How to Become an Aircraft Accident Investigator (Fly High, Dive Deep)

If you’ve ever been fascinated by the intricacies of aviation safety or wondered what it takes to become an Aircraft Accident Investigator, you’ve come to the right place.
In this guide, we’ll demystify the EXACT steps you need to embark on a career as an Aircraft Accident Investigator. We’ll discuss:
- The skills you need.
- The education that will boost your chances.
- How to secure a job as an Aircraft Accident Investigator.
So, whether you’re a novice in the aviation field or an experienced professional looking to specialise, stay with us.
We’re about to unfold the roadmap to become an Aircraft Accident Investigator.
Let’s take off!
Steps to Become an Aircraft Accident Investigator
Step 1: Understand the Role and Responsibilities
As an aspiring Aircraft Accident Investigator, it is crucial to first understand the role and its responsibilities.
This job entails examining and investigating aircraft accidents, incidents, and failures in order to identify the causes and contributing factors.
You will need to systematically analyze all the data gathered from the crash site, including the wreckage, flight data recordings, weather conditions, and witness statements.
Also, it is important to understand that this role often involves working in stressful conditions and requires a high level of precision and detail orientation.
You will be responsible for presenting findings to aviation authorities, manufacturing companies, and sometimes to the public, which will be used to improve aviation safety standards and prevent future accidents.
At times, you might also be required to testify in court as an expert witness.
Furthermore, you may need to work irregular hours and be prepared to travel frequently, often at short notice, to accident sites that could be located anywhere in the world.
Understanding these aspects will help you determine whether this job role aligns with your career goals and personal preferences.
Step 2: Obtain a Degree in Aeronautical Engineering or a Related Field
To become an Aircraft Accident Investigator, it is important to have a strong understanding of aircraft systems and operations.
A bachelor’s degree in Aeronautical Engineering, Aerospace Engineering, or a related field provides a solid foundation in these areas.
During these degree programs, you will study subjects such as aerodynamics, aircraft structures, propulsion systems, flight mechanics, and control systems.
You will also gain practical experience in laboratories and workshops, where you will learn about aircraft design and manufacturing.
Having a degree in these fields gives you an edge in understanding the mechanics of flight, aircraft systems, and potential failures, which are critical when investigating accidents.
To increase your competitive edge, you may consider pursuing a master’s degree or a doctorate in these or related fields.
While in school, it’s beneficial to start specializing in a particular area of aircraft operations or engineering.
This could be anything from pilot training methodologies, aircraft design principles, to aviation safety regulations.
Specializing can help you narrow down your career focus and develop expert knowledge in that area, which can be particularly useful when investigating specific types of aircraft accidents.
Step 3: Gain Experience in Aviation
In order to effectively investigate aircraft accidents, it’s crucial to have a solid understanding and experience in the field of aviation.
This can be achieved by working in various roles within the aviation industry, such as a pilot, flight engineer, air traffic controller, or aircraft maintenance technician.
Working as a pilot can provide you with hands-on experience in flight operations, navigation, and control systems.
As a flight engineer, you would gain knowledge about aircraft systems and their operation.
An air traffic controller role could offer insights into coordination, communication, and safety procedures, while a job as an aircraft maintenance technician would focus on the mechanical aspects of an aircraft.
This practical exposure will help you understand the intricate details of aircraft operation, flight mechanics, and aviation safety protocols.
It will also enable you to understand the complexities of accident scenes and provide a framework for determining probable causes and contributing factors.
Remember, the more years of experience and the wider the range of experience, the better equipped you will be to handle the complexities and challenges of aircraft accident investigation.
Besides, this experience is often a prerequisite for certification programs and job positions in aircraft accident investigation.
Step 4: Acquire Specialized Training
Aircraft Accident Investigation is a highly specialized field that requires specific training beyond a basic aviation degree.
You will need to acquire this specialized training to further your career as an Aircraft Accident Investigator.
Numerous institutions provide specialized courses in accident investigation, which encompass the study of aircraft systems, wreckage analysis, crash survival analysis, human factors in aviation accidents, and air traffic control.
You should aim to gain a well-rounded knowledge in all these areas.
This training may also involve practical crash simulations, allowing you to gain hands-on experience in accident scene management and evidence collection.
It’s not uncommon for training programs to include courses on aviation law and accident report writing, as communication skills are essential in this role.
In addition to formal training, you may also seek certification from recognized bodies like the International Society of Air Safety Investigators (ISASI) or the National Transportation Safety Board (NTSB) in the US, which will boost your credibility and employability.
Further, attending seminars and workshops on recent advancements and changes in aviation technology and safety regulations will keep your knowledge updated and relevant.
Remember, the aviation industry is constantly evolving, and so too should your expertise.
Working closely with experienced investigators and gaining practical knowledge is also beneficial.
Remember, the more practical experience you have, the more prepared you will be when you have to lead an investigation.
Step 5: Enhance Investigations Skills
As an Aircraft Accident Investigator, it is crucial to continuously enhance and refine your investigation skills.
This includes improving your technical knowledge, strengthening your analytical capabilities, and honing your problem-solving skills.
Firstly, you should have a deep understanding of aircraft systems, aviation mechanics, flight operations, and safety procedures.
Regularly updating yourself with the latest technology and improvements in aviation can help you better understand potential factors in accidents.
Secondly, analytical skills are crucial in determining the cause of an accident.
This involves interpreting complex data from flight recorders, assessing damage, and understanding the implications of every minute detail.
Consider enrolling in courses or training programs that focus on analytical thinking and data interpretation.
Lastly, problem-solving is a critical part of an Aircraft Accident Investigator’s role.
You need to be able to identify potential issues, form hypotheses, and test them systematically to reach a conclusion.
This includes liaising with aviation experts, engineers, and other relevant professionals to gather necessary information.
Remember, effective communication and report-writing skills are also essential, as you will need to explain technical information to individuals who may not have a background in aviation.
You may also want to consider training in areas such as crisis management and human factors, which can contribute to a more comprehensive investigation.
Step 6: Learn Relevant Laws and Regulations
The role of an Aircraft Accident Investigator requires a comprehensive understanding of various laws, regulations and protocols associated with aviation and aircraft accident investigation.
This includes local, national, and international laws as well as industry-specific regulations.
You will need to familiarize yourself with the aviation rules and regulations established by the Federal Aviation Administration (FAA) and National Transportation Safety Board (NTSB) in the United States, or the equivalent regulatory bodies in your country.
These regulations cover everything from aircraft design and maintenance, to flight operations, safety standards, and procedures for conducting accident investigations.
Furthermore, understanding the International Civil Aviation Organization’s (ICAO) Annex 13, which provides international standards and recommended practices for aircraft accident and incident investigation, is crucial for investigations that involve foreign airlines or occur outside of your home country.
Staying abreast of changes and updates to these regulations is also key, as aviation laws and standards are often subject to revision.
Being well-versed in these laws and regulations will ensure your investigations are legally sound and your findings are credible and valid.
Step 7: Get Certified
After gaining substantial experience and knowledge in the field of aircraft accident investigations, it’s time to get certified.
Having a certification is not mandatory but it often provides a competitive edge in the job market and demonstrates your competence to potential employers.
It also ensures that you are up to date with the latest practices and technologies in the field.
The International Society of Air Safety Investigators (ISASI) and the National Transportation Safety Board (NTSB) Academy in the United States offer various certifications for aircraft accident investigators.
The NTSB’s Aircraft Accident Investigation Course is widely recognized worldwide.
These certifications typically involve passing an exam that tests your knowledge on various aspects of aircraft accident investigation, including accident analysis, wreckage reconstruction, human factors, survival factors and more.
In addition, you may also consider completing a Federal Aviation Administration (FAA) certification, which could help in gaining expertise in specific types of aircraft or systems.
Remember, maintaining your certification typically requires continuing education or retesting, which will ensure you stay current with the industry’s best practices and the latest technologies.
Step 8: Gain Experience in Aircraft Accident Investigation
To become a proficient Aircraft Accident Investigator, you need to gain hands-on experience in the field.
This can be achieved by working with various aviation safety organizations, airlines, or government agencies such as the National Transportation Safety Board (NTSB) in the United States.
In these roles, you will likely assist in investigating minor incidents and accidents under the guidance of more experienced investigators.
This is crucial for developing a deep understanding of the investigative process, which includes conducting interviews, examining wreckage, analyzing flight data and other technical information, and writing reports.
Also, participation in accident simulations and drills can provide valuable training and experience without the high-stakes pressure of an actual accident.
Remember, the ultimate goal is to prevent future accidents by identifying the root cause of the incident, so all experience gained will be invaluable in honing your skills.
You may also consider attending workshops or seminars on aircraft accident investigation for further exposure to the field.
These events can provide networking opportunities and the chance to learn from experienced professionals.
As you grow in your career, you’ll also need to stay updated with the latest advancements in aviation technology and safety measures.
Continuous learning and staying abreast of industry developments is key in this dynamic field.
Step 9: Network with Professionals in Aviation Safety
Networking is a crucial step in advancing your career as an Aircraft Accident Investigator.
Establishing relationships with other professionals in the field of aviation safety can provide you with insights and knowledge that may not be readily available through conventional learning methods.
It can also open up opportunities for career advancement, job opportunities, and professional development.
You can start by joining professional organizations such as the International Society of Air Safety Investigators (ISASI) or the National Transportation Safety Board (NTSB).
These organizations often host conferences, workshops, and meetings where you can meet other aviation safety professionals.
Additionally, you can network online through professional networking sites like LinkedIn. You can join aviation safety groups, participate in discussions, and connect with professionals in the field.
Lastly, consider attending industry conferences, seminars, and workshops.
These are great opportunities to meet industry experts, learn about the latest developments in aviation safety, and establish your presence in the field.
Remember, networking is not just about taking; it’s also about giving.
So, when you connect with other professionals, be prepared to share your knowledge and experiences as well.
This can establish you as a knowledgeable professional in your field and open doors for future collaborations and opportunities.
Step 10: Stay Informed About Advances in Aviation Technology and Safety Practices
As an Aircraft Accident Investigator, it’s crucial to stay informed about the latest developments in aviation technology and safety practices.
With the rapid advancements in technology, aircraft systems and operations are constantly evolving, and as an investigator, you should possess up-to-date knowledge of these changes.
This will allow you to better understand the factors that could contribute to accidents and thus, help prevent them.
Subscribe to aviation magazines, journals, and online platforms where research papers and articles related to aviation technology and safety are published.
Join aviation-related organizations or forums where new ideas, advancements, and practices are discussed.
Attend seminars, webinars, and workshops that focus on the latest advancements in aviation technology and safety.
Further, you may also consider undergoing additional training or courses that deal with new technologies or safety protocols.
Some organizations offer advanced courses in subjects like avionics, next-gen navigation systems, or emerging safety standards.
Remember, as an Aircraft Accident Investigator, your prime goal is to prevent future accidents by learning from past ones.
Therefore, staying current on the latest developments in your field is a continuous and vital part of your job.
Your knowledge and expertise not only help in thorough investigations but also play an integral role in improving overall aviation safety.
Step 11: Apply to Aircraft Accident Investigation Agencies
After acquiring the necessary education and experience, it’s time to apply to aircraft accident investigation agencies.
These agencies are often government entities, like the National Transportation Safety Board (NTSB) in the United States, or private consulting firms specializing in aircraft accident investigations.
Start by researching potential employers, understanding their requirements, and tailoring your resume to highlight your relevant skills and experience.
Keep an eye on job boards, networking events, and agency websites for job openings.
It’s also a good idea to reach out to professionals in the field for advice or potential job leads.
When applying, ensure that your application clearly demonstrates your knowledge of aircraft systems, principles of accident investigation, and any specific specialties you may have, like avionics or structural analysis.
During this time, it can also be beneficial to continue your education and training, as some agencies may require additional qualifications or certifications.
For example, the NTSB offers a training center with courses in aircraft accident investigation techniques and procedures.
Remember, competition for these roles can be fierce, and it may take several applications before you secure a position.
Persistence and continuous learning are key to success in this field.
Step 12: Continue Professional Development
As an Aircraft Accident Investigator, it’s crucial to stay abreast of the latest developments in aviation technology, safety protocols, and investigation techniques.
Continuous professional development is the key to maintaining competence in the role and enhancing your career prospects.
You can stay updated and improve your knowledge by attending conferences, seminars, and workshops related to aviation safety and accident investigation.
Participate in discussions and networking events with other professionals in the field, as this can provide valuable insights and opportunities for collaborative learning.
Additionally, consider subscribing to relevant professional journals and online resources, where you can access the latest research and developments in the field.
Taking part in webinars and online courses can also be a good way to keep your skills up-to-date.
You can also pursue additional certifications that may be beneficial in your role.
These certifications could be in advanced investigation techniques, aviation safety management, or other relevant areas.
Not only will this enhance your professional profile, but it will also ensure that you are fully equipped with the necessary tools and knowledge to effectively investigate and prevent aircraft accidents.
Remember, the aviation industry is constantly evolving, and so are the methods to investigate accidents.
Hence, a commitment to lifelong learning and professional development is essential for success in this role.
Aircraft Accident Investigator Roles and Responsibilities
Aircraft Accident Investigators are professionals who apply their knowledge of aviation, engineering, and safety to investigate and determine the causes of aircraft accidents.
Their goal is to prevent future occurrences by recommending appropriate safety measures.
They have the following roles and responsibilities:
Accident Investigation
- Visit accident sites to collect evidence and data.
- Analyze wreckage, flight data recorders, and cockpit voice recorders.
- Conduct interviews with witnesses, crew members, and air traffic control.
Data Analysis
- Examine flight data and recorded information to reconstruct the events leading to accidents.
- Use computer simulation and modeling to analyze accidents and incidents.
- Identify trends and patterns in accident data.
Report Writing
- Prepare detailed and comprehensive reports on accident investigations.
- Present findings to regulatory bodies, airlines, and the public.
Recommendation of Safety Measures
- Suggest safety improvements and preventative measures based on investigation findings.
- Work with aviation industry and regulatory bodies to implement safety recommendations.
Testifying
- Provide expert testimony in court cases related to aircraft accidents.
- Present investigation findings in public inquiries and hearings.
Collaboration
- Work with other investigators, aviation experts, engineers, and regulatory bodies.
- Coordinate with international teams for investigations involving foreign aircraft or overseas accidents.
Educational Outreach
- Conduct seminars and workshops to share investigation findings and promote safety awareness.
Continuous Learning
- Stay updated with latest technologies, aviation safety trends, and investigation techniques.
- Participate in professional development activities like conferences and training programs.
What Does an Aircraft Accident Investigator Do?
Aircraft Accident Investigators typically work for government bodies such as the National Transportation Safety Board (NTSB) or for private sector aviation companies.
Their primary role is to investigate aviation accidents and incidents to determine the cause of an accident and to propose strategies to avoid similar accidents in the future.
This involves conducting a thorough examination of the crash site, collecting and analyzing evidence, and studying flight data records and voice recordings from the cockpit.
They may also conduct interviews with witnesses, survivors, and personnel involved in aircraft operation.
Aircraft Accident Investigators also write detailed reports outlining the facts of the accident, their analysis, and their conclusions as to the cause of the accident.
In addition, they may be tasked with providing recommendations to regulatory authorities and airline companies on measures that can be taken to improve safety and prevent future accidents.
A key part of their role is to maintain meticulous records of their investigations and to adhere strictly to safety regulations and guidelines.
They may also be called upon to testify in court regarding their findings in legal proceedings related to aviation accidents.
Essential Aircraft Accident Investigator Skills
- Communication: Investigators need to coordinate with various parties involved in an accident, including pilots, air traffic controllers, aircraft engineers, safety regulators, and even legal professionals. They must be able to express complex technical information clearly and accurately.
- Detail-Oriented: Accident investigators must be meticulous in their work, as they need to examine and document every detail of an accident scene and review vast amounts of data.
- Knowledge of Aviation Laws and Regulations: Familiarity with aviation laws and safety regulations at national and international levels is crucial as these provide the standards by which accidents are assessed.
- Technical Expertise: A strong understanding of aircraft systems, structures, and operations is critical. This includes knowledge of flight dynamics, meteorology, aerodynamics, and aircraft design.
- Problem-Solving: Investigators must identify the cause of accidents and propose effective solutions to prevent similar incidents in the future. This requires strong analytical and problem-solving skills.
- Critical Thinking: The ability to evaluate complex situations objectively and draw accurate conclusions based on evidence is a key skill.
- Report Writing: Investigators need to present their findings in clear, concise reports. These reports must be accessible to a variety of readers, including aviation professionals, regulators, and the public.
- Investigation Techniques: Knowledge of accident investigation methodologies, such as wreckage analysis, interviewing witnesses, and data recovery, is vital.
- Stress Management: Accident investigation can be a high-pressure job, especially when dealing with major incidents. The ability to manage stress and maintain a clear focus is important.
- Physics and Mathematics: Strong skills in physics and mathematics are necessary to understand and interpret flight data, calculate impact angles, and analyze structural failures.
- Computer Proficiency: As a lot of analysis involves using complex software, investigators should be proficient in the use of computers and specialized software such as flight simulators and data analysis tools.
- Teamwork: Aircraft accident investigators often work in teams and must be able to collaborate effectively, share insights, and respect diverse viewpoints.
- Patience: Investigations can be lengthy and complex. Investigators need patience to thoroughly analyze and interpret data, and to persevere with lengthy enquiries.
- Integrity: The role requires a high level of honesty and ethical conduct, as investigators’ findings can have far-reaching implications for safety regulations, manufacturers, airlines, and individuals.
- Physical Fitness: Investigators may need to work in challenging conditions, such as at remote crash sites, and must be physically fit to cope with the demands of the job.
Aircraft Accident Investigator Career Path Progression
The Foundation: Junior Aircraft Accident Investigator
The journey generally begins as a Junior Aircraft Accident Investigator.
At this phase, you are learning about the industry, familiarizing yourself with the techniques of investigation, and being part of the team working on smaller scale investigations.
Here are some tips for succeeding in this role:
- Investigative Training: Participate in investigative training programs, workshops, and seminars to increase knowledge.
- Learn From Experienced Investigators: Learn from senior investigators, absorb their techniques, and understand how to analyze an accident.
- Detail-Oriented: Pay attention to detail as every small piece of evidence could be vital to the investigation.
The Ascent: Aircraft Accident Investigator
With experience and expertise, you transition into the role of a fully-fledged Aircraft Accident Investigator.
At this stage, you are leading investigations, analyzing complex incidents, and writing detailed investigation reports.
Here’s how to thrive in this stage:
- Interdisciplinary Knowledge: Understanding of various disciplines like engineering, meteorology, human behavior is essential.
- Communication Skills: Develop strong communication skills as you’ll be interacting with various entities including airlines, regulatory bodies, and potentially media.
- Report Writing: The ability to write clear, concise, and comprehensive reports is crucial.
Reaching New Heights: Senior Aircraft Accident Investigator
Next step in your career ladder is the Senior Aircraft Accident Investigator position.
Here, you are recognized for your deep expertise and leadership within the investigation team.
You will likely mentor junior investigators and lead high-profile accident investigations.
To excel in this role:
- Mentorship: Use your experience to help junior investigators grow and develop.
- Crisis Management: Develop strong crisis management skills as high-profile accidents often bring intense scrutiny and pressure.
- Leadership: Lead by example, inspire your team with your work ethics and problem-solving abilities.
Beyond the Horizon: Lead Investigator and Beyond
As you move ahead in your career, you might choose to specialize in a specific type of aircraft or accident, or move into a leadership role such as a Lead Investigator or Head of Investigations.
These roles involve increased responsibility, leadership, and strategic decision-making.
- Technical Specialization: Continue to learn and specialize in particular types of aircraft or accidents.
- Leadership Skills: If moving into leadership, hone your leadership and decision-making skills to guide your team effectively.
- Policy Influence: Use your extensive experience and knowledge to influence safety regulations and policies.
Pinnacle of Success: Director of Aviation Safety
At the zenith of your career, you might find yourself in roles like the Director of Aviation Safety.
At this level, you are not only responsible for leading major investigations but also shaping the overall safety strategy of the aviation industry, making crucial decisions, and leading larger investigation teams.
Aircraft Accident Investigator Salary
Entry-Level Aircraft Accident Investigator
- Median Salary: $50,000 – $70,000 per year
- Entry-level aircraft accident investigators typically have 0-2 years of experience and may hold bachelor’s or master’s degrees in aviation or related fields.
Mid-Level Aircraft Accident Investigator
- Median Salary: $70,000 – $95,000 per year
- Mid-level investigators have 2-5 years of experience and often take on more complex investigations and handle larger caseloads.
Senior Aircraft Accident Investigator
- Median Salary: $95,000 – $120,000 per year
- Senior investigators possess 5+ years of experience and often lead investigations, make critical safety recommendations, and mentor junior investigators.
Lead Aircraft Accident Investigator / Investigation Team Lead
- Median Salary: $120,000 – $160,000 per year
- These roles come with significant experience and often involve leading large-scale investigations, guiding teams, and interfacing with regulatory authorities.
Principal Investigator / Director of Investigations
- Median Salary: $140,000 – $200,000+ per year
- These high-level positions require extensive experience, deep knowledge of aviation safety, and often involve setting investigation strategies and policies for an airline or regulatory body.
Aircraft Accident Investigator Work Environment
Aircraft Accident Investigators typically work for government agencies, airline companies, or private aviation companies.
They might also be employed by aircraft manufacturers or insurance companies.
They often work in an office environment but are also required to travel frequently to accident sites, which can be located anywhere in the world and might be in harsh or dangerous conditions.
Aircraft Accident Investigators often work irregular hours and may need to be on call, ready to respond immediately when an accident occurs.
This can involve working long hours under stressful and emotionally challenging circumstances, given the nature of the incidents they investigate.
Much of their work is team-based, collaborating with other investigators, engineers, and aviation experts.
Despite the challenging aspects, these professionals play a crucial role in improving aviation safety and preventing future accidents.
FAQs About Becoming an Aircraft Accident Investigator
What qualifications do I need to become an Aircraft Accident Investigator?
To become an Aircraft Accident Investigator, you will typically need a bachelor’s degree in aeronautical engineering, mechanical engineering, electrical engineering, or a related field.
Additional qualifications can include a pilot’s license, aircraft maintenance experience, or advanced degrees in aviation safety or accident investigation.
Proficiency in data analysis, problem-solving, and communication is also essential.
Some employers may prefer candidates with experience in aviation law enforcement or military aviation.
How long does it take to become an Aircraft Accident Investigator?
The timeline to become an Aircraft Accident Investigator can vary depending on your background and the specific pathway you choose.
If starting with a bachelor’s degree in a relevant field, it will typically take four years.
Additional training or certification programs can take a few months to a year.
You will also likely need several years of work experience in aviation or a related field before you can qualify to work as an investigator.
Can I become an Aircraft Accident Investigator if I am already a pilot?
Yes, being a pilot can be a significant advantage in becoming an Aircraft Accident Investigator.
The first-hand knowledge and experience you gain as a pilot can be invaluable in understanding the complexities of aircraft operation and navigation.
Many investigators have backgrounds as pilots or aircraft mechanics.
However, you will likely still need to pursue further training or certification in accident investigation or a related field.
Is being an Aircraft Accident Investigator a dangerous job?
Being an Aircraft Accident Investigator can involve certain risks, as it often requires visiting crash sites, which may be in remote or hazardous locations.
However, proper safety measures and protocols are always in place to protect investigators.
The job can be physically and emotionally challenging given the nature of the work, but many investigators find it rewarding to contribute to improving aviation safety.
What are the career prospects for an Aircraft Accident Investigator?
The need for Aircraft Accident Investigators is relatively steady, as their skills are essential in maintaining and improving aviation safety.
Career progression can lead to senior investigator roles, team leadership positions, or specialization in specific types of investigations.
Opportunities also exist in related fields such as safety auditing, aviation consulting, or working with aviation insurance companies.
Conclusion
And there you have it.
Embarking on a journey to become an aircraft accident investigator is indeed a serious commitment, but it’s undeniably fulfilling.
With the right expertise, training, and persistence, you’re already on the path to making a significant difference in aviation safety.
Remember, the journey may be rigorous, but the potential for impact is immeasurable. Your investigations could lead to changes that save lives, improve aircraft design, and shape the future of air travel.
So, take that leap. Immerse yourself in the world of aviation. Network with industry professionals. And most importantly, never stop learning.
Because the world is waiting for what you can uncover.
And if you’re looking for personalized guidance on starting or advancing your career in aircraft accident investigation, explore our AI Career Path Advisor.
This complimentary tool is designed to provide tailored advice and resources to help you navigate your career path effectively.
Rising Stars: The Fastest Growing Jobs of the Year
Oddly Amazing: Unusual Jobs That Actually Exist
Bored of the Hustle? Try These Easy Jobs for a Stress-Free Payday!
The Edge of Employment: Jobs That Are Literally Death-Defying