A Boeing 737-377 (B737) was inbound to Canberra for a landing on runway 35. The crew had established the aircraft on the extended runway centreline from 10 NM (18.5 km). At approximately 4 NM the aerodrome controller (ADC) instructed the crew that they were clear to land. As the aircraft was about 1.85 km from the runway threshold, the ADC saw a truck enter taxiway Delta. Taxiway Delta was approximately 1427 m from the threshold of runway 35. The ADC considered that the truck was unlikely to stop and instructed the crew to go around. The crew acknowledged the instruction and conducted a missed approach, a left circuit and then landed.
The driver of the truck had entered the runway strip without a clearance and had not complied with procedures. Later analysis of recorded radar data showed that the B737 had descended to 310 ft above the aerodrome elevation during the approach and go around.
Air traffic control
The air traffic control tower operating positions faced south-south-west, overlooking the Royal Australian Air Force (RAAF) Fairbairn aircraft apron, the intersection of the runways and the runway 35 threshold. The tower had three operating positions: ADC, tower coordinator (COORD) and surface movement controller (SMC). The ADC operating position was situated on the north-western end of the console with the COORD to the left and then the SMC position on the south-eastern end of the console. All positions were staffed at the time of the occurrence. The COORD and SMC saw the truck approaching and enter the apron from the south before turning left onto taxiway Delta. The ADC was conducting the final scan of runway 35 prior to the B737 landing when the SMC advised that the truck was going to enter the runway. Simultaneously, as the COORD suggested to the ADC to instruct the crew to go around, the ADC issued the instruction to the B737 crew.
The SMC saw the truck stop on taxiway Delta, after crossing the holding point and entering the runway strip, and then reverse as the B737 went around. The SMC notified an airport safety officer who then drove to Delta and spoke to the truck driver.
Runway 35/17 was bounded by the runway strip that was an area around the runway, up to 75 m either side of the runway centre line and included the runway clearways that extend 60 m from the thresholds. The purpose of the runway strip was to reduce the risk of damage to aircraft inadvertently running off the runway and to protect them when flying over it during take-off, landing or missed approaches. Gable markers indicated the limit of a runway strip. On taxiways the limit of a runway strip was marked as a holding point. A clearance from air traffic control was required before personnel, vehicles or machinery could enter a runway strip. Personnel, vehicles or machinery were normally excluded from a runway strip when a runway was in use or a pilot had a clearance that enabled an aircraft to use the runway.
Runway 35/17 was 45 m wide and the position the truck reached before stopping could not be accurately established. Reports from the driver and witnesses indicated that the truck reached a position somewhere between 35 m to 65 m from the runway centreline.
Canberra airport works
Canberra airport was halfway through a period of major works to construct:
- 7.5 m shoulders on runway 35/17;
- a turning node on the northern end of runway 35/17;
- drains along runway 35/17; and
- widened turn fillets at runway/taxiway intersections for runway 35/17.
The works also included the replacement of runway lights.
The airport operator had awarded the contract to a company that had recently completed similar major works at another capital city airport. That company was the prime contractor (contractor) and the task was scheduled for completion by 31 August 2001. Planning was fast tracked to meet the schedule and both the airport operator and the contractor believed it was achievable. The truck driver's company was a sub-contractor to the contractor.
Management of the works site was a joint responsibility between the airport operator and contractor. The contractor was responsible for managing the works area while the airport operator was responsible for managing the interaction of works and airport activities.
A method of work plan (MOWP) was prepared by the airport operator and was provided to the contractor to assist in the development of their work method statement and project management plan. The airport operator reviewed the project management plan. The MOWP detailed how areas would be delineated to ensure airport users and contractor activities did not conflict. The airport operator also arranged for aeronautical information circular (AIC) H7/01 to be issued on 14 June 2001. The AIC detailed the scope of the work during the four work stages, operational restrictions required during each stage and advised that the dates and times of activation of each stage would be advised by a notice to airmen (Notam). The AIC included draft Notams for each stage.
The contractor was working on stages 1 and 2. The MOWP stated that taxiway Delta would be unavailable during stage 2 between 2200 Eastern Standard Time and 0600 (overnight hours). The MOWP did not have any restrictions on the use of taxiway Delta during the period from 0600 to 2200 (daylight and early evening hours). Seven Notams, that described the work stages and the operational restrictions, were current at the time of the occurrence. Those Notams were in accordance with the MOWP except there was no Notam regarding taxiway Delta overnight.
The airport operator prepared and conducted a site induction brief for the contractor and associated sub-contractor staff prior to commencing the work. That briefing included aspects of site safety including movement of persons and vehicles, "no-go" areas, contractor vehicle routes and that contractor staff were to comply with any directions from an airport safety officer. Following the initial induction, the contractor assumed responsibility for ensuring that all persons employed on the works underwent a one hour induction briefing and that copies of the induction brief were made available to staff. The contractor was also responsible for maintaining a record of the staff who had been briefed. Those records indicated that the truck driver had received an induction brief on 27 June 2001. The truck driver later reported that he was aware of the need for vigilance when working on the airport and had often consulted the maps provided that detailed approved routes for works vehicles and staff.
Effect of the works on runway 35/17
A displaced threshold for runway 17 had been imposed to enable work on the northern end of runway 35/17. Taxiway Alpha, parallel to the runway and taxiway Foxtrot that linked Alpha and the runway were both closed to aircraft operations for this stage. The runway 17 displaced threshold was located south of taxiway Foxtrot.
The contractor had implemented a new route for works vehicles for the current stage of works. The route had been used for 10 days by trucks to cart soil from the runway 17 undershoot (at the northern end of the runway 35/17) to an area outside the airport at the south-western end (adjacent to the southern end of the runway 35/17). That route was marked with stanchions and used taxiways Foxtrot and Alpha, across the intersection of Alpha/Delta and the RAAF apron, along a gravel road parallel to runway 30, around the eastern end of runway 30 and then along the perimeter fence to the dump area. The route was sign posted with a speed restriction of 40 kph with a reduction to 25 kph in the area near the runway 30 threshold.
The segment of the route across the intersection of taxiway Delta and the RAAF apron was not marked. The contractor considered that the gap in markers at Delta was sufficiently small for staff to appreciate route continuation, and that the intersection was referred to in the induction brief and was marked on the maps. Taxiway Delta remained open to enable aircraft to use the RAAF apron. There was no restriction on vehicles crossing taxiway Delta but generally drivers of vehicles stopped or slowed when approaching that taxiway to check for aircraft before continuing.
The truck driver had been on the site for five weeks and generally worked a 12-hour day. Prior to the week of the occurrence he had had four days leave as a result of rain that prevented work being carried out. He had little previous experience of operating on airports. He had worked from 0700 to 1900 Eastern Standard Time on Monday, 0630 to 1730 on Tuesday and had started at 0600 on the day of the occurrence. The truck driver was supervising two work teams. One team was at the northern end of runway 35/17, while the other team was working outside the eastern runway strip near the intersection of runways 35/17 and 30/12. He started the team at taxiway Alpha near the northern end of runway 35 and then commenced a task himself at about 1700 in the northern area. Shortly after, he received a request to provide equipment to the team near the runway intersection. He drove to the north-western boundary of the airport to get the equipment and then travelled via the northern and eastern route to the team's location. He delivered the equipment and was returning to the northern area when he drove onto taxiway Delta and entered the runway strip.
The truck driver reported that he had a lot on his mind at the time. His last break had finished at 1330. The truck driver knew that he had insufficient time in which to complete the job he had started and that he had to supervise the clean up by his teams before finishing work that afternoon. He had been warned to watch for aircraft and consequently, whenever he was crossing a taxiway, would check for aircraft. As he turned onto taxiway Delta he was watching the approaching B737 through the passenger's window of the truck but thought he was turning onto the northern works area via taxiway Foxtrot. He became aware that there were no markers in the area and that he was on the wrong taxiway. He stopped the truck and reversed as quickly as possible off taxiway Delta back onto taxiway Alpha. The truck driver reported that he had used the designated route about 25 times previously on the day of the occurrence.
The plans developed by the airport operator and contractor did not adequately address the use of taxiway Delta by both aircraft and works vehicles during the day. The plan relied on work staff to remember that the taxiway was also available for aircraft use. Consequently route markers were not used across taxiway Delta, leaving a gap in the markers defining the work area and site route. That was a fail unsafe situation.
It is possible that the truck driver was fatigued as he was near the end of his shift and had not had a break for several hours. The level of possible fatigue combined with the competing demands, to remain vigilant and to complete numerous tasks, may have caused the truck driver to approach information overload and reduce his overall performance, or to make a slip or lapse type error. A reduction in vigilance and awareness of the environment, combined with the driver's preoccupation with watching the approaching aircraft and the absence of any visual cues to indicate that he was entering an active taxiway, were probably the main reasons for him not recognising that he was turning onto Delta instead of taxiway Foxtrot.
If the works plan had included traffic management procedures for taxiway Delta during the day and had the route marking been continued across the taxiway, it is likely that the situation would have been prevented.
- The route for work vehicles across taxiway Delta was not marked.
- The truck driver was probably distracted and fatigued by the task demands.
- The truck driver was unaware of his position on the work site.
- Taxiway Foxtrot and Delta were similar parallel taxiways between taxiway Alpha and runway 35/17.
Local safety action
Following the occurrence the contractor, in conjunction with the airport operator, implemented the following measures:
- Installed additional stanchions at Delta to delineate the route.
- Conducted a number of all-staff briefings to remind them of the need for vigilance.
- Introduced a procedure whereby a safety officer would attend and control works traffic at taxiway Delta when required to do so for aircraft movements on the RAAF apron.
- The contractor arranged for their safety manager to spend a part of each day on-site to assess and monitor safety aspects.
|Date:||01 August 2001||Investigation status:||Completed|
|Time:||1712 hours EST|
|State:||Australian Capital Territory||Occurrence type:||Runway incursion|
|Release date:||21 January 2002||Occurrence category:||Incident|
|Report status:||Final||Highest injury level:||None|
|Aircraft manufacturer||The Boeing Company|
|Type of operation||Air Transport High Capacity|
|Damage to aircraft||Nil|
|Departure point||Sydney, NSW|