Kiwi 52 passing behind VH-PZL.

Factors

The following factors were considered relevant to the development of the incident:

1. The pilot of Kiwi 52 failed to follow an air traffic control instruction to maintain an altitude.

The Airbus A300 aircraft was intercepting the runway 16R localiser for an ILS approach. During the intercept and while the A300 was on final approach in cloud, ATC requested its pilot to slow his aircraft. On the final request, the pilot was informed that his aircraft had a closure rate of 60 kts on a preceding F50 aircraft. When the A300 broke out of cloud at 1,300 ft, its pilot saw that the F50 aircraft was only about two miles ahead. He suggested to ATC that he sidestep his aircraft to approach for runway 16L but the aerodrome controller directed a go-around.

A Boeing B737 was operating a scheduled flight from Darwin to Brisbane via route A464. The aircraft passed overhead Tindal at 1455, maintaining FL330, estimating the ATEGA waypoint (150 NM north-west of Mount Isa) at 1549. The aircraft was subsequently transferred from Brisbane ATC Sector 11K jurisdiction to Brisbane Sector 11 at 1515. Opposite direction traffic on A464 was a Boeing B747, operating a scheduled flight from Brisbane to Singapore. The aircraft passed overhead Mount Isa at 1430, maintaining FL310, estimating Tindal at 1613, and requesting a flight planned climb to FL350. The aircraft subsequently contacted Brisbane Sector 11 at ATEGA at 1525.

The Sector 11 controller had calculated an estimated time of passing of 1538 for both aircraft and correctly notated both flight progress strips. The B747 was co-ordinated to Sector 11K with the current and planned cruising levels. However, at about 1528, Sector 11 cleared the B747 to climb to FL350. At 1535, the B747 reported maintaining FL350 but one minute later queried opposite direction traffic below. The Sector 11 controller immediately recognised that the prescribed separation standards had not been provided and the B747 had climbed through the level of the B737 about five minutes, or 80 NM, prior to the time of passing.

A subsequent investigation found that the Sector 11 controller had been distracted by resolving a potential separation problem between two other aircraft within his area of responsibility. In addition, he had erroneously judged that all southbound traffic was below the B747, prior to issuing the climb clearance, although the relevant flight progress information available to him did not support this perception. A final opportunity to prevent the occurrence was lost when the crew of the B737 had apparently not recognised that the B747 had been cleared to climb through their level without adequate separation. The B737 had been on the same frequency as the B747 for some 10 mins prior to ATEGA.

CIRCUMSTANCES

At the time of the incident, control tower staff comprised an aerodrome controller, a surface movement controller and a coordinator. Aircraft traffic was a Cessna 172 engaged in circuit training, a helicopter operating close to the airport boundary, two other aircraft inbound to the circuit and a Piper PA 28 taxying for take-off. In addition, a maintenance vehicle was working in the vicinity of the runway.

The pilot of the PA 28 requested and was given a clearance, by the aerodrome controller, to line up on runway 32. The aircraft was lined up adjacent to taxiway F which is 430 m from the runway threshold. The PA 28 was held on the runway whilst the controller coordinated requirements for some of the other traffic. Shortly after the PA 28 lined up the pilot of the Cessna 172 requested a clearance to land on runway 32. The controller checked that the runway appeared to be unoccupied and cleared the pilot of the Cessna 172 to land. Shortly before the Cessna 172 touched down, the controller noticed that the PA 28 was still on the runway. He did not give any instructions to the pilot of either aircraft. The Cessna 172 landed on the threshold and turned off the runway at taxiway D, 390 m further on. The controller then cleared the pilot of the PA 28 to take-off.

The Manual of Air Traffic Services indicates that a controller should not clear an aircraft to land unless he or she is assured that the landing area will be available. Similar rules are set out in the Aeronautical Information Publications for pilots. Experience suggests that controllers normally use a combination of situational awareness and visual cues to help meet their runway requirements. The aerodrome controller reported his situational awareness was reduced by the distraction caused by the coordination requirements for other traffic and the maintenance vehicle. As a result, he forgot about the PA 28 after he had cleared it to line up. When the controller checked the runway for obstructions, after the pilot of the Cessna 172 had requested a landing clearance, his vision was partly obstructed by a visual display unit located on the console in front of him. As a result, he did not see the PA 28 until he stood up from his normal operating position. This did not occur until after he had given the clearance to land. At that point the Cessna 172 was about to touch down. The controller considered that any instructions from him might make the situation worse and he decided to say nothing. He knew the pilot of the Cessna 172 was very experienced and would avoid any conflict, if possible.

The other tower staff reported they were busy with their own tasks and were not aware of the impending conflict.

The pilot of the PA 28 was inexperienced and reported that he had not fully assimilated the other circuit traffic when he lined up on the runway. As a result, he did not recognise that the Cessna 172's clearance to land would place that aircraft in conflict with his.

The pilot of the Cessna 172 reported that he was concentrating on his student's performance and was not paying attention to other traffic. Therefore, he was not aware the PA 28 had not been cleared for take-off. He observed that the PA 28 was still on the runway as his aircraft approached touchdown. Assuming it had been given a clearance to take-off, he initially thought the PA 28 would get airborne before his aircraft landed. When the PA 28 did not move he reassessed the situation and decided it was safer to continue with the landing than to attempt a go-around. His student had to apply power to roll through to taxiway D, after landing.

Although the visual display unit obstructed the controller's vision of the runway from his normal operating position (seated), it is not unusual for similar obstructions to exist, particularly in older control towers where roof support-posts are used. Consequently, it is accepted practice for controllers to move their position when checking that a runway is not occupied. In this incident the controller did not do this before he cleared the Cessna 172 to land. It is probably that, in the pressure of the moment, he did not recognise that his vision was obstructed.

SIGNIFICANT FACTORS

The following significant factors were identified as contributing to the incident.

1. The aerodrome controller's situational awareness was reduced, by distraction, to a point where he forgot about the position of an aircraft that was critical to his clearance decision.
2. The aerodrome controllers scan of the active runway was obstructed by a part of the tower equipment, and, in the pressure of the moment, he did not recognise the obstruction. Consequently, the controller did not move to check the complete runway, and he did not observe the runway was still occupied, when he cleared the Cessna 172 to land.
3. The inexperience of the PA 28 pilot was a factor in his not recognising that the Cessna 172's clearance could place that aircraft in conflict with his.
4. The pilot of the Cessna 172 was distracted by his instructional activities and did not recognise that the PA 28 had not been cleared for take-off. Consequently, he allowed the student to continue the approach in anticipation the landing area would be clear before the aircraft touched down.
5. When the pilot of the Cessna 172 realised the landing area would not be clear, he assessed that the safest alternative was to continue to a landing rather than attempt a go-around. As a result, the Cessna 172 landed on an occupied runway.

The Sector 8 (Oceanic) controllers’ area of responsibility extended from 58 to 320 km east of Sydney. In the period preceding the incident, there was significant military traffic operating in the area above FL300.

VH-TJD was identified on radar 45 km NE of position LOTRA. (LOTRA is a reporting point 071 degrees M, 240 km from Sydney.) VH-TJD was then cleared to track from LOTRA to position CHEZA (084 degrees M, 96 km Sydney) and to descend to 8000 ft.

About 10 minutes later, N188UA departed Sydney. The standard procedure was for this aircraft to intercept the

Sydney-LOTRA track inside 50 km Sydney. On this occasion, however, the Sydney Departures controller asked the Sector 8 (Oceanic) controller if N188UA could track direct to LOTRA. The Sector 8O controller approved the request. As a result, N188UA was in potential conflict with VH-TJD.

At the time of the request from the Sydney Departures controller, the Sector 8 (Oceanic) controller had been distracted by a telephone call concerning a radar technical matter. He checked the radar display for conflicting traffic before agreeing to the request and did not see any confliction. At this time, however, the radar symbol for VH-TJD was amongst the military traffic radar symbols and was not noticed by the controller. The controller approved the request from Sydney Departures on this basis, and without checking the flight progress strips which displayed the flight details of all aircraft under his control at the time, including VH-TJD and the military traffic. In not checking the strips, the controller failed to comply with standard procedures, thus bypassing an element of the safety net which may have alerted him to the conflict.

As N188UA was climbing through about 15000 ft, the crew advised the Sector 8 (Oceanic) controller that they were deviating left as they had sighted descending traffic ahead. Examination of the recorded radar data showed the two aircraft to have been at the same level at 7nm (12 km) lateral separation.  The minimum separation standard which applied in the circumstances was 1000 ft vertical separation, or 5 nm (8km) lateral separation. The 1000 ft standard was infringed when the aircraft were between 8 km and 6 km apart.

AMENDED TEXT

The Sector 8 (Oceanic) controller's area of responsibility extended from 58 to 320 km east of Sydney. In the period preceding the incident, there was significant military traffic operating in the area above FL300.

The B737 was identified on radar 45 km NE of position LOTRA. (LOTRA is a reporting point 071 degrees M, 240 km from Sydney). It was then cleared to track from LOTRA to position CHEZA (084 degrees M, 96 km from Sydney) and to descend to 8,000 ft.

About 10 minutes later, the B747 departed Sydney. The standard procedure was for this aircraft to intercept the Sydney-LOTRA track inside 50 km Sydney. On this occasion, however, the Sydney Departures controller asked the Sector 8 (Oceanic) controller if the B747 could track direct to LOTRA. The Sector 8 controller approved the request. As a result, the outbound B747 was in potential conflict with the inbound B737.

At the time of the request from the Sydney Departures controller, the Sector 8 (Oceanic) controller had been distracted by a telephone call concerning a radar technical matter. He checked the radar display for conflicting traffic before agreeing to the request and did not see any confliction. At this time, however, the radar symbol for the B737 was amongst the military traffic radar symbols and was not noticed by the controller. The controller approved the request from Sydney Departures on this basis, and without checking the flight progress strips which displayed the flight details of all aircraft under his control at the time, including the B737 and the military traffic. In not checking the strips, the controller failed to comply with standard procedures, thus bypassing an element of the safety net which may have alerted him to the conflict.

As the B747 was climbing through about 15,000 ft, the crew advised the Sector 8 (Oceanic) controller that they were deviating left as they had sighted descending traffic ahead. Examination of the recorded radar data showed the two aircraft to have been at the same level at 7 NM (12 km) lateral separation.  The minimum separation standard which applied in the circumstances was 1,000 ft vertical separation, or 5 NM (8km) lateral separation. The 1,000 ft standard was infringed when the aircraft were between 8 km and 6 km apart.

FACTUAL INFORMATION

History of the flight

The B747 had been cleared to depart from Sydney for Noumea via a Runway 16 Right Jet Three departure. This departure required a track of 155 degrees after take-off to an altitude of 800 ft, then a right turn to intercept the 163-degree radial from the Sydney very high frequency omni-directional radio range beacon (VOR). The B737 had been cleared to depart from Sydney for Brisbane via a Runway 16 Left West Maitland Seven standard instrument departure (SID). This departure required a track of 155 degrees after take-off to an altitude of 600 ft, then a left turn to intercept the 126-degree radial from the Sydney VOR.

After receiving the clearance from air traffic control, the B747 crew read it back correctly.

The B747 took off from runway 16R, followed by the B737 which took off from runway 16L. When the B747 reached 800 ft altitude, the pilot initiated a left turn, putting the aircraft in conflict with the B737. The Departures North controller asked the pilot of the B747 to confirm that he was turning right to intercept the 163-degree radial, and the pilot replied that he was turning left to intercept the 126-degree radial. The controller immediately instructed the B747 to turn right onto a heading of 180 degrees and passed traffic information on the B737 to the B747 crew. The B747 crew complied with the instruction immediately.

The pilot of the B737 reported that he had the B747 in sight and that both aircraft were turning away from each other. Recorded radar information indicated a minimum separation of 0.5 NM horizontally and 200 ft vertically. The procedural separation standard of 1,000 ft vertically and the radar separation standard of 3 NM horizontally had both been breached.

The aerodrome controllers observed both aircraft become airborne, but they became diverted by other tasks and did not see the B747 commence the left turn. As a result, visual observation was not maintained, and a breakdown of separation standards occurred.

Pilot's understanding of procedures

Two days before this occurrence, a B747 crew of the same operator, with the same pilot in command and carrying out the same departure, had made the same error. However, on that occasion, the Departures North controller instructed the crew to take up headings to achieve the required departure track. The crew was not advised of its error and no conflict with other traffic occurred.

After the second occurrence, the pilot reported that he had felt some confusion due to the naming of the departure procedures but had realised his mistake when he looked at the departure chart after being advised to alter heading to 180 degrees.

While admitting his mistake, the pilot added that there were contributing factors, namely:

1. the two departures were depicted diagrammatically on the same sheet of his documentation (Atlas chart number7);
2. he had not been aware of his error two days previously; and
3. the aircraft taking off from runway 16L was on a different tower frequency and he had no information on this traffic.

Documentation

The pilot was using the Atlas chart entitled "JET 3 DEPARTURE RWY 16L/R, 34L", dated 22 June 1995. The chart was bounded by a border 27.0 cm by 18.5 cm in width (approximately A4 size) and depicted three departures plus airspace and terrain information to 40 NM by distance measuring equipment (DME). The chart was designed to be read in the landscape orientation. Despite the size of the sheet, the departure details were depicted within a circular area 10.7 cm in diameter. The details of the procedures out to 10 DME were depicted within a circular area 7 cm in diameter. There were no warnings about parallel runway operations on runways 16L and 16R to alert crews not to turn toward the other runway centreline after take-off.

The Atlas documentation included another page headed "SIDs RWY 16R...SYDNEY (Austr)". The sheet was bounded by a border 18.3 cm by 13 cm (approximately A5 size) and was designed to be read in the portrait orientation. The page contained textual descriptions of seven SIDs from Sydney runway 16R. The description of the Jet-3 departure was headed "Sydney Jet 3" and was written in letters approximately 2 mm in height. The description was contained within an area 10 cm by 1cm and was worded:

"Sydney Jet 3, Climb on 155 (degrees), Initial turn at 800, RT to intercept R163 SY, 115.4. Expect radar vectors at or before BELLA (DME 15 SY)"

Nomenclature of procedures

There were three Sydney Jet Three departures differentiated only by the runway designator, runway 16R, 16L or 34L. All three procedures were totally different, despite the similarity of their names. The pilot in command reported that he found the similarity of procedure naming confusing and conducive to error.

The use of the one title, differentiated only by the runway designator, for a number of departures was common practice. There were five (Sydney) Radar Six, three Wollongong Three, three Shellys Three, two Richmond Five, two Mudgee Five, two Katoomba Five, three West Maitland Seven and three Williamtown Seven departures.

ANALYSIS

Crew awareness

Despite the crew's correct readback of the allocated departure to Air Traffic Control, the crew members were obviously unsure of the procedure. The fact that the same pilot in command had made the same error two days earlier and that the air traffic services staff did not highlight the error to the pilot, meant that an opportunity to clarify any uncertainty in the pilot's mind was lost.

Tower monitoring

The closest proximity between the two aircraft was 0.5 NM horizontally and 200 ft vertically, thus breaching the procedural and radar separation standards. This would not normally have been a problem as the tower controllers would be providing visual separation; but on this occasion, they were concentrating upon other traffic and did not observe the B747 turn left. As there were no radar or procedural standards in place, this action resulted in no separation being applied by Air Traffic Control. However, as the B737 pilot had the B747 in sight throughout the sequence of events, no serious collision risk was present. The rapid response of the Departures North controller, who detected the error and instructed the B747 crew to turn right onto 180 degrees immediately, prevented the situation deteriorating further.

The Manual of Air Traffic Services, Chapter 4, "Separation Standards", Section 1, Para 26 describes the obligation of a controller to issue a safety alert when he/she believes that an aircraft is in an unsafe proximity to terrain, obstructions, or other aircraft. The paragraph recognises that a controller cannot immediately see the development of every situation where a safety alert must be issued, but he/she must remain vigilant for such situations and issue a safety alert when the situation is recognised.

Documentation

The Atlas chart depicted the departure procedures in a small central section of the chart but also showed a considerable quantity of additional detail that was not part of the procedures. In contrast, the Airservices and Jeppesen charts showed only the details of the procedures. The Jeppesen and Airservices charts carried warnings about parallel runway operations, but the Atlas chart did not carry this warning. Although any useability comparisons must be subjective, as crews become accustomed to the charts that they use, the Atlas chart seemed to be less convenient for crew use than either the Airservices or Jeppesen charts.

The Airservices and Jeppesen charts depicted the procedures both diagrammatically and in text on the same sheet. The Atlas chart depicted the procedures only diagrammatically on the sheet, the description in text was on a separate sheet. Arguably, this would further reduce the Atlas chart's user convenience.

None of the Jet Three departure charts contained a hachured region between the 126 and 163-degree radials as a clear warning to crews that parallel runway operations take place and that aircraft must not turn toward the extended centreline of the other runway. However, other Airservices charts depicting the standard instrument departures for jet aircraft departing north, south and west contained hachured areas with warnings.

Nomenclature of procedures

In the case of parallel runways where the nomenclature of different procedures differs by only the words "left" or "right", there may be a greater likelihood of crew confusion and error than in the case of a single runway. In addition, if parallel runway operations are taking place, the consequences of an error could be more serious than in the case of a single runway.

SIGNIFICANT FACTORS

1. The Sydney Jet Three departure chart used by the B747 crew was relatively easy to misread.
2. The B747 pilot did not follow the departure procedure as cleared by Air Traffic Control.
3. The tower controllers did not adequately monitor the B747 from its take-off to the commencement of its turn, resulting in a breakdown of separation standards.

SAFETY ACTION

As a result of this investigation, on 21 September 1995, the Bureau issued Interim Recommendation IR950203 to Airservices Australia as follows:

'IR950203

"The Bureau of Air Safety Investigation recommends that Airservices Australia review the presentation of parallel runway operations on the Sydney Jet Departure charts, to improve the indication of the dangers of turning across the departure path of the other parallel runway.

"It is also recommended that the number and naming of departure procedures should be reviewed to ensure that any likelihood of flight crew selecting the wrong procedure is reduced."

An information copy of the interim recommendation was issued to the Civil Aviation Safety Authority.

On 13 November 1995, the Civil Aviation Safety Authority responded as follows:

"I refer to your interim recommendation IR950203 concerning an incident involving Boeing 747, F-GEXA and Boeing 737, VH-TJN near Sydney Airport on 25 August 1995.

"Summary

"A revised Sydney Jet Departure Procedure plate will become effective on 7 December 1995.

"A forthcoming "Terminal Area Workshop" sponsored by Airservices Australia and attended by industry representatives will discuss the adequacy of the current SID naming convention.

"Background to Response

"Following the earlier similar incident by this operator, the Sydney Jet Departure Procedure plate was amended by the hachuring of the area between the two runways and the re-organisation of the presentation of the departure wording in the text section of the procedure. The line weight of the Caution note was also increased to make it more prominent. The revised presentation reflects the intent of the BASI interim recommendation. The revised plate will become effective on 7 December 1995. Copy of the 07 DEC 95 plate is attached.

"With reference to the BASI comments on the naming of the multiple departure instructions, the naming format used conforms with the ICAO Annex 4 naming convention. This format was introduced with the revised SID presentation some years ago which allowed the number of SID procedures to be considerably reduced. For instance, the Sydney SIDs were reduced from 72 to the current 11 procedures and the DAP page numbers from 22 to 6. At that time, this initiative was applauded by both industry and ATC.

"The foregoing notwithstanding, the subject of SID naming will be discussed at the Terminal Area Workshop on

20 - 21 November 1995. This workshop is sponsored by Airservices Australia and will be attended by representatives of the industry. The discussion should give a good indication of the adequacy of the current SID naming convention."

On 22 January 1996, Airservices Australia responded as follows:

"I refer to your interim recommendation IR950203, concerning an incident near Sydney Airport on 25 August 1995.

"In response to your recommendations, I can advise that a revised Sydney Jet Departure Procedure plate became effective on 7 December 1995. The main amendments involved hachuring of the area between the two runways and the re-organisation of the presentation of the departure wording in the text section of the procedure. In addition, the line weight of the caution note has been increased to make it more prominent.

"In respect of your comments relating to the naming of the multiple departure instructions, I am advised that the naming format complies with the ICAO Annex 4 naming convention."

Classification of response: CLOSED - ACCEPTED

Circumstances

ANA914 was northbound on route B462 and cruising at FL310.  At 0130 UTC, the Brisbane Sector 10 controller coordinated with Moresby Control ANA914 estimating position APAVO at 0221, FL330 (the aircraft was at FL310 and maintained that level throughout the period of the occurrence). The Moresby controller read back FL330. The Sector 10 Flight Progress Strip for ANA914 showed the aircraft's level as FL310. There was no reference to FL330 on the strip. The Sector 10 controller did not include the words non-standard in the coordination, as was required by standard procedures, and the Moresby controller did not query this omission.  At approximately 0200, there was a shift change at the Sector 10 control position. There was nothing to indicate to the new controller that anything other than FL310 had been coordinated to Moresby Control.

At 0210, Moresby Control coordinated the departure of ANG3 Port Moresby for Brisbane on route B462 at 0208 on climb to FL370, estimating APAVO at 0252. The controller also said that she would provide separation with ANA914. She had planned to provide this separation by maintaining ANG3 at FL310, a level she understood to be below ANA914.  She would then climb ANG3 to the planned level, FL370, after the two aircraft had passed.

Information from the Department of Civil Aviation, Papua New Guinea, indicated that, at 0221, Moresby Control contacted ANA914 advising ANG3 as opposite direction traffic passing beneath ANA914 at an estimated time of 0226, and requesting ANA914 to report sighting and passing the traffic. ANA914 requested Moresby Control to repeat the information. This was done but the response from the ANA914 pilot indicated that the message had not been understood.  Two further attempts were made by the controller to convey the information but the response from ANA914 continued to indicate that the message had not been understood.

At 0224, the pilot of ANG3 asked ANA914 his level. ANA914 responded that he was at FL310, had traffic in sight, and was descending.  The crew of ANA914 was alerted to the confliction with ANG3 by the aircraft's TCAS equipment. ANG3 was not equipped with TCAS. However, the crew of ANG3 sighted ANA914 passing below their aircraft and estimated the vertical separation to have been less than 500 ft. The required vertical separation standard was 2000 ft.

The aircraft level (FL310) written on the flight progress strip for the aircraft had not been ticked (in accordance with normal procedures) by the Sector 10 controller to indicate that coordination had been completed. No other aircraft in the Sector 10 control area was at FL330. The basis for the controller coordinating FL330 was, therefore, not established. However, he did report what, in his view, were minor but irritating difficulties in operating the telephone link to Port Moresby to initiate the coordination. There was also some evidence of the controller suffering fatigue.

Discussion

The agreement between the air traffic control agencies of Australia and Papua New Guinea allows for non-standard levels to be used only when prior co-ordination between controllers has been carried out.  Therefore, the use of FL330 for ANA914 was contrary to this agreement as no prior co-ordination had been initiated.  The fact that the phrase non-standard was not used in the co-ordination should have provided an additional cue that an error had been made. Beyond this point, however, in the procedural environment in which the aircraft were operating, the sole remaining element in the safety net was TCAS on ANA914.

The difficulties experienced by the Port Moresby controller in communicating the opposite direction traffic to ANA914 highlight the language and comprehension problems which can arise in the control of international air traffic.  TCAS takes on added importance in such situations.

Significant Factors

1. The Sector 10 controller may have experienced some frustration operating the telephone link to Port Moresby.
2. The Sector 10 controller may have been fatigued.
3. The Sector 10 controller coordinated an incorrect level and did not use the prefix non-standard to describe that level.
4. The Port Moresby controller did not query the omission of the prefix non-standard when reading back the coordination.

Safety Action

As a result of the TCAS implications of this occurrence and as similar implications were found to be present in occurrence B9501346, the Bureau considers it is of significant safety value to reproduce interim recommendation IR950117 in this report. IR 950117 was addressed to the Civil Aviation Safety Authority on 6 June 1995.

IR 950117

The Bureau of Air Safety Investigation recommends that the Civil Aviation Authority:

1. mandate the fitment and use of an Airborne Collision Avoidance System (ACAS) in all aircraft engaged in Regular Public Transport (RPT) operations;
2. consider the requirement for the fitment and use of a suitable ACAS in other aircraft engaged in the carriage of passengers for hire or reward;
3. review the requirements for the carriage and activation of transponders with the objective of maximising the effectiveness of ACAS;
4. mandate the standard of ACAS equipment to be carried in each aircraft classification;
5. set a timetable for the introduction of ACAS equipment; and
6. ensure that air traffic services officers are given adequate and timely education and continuation training in the capabilities and operational impact of ACAS equipment.

VH-JIJ was being flown by a student pilot on her first solo navigation exercise. Approaching Moorabbin from the east on the last leg of the exercise, the aircraft entered controlled airspace at 4800 feet (lower level 4000 feet) without an airways clearance. The radar advisory service (RAS) controller had observed VH-JIJ on an easterly heading for some time previously at 4000 feet before climbing.

When VH-JIJ entered controlled airspace at 4800 feet, VH-NCE was proceeding in the opposite direction on climb to 7000 feet and approaching the same altitude as VH-JIJ. The RAS controller gave the pilot of VH-NCE a suggested heading to avoid VH-JIJ, which at that time was unidentified traffic. The pilot of VH-NCE advised visual contact with the other aircraft as the two aircraft passed. Separation was estimated to be one to two miles laterally when both aircraft were at the same level.

The pilot of VH-NCE advised that cloud in the area was scattered/broken with a base of 4000 feet. VH-JIJ was identified by transponder code as it got closer to Moorabbin.

Factors

The following factors were considered relevant to the development of the incident:

• VH-JIJ entered controlled airspace without a clearance.
• The pilot of VH-JIJ was an inexperienced student pilot.

The student pilot was operating the last sector of a solo navigation exercise, tracking from Murray Bridge to Adelaide where a touch-and-go landing was made, before returning to Parafield at 1,500ft.

Parafield Tower cleared the aircraft for a straight-in approach to runway 03 L, with a clearance to land. The pilot reported on final at 1,500ft, but the aircraft was not initially sighted by the controller. It was then observed north west of the field, inside the RAAF Edinburgh Control Zone.

An Orion aircraft, conducting right hand circuits for runway 36 at Edinburgh, was on right base heading west when the other aircraft entered the control zone.

Radar plots revealed that VH-YHH passed behind the Orion at about the same level, with a horizontal separation of about 1000 metres.

The student pilot then made a right turn to enter left downwind for runway 03 L, Parafield, and continued for a landing.

QFA10, VH-OJI, departed Melbourne on radar vectors on climb in stages to 5,000 ft. At the same time VH-UJL was on track Essendon - Owens maintaining 6,000 ft. The radar controller observed QFA10 climb through 5,400 ft and turned the aircraft onto a new heading to avoid conflict with VH-UJL. Separation reduced to 500 ft vertically and 1.5 miles laterally.

Between 3,000 ft and 4,500 ft the first officer and second officer changed seats to enable the second officer to climb the aircraft. The captain had been flying manually until handing over to the second officer at about the time the aircraft was cleared from 4,500 to 5,000 ft. The second officer continued to manually fly the aircraft. 5,000 ft had been dialled up on the altitude selector, but altitude hold had not been selected because the pilots were anticipating a further climb clearance. The flaps were fully retracted normally approaching 5,000 ft. However, once the flaps retracted the flight management computer (FMC) automatically increased thrust to accelerate the aircraft to climb speed of 320 kts. With the sudden thrust increase, the rate of climb increased, and the aircraft overshot 5,000 ft. By about 5,460 ft thrust was manually retarded and the aircraft was descended back to 5,000 ft.

At the time of the incident the traffic alert and collision avoidance system (TCAS) on QFA10 showed conflicting traffic at approximately the 10 o'clock position, two miles ahead and 500 ft higher. No traffic advisory (TA) or resolution advisory (RA) indication occurred because the breakdown in separation was not severe enough.

Significant Factors

The following factors were considered relevant to the development of the incident:

1. Altitude hold had not been selected so the FMC did not level off the aircraft at 5,000.

2. Aircrew had changed seats not long before the aircraft reached 5,000 ft.

3. The second officer did not anticipate the FMC induced increase in thrust/ rate of climb as the flaps fully retracted approaching 5000 ft.

4. The captain was not properly monitoring the situation.

SAFETY ACTION

QANTAS advised that the company would review when pilots would be permitted to change seats.