Birds still pose costly hazards to aircraft despite better technology

Bird strikes are a major problem in the aviation industry, causing billions of shillings worth of damage every year. Photo/FILE 

By Daniel Ondieki

In Summary

• Despite bird-proofing the planes, prevention is better than cure.

Bird strikes are a major problem in the aviation industry, causing billions of shillings worth of damage every year

Compared with other aviation incidents, bird strikes are fairly common. In my relatively short career, I have already hit birds five times. One was shredded by a propeller of a piston-engined airplane, while others have hit various sections of the fuselage with no damage to the plane.

The last one went through the engine, filling the cabin with a foul smell and later necessitating a thorough inspection of the engine and a cancelled flight.

 

The low level manoeuvring necessary to miss the birds is likely more dangerous than hitting them. In any case, the time between seeing a bird and the collision is usually too short to permit any avoidance action.

However, not all bird strikes are harmless. The most dramatic incident is of course the ditching in the Hudson after a dual engine failure caused by flying through a flock of geese. Pilot skill and probably some luck prevented that incident from resulting in several fatalities.

For this reason, authorities and regulators have invested a lot in trying to stop bird strikes from happening in the first place and to mitigate the consequences when it does.

Regulatory agencies require that an engine be able to ingest a certain size of bird and continue functioning or fail gracefully. A mesh in front of an engine is unlikely to work since the disruption to the intake airflow will result in less thrust and lower fuel efficiency.

Engine manufacturers must demonstrate practically to regulators the ability of an engine to suffer a bird strike and not endanger the aircraft occupants.

The tail section which is also vulnerable is strengthened and the windscreen also tested to ensure it meets both the strength standards and that is does not shatter when hit by a bird. Improvements in windscreen manufacturing are the reason that today’s windscreens are curved rather than the flat panels used in the past.

Despite bird-proofing the planes, prevention is better than cure. Most bird strikes occur at low altitudes just after take off or when approaching to land. Airports frequently control large tracts of land which are covered in grass and thus attract birds which find a pleasant habitat and plenty of food.

Airports authorities have tried to control the birds by cutting the grass, using pyrotechnics to scare away the birds, deploying dogs or falcons and using stuffed animals.

Others have resorted to culling the birds to reduce their numbers. On occasion when a large flock of birds has been spotted, the pilot will be advised to delay the take off or a vehicle will be sent to the runway to chase them away.

Military pilots who fly at lower altitudes and probably have a bigger problem with birds may use radar or predictive modelling to determine when to schedule their flights.

Despite these advances, the decades-old low tech methods will probably be used for some time in the future.

Dr Ondieki is a pilot with an international airline.