DAVID LEARMOUNT / LONDON

Threat posed by flocking birds to aviation is on the increase worldwide, says UK body

Certification requirements demanding higher levels of birdstrike resistance for new aircraft engines are on the cards because the risk of serious birdstrikes is growing, says the UK Civil Aviation Authority.

The risk of danger to aircraft is increasing, says the CAA, because the population of large flocking birds, particularly Canada geese, is climbing significantly. This echoes concerns raised in Canada and the USA (Flight International, 15-21 August 2000).

As a result, says CAA chairman Sir Roy McNulty, the authority is working with engine manufacturers to determine the potential for increasing the birdstrike resistance of new engines. The CAA says it hopes to use larger birds in certification testing for multiple strikes on large fan engines from 1.13kg (2.5lb) to 2.5kg, but the 3.7kg requirement for single strikes may remain the same - that an engine should be able to operate at 75% power for 20min after birdstrike.

The CAA is also, however, trying to raise awareness of the seriousness of the problem, both in the industry and among those outside it who are responsible for features, such as landfill sites and man-made wetlands, which attract flocking birds to areas near airports.

Airlines must be encouraged to report all birdstrike incidents so that the CAA can assess the degree of risk and collect the data necessary to persuade companies and organisations to take action, it says.

Head of the CAA's Aerodrome Standards Division Stan Brown says: "We believe that one of the UK's major airlines experiences more birdstrikes in a month than they report to the CAA in a whole year. It is vitally important that controllers, pilots and airport staff report incidents to the CAA. Without accurate data it is impossible to assess the threat birds pose - and it is also difficult to convince those outside the industry to take action."

The CAA quotes the example of a United Airlines Boeing 767 inbound to London Heathrow in September 1998 that sustained severe damage to its left wing, left engine, and nose. At Elmendorf AFB, Alaska, USA, in September 1995, a US Air Force Boeing E3A Sentry Airborne Warning and Control System aircraft crashed just after take-off, killing the 24 people on board when a flock of seagulls damaged all four of its engines.

Source: Flight International