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A320 / B738, vicinity Launceston Australia, 2008

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Summary
On 1 May 2008 an Airbus A320-200 being operated by JetStar on a scheduled passenger flight from Melbourne to Launceston, Tasmania was making a missed approach from runway 32L when it came into close proximity in night VMC with a Boeing 737-800 being operated by Virgin Blue and also inbound to Launceston from Melbourne which was manoeuvring about 5nm north west of the airport after carrying out a similar missed approach. Minimum separation was 3 nm at the same altitude and the situation was fully resolved by the A320 climbing to 4000 feet.
Event Details
When May 2008
Actual or Potential
Event Type
HF, LOS
Day/Night Night
Flight Conditions VMC
Flight Details
Aircraft AIRBUS A-320
Operator Jetstar Airways
Domicile Australia
Type of Flight Public Transport (Passenger)
Origin Melbourne Airport
Intended Destination Launceston Airport
Flight Phase Missed Approach
APR
Flight Details
Aircraft BOEING 737-800
Operator Virgin Blue
Domicile Australia
Type of Flight Public Transport (Passenger)
Origin Melbourne Airport
Intended Destination Launceston Airport
Flight Phase Missed Approach
APR
Location - Airport
Airport vicinity Launceston Airport
General
Tag(s) Aircraft-aircraft near miss
HF
Tag(s) Ineffective Monitoring
LOS
Tag(s) Released to Own Separation
Near Miss
Safety Net Mitigations
TCAS Effective
Outcome
Damage or injury No
Causal Factor Group(s)
Group(s) Aircraft Operation
Safety Recommendation(s)
Group(s) None Made
Investigation Type
Type Independent

Description

On 1 May 2008 an Airbus A320-200 being operated by JetStar on a scheduled passenger flight from Melbourne to Launceston, Tasmania was making a missed approach from runway 32L when it came into close proximity in night VMC with a Boeing 737-800 being operated by Virgin Blue and also inbound to Launceston from Melbourne which was manoeuvring about 5 nm9,260 m
9.26 km
30,380.577 ft
north west of the airport after carrying out a similar missed approach. Minimum separation was 3 nm5,556 m
5.556 km
18,228.346 ft
at the same altitude and the situation was fully resolved by the A320 climbing to 4000 ft1,219.2 m.

Investigation

An Investigation was carried out by the ATSB. It was established that the incident took place in Class ‘G’ airspace outside the hours of ATC service at Launceston, which had closed half an hour earlier. Such operations are governed by Common Traffic Advisory Frequency (CTAF) procedures which require flight crew of radio-equipped aircraft to communicate by making prescribed broadcasts. Recorded ATS data indicated that the radio broadcasts by both flight crews were in accordance with the published requirements.

The forecast weather for Launceston indicated the likelihood of fog at the time of arrival and a departing aircraft had reported the base of the overcast as 200 feet agl. Because of this, the flights involved in the incident decided to carry out an ILS approach to Runway 32L and, given that the applicable DH for the procedure was similar to the reported cloud base, both crews knew that the probability of a go around was relatively high.

The 737 crew conducted their ILS approach which ended in a go around for which the procedure was to climb ahead 3,100 feet. When asked by the A320 crew to advise of their intended manoeuvring altitude, the 737 crew advised that they would maintain 3,100 feet, but continue on the missed approach track ‘… for another 10 miles just to keep us clear of you…’. The A320 crew acknowledged these intentions and advised that, if they carried out a go around, they would climb to 3,100 feet and arrange further separation.

As advised, the 737 continued on track for about 10 NM (19 km) before making a turn to enter a pilot-specified left hand holding pattern. The outbound leg of that pattern took the aircraft back toward the airport at 3,100 feet. Meanwhile, the A320 approach was not successful and a go around followed. Climbing through about 2,000 ft, the A320 cleared the cloud and the crew observed the lights of the 737 in their 11 o’clock position. The 737 crew were turning left to fly the inbound leg of their holding pattern and, being aware of the A320, the First Officer made a broadcast to update their position, which put them about 5nm apart and closing. However, although the separation subsequently closed to about 2.8nm, the rate of closure also decreased as the 737 continued its left turn. The A320 flight crew decided to continue to climb through the 737’s level while maintaining visual separation since 3,100 feet was the applicable SSA and leveled off at an altitude of 4,100 feet and advised their intention to remain at that altitude until the 737 had completed a second ILS approach. The cloud base at Launceston subsequently lifted sufficiently to allow both aircraft to land. The diagram below, taken from the official report, shows the radar recording of the incident.

Recorded radar data of the tracks of the two aircraft

The Investigation noted that both aircraft received a TCAS TA, but neither had received a TCAS RA. Since separation between the two aircraft was the responsibility of the respective flight crews, it was concluded that “a breakdown in the communication and interpretation of the respective flight crews' separation planning contributed to the proximity event.”

The Final Report of the Investigation was published on 30 June 2010 and may be seen in full at SKYbrary bookshelf: Aviation Occurrence Investigation - AO-2008-030 Final

No Safety Recommendations were made.

Further Reading