On 25 May 2010 a Swearingen SA227 Metroliner being operated by Airwork on a scheduled cargo flight from Christchurch to Dunedin narrowly missed colliding with a vehicle during its night landing roll in normal visibility at destination. The aircraft crew were unaware of the presence of the vehicle until advised later and the vehicle driver was unaware of the close proximity of the aircraft prior to its occurrence.
An Investigation was carried out by the TAIC. It was established that an aviation security officer had driven his patrol vehicle on to the runway in heavy rain ahead of the just-landed aircraft. The driver had apparently accessed the runway in order to conduct a routine inspection of the integrity of the airfield perimeter fence because flooding after recent heavy rain was affecting parts of the dirt perimeter road and the grassed areas from which such inspections were normally accomplished. Because he had co-incidentally kept to the shoulder of the runway and stopped soon after entering it, there had been no actual risk of collision. However, it was noted that the driver had been unaware that an aircraft had just landed and the pilots of the aircraft were also unaware of the vehicle and would have been in no position to take effective avoiding action to prevent a collision had the vehicle been driven in front of their aircraft.
It was established that the incident had occurred outside the normal opening hours of the airport and that this meant that air traffic control service was not being provided. It was found that the operational rules in place at the time stated only that “Vehicle movements on the manoeuvring area are restricted to those vehicles under Air Traffic Control” and that they had not addressed the issue of or the concomitant risks arising from vehicle movements when ATC service was not being provided.
It was also found that there were no procedures in place whereby the Airport Operator would advise the security agency of aircraft movements expected outside the hours of ATC service because the company had been unaware of the inspections being made.
It was noted that prior to and during their approach, the aircraft crew had made the standard radio calls for an unattended aerodrome on the correct radio frequency and had been aware of the actual weather conditions after contact with the airport night security agent. They had commenced an instrument approach confident that they would be able to land off it and when they became visual with the runway at about 600 feet aal, the runway lights were in sight and there was no visible obstruction on the runway.
It was found that there had been a general lack of appreciation amongst the security vehicle drivers of the potential significance of illuminated runway lighting outside of ATC service hours. In respect of airside radio use by the security vehicle driver, it was found that he had not turned on his radio until after the last of the transmissions made by the approaching aircraft. Shortly before entering the runway, he had then switched it on and made a radio call but this had not been heard by the pilots. It was concluded that it was “almost certain that the pilots were engaged in the critical touchdown phase of flight” at the time and that the radio call had been masked by the noise of the aircraft propellers being selected to reverse pitch following touchdown.
The Investigation found that:
“a very high potential collision risk had existed, which had been mitigated only by the fact the vehicle on the runway during the aircraft landing roll had elected, outwith any consideration or awareness of a collision risk, to keep to the side of the runway”.
and concluded that:
“the Security Patrol Vehicle involved had conducted an unauthorised but nevertheless custom-and-practice manoeuvre whilst being driven by an inadequately trained driver. The context for the established and inappropriate custom and practice was a lack of proper procedures for airside and, in particular, runway access by the organisation responsible for airport security".
The Investigation noted that, despite the serious shortcomings in security training and local procedures disclosed, five years of internal audit and six years of Civil Aviation Authority audits of the Dunedin Security function had made “no findings or observations relevant to the runway incursion incident”.
Safety Action taken by the Aviation Security Service since the incident to improve both the training of aviation security officers and the applicable procedures for airside access were noted.
The Final Report of the Investigation: Report 10-006 was approved for publication in December 2010. No Safety Recommendations were issued but the completion of a comprehensive series of necessary Safety Actions by the Security Agency involved in respect of the procedures and training applicable to their personnel was noted.