Sunday, April 26, 2015

Bird Strikes

‘Bird Strike’ is a term used to define collision between birds and vehicles. In aviation it refers to a bird’s collision with aircraft during any phase of flight, whether it is a take-off run or a landing roll, bird strikes have always been a serious concern. Comparatively there are not many reported accidents caused due to bird strikes yet there are thousands of incidents which result in major economic and reputation losses of the operator as well as the airport authority.

Impact on Aviation

Although not always resulting in a crash or accident bird strikes do pose a significant threat to aircraft safety. Monetary losses due to expensive aircraft repairs and increased grounding time are yet another negative contribution from bird strikes. In USA alone 600 million USD are spent each year for damage caused by birds and wild life strikes. As an example If we look at the graph of statistics of Bird Strikes reported in USA from1990-2013 (Source: FAA) we can conclude that bird strike is a constantly rising factor and has increased nearly 6 times in 25 years. This increased number of occurrences is due to increased number of flights as well as a pronounced increase in number of birds itself. One more thing to note is that on average only around 9.5% (13497) strikes have caused damage to aircraft, this is also a big number for the operators if maintenance cost is considered.

Reducing the Risks

Bird strikes can never be eliminated, yet they can be controlled/reduced generally by these steps:
1. ReportingBird Strikes are specific to aerodrome location, season, bird types etc. and this important data can be collected by inputs from occurrences. Reporting is the most important part of identifying and mitigating the risks involved in a certain location during a certain period of the year. Proper reporting should be made mandatory for every strike, no matter if it has caused damage or not, and then the collected data should be analysed for a trend of strikes. Generally there is a pattern of these events depending upon several factors, and once the pattern is established and understood it would be easier to reduce the number of strikes. For example see the 5 yearly charts below that show strikes in the UK, the general pattern is increased number in strikes during the month of June-July. The interesting thing is this chart follows nearly the same trend either from 1990s or the 2000s i.e. curve’s peak is highest during June-July       
 
 2. Habitat ManagementBird hazard cannot only be controlled by airport authorities, a firm environmental control is required and for that purpose a proper habitat management program should be followed keeping following key points a primary concern:
a) People living in the vicinity of the airport shall be informed of the risks involved from bird strikes and educating them to avoid attracting birds, like by planning waste disposal sites away from the runways
b) Ponds and lakes should be netted, streams should be drained.
c) Proper length of grass within the aerodrome should be maintained: if too long it would encourage birds for nesting, and too short will allow them to roost.

3. The “Scarecrow” theoryThere are several ways of scaring birds away once it has been analysed that what type of birds are causing trouble in a certain region.
a) Spirals
These white painted spirals apart from telling the ground crew about running engines play a vital role in distracting birds away as the appear as white flashing signals to the bird discouraging them to get ingested.
According to an AOPA report: One air carrier detected slightly reduced bird strike rates after painting the jet engine spinners white. Anything that increases contrast seems to help birds to avoid airplanes. Birds see colors in the ultraviolet range beyond what humans can see, and that information may be useful in future research on markings for aircraft that could reduce bird strikes
b) Distress Calls and Gunshots
Once the type of birds have been identified using previous strike reports birds can be scared away playing distress calls on loud speakers by using Bio-Acoustic Systems.  Another method is to fire blank bullets to shoo' the birds away. 



Conclusion

Bird Strike issues should be addressed seriously and appropriate actions should be taken as this is a factor that can be controlled using some easy techniques and once a proper safety plan has been established and maintained, it will save the operator as well as the authorities of monetary and reputation losses.

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