Lovtaler: Aircraft Forensics - May 10 2024

Small aircraft, including private planes and helicopters, have become reliant on digital systems for navigation, communication, engine monitoring, and other critical functions.

While this technology has made aviation safer and more efficient (and more fun!), it has also created additional vulnerabilities and challenges from a digital forensics perspective.

In the event of an accident or incident involving a small aircraft, investigators must be able to extract and analyze data from these systems to determine the cause and prevent future occurrences.

This article will provide an overview of digital forensics techniques and considerations specific to small aircraft.

Aircraft Digital Systems Overview Modern small aircraft contain a variety of digital systems that generate and store data :

Avionics: The aircraft's navigation, communication, and flight control systems. Key components include GPS, radio, transponder, autopilot, and electronic flight instrument systems (EFIS). These generate data on the aircraft's position, altitude, heading, speed, and control inputs.

Engine Monitoring: Digital engine monitoring systems track parameters like RPM, temperature, pressure, fuel flow, etc. This data can reveal engine malfunctions, mismanagement or faults.

Onboard Maintenance: Some aircraft have computerized maintenance tracking that logs fault codes, inspection/service history, and much more. Don't forget cloud.....

Tablets/Apps: Many pilots now use tablets or smartphones with aviation apps for flight planning, weather, charts, and as backup avionics. These may contain interesting data.

CVR/FDR: Larger, more sophisticated small aircraft may have cockpit voice recorders and/or flight data recorders, similar to airliners but on a smaller scale.

In addition to these aircraft-specific systems, small aircraft may also contain more generic digital evidence like passenger smartphones, laptops, cameras, etc. that could be relevant to an investigation depending on the circumstances.

Digital Evidence Acquisition

The first step in any digital forensic examination is acquiring a forensically-sound copy of the digital evidence. With small aircraft, this process has some unique challenges compared to traditional computer forensics:

Crash Damage: If the aircraft has crashed, digital components may be damaged by impact forces, fire, or water. Investigators must carefully document and photograph the state of the wreckage before removing any components. Damaged devices may require special techniques like chip-off forensics to extract data.

Non-Standard Interfaces: Unlike PCs which mostly use standard USB/SATA/PCIe interfaces, avionics units often have unique, proprietary connectors and interfaces. Investigators need adapters and software tools compatible with each specific unit.

Encrypted Storage: Some newer avionics units use encrypted storage for security and intellectual property reasons. Encryption keys may be needed from the manufacturer to access this data.

Volatile Memory: Avionics units and engine monitors may store certain data in volatile memory (RAM) which is lost when power is removed. If possible, these devices should be powered on and have their memory dumped before being unplugged.

Scene Control: Small aircraft accident scenes, especially in remote areas, may have poor physical security allowing someone to tamper with or remove digital evidence before investigators arrive. Protocols should be in place for first responders to secure digital devices.

Whenever possible, digital evidence should be acquired using write-blockers to prevent any changes to the original media. Each digital evidence item should be carefully documented, photographed, and hashed to establish chain of custody and integrity. Anti-static packaging and proper labeling should be used for transportation and storage.

Data Analysis Techniques

Once the digital evidence has been acquired, there are a variety of analysis techniques investigators can use depending on the type of data and investigation goals:

Log Analysis: Avionics and engine monitoring systems generate detailed logs of aircraft parameters over time. Visualizing this data on a timeline and correlating it to other events (ATC communications, weather, witness statements, etc.) can reveal factors that contributed to an incident.

Anomaly Detection: Comparing data from the incident aircraft to data from normal flights of the same aircraft type can help detect anomalies in things like control inputs, engine parameters, or navigation. This may indicate issues like pilot error, mechanical problems, or sensor failures.

Geospatial Analysis: GPS data from the aircraft can be plotted on a map to analyze the flight path, altitude, speed, and identify the key locations/times of events. 3D animations may be created.

Media Analysis: Cockpit audio from CVRs, passenger phone video/audio, and airport security video can provide additional context about an incident. Audio/video forensics techniques may be needed to enhance media and extract information.

App/OS Analysis: Data from pilot tablet/phone apps, as well as the operating systems of any relevant devices, can reveal important details about preflight activities, flight planning, pilot decision-making, etc.

Malware Analysis: In the case of suspected cyber-attacks on aircraft systems, malware analysis techniques may be used to identify suspicious code and determine its functionality and origin.

Historical Analysis: In some cases, it may be necessary to analyze historical data from an aircraft's systems beyond the current accident flight. Things like past flights, maintenance logs, pilot records, etc. may provide clues about developing issues that led to an incident.

Effective analysis often requires correlating multiple independent sources of digital evidence and comparing them to physical evidence and witness statements to develop a complete understanding of the incident.

Reporting and Testimony

The final stage of aircraft digital forensics is reporting the findings and potentially testifying about them in court. Forensic reports should include details on all evidence items collected, data acquisition methods, analysis techniques/tools used, and any conclusions reached. Key findings should be presented clearly using timelines, maps, graphs, and other visuals as much as possible.

In the event of legal proceedings, digital forensic examiners may be called to testify about their findings. They must be prepared to explain technical concepts in plain terms to judges and juries. Their qualifications, methods, and conclusions may be challenged by opposing experts. Examiners should stick to testifying about the facts of what the digital evidence shows, not speculation or opinions beyond their expertise.

Challenges and Future Directions

While digital forensics can reveal a wealth of information about small aircraft incidents, there are still challenges and limitations investigators face:

Lack of Standardization: Unlike the heavily regulated airline industry, small aircraft have a huge diversity of avionics systems with varying capabilities and interfaces. This makes it difficult to have standard investigation protocols and tools.

Proprietary Data Formats: Many avionics manufacturers use proprietary data logging formats which can impede easy analysis by investigators. Conversion to standard formats may be needed.

Increasing Data Volume: As small aircraft systems become more sophisticated, the amount of data generated is increasing exponentially. This can overwhelm investigators and require Big Data analysis techniques.

Cybersecurity: There are concerns about the potential for cyber-attacks against small aircraft digital systems. This would greatly complicate forensic investigations.

Unmanned Aircraft: Small unmanned aircraft (drones) are proliferating rapidly and present new challenges for digital forensic investigations in the event of accidents or misuse.

Theres definitely opportunity in this field, compared to phone, laptop or even automobile forensics, the recovery process is quite nascent and unstructured.

Aviation industry and digital forensics community need to work together to develop standards, tools, and training specific to small aircraft. Information sharing between manufacturers, operators, and investigators should be encouraged. Research into areas like advanced data visualizations, automated anomaly detection, and trustworthy AI assistants for investigations should be prioritized.

By continuously improving digital forensic capabilities, we can better understand the causes of small aircraft accidents and make aviation safer for all. While we may never eliminate incidents completely, extracting and analyzing digital evidence can provide valuable lessons to prevent recurrences and inspire safety innovations. Digital forensics will only become more important as technology advances.

Digital forensics plays a crucial role in the investigation of small aircraft accidents and incidents. By extracting and analyzing data from avionics, engine monitors, and other digital systems, investigators can reconstruct events, identify contributing factors, and determine the probable cause(s). However, small aircraft digital forensics presents unique challenges in terms of crash damage, non-standard interfaces, data volume and variety, cybersecurity, and more.

To meet these challenges, there is real opportunity for standards and new tools and techniques.