Non-Subscriber Extract
Radars offer bird-strike warning
By Wes Carleton and Ben Vogel
20 May 2009
Despite dire media accounts of the threat of bird strikes following the January 2009 ditching of a US Airways A320 in New York's Hudson River, aircraft have been colliding with birds since the earliest days of powered flight. In fact, the Wright brothers reported close encounters during their test flights more than 100 years ago.
Aviation authorities can, therefore, only attempt to minimise, rather than completely prevent, the risk of aircraft and birds colliding.
Currently, airports employ wildlife control staff who regularly monitor and record bird activity, while ensuring that habitats that attract them, such as standing water and nesting sites, are removed and that other operations like rubbish dumps are kept as far as possible away from the airport. Grass is also left long to discourage nesting and collie dogs, falcons, pyrotechnics and noisemaking devices are used at several airports to scare birds away from runways.
Radar developments
While all these measures help to reduce local bird activity, none could warn of the flock of Canada geese flying just below 3,000 ft a couple of miles away and heading straight towards the departure path of the US Airways jet. This is where recent developments in radar are showing great promise.
Before discussing these developments, however, it is useful to assess just how serious bird strikes are. Here, unfortunately, records have until recently been sketchy, primarily because there are no requirements that aircraft operators report strikes unless there is damage affecting airworthiness. From 24 April, however, the FAA made its bird-strike database available on a public website, withdrawing a proposal to keep certain data confidential.
The FAA list details almost 90,000 incidents since 1990 – around two-thirds since 2000. Pilots reported hitting 2,291 doves between 2000 and 2008. Other airborne victims included gulls (2,186), European starlings (1,427) and American kestrels (1,422).
It is clear, therefore, that bird strikes are an ever present hazard to the airline community and military forces and that worldwide annual costs could easily exceed many tens of millions of dollars for repairs to airframes and engines and for the associated aircraft downtime.