Bird Strike (eBook)

An Experimental, Theoretical and Numerical Investigation

Reza Hedayati, Mojtaba Sadighi (Autoren)

eBook Download: PDF | EPUB

2015 | 1. Auflage
258 Seiten
Elsevier Science (Verlag)
978-0-08-100113-4 (ISBN)

Infos

Bird strikes are one of the most dangerous threats to civil and military flight safety: between 1960 and 2014, they were responsible for the destruction of approximately 150 civil aircraft and the deaths of 271 people.

Bird Strike presents a summary of the damage imposed on the aviation industries by their avian counterparts. This book first presents and analyzes the statistics obtained from bird strike databases and offers various methods for minimizing the overall probability of bird-strike events. The next chapters explore how to analyze the ability of aero-engine critical structures to withstand bird-strike events by implementing reliable experimental, theoretical, and numerical methods. Finally, the book investigates the impact of bird strikes on different components of aircrafts, such as the metal fuselage, composite fuselage, engines, wings, and tail, and proposes two new bird models, with explanations of their use.

• Provides up-to-date information for aviation staff and researchers working on aircraft safety
• Offers comprehensive investigations on all the statistical, theoretical, experimental, and numerical aspects of bird strike
• Includes studies carried out on bird strike and provides the reader with the important findings of each paper

Reza Hedayati is a Researcher in the Department of Mechanical Engineering at the Amirkabir University of Technology, Tehran, Iran. He completed his Ph.D. at Amirkabir University of Technology (Tehran Polytechnic) and his undergraduate studies at Isfahan University of Technology. His research interests lie in the area of Biomedical engineering, Biomaterials, metal foams, Composite structures, Multiscale Finite Element modeling, and beam and plate analytical analyses. Reza has also cooperated with TU Delft on analytical solutions, experimental testing, and multiscaling modeling of porous materials under static, dynamic, and fatigue loadings since 2013. In recent years, he has focused on better techniques for modeling and analyzing bird impact on different components of aircraft such as tailplane, windshield, and fuselage. He has proposed two novel bird models which have explained many discrepancies between the numerical, experimental and theories of bird strike. He has also collaborated actively with researchers in other fields of Mechanical Engineering, particularly 3D geometry modeling using CT images, Fatigue and Fracture, and Biomechanics.

Textauszug

1

Introduction

Abstract

In this chapter, the term “bird strike” is defined and its effects – as the most important foreign object damage (FOD) are presented. The most important bird strike events in history are also reviewed. The importance of bird strike as a threat to both the international aviation industry and its passengers, which is the motivation behind the writing of this book, will be the next topic discussed. Mechanical solutions to bird strike problems including experimental, analytical, and numerical techniques will be reviewed and examined in summary. Finally, the outline of the book will be stated.

Keywords

bird strike

special bird strike cases

importance of bird strike

approaches to bird strike

1.1 Introduction

What is a bird strike? Any contact between a moving vehicle (usually an aircraft) and an airborne avian creature (usually a bird or bat) or a group of such avian creatures is called a bird strike. The term is usually expanded to include other wildlife species including terrestrial mammals. The result of such contact for a bird is, of course, usually fatal. For an aircraft, however, the result can vary from a blood smear, an indentation or small hole in the aircraft’s frame, substantial damage to an aircraft component, or even complete aircraft destruction; this is usually caused by significant bird strikes that disable engines (Blokpoel, 1976).

A bird strike can, therefore, be a significant threat to the safety of aircraft travel. In fact, more than 90% of foreign object damages (FODs) can be attributed to avian creatures (Mao, Meguid, & Ng 2008). Consequently, bird strike is one of the most important safety concerns in the aviation industries (Hedayati, Sadighi, & Mohammadi-Aghdam 2014). Bird strikes have caused numerous accidents resulting in aircraft damage and human casualties. The risk of bird strike to the aviation industries is, however, within acceptable limits (it is estimated that bird strikes cause human death in only about 1 in every 109 flying hours (Thorpe, 2003)). Indeed, air travel is considered statistically to be one of the safest modes of travel (Blair, 2008).

However, bird strikes are an increasing problem for the aviation industries. It is thought that there are four main factors involved in the increasing number of reported bird strikes. First, successful wildlife protection programs have increased the number of birds, especially the more hazardous to aircraft migrant birds (that usually have larger body sizes and fly in large flocks). Second, the density of air traffic has increased (Blair, 2008) due to the advent of more low-cost airlines (that usually implement small and inexpensive aircraft) as well as the expanding demands of the emerging economies for faster modes of transport. Third, modern jet aircrafts have fewer, but more powerful engines that produce more thrust than ever; this increased thrust leads to increased bird ingestion. Fourth, more studies and investigations on bird strike have led to an increased awareness of the risks caused by bird strike. Today, the origin of several aircraft crashes is recognized by the aviation industry to be caused by bird strike, while in a few decades ago the cause was unknown in similar accidents.

Modern jet aircrafts are now carrying more and more passengers, and it is known that even a small amount of damage in the aircraft’s windshield or engine can lead to a catastrophic chain of events (Meguid, Mao, & Ng 2008). As a result, it is critical to ensure that the different structural parts, e.g. the compressor blades, the windshield, the wings, and the tail’s leading edges, are able to resist such high-energy impacts, and so guarantee a safe landing of the aircraft after bird strike (Hedayati & Ziaei-Rad, 2012a, 2012b). This is why an aircraft must show compliance with the “continued safe flight and landing” requirements following specified types of high-energy bird impact (Hedayati & Ziaei-Rad, 2013). The regulations regarding bird impact proofing for aircraft will be presented later in Chapter 3.

1.2 History of bird strike

Bird strikes have occurred throughout the history of aviation, with their increased frequency and consequences, mirroring the aviation industry’s growth and global expansion. There have been a considerable number of bird-strike accidents; however, some are more prominent and well known. The first recorded bird-strike event was reported by Orville Wright in 1905. According to the Wright Brothers' diaries, “Orville … flew 4,751 meters in 4 minutes 45 seconds, four complete circles. Twice passed over fence into Beard's cornfield. Chased flock of birds for two rounds and killed one which fell on top of the upper surface and after a time fell off when swinging a sharp curve”.

Six years later, Eugene Gilbert, a French pilot, encountered an angry eagle while traveling from Paris to Madrid. Gilbert, flying an open cockpit Bleriot XI, was able to ward off the large bird by shooting it (Wikipedia, 2014). The other significant bird-strike event was recorded in 1912 by Calbraith P. Rodgers, who trained with the Wright brothers, and made the first transcontinental airplane flight by flying across the United States (Bilstein, 2001), which made him a national celebrity. A few months later, however, while performing in an exhibition flight over Long Beach, California, he flew into a flock of seagulls which subsequently became entangled in the control wires of his plane, causing the plane crash into the ocean (Post, 1912; Blair, 2008).

In the November 1925 issue of the Royal Aeronautical Society Journal, the then Director of Civil Aviation, Sir Sefton Brancker wrote the following in an article entitled “The Lessons of Six Years Experience in Air Transport” (Brancker, 1925; Thorpe, 2003):

There is one form of collision which must not be altogether forgotten; the possibility of colliding with birds in flight. We have had one mysterious incident in which the pilot lost control of his aircraft flying over the sea at a low height, the pilot’s opinion was that he had been struck on the head by a sea bird, several were flying nearby, but nothing was ever clearly proved. In the East, propellers of aircraft taking-off have been broken by kites flying over the aerodrome. I have never heard of an aeroplane encountering a flock of ducks at night; such an eventuality might lead to danger of injury to the pilot, the propeller or wing structure. The best precaution to meet such a danger will be good screening for the pilot and robust metal construction.

Due to a steady increase in the number of flights, passengers per plane, and flight speed, birds began to pose more threat to the aviation industries. However, the piston engines prevalent in the first half of twentieth century were more resistant against avian strikes compared to forthcoming engine types (Solman, 1973).

The bird strike with the greatest recorded human fatalities occurred on 4 October 1960 when a Lockheed Electra flew through several starlings, shortly after taking-off from Boston Logan International Airport. Due to the ingestion of the birds, two of the four turboprop engines lost power and one shut down, causing the plane to stall, and consequently crash into Boston Harbor. Of the 72 passengers, 62 lost their lives (Thorpe, 2003). Subsequently, the Federal Aviation Administration (FAA) developed a minimum bird collision standard for jet engines.

Although no single bird-strike event with fatalities as large as Boston’s accident has since been recorded, the total number of people killed during the subsequent 60 years due to bird strikes exceeds five times of the fatality count in the 1960 Boston accident. The bird strike became a more common occurrence and attracted the concern of both the aviation industries and the authorities, as the commercial airline industry expanded and annual aircraft travel increased (Thorpe, 2003).

The next major bird-strike accident occurred in 1973, when a Learjet 24 flew through a flock of brown-headed cowbirds as it took off from Peachtree-Dekalb Airport in Georgia, USA. The aircraft crashed as a result of cowbird ingestion into both its engines and all seven people onboard were killed (Antonides, 2010).

On 15 September 1988, Ethiopian Airlines flight 737-200 ingested numerous pigeons into both engines during take-off. As a consequence, the engines lost thrust, resulting in a crash landing killing 31 of the 105 passengers on-board.

On 10 November 2008, a Boeing 737-8AS suffered multiple bird strikes (up to 90 strikes) in a flight from Frankfurt to Rome. The bird strikes caused both the engines to fail and the aircraft made an emergency landing. Passengers and crew were evacuated through the starboard emergency exits. Of the 172 people on-board, eight passengers and two crew received minor injuries (Milmo, 2008).

One of the recent famous examples of a catastrophe caused by bird strike is the bird impact on the aircraft engine of the US Airways, Airbus A320 in January 2009 (Fig. 1.1). The plane struck a flock of Canada geese shortly after take-off in a flight from LaGuardia Airport in New York City to Seattle–Tacoma International Airport in SeaTac; the bird strike caused power loss in both turbines and a subsequent ditching of the airplane into the Hudson River. When...

Produkt-Details

• Erscheint lt. Verlag: 15.9.2015
• Sprache: englisch
• Themenwelt: Technik ► Bauwesen
• Themenwelt: Technik ► Fahrzeugbau / Schiffbau
• Themenwelt: Technik ► Luft- / Raumfahrttechnik
• Themenwelt: Technik ► Maschinenbau
• Themenwelt: Wirtschaft
• ISBN-10: 0-08-100113-4 / 0081001134
• ISBN-13: 978-0-08-100113-4 / 9780081001134