Birds and Wildlife Pests Pose Numerous Aircraft Hazards

Editor’s note:  Feras Shakhatreh is an engineer from Jordan with 24 years of experience in aeronautical engineering, logistics, business development, quality and safety, aircraft maintenance and more. He submitted to PCT the following article, which details the dangers birds and wildlife pests can pose to aircraft. 

Awareness of the Problem. Look and imagine what the size of the wildlife and bird hazards are and how it can affect our safety, our lives, our economy, our aircraft, our time, our work and our happiness. Wildlife and bird hazards can be a big problem. 

Are we away from danger? The answer is NO, we are not away from danger, because all of us are travelling in airplanes, and every airplane could face a collision with wildlife/birds, because if a bird or animal gets near a moving or flying airplane, we never know what it is thinking. Maybe it is scared, maybe it wants to attack. This danger should be studied, and we must take counteractions to deter it. Now, you may think that I don’t like animals and birds, but I do like them, just far away from work and from aircraft because these creatures may result in crashes.

References. This article is based on very respected references from around all the world as well as my expertise. We will investigate the other experiences in wildlife and bird hazard management. Examples of these references are: Federal Aviation Administration (FAA), from Jordan, from UAE, International Civil Aviation Organization (ICAO), European Aviation Safety Agency (EASA), as well as from Australians, the Irish, the British and even references  from Africa, etc.

My goal is to show you how the airports deal with wildlife and bird hazards in many countries, in different climates, with different people and under different circumstances in order to create a good understanding about this important subject. It is really a good thing to see other experiences!

Introduction: What is a wildlife hazard? 
A wildlife hazard is the presence of wildlife, including birds and other animals, both wild and domestic. These animals and birds could result in damage to aircraft. 

The risk of a wildlife hazard depends on the size of the animal, their behavior and the number of wildlife. There would be greater damage if an aircraft encountered a collision with many birds, or a large bird. Their proximity to aircraft during different phases of flight also matters. We will see how this happens and what phase of flight poses high strike rates with birds.

The probability of negative effects from wildlife hazards are more likely at airports close to forests or water bodies or while passing through critical airspace. 

According to the Federal Aviation Administration (FAA), from 1988 to 2019, there were 292 human fatalities attributed to wildlife/bird strikes globally. This is a very high number. And this number is based on statistics from 1988, the number could be multiplied by two or three if we take the statistics from the early beginning of flying. 

Wildlife risks fluctuate with the daily and seasonal cycles of wildlife activity. It depends. For example, the highest rate of strikes have been recorded in August based on some studies. These numbers are affected by many factors.

The species and number of wildlife at and around airports may vary over the years due to things like land use, for example planting trees with fruits on the lands at the airport or around it will attract the hungry birds and consequently the number will increase. Environmental changes like agricultural practices, urbanization, conservation and climate change can also be a factor. Every airport has site-specific characteristics regarding habitat, climate and surroundings. All these factors will draw the site-specific characteristics for every airport, and this should be reflected in respective Wildlife Hazard Management Plans (WHMP) for every airport. However, there are other factors which may increase the likelihood of a wildlife strike. The more air traffic, the more strikes!  The development of quieter aircraft engines could also be a factor due to the relatively low noise of these engines. In other words, the bird’s and animal’s fear of aircraft will be reduced, and then the engagement with aircraft will be increased.

To ensure that we have implemented effective wildlife control methods and techniques, we should review wildlife hazard management methods annually and update regularly. We are talking about serious threats to aircraft operational safety, and this intense threat is posed by the presence of wildlife at and around the airport. 

These collisions, strikes and hits will affect two things: No.1 is the safety of aircraft operating at the airport and No. 2 is they will be very costly. In other words, wildlife strikes have resulted with fatalities and loss of aircraft that have cost billions of dollars on a global scale since records of strikes began.

Why are airports concerned about wildlife? Based on respected statistics and studies, most wildlife strikes occur in the vicinity of the airport, with the majority of strikes occurring when an aircraft is less than 3,000 feet above ground level. Based on a respected statistics study, ICAO No. EB2017/25, which took the data analyses of wildlife strike reports from the years 2008 to 2015, based on about 98 thousand reports received from 91 countries:
• 39% occurred during the take-off run or climb phases.
• 57% occurred during the descent, approach or landing roll phases.

This means 96% of wildlife strikes occurred on or near airports. Management efforts to reduce wildlife hazards are focused and concentrated at the airports, and we should use the various techniques which reduce wildlife hazards at airports. All these techniques usually work effectively, provided that they are used in an integrated manner. 

 Wildlife strike consequences. The estimated average cost per strike is about $36,000. The mentioned figures are broad estimates and account for direct costs of the following:
• Delays.
• Cancellations.
• Cost of repairs, including labor, parts, transport costs and aircraft downtime.
• Time spent on inspections, including baroscopic and forensic investigations.
• Resources spent to transport engineers to remote or regional airports to carry out inspections.
• Time spent rescheduling flights and passengers.
• Costs of accommodating passengers that have been rescheduled on other flights.
• Resources spent on follow-up investigations for significant strike incidents.
• Aircraft write-offs.

Historical background. In 1905, Orville Wright had what is believed to be the first collision between an aircraft and a bird, an event now known as a bird strike. In 1912, Calbraith Perry Rodgers became the first person to die as the result of a bird strike due to a flock of gulls. So wildlife incidents and accidents have occurred since the dawn of aviation.

Significant strikes continue to occur regularly worldwide. In the past, aircraft had frail structures, which made the aircraft susceptible to wildlife strike damage, but the early aircraft were also very slow, which gave the pilot more time to take evasive action. Even over the past 100 years with technology making aircraft with more resistant to wildlife strikes, we still have them. 

The deadliest bird strike to date in details.
Date: October 4, 1960
Location: The Boston Logan International Airport, U.S.
Airplane Type: Lockheed Electra L188
Bird: European starlings
What happened: The airplane was struck by a flock of European starlings just as it became airborne. The birds were ingested into three of the aircraft’s four engines, causing the aircraft to lose power, stall and crash into the harbor.
Fatalities: 62 people died out of the 72 passengers and crew members on board. Resulted in more stringent Federal Aviation Administration guidelines for aircraft design and maintenance.  

Wildlife strikes have also impacted changes to aircraft design. On November 23, 1962, a Vickers Viscount struck a flock of whistling swans (Cygnus columbianus) over the state of Maryland while flying at 6,000 feet. One of the horizontal stabilizers was penetrated by a swan, weakening the structure and causing it to separate from the aircraft, which subsequently crashed and killed all crew members and passengers on board. This crash resulted in the design criteria for horizontal stabilizers being raised to withstand eight pounds.

Perhaps the most famous bird strike in recent years took place on January 15, 2009, when an Airbus A320 hit a flock of Canada geese (Branta canadensis) just after taking off from LaGuardia Airport, New York City. The ingestion of multiple geese into both engines resulted in a forced emergency landing on the Hudson River. All 150 passengers and five crew members survived. 

A more recent wildlife strike resulting in fatality was on September 28, 2012, when a Dornier Do-228 with sixteen passengers and three crew members was on initial climb out of Kathmandu Airport in Nepal. The crew reported a bird strike, resulting in a fatal crash that killed all on board. The bird was identified as a black kite (Milvus migrans).

Although the majority of wildlife strikes involve birds, those involving other animals may also have a severe outcome. For example, on Dec, 4, 2015, a SpiceJet landing at Jabalpur Airport in India collided with a herd of wild boars that were crossing the runway. The aircraft went off the runway and the left main and nose gear of the aircraft collapsed. No passenger or crew member was injured.