Accurate estimation of daily and annual aircraft operations at airports is vital for various objectives, including airport planning, funding allocation, and aviation forecasts. However, obtaining precise operational data from airports without control towers has been challenging. In 2018, the Florida Department of Transportation (FDOT) published an assessment of aircraft operations counting technologies at non-towered airports, considering best practices from prior studies. After five years of the arrival of technologies available for object detection applications, it is time to update the assessment. To achieve this, a systematic approach was followed, starting with defining terminology and types of aircraft operations for consistent understanding. A ranking methodology based on critical selection criteria was established. Thorough research was conducted on technologies used in aviation and other relevant fields, and components and costs were obtained from vendors. Feedback from state airport authorities and Florida airports regarding their used technologies was also collected. Onsite evaluation showed that all aircraft operations counting technologies evaluated are prone to introducing both undercounting and overcounting errors.
Incident management teams (IMTs) minimize crash impacts and create a safer highway network for people and communities. Research has shown that optimizing the IMT fleet has strong benefits to the roadway network, but future models indicate that increasing IMT presence may have diminishing returns after excessive roadway saturation. The Utah Department of Transportation (UDOT) would like to improve situational awareness in areas of poor or limited camera coverage, where situational awareness is typically poor. UDOT is considering the use of unmanned aerial systems (UAS) to provide live camera coverage of traffic conditions in these instances. This research report synthesizes practice from case studies within the United States to create a best practice report to guide future UAS implementation during IMT responses. Ten state Departments of Transportation (DOTs) and one state Department of Public Safety were interviewed to create the State-of-the-Practice summary. Interviews focused on understanding UAS livestream implementations during incidents, although some discussions of developing technology are summarized. UAS livestreams are highly feasible and can provide substantial benefits to DOTs. However, there are concerns about technology and potential policy limitations regarding security and safety considerations. Four key findings from the State of the Practice are summarized for UAS livestream integrations. These findings concern the use of UAS manufactured by DJI, tethered UAS, the role of satellite internet connections, and the various streaming solutions. Technology summary tables are provided for quick reference, with general recommendations for future implementations and for UDOT IMT response teams specifically.
In early 2023, a series of incidents at large commercial airports occurred in which aircraft came significantly close to each other on runways. The Federal Aviation Administration (FAA) has taken various actions in response to these incursions, such as holding a safety summit and granting over $200 million to airports for runway incursion mitigation, but challenges persist. The objective of this audit is to assess FAA’s (1) processes for analyzing data and identifying risks associated with runway incursions, and (2) actions for preventing and mitigating runway incursions at primary commercial service airports. The audit focused on FAA’s processes for analyzing runway incursion data and its efforts to prevent and mitigate serious runway incursions (Category A and B) at primary commercial airports since the beginning of fiscal year 2022. The Office of Inspector General (OIG) found that the FAA lacks an integrated approach for analyzing runway incursion data and identifying risks. While FAA has taken some actions to mitigate runway incursions, it has yet to implement several key initiatives. OIG makes five recommendations in this report to improve FAA’s ability to share data between its organizations and to provide stakeholders with pertinent information for preventing and mitigating runway incursions.
This report provides guidance to airport operators on how to create a data governance strategy for airports and stakeholders, including roles and responsibilities, policies, data collection standards, procedures, data exchange, security, and maintenance. The training tools provided with this guide include a sample geospatial data governance policy, best practices, metadata to serve as a template for documentation, and executive-level presentation materials. Airport operators of all sizes will find this guide and associated toolkit useful because it outlines the steps to create a data governance strategy.
The authors present results from a field campaign to measure seasonal snow depth at Cameron Pass, Colorado, using a synthetic ultrawideband software-defined radar (SDRadar) implemented in commercially available Universal Software Radio Peripheral (USRP) software-defined radio hardware and flown on a small hexacopter unmanned aerial vehicle (UAV). The authors coherently synthesize an ultrawideband signal from stepped frequency 50-MHz subpulses across 600-2100-MHz frequency bands using a novel nonuniform nonlinear synthetic wideband waveform reconstruction technique that minimizes sweep time and completely eliminates problematic grating lobes and other processing artifacts traditionally seen in stepped waveform synthesis. The authors image seasonal snow across two transects: a 400-m open Meadow Transect and a 380-m forested transect. The authors present a surface detection algorithm that fuses data from LiDAR, global navigation satellite system (GNSS)/global positioning system (GPS), and features in the radargram itself to obtain high precision estimates of both snow and ground surface reflections, and thus total snow depth, represented as two-way travel time. The measurements are validated against independent ground-based ground-penetrating radar measurements with correlations coefficients as high as 𝜌 = 0.9 demonstrated. Finally, the authors compare backscattered radar data collected by the UAV-SDRadar while hovering proximal to a known snow pit with in situ measured snow dielectric profiles and demonstrate imaging of snow stratigraphy.
Helicopter Air Ambulance (HAA) operations are subject to unique risks due to their time-sensitive and safety critical nature. The Civil Aerospace Medical Institute (CAMI) completed analyses of the National Transportation Safety Board’s (NTSB) Case Analysis and Reporting Online (CAROL) aviation accident and serious incident database and the National Aeronautics and Space Administration’s (NASA) Aviation Safety Reporting System (ASRS) data over a 10-year span. In total, 102 ASRS reports, 53 final NTSB accident reports, and 3 final NTSB incident reports involving HAA from 2013 to 2023 that occurred within the United States (U.S.) were coded for human factors and organizational risk factors. The analyses identified several human factors risks impacting HAA flightcrew related to situation awareness (SA), judgment and decision-making (JDM), adherence to procedures, and experience and training. Further, organizational issues influencing HAA operations, such as communication, safety culture, and those involving operator policy and procedure, were identified. Research recommendations based on the findings broadly involve investigating techniques to improve SA, reevaluating or assessing training needs, and providing additional resources for pilots and flightcrews in HAA operations.
In this paper, the authors introduce a method to uncover Global Navigation Satellite System (GNSS) spoofing by directly decomposing the Complex Cross Ambiguity Function (CCAF) into its authentic and counterfeit components. The authors demonstrate the importance of using complex cross ambiguity measurements compared to the magnitude-only approaches utilized in prior work on spoofing detection. The authors also introduce a CCAF error decorrelation method to mitigate the influence of thermal noise. The detector can identify spoofing in the presence of multipath and when the spoofing signal is power-matched with offsets in code delay and Doppler frequency that are close to the authentic signal.
This report explores the characteristics of checksums and cyclic redundancy codes (CRCs) in an aviation context. It includes a literature review, a discussion of error detection performance metrics, a comparison of various checksum and CRC approaches, and a proposed methodology for mapping CRC and checksum design parameters to aviation integrity requirements. Specific examples studied are Institute of Electrical and Electronics Engineers (IEEE) 802.3 CRC-32; Aeronautical Radio, Incorporated (ARINC)-629 error detection; ARINC-825 Controller Area Network (CAN) error detection; Fletcher checksum; and the Aeronautical Telecommunication Network (ATN)-32 checksum. Also considered are multiple error codes used together, specific effects relevant to communication networks, memory storage, and transferring data from nonvolatile to volatile memory. Key findings include: (1) significant differences exist in effectiveness between error-code approaches, with CRCs being generally superior to checksums in a wide variety of contexts; (2) common practices and published standards may provide suboptimal (or sometimes even incorrect) information, requiring diligence in selecting practices to adopt in new standards and new systems; (3) error detection effectiveness depends on many factors, with the Hamming distance of the error code being of primary importance in many practical situations; (4) no one-size-fits-all error-coding approach exists, although this report does propose a procedure that can be followed to make a methodical decision as to which coding approach to adopt; and (5) a number of secondary considerations must be taken into account that can substantially influence the achieved error-detection effectiveness of a particular error-coding approach.
The purpose of this project was to provide a data driven process to identify sensor technologies with the potential for detecting and identifying low levels of contaminants that may occasionally be present in aircraft engine bleed air supplies. Bleed air from a ground-based aircraft propulsion engine and an auxiliary power unit (APU) were used to supply air through an ozone/volatile organic compound (VOC) converter to the environmental control system on a Boeing 747, while injecting controlled amounts of fluid contaminants (i.e., aircraft engine oil, hydraulic fluid, and deicing fluid). Measurements of contaminants were performed at the ozone/VOC converter inlet and exit, and at the air conditioning pack exit. Ultrafine particles (UFP) were found to be a sensitive marker for engine oil contamination with measurements at all three locations showing similar, highly elevated UFP concentrations with a mean diameter near 40nm and smaller when the sample stream was cooled to near room temperature. In situ measurements showed that UFPs are generated by condensation and high UFP concentrations were not detected in uncooled bleed air. Oil contamination VOC levels were very low upstream of the ozone/VOC converter at bleed air temperatures up to 220˚C and increased at bleed temperatures of around 315˚C; however, oil contamination VOC levels remained at sub-ppmv levels. Fine particle concentrations also increased with oil contamination at lower bleed air temperatures, but not with temperatures around 315 ˚C. Secondary contaminants including pentanoic acid, heptanoic acid, acetic acid, formaldehyde, and acetaldehyde formed in the ozone/VOC converter as the oil aerosol oxidized. Consideration must be given to contaminant deposition within the bleed air system and sample lines as this deposition may lead to delayed responses and contaminant release during temperature transients. Of the sensor technologies assessed, spectrometers provided the best opportunity to detect and identify contaminants. Carbon monoxide (CO) measurements confirmed that CO is not generated in sufficient quantities to be of value as a marker for engine oil or hydraulic fluid contamination of bleed air. CO may be useful as a marker for ingestion of engine exhaust in some cases. However, carbon dioxide (CO2) is a much better marker for engine exhaust ingestion.
Federal agencies, such as the Federal Aviation Administration, U.S. Customs and Border Protection, the Transportation Security Administration, and the U.S. Department of Defense, play key roles in airport operations, safety, and security of the facilities. However, the legal authority defining airports’ rights and obligations to these agencies is varied and can be confusing. It may be unclear what restrictions exist, costs the airports have to incur, and level of obligations airports have when executing a cooperative agreement or other agreements with federal authorities. Airports must plan and comply with these federal agencies, and it is important to understand what is mandatory, discretionary, or prohibited for airports to provide. This digest will be helpful to prepare airports for conversations with federal agencies about accommodating requirements. The objective of this digest is to provide information concerning airports’ rights and obligations to accommodate federal agencies and enter into cooperative agreements and other agreements. It provides a review of federal laws and applicable grant assurances, and information on relevant federal agency orders and policies and guidance, including General Service Administration authority and process. This digest contains a matrix that identifies airport obligations to specific federal agencies and directs the reader to the authority and guidance documents.
