When Flight 624 struck an antenna array and power pole while making its ill-fated landing at the Halifax airport Sunday morning, it interrupted power to the airport. Three backup power generators immediately came on, as designed.
But while the backup generator that powers the airfield lights — primarily, the lights along the runways — operated as it should have, two generators that power the terminal building operated for only eight minutes before shutting themselves down. The airport does not know why that happened, says spokesperson Peter Spurway, but he speculated that the generators are designed to shut themselves down when they become over-heated.
With the power out at the terminal, the electrical gate that allows emergency vehicles into the secured tarmac area where the crashed plane sat could not be opened; on a recording of emergency dispatches and scanner traffic obtained by the Examiner, emergency responders are heard asking how to enter the airfield. Additionally, emergency responders scrambled to find someplace to bring the 138 people who had been on the plane, ultimately finding a nearby hangar, but the passengers and crew had spent nearly an hour on the tarmac. Emergency responders also could not set up a command centre at the terminal building, but were quickly able to set up at the Alt Hotel, which did not lose power.
Hear the radio traffic between emergency responders here:
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Much the same scenario unfolded at the Halifax sewage plant when it failed in February 2008. In that case, one of the two backup generators fired up after a power failure turned itself off, ultimately resulting in the complete loss of the plant and the discharging of millions of litres of raw sewage into Halifax Harbour.
Spurway says the airport is investigating why the backup generators turned themselves off.