ASN Wikibase Occurrence # 190893
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: | Saturday 16 November 2002 |
| Time: | 15:03 |
| Type: |  de Havilland Canada DHC-8-315Q Dash 8 |
| Owner/operator: | QantasLink |
| Registration: | VH-SBT |
| MSN: | 580 |
| Fatalities: | Fatalities: 0 / Occupants: |
| Aircraft damage: | None |
| Category: | Serious incident |
| Location: | near Mackay, QLD (MKY) -
 Australia
|
| Phase: | Unknown |
| Nature: | Passenger - Scheduled |
| Departure airport: | Townsville-Garbutt Airfield, QLD (TSV/YBTL) |
| Mackay Airport, QLD (MKY/YBMK) | |
| Investigating agency: | ATSB |
| Confidence Rating: |  Information verified through data from accident investigation authorities |
A DHC-8-315 (Dash 8) was being operated on a scheduled service to Mackay from Townsville under the instrument flight rules (IFR). The crew had been authorised by Brisbane Centre air traffic control to descend their aircraft to 6,000 ft. The duty runway at Mackay was 14 and, at 1503:00 Eastern Standard Time, the crew reported that they were tracking on the 304 degree radial of the Mackay VHF omni-directional radio range (VOR) navigation aid and were 30 NM from Mackay. The Mackay aerodrome controller (ADC) instructed the crew to `Report approaching 6,000 ft with DME [distance measuring equipment] distance’.
An IFR category Boeing 717-200 (717) was being operated on a scheduled service to Mackay from Brisbane. Its crew reported at 1503:22 that they were tracking on the 130 degree radial of the Mackay VOR, also on descent to 6,000 ft. The Brisbane Centre controller had assigned both crews 6,000 ft prior to instructing them to transfer to the Mackay ADC radio frequency. The assignment of the same level was an authorised practice, because the Brisbane Centre controller would continue to radar monitor the separation of all arriving aircraft until the first aircraft was at or below 5,000 ft. The ADC subsequently instructed the 717 crew to descend to 4,000 ft. The crew asked whether they could expect a left base and the ADC responded saying that they could expect a left base to runway 14.
The Dash 8 was in cloud, and at 1506:17 the ADC instructed that crew to descend to 4,700 ft. There was no separation standard being applied between the Dash 8 and the 717 and separation was no longer assured. The infringement of separation was not recognised by the Mackay ADC. The ADC instructed the 717 crew to descend to 3,000 ft and to reduce speed. The crew was told that they were number two to a Dash 8 from the north and the ADC asked them to report when visual. The Dash 8 crew reported approaching 4,700 ft at 14 DME and was instructed to descend to 2,000 ft, not below the DME steps.
At 1507:53, the crew of the 717 reported visual at 7 NM and advised that they were able to track for left base. The ADC told them to maintain 3,000 ft and to track for left downwind. The crew was asked to sight a helicopter in front of them at 2,000 ft and 4 miles east of the aerodrome. The crew replied `for the base runway 14 and looking’.
The crew of the Dash 8 reported visual (clear of cloud) and was cleared to make a visual approach straight in to runway 14 at 1508:38. The crew of the 717 was cleared for a visual approach at 1508:51. The crew of the 717 responded by reading back the clearance. The controller then said `and maintain downwind heading, the Dash 8’s currently at 9 mile’. The 717 crew neither heard, nor responded to, this subsequent transmission. The ADC did not query the lack of acknowledgment of that requirement.
Approximately 90 seconds later, the ADC observed the 717 turning left base and converging with the Dash 8 on final approach. This was a second, and more critical, infringement of separation between the two aircraft.
The crew of the Dash 8, on final approach, observed the 717 turn onto base towards their aircraft. The ADC instructed the crew of the Dash 8 to turn right, away from the 717. The ADC issued traffic information to the 717 crew who, after sighting the Dash 8, elected to maintain 1,500 ft. The ADC confirmed with the Dash 8 crew that they could see the 717 and authorised them to continue the approach. The ADC subsequently instructed the crew of the 717 to climb to 2,000 ft and make a left circuit before returning for landing.
SIGNIFICANT FACTORS
1. The ADC did not separate the 717 and Dash 8 using procedural separation standards before the aircraft were separated visually.
2. The 717 crew did not hear the sequencing instruction for them to maintain a downwind heading.
3. The controller did not obtain a readback of the sequencing instruction for the 717 crew to maintain a downwind heading.
4. The controller did not provide the 717 crew with accurate traffic information about the Dash 8
Accident investigation:
 |
|
Sources:
https://www.atsb.gov.au/publications/investigation_reports/2002/aair/aair200205540
Revision history:
| Date/time | Contributor | Updates |
|---|
Corrections or additions? ... Edit this accident description
The Aviation Safety Network is an exclusive service provided by:
Quick Links:
| ASN Home | Send Correction / Feedback |
| FSF Home | Disclaimer | Copyright |
| Contact Us | Privacy Policy |
| Press / Media |
CONNECT WITH US:
©2024 Flight Safety Foundation