1

Fang Han

Literature Review

Section L

December 16, 2014

Developing an Effective Technique for Bird Strike Prevention

Introduction

In aviation, a bird strike is defined as a collision between a bird and an aircraft. Such

incidents have been reported since the earliest eras of aviation, with the first known case

documented by the Wright brothers in 1905 (Nicholson & Reed, 2011). The growth in air traffic,

the increase in numerous bird populations, and the development of quieter aircraft have caused

bird strikes to become increasingly more common. In 2013, there were 10,856 reported bird

strikes in the United States alone. Although a number of approaches toward preventing bird

strikes have been shown to have high efficacy, the frequency of incidents is projected to increase

(Dolbeer et al., 2014). It is therefore essential to develop a new means of preventing bird strikes

that utilizes existing techniques, works in an efficient manner, and requires limited attention

from airport personnel. Such a system would save the aviation industry hundreds of millions of

dollars each year while protecting passengers from injury or even death.

Severity of Bird Strikes

Bird strike events are usually of little threat to the safety of aircraft and passengers.

However, in recognizing the progressive increase in both air traffic and bird populations,

organizations such as the Federal Aviation Administration (FAA) and the U.S. Department of

Agriculture (USDA) predict that bird strikes will become more frequent. With the majority of

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incidents occurring either on the ground or at low altitudes (Nicholson & Reed, 2011), areas on

and near airports are considered most susceptible to bird strikes (Godin, 1994). Additionally,

numerous misconceptions about bird strikes limit awareness in pilots. These false assumptions

include the beliefs that birds are not active at night; that bird are not active in poor weather; that

aircraft lights warn birds of potential danger; that aircraft colors and markings deter birds; and

that birds intentionally fly away from aircraft (Nicholson & Reed, 2011).

Between 1988 and 2013, wildlife strikes in the United States resulted in over 255 human

deaths and have damaged over 243 aircraft beyond repair. According to a publication of U.S.

bird strike data provided by the FAA, the number of reported bird strikes in 2013 (10,856

incidents) was approximately six times that of 1990 (1,795 incidents). There were a total of

138,257 reported bird strikes during the 24-year period, and notably, this accounted for nearly 97%

of all wildlife strikes during that same period.

Figure 1. A Boeing 747 passenger jet struck a

red-tailed hawk, which became lodged in the

aircraft wing, while landing at an airport in Texas

in February 2013 (Boyles, 2013).

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Year Number of Reports

1990 1,795

1991 2,336

1992 2,499

1993 2,504

1994 2,554

1995 2,675

1996 2,852

1997 3,353

1998 3,689

1999 5,020

2000 5,866

2001 5,676

2002 6,099

2003 5,886

2004 6,409

2005 7,090

2006 7,053

2007 7,536

2008 7,417

2009 9,231

2010 9,557

2011 9,774

2012 10,530

2013 10,856

24-year Total 138,257

Although bird strikes are becoming significantly more common, the amount of damage

they cause on aircraft has decreased. In 1990, 20% of bird strikes caused damage; by 2013, this

percentage had already decreased to 5%. Additionally, only 6% of bird strikes resulted in a

negative impact on flight, which prevented the aircraft from continuing to operate safely and

typically involved an emergency landing or aborted take-off (Dolbeer et al., 2014).

Table 1. Number of reported bird strikes in the

United States from 1990 to 2013 (Dolbeer et al.,

2014).

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Financial Losses due to Bird Strikes

In spite of these currently low percentages, the financial costs are still of concern.

Between 1990 and 2013, the average annual cost of bird strikes in the United States was at least

$187,000,000 (Dolbeer et al., 2014). However, because only an estimated one in five of these

incidents is actually reported (Allan, 2000), the annual cost could have been as high as

$937,000,000. The aircraft downtime resulting from bird strikes must also be considered. The

annual downtime between 1990 and 2013 was 117,740 total hours at minimum. Again due to the

low number of reports and the lack of information on certain reports, there could have been as

many as 588,699 hours of aircraft downtime each year (Dolbeer et al., 2014). Beyond the costs

of damages and downtime, bird strikes cause delays and cancellations, increased insurance

premiums, and decreased customer loyalty for airlines. A single flight delay or cancellation can

result in approximately $75,000 in financial losses, and importantly, each can affect up to four

other scheduled flights (Allan, 2000).

The effort to prevent bird strikes can also be costly. Current programs implemented by

airport wildlife management can cost up to $150,000 annually. The depth and complexity of the

program is directly proportional to its cost, and increased investments are only plausible if the

program demonstrates satisfactory efficacy (Allan, 2000).

Causes of Bird Strikes: Growth of the Aviation Industry

The rapid growth of the aviation industry is one of the most notable elements of the

increase in bird strikes. Approximately 86% of all wildlife strikes in the United States that

occurred between 1990 and 2013 involved commercial aircraft. This percentage could have in

reality been higher because there were 32,091 reports filed during the period in which the aircraft

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type was not recorded. Commercial air traffic is expected to increase by 1.5% each year. Thus,

the 24.6 million aircraft movements recorded in 2013 is projected to become 32 million by year

2030. The number and frequency of bird strikes would increase proportionally with the number

of aircraft in the air. Between 2000 and 2013, the number of wildlife strikes in the United States

increased by 51%. Correspondingly, the rate of wildlife strikes increased from approximately

5.35 incidents per 100,000 aircraft movements in 1990 to 20.45 incidents in 2013. The

aforementioned data identifies the growth in air traffic, especially in commercial airliners, as a

major contributor to bird strikes (Dolbeer et al., 2014).

Causes of Bird Strikes: Changes in Bird Populations

The second reason for the increase in bird strike events is the growth in population of

various species of large birds. Between 1990 and 2013, the birds that were most commonly

involved in collisions with aircraft in the United States were hawks, eagles, and vultures (5,038

incidents) and waterfowl (4,418 incidents). There were a total of 503 bird species that were

confirmed to have been involved in a bird strike. Wildlife data confirms a growth in population

for numerous species, including the bald eagle, the wild turkey, the American white pelican, the

double-crested cormorant, and the sandhill crane, since 1990. The non-migratory Canada goose

population in the United States and Canada increased from 0.5 million in 1990 to 3.8 million in

2013. Comparatively, the North American snow goose population increased from 2.1 million to

6.6 million (Dolbeer et al., 2014). The amount of damage caused by a bird strike is proportional

to the amount of kinetic energy generated by the impact, which is in turn proportional to the

mass of the object. The aforementioned large birds would therefore cause the most damage in the

event of a collision (Nicholson & Reed, 2011). For example, on 15 January, 2009, an Airbus

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A320 passenger jet was forced to make an emergency landing on the Hudson River in New York

after its engines ingested a flock of Canada geese. This event demonstrated the severity of

wildlife strikes to the public (Dolbeer et al., 2014).

Causes of Bird Strikes: Development of Technology in Aircraft

Another major cause of bird strikes is the development of new two-engine turbine-

powered aircraft that are both quieter and more powerful than older models. These aircraft,

although reliable, are difficult for birds to detect. This is especially true under circumstances in

which the birds have already adapted to noisy urban environments such as airports. In 1965, only

13% of turbine-powered aircraft had two engines as opposed to having three or four. In 2008,

approximately 92% were two-engine aircraft (Dolbeer et al., 2014). Together with increasing air

traffic and bird populations, modern technology in aircraft further extends the likelihood of bird

strikes.

Figure 2. US Airways Flight 1549. The Airbus A320

was forced to ditch on the Hudson River in New York

after colliding with a flock of Canada geese (Ng,

2009).

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Aircraft Components Prone to Bird Strikes

Birds are more likely to collide with certain components of the aircraft than others.

Logically, these components are often located at the front of the aircraft or are forward-facing.

Additionally, depending upon the location of the impact, the aircraft may be more prone to

damage (Dolbeer et al., 2014).

Aircraft

Component

Number Struck Number

Damaged

Windshield 20,302 926

Engine(s) 15,814 4,321

Nose 17,654 931

Wing 16,743 3,508

Radome 15,415 1,433

Fuselage 15,046 607

Landing Gear 5,526 1,156

Propeller 2,783 483

Tail 1,617 252

Light 850 603

Other 11,381 625

Phases of Flight and Bird Strikes

Between 1990 and 2013, a total of 94,822 bird strike reports in the United States included

information concerning the phase of flight at which the incident occurred. It should be noted that

the most widespread unit of measurement for altitude in aviation is the foot; the metric system is

only used to assign altitudes below 33,000 feet in Russia and in a number of other nations in

Central Asia (“Metric altitude”, n.d.). For commercial aircraft, 71% of the cases were reported to

have occurred at or below 500 feet above ground level (AGL). Similarly, 74% of bird strikes

involving general aviation occurred within this altitude range. Because most bird strikes occur at

lower altitudes, the majority of them happen on or near airports. Approximately 41% of the

reported phases of flight were during final approach towards a runway. The second most

Table 2. Number of aircraft components struck and damaged in

bird strikes, United States, 1990-2013 (Dolbeer et al., 2014).

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commonly reported phase of flight, at 18%, was the take-off run, which occurs on the ground.

The third most common phases, both at 17%, are the climb and the landing roll.

Phase of Flight Total Number of Incidents Percentage of Total

Take-off Run 17,500 18

Climb 16,561 17

Approach 38,662 41

Landing Roll 16,116 17

Other 5,983 7

Analysis of the reports shows that for every 1000 feet of climb, the likelihood of a bird strike

decreases by 34% for commercial aircraft and 43% for general aviation (Dolbeer et al., 2014).

Seasonal and Daily Patterns of Bird Strikes

The frequency of bird strike events varies throughout the course of a year. Data obtained

from 1990 to 2013 by the FAA shows that the number of incidents tends to increase during the

spring, summer, and fall months, peaking during the month of August.

4 3

5

7

10

8

12

14 13 13

7

4

0

2

4

6

8

10

12

14

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Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Percentage of Total Bird Strikes

Figure 3. Percentage of total reported bird strikes in United States in each month,

1990-2013 (Dolbeer et al., 2014).

Table 3. The number of bird strike incidents in various phases of flight, United States, 1990-2013. There were

94,822 reports that stated the phase of flight (Dolbeer et al., 2014).

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Moreover, the likelihood of bird strike events changes during the course of a 24-hour period. Of

the 138,257 reported bird strikes between 1990 and 2013, a total of 88,242 reports stated the time

of day at which the incident occurred. Approximately 62% of these cases occurred in daylight

whereas 30% occurred at night. Far fewer incidents took place during dawn and dusk (Dolbeer et

al., 2014).

Reasons for the Presence of Birds at Airports

There are many contributing factors to the presence of birds on and near airports.

Although the circumstances at a given airport varies constantly depending upon changes in

environment, weather, season, and time of day, the major attractions for birds are generally food,

water, and shelter. Thus, an important procedure in the effort to disperse birds is to remove these

attractions, which are, however, largely uncontrollable. In addition, the patterns of movement of

birds sometimes come into conflict with the location of an airport. For example, some airports

are situated within the migratory paths of various bird species. Local birds, on the other hand,

often need to travel across the airport to roost or to feed (Godin, 1994).

Figure 4. A Turkish Airlines Airbus A319 encounters a

flock of birds at Istanbul Ataturk Airport in Turkey, 2009

(Diler, 2009).

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Reactions of Birds to Aircraft

Information regarding the reactions of birds to an oncoming aircraft relies heavily on

reports from pilots and observations made by researchers. Personal accounts from pilots suggest

that birds generally treat approaching aircraft as stationary objects, only taking evasive action

when the aircraft is just 100 to 200 meters away. Because aircraft are usually of no harm to birds,

birds tend not to treat them as threats (Lima, Blackwell, DeVault, & Fernández-Juricic, 2014).

Few studies concerning the reactions of birds to aircraft have been conducted. However,

in 1999, a research team in Ireland observed four distinctive evasive maneuvers performed by

low-flying birds crossing an active airport runway. The observed birds were mostly rooks, black-

headed gulls, and woodpigeons. The majority of these birds flew in an “S”-shaped pattern by

first turning perpendicular to their original path and then flying around the rear of the aircraft.

The second observed maneuver was a forward acceleration with no change in direction, which is

likely the birds’ attempt to cross the runway in front of the approaching aircraft. Other birds flew

in a loop before crossing the runway to allow time for the aircraft to pass first. Finally, some

birds flew in an erratic pattern associated with anti-predator behavior. In all four cases, the birds

returned to their original flight path at the end of the maneuver (Lima et al., 2014).

In approximately 75% of bird strikes, evidence suggests that the bird(s) attempted to take

evasive action. However, certain behavioral patterns in birds tend to facilitate collisions with

aircraft. To escape from a predator, some birds allow it to approach them closely before suddenly

changing in direction. In instances in which an aircraft is mistaken as a predator, a bird strike

becomes far more likely to occur. Also, faster birds may instinctually attempt to outfly a predator,

but an aircraft undoubtedly travels at a much higher rate of speed, making a collision

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unavoidable. Large flocks of birds are also at a disadvantage in taking evasive action because of

delays and confusions in decision-making and communication (Lima et al., 2014).

Overview of Sensory Systems in Birds

Avian species are generally most sensitive to visual and auditory stimuli. Although the

sense of taste does allow birds to detect potentially harmful toxicants, the gustatory and the

olfactory organs are not as sensitive (Boudreau, 1972). Most birds are able to see colors between

400 and 700 nanometers in wavelength. Hearing abilities in birds vary from species to species,

but birds are typically capable of detecting sounds between 1000 and 3000 hertz, with a

minimum volume between -10 and 10 decibels at sound pressure level (Belant & Martin, 2011).

Social bird species usually have a strong alarm system that makes them more sensitive to

stimuli. The larger the size of a flock, the more likely it is that there are more timid individuals.

These individuals would be the first to respond to potential danger, and in doing so, they warn

other members of the group. Species that have few, if any, predators are naturally less sensitive

to stimuli. This is especially true for pelagic, or oceanic, birds (Boudreau, 1972).

Factors Influencing Sensory Systems

Numerous factors can influence the effectiveness of stimuli. First, a bird’s habitat and

environment can determine its sensitivity to visual or auditory cues. Birds in open areas, such as

fields, rely more heavily on visual stimuli to detect dangers. On the other hand, bush and forest

species are more sensitive to sound. A number of species have shown limited response to

auditory alarms unless they are reinforced by visual stimuli. Second, sensitivity can be

influenced by the bird’s physical position. For instance, during feeding, the peripheral vision of

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birds is restricted. In such circumstances, they demonstrate faster and more significant reactions

to auditory stimuli. Third, species including Sturnis vulgaris (starlings) and Agelaius phoeniceus

(red-winged blackbirds) appear to be more sensitive to stimuli during the morning hours. As the

day progresses, they show gradually less response. Sensitivity is at a minimum during feeding

time before night roosting, indicating that hunger and thirst in birds reduce their response to

stimuli (Boudreau, 1972).

Approaches Toward Bird Strike Prevention

Simultaneously implementing multiple bird strike prevention techniques is generally the

most effective way to disperse birds from airports. Due to inconsistencies in the behavior of birds

as a result of the environmental changes, it is difficult to determine the efficacy of individual

prevention techniques. The performance of these techniques is dependent upon the time of day,

the time of year, long-term environmental changes, and, very importantly, the ability of birds to

adapt (Belant & Martin, 2011).

In general, airport wildlife management personnel take four distinct approaches toward

avoiding bird strikes. They are:

1. the use of bird repellents, including auditory, visual, and chemical

harassment;

2. habitat modification, specifically the removal of food, water, and

shelter;

3. the exclusion of birds from airports using barriers;

4. bird population control, involving the capturing, displacing, and/or

killing of birds.

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The approach selected at a particular airport should correspond with the site fidelity of birds in

the area. Also, in order to maximize the efficacy of an implemented system, it is critical to allow

birds to periodically encounter negative consequences, such as death. This decreases the

likelihood that the surviving birds of the flock would return to the area (Belant & Martin, 2011).

Transient Loafing Feeding Roosting Foraging Nesting Brooding

Harassment Techniques Deterrent Techniques Exclusionary Techniques

Repellent, or harassment, techniques are considered to be either primary or secondary.

Primary repellents irritate birds by stimulating their senses, thus encouraging them to leave the

area. Secondary repellents, which are more effective, physiologically affect birds, causing them

to permanently abandon the area. Repellents can be activated periodically or at random, or they

can be triggered by motion. Randomly activated and motion activated devices are difficult for

birds to adapt to and thus have better long-term effects (Belant & Martin, 2011).

Existing Bird Strike Prevention Techniques

Birds are generally most sensitive to auditory and visual disturbances, with sight being

the dominant sense in birds. Imitating alarm and distress calls can have high efficacy because

they are difficult for birds to adapt to. These sounds are developed upon the basis that birds use

various calls to protect territory and to avoid predators. Birds have not been shown to be able to

detect sounds at high frequencies. Therefore, ultrasonic repellents are not useful (Belant &

Martin, 2011).

Figure 5. Appropriate treatment techniques for various bird behaviors ranging from low (green) to high (red) site

fidelity (Belant & Martin, 2011).

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Harassment techniques that involve auditory and visual stimuli are primary repellents that

have mostly temporary effects. Gas exploders, pyrotechnics, biosonics, and dogs have been

demonstrated to have the best efficacy. Gas exploders have been in use in airports and in

agricultural settings since the 1940s. However, birds can adapt to them, so they must be relocated

periodically. Pyrotechnics effectively incorporates both auditory and visual repellents. Biosonics,

which are essentially alarm and distress calls, require more research but appear to be one of the

most effective bird repellents. Using dogs to drive away birds is useful in a small setting but does

not affect birds that are a farther distance away (Belant & Martin, 2011).

Deterrent techniques are more aggressive than harassment but are not as severe as

exclusion. Effigies, including models of dead birds, have been found to be an effective bird

repellent. However, they require a strong focus on physical details to be realistic. Stationary

predator models are only effective for a short amount of time. Balloons successfully repel birds

as well, but they are not efficient for airport personnel to use. Repellents using lights and mirrors

require further research, and reflectors and flags have little effectiveness. Chemicals such as

methyl anthranilate and anthraquinone are generally effective, but do depend upon the bird

species (Belant & Martin, 2011).

A number of strategies have been employed to create physical or virtual barriers that

prevent birds from entering an area. Such methods include the use of razor wire, overhead wires,

netting, covers, and so on. Because the complete exclusion of birds from an area is unrealistic,

most wildlife management programs work to provide partial barriers. Additionally, there have

been attempts to build virtual barriers with materials such as laser beams. A large number of

exclusionary techniques have not been quantitatively assessed and therefore, their efficacy is

unknown (Belant & Martin, 2011).

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Methyl Anthranilate

Methyl anthranilate is a naturally occurring chemical found in concord grapes and other

plant species. It is commonly used for food flavoring or for fragrance and it GRAS (Generally

Recognized as Safe) listed by the United States Food and Drug Administration. As a bird

repellent, methyl anthranilate stimulates pain receptors in the mouth and nostrils. The chemical

has been approved by the United States Environmental Protection Agency as an agricultural bird

repellent, specifically for use on cherries, blueberries, and grapes (Umeda & Sullivan, 2001).

Table 4. The effectiveness of existing harassment, deterrent, and exclusion

techniques on various bird species (Belant & Martin, 2011).

Effectiveness: G = Good; F = Fair; P = Poor; N = Not Recommended

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Proposed Methyl Anthranilate Dispersal System

A methyl anthranilate dispersal system proposed by Kelly L. Boren of the Boeing

Company is designed to prevent bird strikes that occur within the runway flight path corridor at

altitudes below 3000 feet above ground level. The apparatus, which is placed on the aircraft,

releases a methyl anthranilate mist during take-off and landing. By discouraging birds from

entering the runway flight path corridor, the methyl anthranilate mist protects subsequent aircraft

that travel through the area from bird strikes (U.S. Patent Application No. 13/689743).

The apparatus consists of three parts: a tank, a vaporizing nozzle, and a control system.

Methyl anthranilate is filled into the tank via an inlet on the device. A temperature regulation

system maintains the internal temperature of the tank to keep the chemical in a liquid state.

Gravitational force or a pump system transfers the methyl anthranilate to the nozzle, which

vaporizes the liquid and releases it into the air. To ensure that the methyl anthranilate stays in the

air for a longer duration of time, the size of its particles should be less than 30 microns. The

apparatus receives electrical power from the aircraft and can be controlled by the pilots in the

cockpit (U.S. Patent Application No. 13/689743).

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Literature Cited

Allan, J. R. (2000). The costs of bird strikes and bird strike prevention. In L. Clark (Ed.), Human

conflicts with wildlife: economic considerations (pp. 147-153). Fort Collins, CO:

National Wildlife Research Center.

Belant, J. L., and Martin, J. A. (2011). Bird harassment, repellent, and deterrent techniques for

use on and near airports. Washington, D.C.: Transportation Research Board.

Boren, K. L. (2014). U.S. Patent Application No. 13/689743. Washington D.C.: U.S. Patent and

Trademark Office.

Boudreau, G. W. (1972). Factors relating to alarm stimuli in bird control. In Marsh, R. E. (Ed.),

Proceedings of the 5th vertebrate pest conference. Paper presented at The

Vertebrate Pest Conference: The 5th Vertebrate Pest Conference, Fresno, CA, 7-9 March

(pp. 121-123). Davis, CA: University of California.

Boyles, C. (Photographer). [Untitled photograph of Boeing 747 bird strike]. Retrieved December

5, 2014, from http://www.faa.gov/

Diler, A. (Photographer). [Untitled photograph of birds and airplane]. Retrieved December

15, 2014, from http://www.airliners.net/

Dolbeer, R. A., Wright, S. E., Weller, J. R., and Begier, M. J. (2014, July). Wildlife strikes to

civil aircraft in the United States 1990-2013. Retrieved from http://www.faa.gov

Godin, A. J. (1994). Birds at airports. In S. E. Hygnstrom, R. M. Timm, and G. E. Larson (Eds.),

Prevention and control of wildlife damage (pp. E1-E4). Lincoln, NE: University of

Nebraska-Lincoln.

Lima, S. L., Blackwell, B. F., DeVault, T. L., and Fernández-Juricic, E. (2014). Animal reactions

to oncoming vehicles: a conceptual review. Biological Reviews, 000-000. doi:

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10.1111/brv.12093

Metric altitude reference. (n.d.). Retrieved December 4, 2014 from http://www.skybrary.aero/

index.php/Metric_Altitude_Reference

Ng, G. L. P. (Photographer). (2009). Plane crash into Hudson River [Photograph],

Retrieved December 4, 2014, from http://www.flickr.com/

Nicholson, R., and Reed, W. S. (2011). Strategies for prevention of bird-strike events. AERO, pp.

17-24. Retrieved from http://www.boeing.com/commercial/aeromagazine/

Umeda, K., and Sullivan, L. (2001). Evaluation of methyl anthranilate for use as a bird repellent

in selected crops. In Byrne, D. A., and Baciewicz, P. (Eds.), 2001 Vegetable Report.

Retrieved October 20, 2014 from http://ag.arizona.edu/pubs/

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Engineering Plan

A. Researchable question or engineering problem being addressed:

Bird strikes are a frequent threat to aircraft on the ground and at low altitudes, and current

prevention techniques fail to limit the frequency of such incidents.

B. Hypothesis or Engineering Goals:

The goal of this project is to develop a method for use in aviation that will repel birds at airports

to prevent bird strike events during the take-off run and the landing roll.

C. Description in detail of methods or procedures:

Procedures – One of the existing methods of bird strike prevention is the use of chemical

repellents, especially methyl anthranilate. An apparatus that automatically sprays this chemical

solution will be developed. It will not be necessary to obtain methyl anthranilate or any other

chemical because they have already been shown to be effective; only a system that can use these

chemicals will be designed. The apparatus will act as a protection system for runways by

spraying the chemical bird repellent in such a way that a wall or barrier of the chemical is

essentially created. It would thus be difficult for birds to enter the periphery of a runway. The

chemical will be transported using a pump system and will be released into the air using a series

of misting nozzles. A scaled version of this apparatus will be built using PVC pipes, air pumps,

nozzles, vinyl tubing, and water, which will be a substitute for methyl anthranilate.

Data analysis – The methyl anthranilate sprayer system will be analyzed for its ability to spray

the chemical effectively. It must cover a satisfactory range and distribute the chemical evenly

across the range. Photographs taken during the test trials will be analyzed to mathematically

calculate the amount of coverage.

Design criteria and secondary engineering goals – Most importantly, the apparatus must be able

to effectively repel birds near airports and have absolutely no negative effect on the proper

operations of aircraft and airports. Secondary engineering goals include mechanical/electrical

efficiency and cost efficiency.

Testing – The apparatus will be tested for its ability to spray a liquid solution into the air upon

detecting an object. No real birds will be used for testing, and water will be used instead of

methyl anthranilate. Colored dyes will be mixed with the water so that when the sprayer is turned

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on, it will be easier to observe the amount of coverage obtained by the sprayers. Various types of

atomizing nozzles will be tested at various pressures to find the optimal result. Photographs of

the system will be taken during all test trials.